Trial Outcomes & Findings for Strategic Management to Optimize Response To Cardiac Resynchronization Therapy (NCT NCT03089281)

NCT ID: NCT03089281

Last Updated: 2022-04-05

Results Overview

Comparing cardiac resynchronization therapy (CRT) response rates between AV Delay programming schemes defined by SmartDelay or a Fixed AV Delay of 120ms. A negative change in LVESV is considered an improvement; CRT response is defined by a change in Left Ventricular End Systolic Volume (LVESV) \< -15% at 6 months compared to pre-implant baseline.

• Recruitment status: COMPLETED
• Study phase: NA
• Target enrollment: 699 participants
• Primary outcome timeframe: Pre-Implant baseline to 6 months
• Results posted on: 2022-04-05

Participant Flow

Commercially approved quadripolar Boston Scientific CRT-D devices and future generations of BSC X4 CRT-D devices approved by the appropriate regulatory bodies were included in the trial. All devices utilized in the study will include SmartDelay™ and must be capable of providing SmartDelay recommendations for both biventricular pacing (BiV) and Left Ventricular (LV) only pacing.

699 subjects were enrolled. 259 were exited prior to randomization (88 not implanted, 7 no RV-LV measurement, 161 RV-LV < 70ms, 3 no viable pacing vector). Subjects with an RV-LV delay >= 70ms were randomized (n = 440). Randomized subjects received a Boston Scientific Cardiac Resynchronization Therapy Defibrillator (CRT-D) and were randomized 1:1 to have either an AV Delay and pacing chamber determined by SmartDelay or a Fixed AV Delay of 120ms with BiV pacing.

Participant milestones

Measure	SmartDelay™ Algorithm AV Delay and pacing chamber were determined by SmartDelay algorithm	Fixed AV Delay With BiV Pacing Fixed AV Delay of 120ms with BiV pacing was programmed
Overall Study STARTED	225	215
Overall Study COMPLETED	197	198
Overall Study NOT COMPLETED	28	17

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Data not reported on 44 participants.

Baseline characteristics by cohort

Measure	SmartDelay™ Algorithm n=225 Participants AV Delay and pacing chamber were determined by SmartDelay algorithm	Fixed AV Delay With BiV Pacing n=215 Participants Fixed AV Delay of 120ms with BiV pacing was programmed	Total n=440 Participants Total of all reporting groups
Age, Continuous	66.0 years STANDARD_DEVIATION 10.6 • n=225 Participants	67.6 years STANDARD_DEVIATION 10.1 • n=215 Participants	66.8 years STANDARD_DEVIATION 10.4 • n=440 Participants
Sex: Female, Male Female	89 Participants n=225 Participants	72 Participants n=215 Participants	161 Participants n=440 Participants
Sex: Female, Male Male	136 Participants n=225 Participants	143 Participants n=215 Participants	279 Participants n=440 Participants
Race/Ethnicity, Customized Black or African Heritage	30 Participants n=206 Participants • Data not reported on 44 participants.	22 Participants n=190 Participants • Data not reported on 44 participants.	52 Participants n=396 Participants • Data not reported on 44 participants.
Race/Ethnicity, Customized Caucasian	160 Participants n=206 Participants • Data not reported on 44 participants.	155 Participants n=190 Participants • Data not reported on 44 participants.	315 Participants n=396 Participants • Data not reported on 44 participants.
Race/Ethnicity, Customized Hispanic or Latino	12 Participants n=206 Participants • Data not reported on 44 participants.	9 Participants n=190 Participants • Data not reported on 44 participants.	21 Participants n=396 Participants • Data not reported on 44 participants.
Race/Ethnicity, Customized Asian	3 Participants n=206 Participants • Data not reported on 44 participants.	3 Participants n=190 Participants • Data not reported on 44 participants.	6 Participants n=396 Participants • Data not reported on 44 participants.
Race/Ethnicity, Customized Other	1 Participants n=206 Participants • Data not reported on 44 participants.	1 Participants n=190 Participants • Data not reported on 44 participants.	2 Participants n=396 Participants • Data not reported on 44 participants.
Region of Enrollment United States	134 participants n=225 Participants	123 participants n=215 Participants	257 participants n=440 Participants
Region of Enrollment France	18 participants n=225 Participants	19 participants n=215 Participants	37 participants n=440 Participants
Region of Enrollment Canada	15 participants n=225 Participants	16 participants n=215 Participants	31 participants n=440 Participants
Region of Enrollment Germany	14 participants n=225 Participants	16 participants n=215 Participants	30 participants n=440 Participants
Region of Enrollment United Kingdom	14 participants n=225 Participants	13 participants n=215 Participants	27 participants n=440 Participants
Region of Enrollment Spain	14 participants n=225 Participants	12 participants n=215 Participants	26 participants n=440 Participants
Region of Enrollment Japan	5 participants n=225 Participants	5 participants n=215 Participants	10 participants n=440 Participants
Region of Enrollment Netherlands	5 participants n=225 Participants	4 participants n=215 Participants	9 participants n=440 Participants
Region of Enrollment Italy	4 participants n=225 Participants	4 participants n=215 Participants	8 participants n=440 Participants
Region of Enrollment Switzerland	2 participants n=225 Participants	2 participants n=215 Participants	4 participants n=440 Participants
Region of Enrollment Ireland	0 participants n=225 Participants	1 participants n=215 Participants	1 participants n=440 Participants
New York Heart Association (NYHA) Classification Class I	4 Participants n=225 Participants	5 Participants n=215 Participants	9 Participants n=440 Participants
New York Heart Association (NYHA) Classification Class II	97 Participants n=225 Participants	91 Participants n=215 Participants	188 Participants n=440 Participants
New York Heart Association (NYHA) Classification Class III	122 Participants n=225 Participants	115 Participants n=215 Participants	237 Participants n=440 Participants
New York Heart Association (NYHA) Classification Class IV	2 Participants n=225 Participants	4 Participants n=215 Participants	6 Participants n=440 Participants
Left Ventricular Ejection Fraction (LVEF)	27.4 % of blood ejected during LV contraction STANDARD_DEVIATION 9.9 • n=205 Participants • LVEF data was unavailable for some participants due to missing measurement or unreadable echocardiogram data.	28.0 % of blood ejected during LV contraction STANDARD_DEVIATION 8.9 • n=195 Participants • LVEF data was unavailable for some participants due to missing measurement or unreadable echocardiogram data.	27.7 % of blood ejected during LV contraction STANDARD_DEVIATION 9.4 • n=400 Participants • LVEF data was unavailable for some participants due to missing measurement or unreadable echocardiogram data.
Left Ventricular End Systolic Volume (LVESV)	148 milliliters STANDARD_DEVIATION 64 • n=205 Participants • LVESV data was unavailable for some participants due to missing measurement or unreadable echocardiogram data.	140 milliliters STANDARD_DEVIATION 60 • n=195 Participants • LVESV data was unavailable for some participants due to missing measurement or unreadable echocardiogram data.	144 milliliters STANDARD_DEVIATION 62 • n=400 Participants • LVESV data was unavailable for some participants due to missing measurement or unreadable echocardiogram data.
Conduction Disorder Left Bundle Branch Block (LBBB)	204 Participants n=225 Participants • Data not reported for one participant.	193 Participants n=214 Participants • Data not reported for one participant.	397 Participants n=439 Participants • Data not reported for one participant.
Conduction Disorder Right Bundle Branch Block (RBBB)	2 Participants n=225 Participants • Data not reported for one participant.	4 Participants n=214 Participants • Data not reported for one participant.	6 Participants n=439 Participants • Data not reported for one participant.
Conduction Disorder Intraventricular Conduction Delay (IVCD)	19 Participants n=225 Participants • Data not reported for one participant.	17 Participants n=214 Participants • Data not reported for one participant.	36 Participants n=439 Participants • Data not reported for one participant.
QRS width (ms)	164 milliseconds STANDARD_DEVIATION 20 • n=225 Participants	160 milliseconds STANDARD_DEVIATION 16 • n=215 Participants	162 milliseconds STANDARD_DEVIATION 18 • n=440 Participants

PRIMARY outcome

Timeframe: Pre-Implant baseline to 6 months

Population: A total of 130 randomized subjects did not contribute data to the primary endpoint analysis due to death or withdrawal prior to six months, missed six-month visit or incomplete/insufficient echocardiogram.

Comparing cardiac resynchronization therapy (CRT) response rates between AV Delay programming schemes defined by SmartDelay or a Fixed AV Delay of 120ms. A negative change in LVESV is considered an improvement; CRT response is defined by a change in Left Ventricular End Systolic Volume (LVESV) < -15% at 6 months compared to pre-implant baseline.

Outcome measures

Measure	SmartDelay™ Algorithm n=155 Participants AV Delay and pacing chamber were determined by SmartDelay algorithm	Fixed AV Delay With BiV Pacing n=155 Participants Fixed AV Delay of 120ms with BiV pacing was programmed
CRT Response	116 Participants	105 Participants

SECONDARY outcome

Timeframe: Implant to 6 Months

Population: A total of 130 randomized subjects did not contribute data to the secondary endpoint analysis due to death or withdrawal prior to six months, missed six-month visit or incomplete/insufficient echocardiogram.

Comparing absolute changes in Left Ventricular End Systolic Volume from Implant to 6 Months between AV Delay programming schemes defined by SmartDelay or a Fixed AV Delay of 120ms. Change is defined as 6-Month measurement - Implant measurement, in milliliters. A negative change in LVESV is considered an improvement.

Outcome measures

Measure	SmartDelay™ Algorithm n=155 Participants AV Delay and pacing chamber were determined by SmartDelay algorithm	Fixed AV Delay With BiV Pacing n=155 Participants Fixed AV Delay of 120ms with BiV pacing was programmed
Change in Left Ventricular End Systolic Volume (Absolute Change)	-51.5 milliliters Standard Deviation 51.1	-37.8 milliliters Standard Deviation 42.3

SECONDARY outcome

Timeframe: Implant to 6 Months

Population: A total of 130 randomized subjects did not contribute data to the secondary endpoint analysis due to death or withdrawal prior to six months, missed six-month visit or incomplete/insufficient echocardiogram.

Comparing relative changes in Left Ventricular End Systolic Volume from Implant to 6 Months between AV Delay programming schemes defined by SmartDelay or a Fixed AV Delay of 120ms. Change is defined as 100*(6-Month measurement - Implant measurement)/(Implant Measurement), in %. A negative change in LVESV is considered an improvement.

Outcome measures

Measure	SmartDelay™ Algorithm n=155 Participants AV Delay and pacing chamber were determined by SmartDelay algorithm	Fixed AV Delay With BiV Pacing n=155 Participants Fixed AV Delay of 120ms with BiV pacing was programmed
Change in Left Ventricular End Systolic Volume (Relative Change)	-33.2 % change Standard Deviation 25.2	-26.7 % change Standard Deviation 27.4

SECONDARY outcome

Timeframe: Implant to 6 Months

Population: A total of 129 randomized subjects did not contribute data to the secondary endpoint analysis due to death or withdrawal prior to six months, missed six-month visit or incomplete/insufficient echocardiogram.

Comparing absolute changes in Left Ventricular Ejection Fraction from Implant to 6 Months between AV Delay programming schemes defined by SmartDelay or a Fixed AV Delay of 120ms. Change is defined as 6-Month measurement - Implant measurement, in % of blood ejected during LV contraction. A positive change in LVEF is considered an improvement.

Outcome measures

Measure	SmartDelay™ Algorithm n=155 Participants AV Delay and pacing chamber were determined by SmartDelay algorithm	Fixed AV Delay With BiV Pacing n=156 Participants Fixed AV Delay of 120ms with BiV pacing was programmed
Change in Left Ventricular Ejection Fraction (Absolute Change)	12.6 % of blood ejected during LV contraction Standard Deviation 11.5	10.2 % of blood ejected during LV contraction Standard Deviation 11.4

SECONDARY outcome

Timeframe: Implant to 6 Months

Population: A total of 129 randomized subjects did not contribute data to the secondary endpoint analysis due to death or withdrawal prior to six months, missed six-month visit or incomplete/insufficient echocardiogram.

Comparing relative changes in Left Ventricular Ejection Fraction from Implant to 6 Months between AV Delay programming schemes defined by SmartDelay or a Fixed AV Delay of 120ms. Change is defined as 100*(6-Month measurement - Implant measurement)/(Implant Measurement), in %. A positive change in LVEF is considered an improvement.

Outcome measures

Measure	SmartDelay™ Algorithm n=155 Participants AV Delay and pacing chamber were determined by SmartDelay algorithm	Fixed AV Delay With BiV Pacing n=156 Participants Fixed AV Delay of 120ms with BiV pacing was programmed
Change in Left Ventricular Ejection Fraction (Relative Change)	57.5 % change Standard Deviation 60	44.8 % change Standard Deviation 54.2

SECONDARY outcome

Timeframe: Implant to 6 Months

Population: Subjects that were followed through the end of the 6-month visit window and those that died and/or or had a heart failure hospitalization within the 6-month visit window contributed to this endpoint. A total of 34 subjects did not meet these conditions are were therefore excluded from endpoint analysis.

Th CCS combines four metrics: all-cause mortality, heart failure hospitalization (HFH), New York Heart Association (NYHA) Class, and quality of life as measured with the patient global assessment (GA) instrument.

The CCS categorizes each subject into one of three groups: Improved, Unchanged or Worsened.

• Improved: Subjects that survived without a HFH through the 6-month visit window and had either an improvement in NYHA class or responded to GA with "much better" or "very much better".
• Unchanged: All patients that reached the end of 6-month visit window that were not categorized as either "Improved" or "Worsened".
• Worsened: Subjects that died or had HFH within 6-month visit window or had either a worsening in NYHA class or responded to GA with "much worse" or "very much worse".

Outcome measures

Measure	SmartDelay™ Algorithm n=207 Participants AV Delay and pacing chamber were determined by SmartDelay algorithm	Fixed AV Delay With BiV Pacing n=199 Participants Fixed AV Delay of 120ms with BiV pacing was programmed
Clinical Composite Score (CCS) Improved	153 Participants	154 Participants
Clinical Composite Score (CCS) Unchanged	31 Participants	25 Participants
Clinical Composite Score (CCS) Worsened	23 Participants	20 Participants

SECONDARY outcome

Timeframe: Implant to 6 Months

Population: Subjects that completed the KCCQ at both the implant and 6 month visits contributed to this endpoint. A total of 51 subjects did not contribute data to the endpoint.

The KCCQ is a disease-specific instrument for monitoring the health status and quality of life of subjects with congestive heart failure. It includes a total of 23 items that assess quality of life in the following domains: physical function, symptom frequency and severity, symptom stability, self-efficacy and knowledge, social function, and overall quality of life. These domains can be combined into a functional status summary score (derived from the physical function and symptom scales) and an overall summary score which combines the physical function, symptom, social function and quality of life domains.

KCCQ scores have a minimum of 0 and a maximum of 100. Higher score indicates better quality of life.

Outcome measures

Measure	SmartDelay™ Algorithm n=194 Participants AV Delay and pacing chamber were determined by SmartDelay algorithm	Fixed AV Delay With BiV Pacing n=195 Participants Fixed AV Delay of 120ms with BiV pacing was programmed
Change in Kansas City Cardiomyopathy Questionnaire (KCCQ) Overall Summary Score	18.3 score on a scale Standard Deviation 21.0	20.2 score on a scale Standard Deviation 19.7

OTHER_PRE_SPECIFIED outcome

Timeframe: Implant to 6 Months

Population: Subjects that completed the KCCQ at both the implant and 6 month visits contributed to this endpoint. A total of 51 subjects did not contribute data to the endpoint.

The KCCQ Social Limitation Domain quantifies the extent to which heart failure symptoms impair patients' ability to interact in a number of gender-neutral social activities.

KCCQ scores have a minimum of 0 and a maximum of 100. Higher score indicates better quality of life.

Outcome measures

Measure	SmartDelay™ Algorithm n=194 Participants AV Delay and pacing chamber were determined by SmartDelay algorithm	Fixed AV Delay With BiV Pacing n=195 Participants Fixed AV Delay of 120ms with BiV pacing was programmed
Change in Kansas City Cardiomyopathy Questionnaire (KCCQ) Social Limitation Score	17.1 score on a scale Standard Deviation 28.1	20.6 score on a scale Standard Deviation 25.1

OTHER_PRE_SPECIFIED outcome

Timeframe: Implant to 6 Months

Population: Subjects that completed the KCCQ at both the implant and 6 month visits contributed to this endpoint. A total of 51 subjects did not contribute data to the endpoint.

KCCQ Quality of Life Domain is designed to reflect patients' assessment of their quality of life, given the current status of their heart failure.

KCCQ scores have a minimum of 0 and a maximum of 100. Higher score indicates better quality of life.

Outcome measures

Measure	SmartDelay™ Algorithm n=194 Participants AV Delay and pacing chamber were determined by SmartDelay algorithm	Fixed AV Delay With BiV Pacing n=195 Participants Fixed AV Delay of 120ms with BiV pacing was programmed
Change in Kansas City Cardiomyopathy Questionnaire (KCCQ) Quality of Life Score	25.0 score on a scale Standard Deviation 26.9	27.6 score on a scale Standard Deviation 26.3

OTHER_PRE_SPECIFIED outcome

Timeframe: Implant to 6 Months

Population: Subjects that completed the KCCQ at both the implant and 6 month visits contributed to this endpoint. A total of 51 subjects did not contribute data to the endpoint.

KCCQ Self-efficacy Domain quantifies patients' perceptions of how to prevent heart failure exacerbations and manage complications when they arise. This scale is not included in the summary scores.

KCCQ scores have a minimum of 0 and a maximum of 100. Higher score indicates better quality of life.

Outcome measures

Measure	SmartDelay™ Algorithm n=194 Participants AV Delay and pacing chamber were determined by SmartDelay algorithm	Fixed AV Delay With BiV Pacing n=195 Participants Fixed AV Delay of 120ms with BiV pacing was programmed
Change in Kansas City Cardiomyopathy Questionnaire (KCCQ) Self-Efficacy Score	6.5 score on a scale Standard Deviation 21.8	4.9 score on a scale Standard Deviation 21.2

OTHER_PRE_SPECIFIED outcome

Timeframe: Implant to 6 Months

Population: Subjects that completed the KCCQ at both the implant and 6 month visits contributed to this endpoint. A total of 51 subjects did not contribute data to the endpoint.

KCCQ Symptom Domain quantifies the frequency of clinical symptoms in heart failure, including fatigue, shortness of breath, paroxysmal nocturnal dyspnea and patients' edema/swelling.

KCCQ scores have a minimum of 0 and a maximum of 100. Higher score indicates better quality of life.

Outcome measures

Measure	SmartDelay™ Algorithm n=194 Participants AV Delay and pacing chamber were determined by SmartDelay algorithm	Fixed AV Delay With BiV Pacing n=195 Participants Fixed AV Delay of 120ms with BiV pacing was programmed
Change in Kansas City Cardiomyopathy Questionnaire (KCCQ) Symptom Frequency Score	15.6 score on a scale Standard Deviation 23.5	17.4 score on a scale Standard Deviation 23.2

OTHER_PRE_SPECIFIED outcome

Timeframe: Implant to 6 Months

Population: Subjects that completed the KCCQ at both the implant and 6 month visits contributed to this endpoint. A total of 51 subjects did not contribute data to the endpoint.

KCCQ Symptom Domain quantifies the burden of clinical symptoms in heart failure, including fatigue, shortness of breath, paroxysmal nocturnal dyspnea and patients' edema/swelling.

KCCQ scores have a minimum of 0 and a maximum of 100. Higher score indicates better quality of life.

Outcome measures

Measure	SmartDelay™ Algorithm n=194 Participants AV Delay and pacing chamber were determined by SmartDelay algorithm	Fixed AV Delay With BiV Pacing n=195 Participants Fixed AV Delay of 120ms with BiV pacing was programmed
Change in Kansas City Cardiomyopathy Questionnaire (KCCQ) Symptom Burden Score	15.9 score on a scale Standard Deviation 23.5	15.6 score on a scale Standard Deviation 23.2

OTHER_PRE_SPECIFIED outcome

Timeframe: Implant to 6 Months

Population: Subjects that completed the KCCQ at both the implant and 6 month visits contributed to this endpoint. A total of 51 subjects did not contribute data to the endpoint.

KCCQ Physical Function Domain measures the limitations patients experience, due to their heart failure symptoms, in performing routine activities. Activities are common, gender-neutral, and generalizable across cultures, while also capturing a range of exertional requirements.

KCCQ scores have a minimum of 0 and a maximum of 100. Higher score indicates better quality of life.

Outcome measures

Measure	SmartDelay™ Algorithm n=194 Participants AV Delay and pacing chamber were determined by SmartDelay algorithm	Fixed AV Delay With BiV Pacing n=195 Participants Fixed AV Delay of 120ms with BiV pacing was programmed
Change in Kansas City Cardiomyopathy Questionnaire (KCCQ) Physical Limitation Score	14.6 score on a scale Standard Deviation 23.0	15.9 score on a scale Standard Deviation 23.2

Adverse Events

SmartDelay™ Algorithm

Serious events: 49 serious events

Other events: 20 other events

Deaths: 7 deaths

Fixed AV Delay With BiV Pacing

Serious events: 46 serious events

Other events: 22 other events

Deaths: 0 deaths

Serious adverse events

Measure	SmartDelay™ Algorithm n=225 participants at risk AV Delay and pacing chamber were determined by SmartDelay algorithm	Fixed AV Delay With BiV Pacing n=215 participants at risk Fixed AV Delay of 120ms with BiV pacing was programmed
Product Issues Infection > 30 Days Post-Implant (Pulse Generator-related)	0.89% 2/225 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.00% 0/215 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Product Issues Unable to Capture (Right Atrial Lead-related)	0.00% 0/225 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.47% 1/215 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Product Issues Dislodgment (Right Atrial Lead-Related)	0.00% 0/225 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.47% 1/215 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Product Issues Dislodgment (Right Ventricular Lead-Related)	0.44% 1/225 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.00% 0/215 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Product Issues Dislodgment (Left Ventricular Lead-Related)	2.2% 5/225 • Number of events 5 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	1.9% 4/215 • Number of events 4 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Injury, poisoning and procedural complications Post-Surgical Wound Discomfort/Bruising/Swelling	0.00% 0/225 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.47% 1/215 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Injury, poisoning and procedural complications Post-Surgical Infection (<=30 Days Post-Implant)	0.44% 1/225 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.93% 2/215 • Number of events 2 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Injury, poisoning and procedural complications Adverse Reaction - General	0.00% 0/225 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.47% 1/215 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Injury, poisoning and procedural complications Hematoma - Pocket (<=30 Days Post-Implant)	1.3% 3/225 • Number of events 3 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.00% 0/215 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Injury, poisoning and procedural complications Thromboembolic Events	0.44% 1/225 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.00% 0/215 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Injury, poisoning and procedural complications Pneumothorax	0.44% 1/225 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.47% 1/215 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Injury, poisoning and procedural complications Venous Occlusion	0.44% 1/225 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.00% 0/215 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Cardiac disorders Heart Failure	6.2% 14/225 • Number of events 17 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	7.4% 16/215 • Number of events 24 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Cardiac disorders Ventricular Fibrillation	1.3% 3/225 • Number of events 3 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.93% 2/215 • Number of events 2 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Cardiac disorders Ventricular Tachycardia/Monomorphic VT	0.44% 1/225 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.93% 2/215 • Number of events 2 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Cardiac disorders Atrial Fibrillation	0.89% 2/225 • Number of events 3 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.47% 1/215 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Cardiac disorders Premature Ventricular Contractions (PVC)	0.44% 1/225 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.00% 0/215 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Cardiac disorders Hypotension/Orthostatic Hypotension	0.44% 1/225 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.00% 0/215 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Cardiac disorders Cardiogenic Shock	0.89% 2/225 • Number of events 2 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.00% 0/215 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Cardiac disorders Myocardial Infarction	0.44% 1/225 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.47% 1/215 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Cardiac disorders Coronary Artery Disease	0.44% 1/225 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.00% 0/215 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Cardiac disorders Peripheral Vascular Disease	0.00% 0/225 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.93% 2/215 • Number of events 2 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Cardiac disorders Mitral Stenosis	0.00% 0/225 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.47% 1/215 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Cardiac disorders Valvular Damage/Valvular Insufficiency	0.00% 0/225 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.47% 1/215 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Cardiac disorders Syncope	0.00% 0/225 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.47% 1/215 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Cardiac disorders Dizziness	0.00% 0/225 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.47% 1/215 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Cardiac disorders Chest Pain - Ischemic	0.00% 0/225 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.47% 1/215 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Cardiac disorders Dyspnea	0.44% 1/225 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.00% 0/215 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Cardiac disorders Cerebrovascular Accident (CVA)	0.00% 0/225 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.47% 1/215 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Cardiac disorders Pulmonary Embolism	0.44% 1/225 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.93% 2/215 • Number of events 2 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Cardiac disorders Intracardiac Thrombus	0.44% 1/225 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.00% 0/215 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Cardiac disorders Pericarditis	0.00% 0/225 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.47% 1/215 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Cardiac disorders Atrial Septal Defect	0.00% 0/225 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.47% 1/215 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
General disorders Adverse Reaction - General	0.44% 1/225 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.00% 0/215 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Immune system disorders Adverse reaction - Allergic Reaction	0.44% 1/225 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.00% 0/215 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
General disorders Adverse reaction - Medication	0.00% 0/225 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.47% 1/215 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
General disorders Death	0.44% 1/225 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.00% 0/215 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Infections and infestations Systemic Infection	0.44% 1/225 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	1.4% 3/215 • Number of events 3 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
General disorders Fever/Virus	0.00% 0/225 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.47% 1/215 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
General disorders Physical Trauma	1.3% 3/225 • Number of events 3 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	1.4% 3/215 • Number of events 5 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
General disorders Abnormal Laboratory Values	0.44% 1/225 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.47% 1/215 • Number of events 2 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
General disorders Neurological	0.89% 2/225 • Number of events 2 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.93% 2/215 • Number of events 2 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Respiratory, thoracic and mediastinal disorders Pulmonary	1.3% 3/225 • Number of events 3 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.93% 2/215 • Number of events 2 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Renal and urinary disorders Genitourinary	0.44% 1/225 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.47% 1/215 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Gastrointestinal disorders Gastrointestinal	2.7% 6/225 • Number of events 6 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	1.9% 4/215 • Number of events 4 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Renal and urinary disorders Renal	1.8% 4/225 • Number of events 6 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.93% 2/215 • Number of events 3 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Musculoskeletal and connective tissue disorders Musculoskeletal	0.44% 1/225 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.93% 2/215 • Number of events 3 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Psychiatric disorders Psychological	0.00% 0/225 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.47% 1/215 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Skin and subcutaneous tissue disorders Integumentary	0.44% 1/225 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.47% 1/215 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Endocrine disorders Endocrine	0.44% 1/225 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.00% 0/215 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Immune system disorders Immune	0.00% 0/225 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.47% 1/215 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
General disorders Cancer	1.3% 3/225 • Number of events 3 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.93% 2/215 • Number of events 2 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.

Other adverse events

Measure	SmartDelay™ Algorithm n=225 participants at risk AV Delay and pacing chamber were determined by SmartDelay algorithm	Fixed AV Delay With BiV Pacing n=215 participants at risk Fixed AV Delay of 120ms with BiV pacing was programmed
Product Issues Oversensing (Pulse Generator-related)	0.00% 0/225 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.47% 1/215 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Product Issues Inappropriate Tachy Therapy (Pulse Generator-Related)	0.89% 2/225 • Number of events 2 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.47% 1/215 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Product Issues Fatigue (Pulse Generator-Related)	0.44% 1/225 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.00% 0/215 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Product Issues Dislodgment (Right Atrial Lead-Related)	0.44% 1/225 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.47% 1/215 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Product Issues Dislodgment (Right Ventricular Lead-Related)	0.00% 0/225 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.47% 1/215 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Product Issues Extracardiac Stimulation (Right Ventricular Lead-Related)	0.44% 1/225 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.00% 0/215 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Product Issues Inappropriate Tachy Therapy (Right Ventricular Lead-Related)	0.00% 0/225 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.47% 1/215 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Product Issues Unable to Capture (Left Ventricular Lead-Related)	0.89% 2/225 • Number of events 2 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.93% 2/215 • Number of events 2 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Product Issues Extracardiac Stimulation (Left Ventricular Lead-Related)	1.8% 4/225 • Number of events 4 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	3.3% 7/215 • Number of events 7 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Product Issues Perforation at Implant (Left Ventricular Lead-Related)	0.44% 1/225 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.00% 0/215 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Product Issues Dislodgment (Left Ventricular Lead-Related)	0.89% 2/225 • Number of events 2 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	1.4% 3/215 • Number of events 3 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Surgical and medical procedures Hematoma - Pocket (<=30 days post-implant)	0.44% 1/225 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.47% 1/215 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Surgical and medical procedures Pneumothorax	0.44% 1/225 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.00% 0/215 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Surgical and medical procedures Lower Extremity Edema	0.00% 0/225 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.47% 1/215 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Cardiac disorders Heart Failure	1.3% 3/225 • Number of events 7 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.93% 2/215 • Number of events 2 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Cardiac disorders Ventricular Tachycardia	0.44% 1/225 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.00% 0/215 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Cardiac disorders Atrial Flutter	0.00% 0/225 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.47% 1/215 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Cardiac disorders Atrial Tachycardia / Other Supraventricular Tachycardia (SVT)	0.44% 1/225 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.00% 0/215 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Cardiac disorders Chest Pain	0.44% 1/225 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.00% 0/215 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.
Cardiac disorders Fatigue / Weakness	0.00% 0/225 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.	0.47% 1/215 • Number of events 1 • Adverse events were collected for the entire duration of subject participation in the study. Subjects were followed for median of 6.5 months.

Additional Information

Clinical Trial Manager

Boston Scientific

Phone: 1-800-227-3422

Email: Sara.Veraghtert@bsci.com

Results disclosure agreements

• Principal investigator is a sponsor employee
• Publication restrictions are in place