Trial Outcomes & Findings for Accelerometer Sensing for Micra AV Study (NCT NCT04245345)

Last Updated: 2023-02-23

Results Overview

Atrioventricular synchrony is defined for each P-wave during the 20-minute resting period. Specifically, for each electrocardiogram (ECG) confirmed P-wave that occurs during the 20-minute resting period at the 1-month visit, the endpoint will be considered met if a ventricular beat (ventricular pace or sensed event) is within 300 ms following an ECG confirmed P-wave. The reported percentage is the average percentage of P-waves considered synchronous across all patients during the 20-minute resting period.

Recruitment status

COMPLETED

Study phase

Target enrollment

157 participants

Primary outcome timeframe

1-month post-implant

Results posted on

2023-02-23

Participant Flow

Subjects were considered enrolled at time of informed consent. Subjects were enrolled between 09 June 2020 and 14 September 2021 at 20 study centers in 2 countries.

Following enrollment, subjects were implanted with the Micra AV device and completed follow-up visits at 1-month and 3-months post implant. The completed cohort includes subjects implanted with the Micra AV device who had a persistent 3rd degree AV block and normal sinus node function at the 1-month visit.

Participant milestones

Participant milestones
Measure	AccelAV Evaluable for Primary Objective Subjects implanted with the Micra AV device with a 3rd degree AV block and normal sinus node function at 1-month
Overall Study STARTED	157
Overall Study Implanted	152
Overall Study 1-month Visit	139
Overall Study Complete Heart Block at 1-month	56
Overall Study At Least 500 Evaluable Beats	54
Overall Study COMPLETED	54
Overall Study NOT COMPLETED	103

Reasons for withdrawal

Reasons for withdrawal
Measure	AccelAV Evaluable for Primary Objective Subjects implanted with the Micra AV device with a 3rd degree AV block and normal sinus node function at 1-month
Overall Study Death	1
Overall Study Exited prior to implant	5
Overall Study Exited prior to 1-month	9
Overall Study Missed 1-month visit	3
Overall Study Predominant rhythm exclusion at 1-month	83
Overall Study Fewer than 500 evaluable beats	2

Baseline Characteristics

3 subjects did not have age reported

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	AccelAV Enrolled Cohort n=157 Participants Subjects enrolled in the AccelAV study
Age, Categorical <=18 years	0 Participants n=154 Participants • 3 subjects did not have age reported
Age, Categorical Between 18 and 65 years	17 Participants n=154 Participants • 3 subjects did not have age reported
Age, Categorical >=65 years	137 Participants n=154 Participants • 3 subjects did not have age reported
Age, Continuous	77.2 years STANDARD_DEVIATION 10.8 • n=154 Participants • 3 subjects did not have age reported
Sex: Female, Male Female	73 Participants n=154 Participants • 3 subjects did not have sex reported
Sex: Female, Male Male	81 Participants n=154 Participants • 3 subjects did not have sex reported
Region of Enrollment Hong Kong	19 Participants n=157 Participants
Region of Enrollment United States	138 Participants n=157 Participants
Body Mass Index (BMI)	28.2 kg/m^2 STANDARD_DEVIATION 7.0 • n=150 Participants • BMI was not available for 7 subjects
Comorbidities Hypertension	123 Participants n=157 Participants
Comorbidities Atrial fibrillation	20 Participants n=157 Participants
Comorbidities Diabetes	63 Participants n=157 Participants
Comorbidities Coronary Artery Disease	66 Participants n=157 Participants
Comorbidities Myocardial infarction	12 Participants n=157 Participants
Comorbidities Chronic Obstructive Pulmonary Disease	29 Participants n=157 Participants
Comorbidities Dialysis	13 Participants n=157 Participants
Preclusion for Transvenous Pacing	37 Participants n=157 Participants
Cardiac Perforation Risk Low	74 Participants n=157 Participants
Cardiac Perforation Risk Medium	39 Participants n=157 Participants
Cardiac Perforation Risk High	37 Participants n=157 Participants
Cardiac Perforation Risk Unavailable	7 Participants n=157 Participants
Pacing Indication Bradyarrhythmia with atrial fibrillation (AF)	5 Participants n=157 Participants
Pacing Indication Sinus Node Dysfunction	7 Participants n=157 Participants
Pacing Indication Atrioventricular (AV) Block	137 Participants n=157 Participants
Pacing Indication Syncope	1 Participants n=157 Participants
Pacing Indication Other	4 Participants n=157 Participants
Pacing Indication Unavailable	3 Participants n=157 Participants

PRIMARY outcome

Timeframe: 1-month post-implant

Outcome measures

Outcome measures
Measure	AccelAV Evaluable for Primary Objective n=54 Participants Subjects implanted with the Micra AV device with a 3rd degree AV block and normal sinus node function at 1-month
Atrioventricular (AV) Synchrony During Rest at 1-month Post-implant in Subjects With Persistent 3rd Degree Atrioventrcular Block (AVB) and Normal Sinus Node Function	85.4 Percentage of P-waves Interval 81.1 to 88.9

SECONDARY outcome

Timeframe: Between 1-month and 3-months post-implant

Population: Subjects were required to have a predominant heart rhythm of persistent 3rd degree AV block and normal sinus node function at both the 1-month and 3-month visits. Of the 54 subjects with persistent 3rd degree AV block an normal sinus function at 1-month, 37 of these remained in persistent 3rd degree AV block an normal sinus function at 3-months and were included in the analysis of this objective.

AV synchrony is defined for each ECG confirmed P-wave that occurs during the 20-minute resting period at both the 1-month visit and 3-months visits. For each P-wave the endpoint will be considered met if a ventricular beat (ventricular pace or sensed event) is within 300 ms following an ECG confirmed P-wave. The reported percentages are the average percentage of P-waves considered synchronous across all patients during the 20-minute resting period at each visit (month 1 or month 3).

Outcome measures

Outcome measures
Measure	AccelAV Evaluable for Primary Objective n=37 Participants Subjects implanted with the Micra AV device with a 3rd degree AV block and normal sinus node function at 1-month
Stability of AV Synchrony During Rest Between 1-month and 3-months Post-implant in Subjects With Persistent 3rd Degree AVB and Normal Sinus Node Function AV synchrony at 1-month	86.1 Percentage of P-waves Interval 81.2 to 89.9
Stability of AV Synchrony During Rest Between 1-month and 3-months Post-implant in Subjects With Persistent 3rd Degree AVB and Normal Sinus Node Function AV synchrony at 3-months	84.1 Percentage of P-waves Interval 78.3 to 88.6
Stability of AV Synchrony During Rest Between 1-month and 3-months Post-implant in Subjects With Persistent 3rd Degree AVB and Normal Sinus Node Function Difference in AV Synchrony (Month 3 - Month 1)	-2.0 Percentage of P-waves Interval -6.8 to 2.9

SECONDARY outcome

Timeframe: 1-month post-implant

AV synchrony is defined for each P-wave during the the 24-hour Holter monitoring period while the subject went about their activities of daily living. Specifically, for each electrocardiogram (ECG) confirmed P-wave that occurs during the 24-hour Holter period at the 1-month visit, the endpoint will be considered met if a ventricular beat (ventricular pace or sensed event) is within 300 ms following an ECG confirmed P-wave. The reported percentage is the average percentage of P-waves considered synchronous across all patients during the 24-hour Holter monitoring period.

Outcome measures

Outcome measures
Measure	AccelAV Evaluable for Primary Objective n=54 Participants Subjects implanted with the Micra AV device with a 3rd degree AV block and normal sinus node function at 1-month
Percentage of Ambulatory AV Synchrony at 1-month Post-implant in Subjects With Persistent 3rd Degree AVB and Normal Sinus Node Function	74.5 Percentage Interval 70.4 to 78.2

SECONDARY outcome

Timeframe: Within 48 hours of procedure

Population: The analysis population is a subset of the enrolled population. Specifically, of the 157 enrolled, 78 subjects had a predominant rhythm of persistent 3rd degree AV block and normal sinus rhythm at the time of implant. Of these, 67 had LVOT VTI measurements in both VVI and VDD modes. Of these 67, 47 had a heart rate within 15 beats per minute in both pacing modes and were included in the analysis of this objective as pre-specified in the study protocol.

Characterize the change in stroke volume, as measured by left ventricular outflow tract (LVOT) velocity time Integral (VTI), during Micra AV mediated VDD (atrioventricular synchronous ventricular pacing) pacing and VVI (asynchronous ventricular pacing) pacing in subjects with persistent 3rd degree AV block and normal sinus node function

Outcome measures

Outcome measures
Measure	AccelAV Evaluable for Primary Objective n=47 Participants Subjects implanted with the Micra AV device with a 3rd degree AV block and normal sinus node function at 1-month
Left Ventricular Outflow Tract Velocity Time Integral LVOT VTI during VDD mode	23.7 cm Interval 21.7 to 25.6
Left Ventricular Outflow Tract Velocity Time Integral LVOT VTI during VVI mode	21.4 cm Interval 19.7 to 23.1
Left Ventricular Outflow Tract Velocity Time Integral LVOT VTI difference (VDD-VVI)	2.3 cm Interval 1.5 to 3.1

Adverse Events

AccelAV Enrolled Cohort

Serious events: 45 serious events

Other events: 27 other events

Deaths: 2 deaths

Serious adverse events

Serious adverse events
Measure	AccelAV Enrolled Cohort n=157 participants at risk Subjects enrolled in the AccelAV study
Blood and lymphatic system disorders Thrombocytopenia	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
Cardiac disorders Acute left ventricular failure	1.3% 2/157 • Number of events 2 • Adverse events were collected from the time of consent through 3-month follow-up
Cardiac disorders Acute myocardial infarction	1.3% 2/157 • Number of events 3 • Adverse events were collected from the time of consent through 3-month follow-up
Cardiac disorders Atrial fibrillation	1.9% 3/157 • Number of events 3 • Adverse events were collected from the time of consent through 3-month follow-up
Cardiac disorders Atrial flutter	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
Cardiac disorders Atrioventricular block complete	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
Cardiac disorders Bradycardia	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
Cardiac disorders Cardiac arrest	2.5% 4/157 • Number of events 4 • Adverse events were collected from the time of consent through 3-month follow-up
Cardiac disorders Cardiac failure	1.9% 3/157 • Number of events 3 • Adverse events were collected from the time of consent through 3-month follow-up
Cardiac disorders Cardiac failure acute	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
Cardiac disorders Cardiac failure congestive	1.3% 2/157 • Number of events 2 • Adverse events were collected from the time of consent through 3-month follow-up
Cardiac disorders Cardiac tamponade	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
Cardiac disorders Cardio-respiratory arrest	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
Cardiac disorders Coronary artery disease	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
Cardiac disorders Intracardiac thrombus	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
Cardiac disorders Pericardial effusion	1.9% 3/157 • Number of events 3 • Adverse events were collected from the time of consent through 3-month follow-up
Cardiac disorders Pericarditis	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
Infections and infestations Endocarditis	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
Infections and infestations Septic shock	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
Nervous system disorders Cerebrovascular accident	1.3% 2/157 • Number of events 2 • Adverse events were collected from the time of consent through 3-month follow-up
Nervous system disorders Haemorrhage intracranial	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
Nervous system disorders Presyncope	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
Nervous system disorders Transient ischaemic attack	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
Product Issues Device pacing issue	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
Respiratory, thoracic and mediastinal disorders Acute respiratory failure	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
Vascular disorders Aortic stenosis	1.3% 2/157 • Number of events 2 • Adverse events were collected from the time of consent through 3-month follow-up
Vascular disorders Deep vein thrombosis	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
Vascular disorders Hypertension	1.3% 2/157 • Number of events 2 • Adverse events were collected from the time of consent through 3-month follow-up
Vascular disorders Intermittent claudication	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
Vascular disorders Peripheral vein occlusion	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up

Other adverse events

Other adverse events
Measure	AccelAV Enrolled Cohort n=157 participants at risk Subjects enrolled in the AccelAV study
Cardiac disorders Atrial fibrillation	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
Cardiac disorders Atrial flutter	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
Cardiac disorders Bradycardia	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
Cardiac disorders Cardiac failure congestive	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
Cardiac disorders Palpitations	1.3% 2/157 • Number of events 2 • Adverse events were collected from the time of consent through 3-month follow-up
General disorders Fatigue	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
General disorders Implant site erythema	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
General disorders Non-cardiac chest pain	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
General disorders Oedema	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
General disorders Pacemaker syndrome	2.5% 4/157 • Number of events 5 • Adverse events were collected from the time of consent through 3-month follow-up
General disorders Puncture site haemorrhage	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
Injury, poisoning and procedural complications Vascular access site haemorrhage	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
Nervous system disorders Dizziness	1.3% 2/157 • Number of events 2 • Adverse events were collected from the time of consent through 3-month follow-up
Nervous system disorders Syncope	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
Respiratory, thoracic and mediastinal disorders Dyspnoea	1.3% 2/157 • Number of events 2 • Adverse events were collected from the time of consent through 3-month follow-up
Respiratory, thoracic and mediastinal disorders Pleuritic pain	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
Vascular disorders Deep vein thrombosis	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
Vascular disorders Hypertension	1.3% 2/157 • Number of events 2 • Adverse events were collected from the time of consent through 3-month follow-up
Vascular disorders Orthostatic hypotension	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up
Vascular disorders Thrombophlebitis superficial	0.64% 1/157 • Number of events 1 • Adverse events were collected from the time of consent through 3-month follow-up

Additional Information

Rachel Vasseur, Sr. Clinical Research Specialist

Medtronic

Phone: 6123550360

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee PIs will not publish/present results until a multi-center pub. is released. If a multi-center pub. is not released within 1 year of completion PI may publish the results pertaining to their activities. Pubs will be provided to MDT at least 60 days prior to submission or presentation for review. Within 60 days of receipt, MDT will verify presence of CI or technical errors. PI will make requested changes prior to publication/presentation. PI will delay publication up to 90 more days if requested.
Publication restrictions are in place

Restriction type: OTHER