Trial Outcomes & Findings for MADIT-CRT: Multicenter Automatic Defibrillator Implantation With Cardiac Resynchronization Therapy (NCT NCT00180271)

NCT ID: NCT00180271

Last Updated: 2018-12-19

Results Overview

MADIT-CRT was an event-driven trial in which patients were monitored for all-cause mortality and HF events. An HF event was defined as either hospitalization for symptoms and/or signs consistent with congestive HF and: 1. administration of intravenous decongestive therapy that does not involve formal in-patient hospital admission, regardless of the setting (i.e. in an emergency room setting, in the physician's office, etc.), or 2. administration of an augmented HF regimen with oral or intravenous medications during an in-hospital stay.

• Recruitment status: COMPLETED
• Study phase: NA
• Target enrollment: 1820 participants
• Primary outcome timeframe: Outcome measured at average follow-up duration of 2.4 years.
• Results posted on: 2018-12-19

Participant Flow

The study enrolled 1820 patients from 110 hospital centers (88 in the United States, 2 in Canada, and 20 in Europe) between December 22, 2004 and April 23, 2008. Follow-up continued thereafter until trial termination.

Data from all patients enrolled were analyzed on an intention-to-treat basis.

Participant milestones

Measure	Cardiac Resynchronization Therapy + Defibrillator Patients randomized to cardiac resynchronization therapy with backup defibrillation (CRT-D) in addition to optimal pharmacologic therapy (as administered by the primary care physician). CRT-D devices both deliver shocks to terminate potentially lethal ventricular arrhythmias and pace both ventricles in patients with ventricular dyssynchrony.	Implantable Cardioverter Defibrillator Alone Patients randomized to implantable cardioverter defibrillator (ICD) in addition to optimal pharmacologic therapy (as administered by the primary care physician). ICDs deliver shocks to terminate potentially lethal ventricular arrhythmias.
Overall Study STARTED	1089	731
Overall Study COMPLETED	1089	731
Overall Study NOT COMPLETED	0	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

MADIT-CRT: Multicenter Automatic Defibrillator Implantation With Cardiac Resynchronization Therapy

Baseline characteristics by cohort

Measure	Cardiac Resynchronization Therapy + Defibrillator n=1089 Participants Patients randomized to cardiac resynchronization therapy with backup defibrillation (CRT-D) in addition to optimal pharmacologic therapy (as administered by the primary care physician). CRT-D devices both deliver shocks to terminate potentially lethal ventricular arrhythmias and pace both ventricles in patients with ventricular dyssynchrony.	Implantable Cardioverter Defibrillator Alone n=731 Participants Patients randomized to implantable cardioverter defibrillator (ICD) in addition to optimal pharmacologic therapy (as administered by the primary care physician). ICDs deliver shocks to terminate potentially lethal ventricular arrhythmias.	Total n=1820 Participants Total of all reporting groups
Age, Categorical <=18 years	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Age, Categorical Between 18 and 65 years	543 Participants n=5 Participants	380 Participants n=7 Participants	923 Participants n=5 Participants
Age, Categorical >=65 years	546 Participants n=5 Participants	351 Participants n=7 Participants	897 Participants n=5 Participants
Age, Continuous	65 years STANDARD_DEVIATION 11 • n=5 Participants	64 years STANDARD_DEVIATION 11 • n=7 Participants	65 years STANDARD_DEVIATION 11 • n=5 Participants
Sex: Female, Male Female	275 Participants n=5 Participants	178 Participants n=7 Participants	453 Participants n=5 Participants
Sex: Female, Male Male	814 Participants n=5 Participants	553 Participants n=7 Participants	1367 Participants n=5 Participants
Region of Enrollment United States	757 participants n=5 Participants	514 participants n=7 Participants	1271 participants n=5 Participants
Region of Enrollment Canada	14 participants n=5 Participants	8 participants n=7 Participants	22 participants n=5 Participants
Region of Enrollment Czech Republic	17 participants n=5 Participants	11 participants n=7 Participants	28 participants n=5 Participants
Region of Enrollment Denmark	22 participants n=5 Participants	13 participants n=7 Participants	35 participants n=5 Participants
Region of Enrollment France	13 participants n=5 Participants	9 participants n=7 Participants	22 participants n=5 Participants
Region of Enrollment Germany	98 participants n=5 Participants	61 participants n=7 Participants	159 participants n=5 Participants
Region of Enrollment Hungary	16 participants n=5 Participants	10 participants n=7 Participants	26 participants n=5 Participants
Region of Enrollment Israel	45 participants n=5 Participants	30 participants n=7 Participants	75 participants n=5 Participants
Region of Enrollment Italy	15 participants n=5 Participants	12 participants n=7 Participants	27 participants n=5 Participants
Region of Enrollment Netherlands	34 participants n=5 Participants	24 participants n=7 Participants	58 participants n=5 Participants
Region of Enrollment Poland	14 participants n=5 Participants	10 participants n=7 Participants	24 participants n=5 Participants
Region of Enrollment Spain	36 participants n=5 Participants	24 participants n=7 Participants	60 participants n=5 Participants
Region of Enrollment Switzerland	4 participants n=5 Participants	2 participants n=7 Participants	6 participants n=5 Participants
Region of Enrollment United Kingdom	4 participants n=5 Participants	3 participants n=7 Participants	7 participants n=5 Participants

PRIMARY outcome

Timeframe: Outcome measured at average follow-up duration of 2.4 years.

Population: Analysis was performed on an intention-to-treat basis and counted the time to first event. The category "Patients with Death at Any Time", includes deaths that occurred after the first heart failure event.

MADIT-CRT was an event-driven trial in which patients were monitored for all-cause mortality and HF events. An HF event was defined as either hospitalization for symptoms and/or signs consistent with congestive HF and:

1. administration of intravenous decongestive therapy that does not involve formal in-patient hospital admission, regardless of the setting (i.e. in an emergency room setting, in the physician's office, etc.), or

2. administration of an augmented HF regimen with oral or intravenous medications during an in-hospital stay.

Outcome measures

Measure	Cardiac Resynchronization Therapy + Defibrillator n=1089 Participants Patients randomized to cardiac resynchronization therapy with backup defibrillation (CRT-D) in addition to optimal pharmacologic therapy (as administered by the primary care physician). CRT-D devices both deliver shocks to terminate potentially lethal ventricular arrhythmias and pace both ventricles in patients with ventricular dyssynchrony.	Implantable Cardioverter Defibrillator Alone n=731 Participants Patients randomized to implantable cardioverter defibrillator (ICD) in addition to optimal pharmacologic therapy (as administered by the primary care physician). ICDs deliver shocks to terminate potentially lethal ventricular arrhythmias.
Mortality From Any Cause or First Heart Failure (HF) Event Patients who are Event Free	901 Participants	543 Participants
Mortality From Any Cause or First Heart Failure (HF) Event Patients with Death or Heart Failure Event	188 Participants	188 Participants
Mortality From Any Cause or First Heart Failure (HF) Event Patients with Heart Failure Event Alone	152 Participants	170 Participants
Mortality From Any Cause or First Heart Failure (HF) Event Patients with Death at Any Time	74 Participants	53 Participants

SECONDARY outcome

Timeframe: Time of event, DSMB review

The MADIT-CRT secondary outcome evaluated the effects of CRT-D, relative to ICD, on the recurrence of heart failure events over the full study period An HF event was defined as either hospitalization for symptoms and/or signs consistent with congestive HF and:

1. administration of intravenous decongestive therapy that does not involve formal in-patient hospital admission, regardless of the setting (i.e. in an emergency room setting, in the physician's office, etc.), or

2. administration of an augmented HF regimen with oral or intravenous medications during an in-hospital stay.

Outcome measures

Measure	Cardiac Resynchronization Therapy + Defibrillator n=1089 Participants Patients randomized to cardiac resynchronization therapy with backup defibrillation (CRT-D) in addition to optimal pharmacologic therapy (as administered by the primary care physician). CRT-D devices both deliver shocks to terminate potentially lethal ventricular arrhythmias and pace both ventricles in patients with ventricular dyssynchrony.	Implantable Cardioverter Defibrillator Alone n=731 Participants Patients randomized to implantable cardioverter defibrillator (ICD) in addition to optimal pharmacologic therapy (as administered by the primary care physician). ICDs deliver shocks to terminate potentially lethal ventricular arrhythmias.
Recurrent Heart Failure Events Participants with 0 events	928 Participants	545 Participants
Recurrent Heart Failure Events Participants with 1 event	93 Participants	107 Participants
Recurrent Heart Failure Events Participants with 2 or more events	68 Participants	79 Participants

Adverse Events

Cardiac Resynchronization Therapy + Defibrillator

Serious events: 164 serious events

Other events: 126 other events

Deaths: 0 deaths

Implantable Cardioverter Defibrillator Alone

Serious events: 55 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Measure	Cardiac Resynchronization Therapy + Defibrillator n=1079 participants at risk Patients randomized to cardiac resynchronization therapy with backup defibrillation (CRT-D) in addition to optimal pharmacologic therapy (as administered by the primary care physician). CRT-D devices both deliver shocks to terminate potentially lethal ventricular arrhythmias and pace both ventricles in patients with ventricular dyssynchrony.	Implantable Cardioverter Defibrillator Alone n=712 participants at risk Patients randomized to implantable cardioverter defibrillator (ICD) in addition to optimal pharmacologic therapy (as administered by the primary care physician). ICDs deliver shocks to terminate potentially lethal ventricular arrhythmias.
Cardiac disorders Lead Dislodgment, Left Ventricular	4.3% 46/1079 • Number of events 51 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.14% 1/712 • Number of events 1 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Cardiac disorders Lead Dislodgment, Right Atrial	3.1% 33/1079 • Number of events 33 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	1.4% 10/712 • Number of events 10 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Surgical and medical procedures Pneumothorax	1.4% 15/1079 • Number of events 15 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.70% 5/712 • Number of events 5 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Surgical and medical procedures Hematoma, Pocket	1.3% 14/1079 • Number of events 14 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.70% 5/712 • Number of events 5 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Cardiac disorders Extracardiac Stimulation, Left Ventricular	1.0% 11/1079 • Number of events 11 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.00% 0/712 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Cardiac disorders Lead Dislodgment, Right Ventricular	0.74% 8/1079 • Number of events 8 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.70% 5/712 • Number of events 5 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Blood and lymphatic system disorders Thromboembolic Events	0.74% 8/1079 • Number of events 8 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.56% 4/712 • Number of events 4 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Surgical and medical procedures Atrioventricular Block	0.56% 6/1079 • Number of events 6 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.28% 2/712 • Number of events 2 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Surgical and medical procedures Adverse Reaction	0.56% 6/1079 • Number of events 6 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.98% 7/712 • Number of events 7 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Cardiac disorders Elevated Threshold, Right Ventricular	0.56% 6/1079 • Number of events 6 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.42% 3/712 • Number of events 3 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Surgical and medical procedures Infection, Post Surgical	0.83% 9/1079 • Number of events 9 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.28% 2/712 • Number of events 2 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Cardiac disorders Inadvertent Ventricular Tachyarrhythmia	0.37% 4/1079 • Number of events 4 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.28% 2/712 • Number of events 2 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Surgical and medical procedures Renal Failure	0.37% 4/1079 • Number of events 4 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.00% 0/712 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Surgical and medical procedures Pericardial Effusion	0.28% 3/1079 • Number of events 4 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.14% 1/712 • Number of events 1 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Surgical and medical procedures Myocardial Perforation with Tamponade	0.28% 3/1079 • Number of events 3 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.14% 1/712 • Number of events 1 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Cardiac disorders Elevated Defibrillation Thresholds	0.56% 6/1079 • Number of events 6 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	1.1% 8/712 • Number of events 8 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Skin and subcutaneous tissue disorders Hemorrhage, Pocket	0.19% 2/1079 • Number of events 2 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.14% 1/712 • Number of events 1 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Cardiac disorders Inappropriate Tachyarrhythmia Therapy	0.19% 2/1079 • Number of events 2 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.14% 1/712 • Number of events 1 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Cardiac disorders Early Elective Replacement Indicator	0.19% 2/1079 • Number of events 2 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.14% 1/712 • Number of events 1 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Cardiac disorders Insulation Breach, Left Ventricular Lead	0.19% 2/1079 • Number of events 2 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.00% 0/712 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Cardiac disorders Inadvertent Supraventricular Tachyarrhythmia	0.19% 2/1079 • Number of events 2 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.00% 0/712 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Surgical and medical procedures Arterial Perforation	0.09% 1/1079 • Number of events 1 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.00% 0/712 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Surgical and medical procedures Venous Occlusion	0.09% 1/1079 • Number of events 1 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.00% 0/712 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Surgical and medical procedures Seroma, Pocket	0.09% 1/1079 • Number of events 1 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.00% 0/712 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Respiratory, thoracic and mediastinal disorders Pleural Effusion	0.09% 1/1079 • Number of events 1 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.00% 0/712 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Cardiac disorders Worsening Heart Failure	0.19% 2/1079 • Number of events 2 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.14% 1/712 • Number of events 1 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Cardiac disorders Elevated Threshold, Left Ventricular	0.09% 1/1079 • Number of events 1 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.00% 0/712 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Cardiac disorders Difficulty Measing Impedance/Amplitude	0.09% 1/1079 • Number of events 1 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.00% 0/712 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Surgical and medical procedures Pulse Generator Migration	0.09% 1/1079 • Number of events 1 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.00% 0/712 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Surgical and medical procedures Set Screws Not Tightened	0.00% 0/1079 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.42% 3/712 • Number of events 3 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Surgical and medical procedures Post Surgical Wound Discomfort	0.00% 0/1079 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.14% 1/712 • Number of events 1 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Cardiac disorders Elevated Shock Impedance	0.09% 1/1079 • Number of events 1 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.00% 0/712 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Cardiac disorders Bigeminy	0.09% 1/1079 • Number of events 1 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.00% 0/712 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.

Other adverse events

Measure	Cardiac Resynchronization Therapy + Defibrillator n=1079 participants at risk Patients randomized to cardiac resynchronization therapy with backup defibrillation (CRT-D) in addition to optimal pharmacologic therapy (as administered by the primary care physician). CRT-D devices both deliver shocks to terminate potentially lethal ventricular arrhythmias and pace both ventricles in patients with ventricular dyssynchrony.	Implantable Cardioverter Defibrillator Alone n=712 participants at risk Patients randomized to implantable cardioverter defibrillator (ICD) in addition to optimal pharmacologic therapy (as administered by the primary care physician). ICDs deliver shocks to terminate potentially lethal ventricular arrhythmias.
Cardiac disorders Extracardiac Stimulation, Left Ventricular	6.5% 70/1079 • Number of events 77 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.00% 0/712 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.
Cardiac disorders Pacemaker Mediated Tachycardia	5.2% 56/1079 • Number of events 67 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.	0.00% 0/712 • 91 Days The primary outcome was performed on an intention-to-treat basis and all participants were followed. However, the number of participants at risk for adverse events is fewer than the total number in the primary outcome. Some participants did not undergo the surgical procedure for device implant and were therefore not subjected to risk.

Additional Information

Jill Leigh

Boston Scientific

Phone: 800 227 3422

Email: jill.leigh@bsci.com

Results disclosure agreements

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