The ECG Belt for CRT response trial: Design and clinical protocol.

The ECG Belt for CRT response trial is designed to test the hypothesis that in patients traditionally less likely to respond to cardiac resynchronization therapy (CRT), an individualized approach utilizing the electrocardiogram (ECG) Belt to guide lead placement, vector selection, and device programming is superior to current standard of care. The ECG Belt is a noninvasive mapping technology designed to measure beat by beat electrical activation of the left ventricle by utilizing unipolar measurements from multiple ECG electrodes on the body surface. The ECG Belt for CRT response trial is a multicenter, prospective, randomized, investigational pre-market research study conducted at 48 centers in the United States, Canada, and Europe and will randomize approximately 400 subjects. The trial has three arms (enrollment will be 2:1:1, respectively): utilization of the Belt to guide implant as well as postimplant programming, utilizing the Belt to guide postimplant programming alone, and a non-Belt control arm. AdaptivCRT will be an option in the treatment arm but not the control arms. The primary endpoint is change in left ventricular end-systolic volume between preimplant and at 6 months. This paper describes the design and analytic plan for the trial.

Implantable defibrillators improve survival in patients with mildly symptomatic heart failure receiving cardiac resynchronization therapy: analysis of the long-term follow-up of remodeling in systolic left ventricular dysfunction (REVERSE).

BACKGROUND: Cardiac resynchronization therapy (CRT) decreases mortality, improves functional status, and induces reverse left ventricular remodeling in selected populations with heart failure. These benefits have been noted with both CRT-pacemakers as well as those devices with defibrillator backup (CRT-D). However, there are little data comparing mortality between these 2 device types. METHODS AND RESULTS: REsynchronization reVErses Remodeling in Systolic left vEntricular dysfunction (REVERSE) was a multicenter, randomized trial of CRT among patients with mild heart failure. Long-term annual follow-up for 5 years was preplanned. The present analysis was confined to the 419 patients who were randomized to active CRT group. CRT-pacemakers or CRT-D devices were implanted based on national guidelines at the time of enrollment, with 74 patients receiving CRT pacemaker devices and the remaining 345 patients receiving CRT-D devices. After 12 months of CRT, changes in the clinical composite score, left ventricular end systolic volume index, 6-minute walk time, and quality of life indices were similar between CRT pacemaker and CRT-D patients. However, long-term follow-up showed lower morality in the CRT-D group. Specifically, multivariable analysis showed that CRT-D (hazard ratio, 0.35; P=0.003) was a strong independent predictor of survival. Female sex, longer unpaced QRS duration, and smaller baseline left ventricular end systolic volume index also were also associated with better survival. CONCLUSIONS: REVERSE demonstrated that the addition of implantable cardioverter-defibrillator therapy to CRT is associated with improved long-term survival compared with CRT pacing alone in mild heart failure. CLINICAL TRIAL REGISTRATION: URL: http://clinicaltrials.gov. Unique Identifier: NCT00271154.

Long-term impact of cardiac resynchronization therapy in mild heart failure: 5-year results from the REsynchronization reVErses Remodeling in Systolic left vEntricular dysfunction (REVERSE) study.

BACKGROUND: The benefit of cardiac resynchronization therapy (CRT) among patients with mild heart failure (HF), reduced left ventricular (LV) function and wide QRS is well established. We studied the long-term stability of CRT. METHODS: REVERSE was a randomized, double-blind study on CRT in NYHA Class I and II HF patients with QRS ≥120 ms and left ventricular ejection fraction (LVEF) ≤40%. After the randomized phase, all were programmed to CRT ON and prospectively followed through 5 years for functional capacity, echocardiography, HF hospitalizations, mortality, and adverse events. We report the results of the 419 patients initially assigned to CRT ON. FINDINGS: The mean follow-up time was 54.8 ± 13.0 months. After 2 years, the functional and LV remodelling improvements were maximal. The 6-min hall walk increased by 18.8 ± 102.3 m and the Minnesota and Kansas City scores improved by 8.2 ± 17.8 and 8.2 ± 17.2 units, respectively. The mean decrease in left ventricular end-systolic volume index and left ventricular end-diastolic volume index was 23.5 ± 34.1 mL/m(2) (P < 0.0001) and 25.4 ± 37.0 mL/m2 (P < 0.0001) and the mean increase in LVEF 6.0 ± 10.8% (P < 0.0001) with sustained improvement thereafter. The annualized and 5-year mortality was 2.9 and 13.5% and the annualized and 5-year rate of death or first HF hospitalization 6.4, and 28.1%. The 5-year LV lead-related complication rate was 12.5%. CONCLUSION: In patients with mild HF, CRT produced reverse LV remodelling accompanied by very low mortality and need for heart failure hospitalization. These effects were sustained over 5 years. Cardiac resynchronization therapy in addition to optimal medical therapy produces long-standing clinical benefits in mild heart failure. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov identifier NCT00271154.