1. All-cause mortality after 5 years was similar for patients in the adaptive and conventional CRT groups.
2. System-related adverse events exhibited no significant disparity between groups.
Evidence Rating Level: 1 (Excellent)
Study Rundown: Cardiac resynchronization therapy (CRT) is the standard of care among patients with decompensated heart failure and left bundle branch block. However, a large proportion of patients may be non-responders. Compared to conventional biventricular CRT, adaptive CRT aims to stimulate the left ventricle in synchronization with intrinsic right ventricular conduction. This randomized controlled trial aimed to assess the clinical outcomes of adaptive CRT versus conventional CRT in patients with heart failure. The primary outcome was a composite of all-cause mortality or intervention for heart failure decompensation. According to study results, adaptive CRT did not significantly reduce the incidence of all-cause mortality or intervention for heart failure decompensation. Although this study was well done, it was limited by early termination due to reaching the futility boundary, thus impacting the overall assessment of the intervention’s effectiveness.
Click to read the study in The Lancet
Relevant Reading: Cardiac-Resynchronization Therapy for the Prevention of Heart-Failure Events
In-depth [randomized-controlled trial]: Between Aug 5, 2014, and Jan 31, 2019, 3797 patients were assessed for eligibility at 227 hospitals in 27 countries. Included were patients aged ≥ 18 years old with class 2-4 heart failure, ejection fraction ≤ 35%, and left bundle branch block meeting QRS duration criteria. Altogether, 3617 patients (1810 in adaptive CRT and 1807 in conventional CRT) were included in the final analysis. The primary outcome of all-cause death or intervention for heart failure decompensation showed no significant difference between the adaptive CRT (Kaplan-Meier occurrence rate 23.5% at 60 months) and conventional CRT groups (Kaplan-Meier occurrence rate 25.7% at 60 months; hazard ratio [HR] 0.89, p=0.077). This was also the case for system-related adverse events (25.0% vs. 24.3%). Overall, findings from this study suggest that adaptive CRT did not significantly reduce all-cause death or heart failure interventions when compared to conventional CRT for patients with decompensated heart failure, left bundle branch block, and intact atrioventricular conduction.
Image: PD
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