Adaptive CRT may not reduce HF decompensation or mortality versus conventional CRT among patients with HFrEF and LBBB

The findings from the AdaptResponse showed low death and heart failure decompensation rates with both CRT therapies, indicating a greater response to CRT occurred in this population than in patients in previous trials.

"The AdaptResponse trial showed that in patients with heart failure, left bundle branch block, and intact AV conduction in whom CRT was indicated, adaptive CRT with isolated LV pacing did not reduce the composite outcome of HF decompensation or all-cause death compared with conventional biventricular CRT," the researchers reported.

Continuous automatic optimisation of CRT, stimulating only the left ventricle to fuse with intrinsic right bundle conduction (synchronised left ventricular stimulation), is suggested to offer better outcomes than conventional CRT in patients with HF, normal atrioventricular conduction, and left bundle branch block. Prof Bruce L Wilkoff, Cleveland Clinic, Cleveland, OH, USA, and colleagues aimed to compare clinical outcomes of adaptive CRT versus conventional CRT in HF patients.

The trial was conducted in 227 hospitals in 27 countries across North America, Europe, Australia, and Asia. It included patients aged 18 years or above with class 2–4 heart failure, an EF of 35% or less, left bundle branch block with QRS duration of 130 ms or more (female patients) or 140 ms or more (male patients), and a baseline PR interval 200 ms or less.

3617 were randomly assigned in the ratio of 1:1 to adaptive CRT (an algorithm providing synchronised left ventricular stimulation; n=1810) or conventional biventricular CRT (n=1807) using a device programmer. The primary outcome of the study was determined as a composite of all-cause death or intervention for heart failure decompensation and was evaluated in the intention-to-treat population. In the intention-to-treat population, safety events were collected and reported.

The study led to the following findings:

• A primary outcome event occurred in 430 of 1810 patients (Kaplan-Meier occurrence rate 23·5% at 60 months) in the adaptive CRT group and 470 of 1807 patients (25·7% at 60 months) in the conventional CRT group (hazard ratio 0·89).
• System-related adverse events were reported in 25·0% of patients in the adaptive CRT group and 24·3% of patients in the conventional CRT group.

"Though exploratory, these findings may support a role for adaptive CRT in a subset of patients who are potentially more likely to gain meaningful clinical benefit," the researchers concluded.

Reference:

Wilkoff BL, Filippatos G, Leclercq C, Gold MR, Hersi AS, Kusano K, Mullens W, Felker GM, Kantipudi C, El-Chami MF, Essebag V, Pierre B, Philippon F, Perez-Gil F, Chung ES, Sotomonte J, Tung S, Singh B, Bozorgnia B, Goel S, Ebert HH, Varma N, Quan KJ, Salerno F, Gerritse B, van Wel J, Schaber DE, Fagan DH, Birnie D; AdaptResponse investigators. Adaptive versus conventional cardiac resynchronisation therapy in patients with heart failure (AdaptResponse): a global, prospective, randomised controlled trial. Lancet. 2023 Sep 30;402(10408):1147-1157. doi: 10.1016/S0140-6736(23)00912-1. Epub 2023 Aug 24. Erratum in: Lancet. 2023 Sep 30;402(10408):1132. PMID: 37634520.