Bruce Wilkoff, MD

Adaptive cardiac resynchronisation therapy (CRT) did not reduce the risk for death or intervention for heart failure (HF) decompensation compared with conventional CRT in patients with HF, left bundle branch block (LBBB), and intact atrioventricular (AV) conduction, according to results from the AdaptResponse trial.

“Although CRT offers health benefits to patients with symptomatic HF, a prolonged QRS duration, and a reduced ejection fraction, up to 30% of the patients have been classified as non-responders to conventional CRT,” said Bruce Wilkoff, MD, who presented the results of his study at the 2023 European Heart Rhythm Association (EHRA) Congress, held from April 16 to 18, in Barcelona, Spain.¹ “Pacing the left ventricle only may be superior to biventricular pacing if conduction to the right ventricle is intact.”²

The AdaptResponse trial randomized 3,618 patients with HF, LBBB, and intact AV conduction 1:1 to adaptive CRT, switching between left ventricular pacing and biventricular pacing based on the patients’ AV and heart rhythm, or conventional CRT.³ The primary endpoint was death from any cause or intervention for HF decompensation, which was not met, and the trial was stopped after the third interim analysis due to futility. The event rate was 33.7% in the conventional CRT group and 30.8% in the adaptive CRT group (HR 0.89; P=0.077).

Similarly, between the two study groups, secondary endpoints did not reach a statistically significant difference.  Dr. Wilkoff observed that a post-hoc analysis revealed that compared with patients in the conventional CRT group, those in the adaptive CRT group with 85% or more synchronised left ventricular pacing had a significantly lower rate of mortality and intervention for HF decompensation (HR 0.76; P=0.0037).