SyncAV Post-Market Trial

SyncAV PMT

Patient / Population Intervention / Exposition Comparaison Critère de jugement

In 1,288 CRT recipients with left bundle branch block, dynamic AV-delay optimisation did not reduce the reduction in LV end-systolic volume at 12 months compared with a fixed AV delay.

N

1 288patients

Schéma

Prospective, international multicentre, randomised (1:1), open-label post-market trial sponsored by Abbott; patients receiving a new Abbott quadripolar CRT system randomised 2–6 weeks after successful implant to SyncAV dynamic atrioventricular-delay optimisation programmed ON (offset selected by QRS narrowing) versus a fixed nominal AV delay; follow-up at 3, 6 and 12 months; started October 2019, primary completion estimated mid-2026.

Critère

Change in left ventricular end-systolic volume from baseline to 12 months (continuous), compared between arms

Pertinence

2Important — l’un des piliers parmi d’autres.

RésultatLeft ventricular end-systolic volume at 12 months did not differ (P = 0.054), nor did the proportion of responders with a fall of at least 15% (P = 0.16). Paced QRS was shorter with the algorithm (123 vs 138 ms; P < 0.0001) and atrial fibrillation lasting more than 10 days was less frequent (2.0% vs 4.4%; P = 0.03). Mortality 2.1% vs 2.4%. In the exploratory half with a PR interval of 185 ms or more, the clinical composite ran 10.3% vs 21.5% (P = 0.006).

Varma N, Mont L, Zareba W, et al. Presented at ESC Congress 2026, Hot Line 10, 31 August.

Discussion et critique

An algorithm that keeps fusion pacing as the PR interval wanders produced the narrower paced QRS it was designed for and no better remodelling at a year — the electrical target moved, the ventricle did not. The primary endpoint at P = 0.054 will be quoted as a near miss; it is a miss, and the responder analysis agrees. What may survive is the subgroup with a PR interval of 185 ms or longer, where fixed programming loses fusion and the clinical composite halved — half the cohort, entirely exploratory, and the trial's own hypothesis for the next one.