経カテーテル大動脈弁留置術後の心房内ブロックおよび正常な心機能における左脚ブロック対尖部ペーシング：PhysTAVI試験

There is currently no evidence of the best pacing mode for high-degree atrioventricular (AV) block occurring after transcatheter aortic valve implantation (TAVI). The objective of this pilot study was to compare a clinical combined endpoint achieved by left bundle branch pacing (LBBP) vs right ventricular (RV) pacing in patients with preserved left ventricular ejection fraction (LVEF) post-TAVI at 12-month follow-up.

Consecutive patients post-TAVI with high-degree AV block and LVEF ≥ 50% were randomized to LBBP or RV pacing. The primary endpoint was survival with an improvement of ≥ 1 point in New York Heart Association functional class or a ≥ 25% increase in distance covered on the 6-minute walking test. Secondary endpoints were change in LVEF, septal flash, mitral regurgitation, N-terminal pro-brain natriuretic peptide, heart failure hospitalization, score on symptoms, and QRS duration.

Twenty-four patients were included in the study, 12 in each arm. Both groups showed a similar incidence of the primary endpoint: 33.3% (n = 4) in the LBBP group vs 25% (n = 3) in the RV group (P = 1.0). In relation to secondary endpoints, significant shortening in the QRS was observed in the LBBP group compared with the RV group (median: -39 ms vs 0 ms, P < 0.001). Septal flash excursion was significantly lower for the LBBP group (median: 0 mm vs 2 mm, P = 0.03). There was no difference between groups on any other endpoint.

Similar midterm outcomes were obtained with LBBP and RV pacing in an elderly population with high-degree AV block and preserved LVEF after TAVI. The pilot Phys-TAVI trial showed the feasibility of LBBP in this population. Larger randomized clinical trials with longer follow-up are needed to test for differential clinical outcomes between pacing modalities.

NCT04482816.