In Japanese patients receiving cardiac resynchronization therapy, intrinsic left bundle branch block with QRS duration ≥150 ms was associated with the lowest incidence of all-cause death or heart failure hospitalization compared to other QRS morphologies.
Cohort (n=510)
Yes
Does intrinsic QRS morphology and duration predict clinical outcomes and echocardiographic response after cardiac resynchronization therapy in Japanese patients with heart failure?
In a Japanese population, patients with LBBB intrinsic QRS morphology and prolonged QRS duration (≥150 ms) exhibited the best echocardiographic and clinical responses to cardiac resynchronization therapy.
Effect estimate: HR 2.50 (95% CI 1.72-3.63)
Absolute Event Rate: 28.6% vs 55.3%
p-value: p=<0.001
BACKGROUND: QRS duration (QRSd) and morphology are established response predictors of cardiac resynchronization therapy (CRT). However, evidence in Japanese populations is lacking. METHODS AND RESULTS: We retrospectively analyzed the Japanese multicenter CRT database. We divided patients according to their intrinsic QRSd and morphology, and assessed echocardiographic responses and clinical outcomes. The primary endpoint was a composite of all-cause death or hospitalization because of heart failure. A total of 510 patients were enrolled: 200 (39%) had left bundle branch block (LBBB) and QRSd ≥150 ms; 80 (16%) had LBBB (QRSd: 120-149 ms); 61 (12%) had non-LBBB (NLBBB) (QRSd: ≥150 ms); 54 (11%) had NLBBB (QRSd: 120-149 ms); 115 (23%), narrow (<120 ms). The proportion of echocardiographic responders was higher in LBBB (QRSd ≥150 ms) 74% vs. 51% vs. 38% vs. 52% vs. 50%, LBBB (QRSd ≥150 ms) vs. LBBB (QRSd 120-149 ms) vs. NLBBB (QRSd ≥150 ms) vs. NLBBB (QRSd 120-149 ms) vs. narrow, respectively, P<0.001. During follow-up (3.2±1.5 years), the incidence of the primary endpoint was lowest in the LBBB group (QRSd ≥150) (28.6% vs. 42.3% vs. 45.9% vs. 55.6% vs. 55.3%, respectively, P<0.001). This difference was still significant after adjusting for other baseline characteristics. CONCLUSIONS: In this Japanese patient population, LBBB intrinsic QRS morphology and prolonged QRSd (≥150 ms) exhibited the best response to CRT.
Oka et al. (2018) conducted a cohort in Heart failure with reduced ejection fraction (n=510). Cardiac resynchronization therapy (CRT) in patients with LBBB and QRSd ≥150 ms vs. CRT in patients with narrow QRS complex (<120 ms) was evaluated on Composite of all-cause death or hospitalization because of heart failure (HR 2.50, 95% CI 1.72-3.63, p=<0.001). In Japanese patients receiving cardiac resynchronization therapy, intrinsic left bundle branch block with QRS duration ≥150 ms was associated with the lowest incidence of all-cause death or heart failure hospitalization compared to other QRS morphologies.