Abstract 13601: Long Term Clinical Outcome of Cardiac Resynchronization Therapy According to Baseline QRS Duration: a Multi-National, Ten-Year Experience. Data From the Mulin-Crt (Multicenter International -Crt) Study
Background: Cardiac resynchronization therapy (CRT) is an established therapy for patients with systolic heart failure and a QRS≥120 ms. Some studies have shown that CRT is not beneficial in patients at the upper extremes of QRS duration.
Methods and Results: In this prospective, longitudinal, observational study of 3,319 consecutive patients undergoing CRT in 8 centers worldwide, pre-implant QRS durations (QRS 120-149 ms: 26%; QRS 150-199 ms: 58%; QRS≥200 ms: 16%) were assessed in relation to mortality over 10 years. Overall mortality rates (per 100 patient yrs) were, 9.2, 9.3 and 13.3% in the three groups, respectively (all p<0.001). Cardiac mortality rates were 6.2, 6.0 and 9.9 per 100 patient year, respectively (all p<0.001). Compared with the QRS120-149 ms group, cardiac mortality was highest in the QRS≥200 ms group (HR: 1.72 (95%C.I. 1.35-2.19 p<0.001), independent of age, gender, NYHA class, presence of atrial fibrillation, heart failure etiology and LVEF. Median survival after CRT was longest in patients with a width a QRS 120-149 ms and shortest in patients with a QRS≥200ms (p<0.001). In multivariable analyses, a QRS≥200ms emerged as a powerful, independent predictor of both overall (HR: 1.44 (95% C.I. 1.07-1.94), p= 0.017) and cardiac mortality (HR: 1.59 (95%C.I.: 1.14-2.24), p=0.007).
Conclusions: At long term follow up there is no difference in overall and cardiac survival after CRT in patients with a pre-implant QRS duration 120-149 ms or 150-199 ms. Overall and cardiac mortality is significantly higher in patients with a QRS≥200ms.
- © 2013 by American Heart Association, Inc.