Abstract 14544: Left Ventricular Septolateral Delay Affects Survival Independent of QRS Duration in Patients With Systolic Heart Failure: Nine Year Outcome in 119 Patients
Background: Although the goal of cardiac resynchronization therapy is to correct left ventricular (LV) mechanical dyssynchrony, the prognostic importance of the latter in patients with systolic heart failure is not known. We investigated this question in 119 consecutive patients with systolic heart failure with an LV ejection fraction (EF) <35% who did not receive an implantable cardioverter defibrillator.
Methods: The cohort is a prospective series of 119 patients with EF <35% and who did not receive a defibrillator between March 2002 and February 2004. Tissue Doppler velocities of the 4 quadrants of the mitral annulus were obtained using pulsed wave technology and time measurements were made referencing the signals to the R wave of the electrocardiogram. Onset to onset septolateral and anteroposterior delays were computed and related to mortality obtained from chart review and National Death Index.
Results: Patient characteristics included age 53±12 years, 73% male, 23% with coronary artery disease, LVEF 24±7%, LV end-diastolic dimension 65±9 mm, LV end-systolic dimension 56±9 mm, QRS duration 110±38 ms and 92 (84%) with QRS duration <120 ms. Over a follow up of 9 years, there were 63 deaths. Univariate predictors of mortality included LV septolateral delay (HR 1.01 per ms, p < 0.0001), anteroposterior delay (p=0.003), and age (p=0.005), but not EF, LV size or QRS duration. Using Cox regression analysis LV septolateral delay was an independent predictor of higher mortality (p=0.0005) after adjusting for age, gender, EF, LV size, QRS duration, coronary artery disease, diabetes mellitus and use of beta blockers or angiotensin converting enzyme inhibitors.
Conclusion: The QRS duration is <120 ms in most patients with systolic heart failure and LVEF ≤ 35%. Septolateral LV mechanical dyssynchrony is a strong and independent predictor of long term survival in these patients independent of QRS duration.
- © 2011 by American Heart Association, Inc.