Abstract 10845: Cardiac Resynchronization Therapy in Patients Without Left Intraventricular Dyssynchrony.
Objectives: Evaluate the outcome of heart failure patients undergoing cardiac resynchronization therapy (CRT) without baseline left intraventricular dyssynchrony (LVdyss).
Methods: A group of 290 heart failure patients (mean age 67 ± 10 years, 81%; male) without significant baseline LVdyss (septal-to-lateral wall delay ≤60 ms) undergoing CRT device implantation were selected. Within 48 hours after CRT implantation, LVdyss was re-assessed. Patients were divided according to the median LVdyss after 48 hours of CRT in 2 groups: those with induced LVdyss (≥40ms) and those with non-induced LVdyss (<40 ms). Response to CRT was then defined by ≥15%; decrease in LV end-systolic volume at 6 months follow-up. All cause mortality was recorded during a median long term follow-up of 30 months.
Results: Baseline median LVdyss was 22 ms (interquartile range: 16–34 ms) and increased to 40 ms (interquartile range: 24–56 ms) within 48 hours post-implantation. There were 145 patients in the non-induced LVdyss group and 145 patients in the induced LVdyss group. Particularly, 93%; of patients with induced LVdyss were non responders, compared to 51%; of patients with non-induced LVdyss (P<0.001). During a median follow-up of 23 months, 72 events were recorded. Patients with induced LVdyss had worse long-term outcome (Log-Rank Chi Square12.709, P<0.001). Moreover, induction of LVdyss was an independent predictor of mortality (P=0.009 for each 20 ms increase in LVdyss) along with older age (P=0.01), ischemic etiology of heart failure (P=0.024) baseline NYHA functional class (P<0.001) and LVEF (P=0.001).
Conclusion: In a considerable proportion of heart failure patients without significant LVdyss, CRT may induce or worsen LVdyss yielding a worse long-term clinical outcome.
- © 2010 by American Heart Association, Inc.