Abstract 2719: Left Ventricular Dyssynchrony Is A Strong Independent Predictor Of Response To Cardiac Resynchronization Therapy
Background Recent studies have demonstrated that response to cardiac resynchronization therapy (CRT) is related to the presence of left ventricular (LV) dyssynchrony before implantation. A cutoff-value for LV dyssynchrony of 65 ms has been proposed, but this value has not been tested in prospective cohorts.
Methods Two hundred and twenty consecutive patients (172 male, 60% ischemic cardiomyopathy) undergoing CRT were included. Clinical and echocardiographic parameters were assessed at baseline and after 6 months of CRT. Clinical improvement was defined as an improvement in 1 or more NYHA class and increase ≥ 25% in walking distance. Echocardiographic response was defined as a decrease in LV end-systolic volume ≥ 15%. LV dyssynchrony was assessed with tissue Doppler imaging (TDI) and calculated as the maximum time delay between the peak systolic velocities of 4 opposing basal walls.
Results At 6 months follow-up, 143 patients (65%) showed clinical response to CRT. Responders and non-responders had comparable baseline characteristics, except for more LV dyssynchrony (93 ± 49 ms vs. 57 ± 43 ms), longer QRS duration (159 ± 31 ms vs. 142 ± 30 ms), larger LV volumes and lower LV ejection fraction (24 ± 7% vs. 26 ± 7%, all p < 0.05) in responders. Multivariate analyses showed that LV dyssynchrony was the only independent predictor for clinical response to CRT (Table⇓). LV dyssynchrony of ≥ 65 ms predicted clinical response to CRT with a sensitivity of 90% and a specificity of 74%. Furthermore, LV dyssynchrony of ≥ 65 ms predicted echocardiographic response at 6 months with a sensitivity of 76% and a specificity of 64%.
Conclusion LV dyssynchrony ≥ 65 ms, as assessed with TDI, is a strong predictor of clinical and echocardiographic response to CRT in patients with moderate to severe heart failure.