Abstract 11035: Characteristics of Responders to Cardiac Resynchronization Therapy: Real World Observations from a Multidisciplinary Cardiac Resynchronization Program
Background In clinical trials, one third who receive cardiac resynchronization therapy (CRT) do not respond. We examined the characteristics of echocardiographic responders in the clinical environment.
Method 98 patients who had at least two follow up visits and dyssynchrony echocardiograms in our multidisciplinary CRT clinic during the 1st year after CRT were examined. CRT echocardiographic response was defined as a decrease in LV end systolic volume (ESV) of ≥ 15% or absolute increase of 5% in LV EF at 6 months.
Results There were no differences in age, NYHA class and baseline LV EF between 66 responders and 32 nonresponders. By univariate analyses, cardiomyopathy (CMP) etiology, baseline QRS width, baseline LV volume indexes differed between groups (table). When gender, CMP etiology, QRS width, baseline LV end diastolic volume (EDV) index were analyzed in a multivariate model adjusted for age, QRS width and LV EDV index were predictors of response (QRS width: Odd ratio [OR] 1.025, 95% CI 1.001 - 1.050, p = 0.039; LV EDV index: OR 0.981, 95% CI 0.963 - 0.999, p= 0.044). LV EDV index ≤ 101 ml/m2 significantly predicted response in this model (OR 3.907, 95% CI 1.245 - 12.262, p=0.02). Though female gender showed a trend towards response on univariate analysis (table), it was not an independent predictor perhaps because it was associated with smaller volume indexes (Female vs Male, ESV index: 69 ± 25 vs 83 ± 27 ml/m2, p=0.026; EDV index: 91 ± 26 vs 109 ± 31 ml/m2, p=0.017) and a higher prevalence of non-ischemic CMP (Female vs Male, 69% vs 42%; p=0.026). Etiology of CMP was not an independent predictor but larger volumes were noted for ischemic etiology (nonischemic vs ischemic, ESV index: 73 ± 26 vs 86 ± 26 ml/m2, p=0.028; EDV index: 97 ± 31 vs 111 ± 29 ml/m2, p=0.039).
Conclusion QRS width and LV EDV index at baseline are independent predictors for echocardiographic CRT response. Differences in response for gender and CMP etiology may be due to differences in the other covariates within these groups.
- © 2011 by American Heart Association, Inc.