Prediction of response to cardiac resynchronization therapy using simple electrocardiographic and echocardiographic tools.

Objective: To predict response to cardiac resynchronization therapy (CRT) in patients with heart failure (HF) and intraventricular conduction delay.

Results: The study population consisted of 82 consecutive HF patients with standard CRT indications. Patients were classified as responders, if they were alive without cardiac decompensation and experienced >or=15% decrease in left ventricular end-systolic volume. Sixty-eight percent of the enrolled patients responded to CRT. When compared with non-responders, responders had a wider baseline QRS width (P = 0.001), more marked QRS shortening (DeltaQRS) immediately after CRT (P = 0.001), and a better improvement in aortic velocity time integral (VTI) 24 h after CRT (P = 0.02). Moreover, there was a trend towards a greater baseline intraventricular dyssynchrony in the responder group (P = 0.07). By multivariable logistic regression, the baseline QRS width (OR: 0.95, 95% CI: 0.90-0.97, P = 0.001), DeltaQRS (OR: 1.038, 95% CI: 1.012-1.064, P = 0.003), and acute aortic VTI (OR: 0.81, 95% CI: 0.68-0.96, P = 0.017) emerged as independent predictors of response to CRT. Receiver operating characteristic curve analysis identified a QRS width >145 ms, DeltaQRS >20 ms, and aortic VTI >14 cm to predict responders.

Conclusions: A positive response to CRT was observed in 68% of the patients. Cardiac resynchronization therapy response is predictable using simple electrocardiographic and echocardiographic data.