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

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

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 ≥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 (ΔQRS) 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), ΔQRS (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, ΔQRS >20 ms, and aortic VTI >14 cm to predict responders.

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