Septal rebound stretch as predictor of echocardiographic response to cardiac resynchronization therapy

Septal rebound stretch (SRSsept) reflects an inefficient deformation of the septum during systole and is a potential new echocardiographic tool to predict response to Cardiac Resynchronization Therapy (CRT). However, there are only limited data on the potential predictive value of SRSsept on echocardiographic response. We evaluated the predictive value of SRSsept on echocardiographic response to CRT in a large population.

A total of 138 consecutive patients with functional class II-IV heart failure who underwent CRT were studied. Echocardiography was performed at baseline and after a mean follow-up period of 22 ± 8 months. Echocardiographic response to CRT was defined as a reduction in LV end-systolic volume ≥ 15%. Receiver operating characteristic curve analysis was performed to define the optimal cut-off value for SRSsept. Multivariable analyses were performed to adjust for potential confounders. Mean age was 68 ± 8 years (30% female). Mean baseline LV ejection fraction was 26 ± 7%, 51% had ischemic etiology. LBBB or LBBB like morphology was present in 95% of patients. Mean SRSsept was 4.4 ± 3.2%, 56% of patients had SRSsept ≥ 4%. Ninety six patients (70%) were echocardiographic responders. Baseline SRSsept was significantly higher in responders compared to non-responders (5.1 ± 3.2 vs 3.0 ± 2.7, P < 0.001). The optimal cut-off value for SRSsept to predict response to CRT was 4.0%. After both univariate (OR 3.74, 95% CI 1.72-8.10) and multivariate analyses (OR 3.71, 95% CI 1.49-9.2), baseline SRSsept > 4% independently predicted the response to CRT.

Baseline septal rebound stretch is independently associated with echocardiographic response to CRT.