Septal Rebound Stretch is a Strong Predictor of Outcome After Cardiac Resynchronization Therapy

Background: Septal rebound stretch (SRSsept) is a distinctive characteristic of discoordination-related mechanical inefficiency. We assessed how intermediate- and long-term outcome after cardiac resynchronization therapy (CRT) relate to baseline SRSsept. Methods and Results: A total of 101 patients (age 65 +/- 11 years, 69 men, 18 New York Heart Association (NYHA) class IV, QRS 173 +/- 23 ms) scheduled for CRT underwent clinical assessment, echocardiography, and brain-type natriuretic peptide (BNP) measurements before and 6.4 +/- 2.3 months after CRT. Baseline SRSsept (all systolic stretch after initial shortening in the septum) was quantified by speckle tracking echocardiography. Primary composite end point was death, urgent cardiac transplantation, or left ventricular assist device implantation at the end of the study. Secondary end points were intermediate-term (6 months) response, quantified as decreases in left ventricular end-systolic volume (Delta LVESV) and BNP (Delta BNP). After a mean clinical follow-up of 15.6 +/- 9.0 months; 23 patients had reached the primary end point. Baseline SRSsept (hazard ratio [HR] 0.742; 95% confidence intervals [CI] 0.601-0.916, P