Septal to posterior wall motion delay fails to predict reverse remodeling or clinical improvement in patients undergoing cardiac resynchronization therapy.

Abstract

The aim of this study was to test the hypothesis that a longer septal-to-posterior wall motion delay (SPWMD) would predict greater reverse remodeling and an improved clinical response in heart failure patients randomized to cardiac resynchronization therapy (CRT) in the CONTAK-CD trial. The SPWMD predicted clinical benefit with CRT in two previous studies from the same center. In this retrospective analysis of the CONTAK-CD trial, SPWMD was measured from the baseline echocardiogram of 79 heart failure patients (ejection fraction 22 +/- 7%, QRS duration 159 +/- 27 ms, 72% ischemic, 84% male) randomized to CRT and compared with six-month changes in echocardiographic and clinical parameters. Patients with a left ventricular end-systolic volume index (LVESVI) reduction of at least 15% were considered responders. The feasibility and reproducibility of performing the SPWMD measurements were poor. Larger values for SPWMD did not correlate with six-month changes in left ventricular end-diastolic volume index (p = 0.26), LVESVI (p = 0.41), or left ventricular ejection fraction (p = 0.36). Responders did not have a significantly different SPWMD than non-responders (p = 0.26). The SPWMD did not correlate with measures of clinical improvement. At a threshold of SPWMD >130 ms, the test characteristics to predict reverse remodeling or a clinical response were inadequate. The previous findings that SPWMD predicts reverse remodeling or clinical improvement with CRT were not reproducible in patients randomized in the CONTAK-CD trial.