Abstract 11403: T-Wave Area as an Additional Predictor of Volumetric and Clinical Response to Cardiac Resynchronization Therapy

Abstract

Purpose: Chronic heart failure (HF) patients with a left ventricular (LV) conduction delay, mostly due to left bundle branch block (LBBB), derive benefit from cardiac resynchronization therapy (CRT). However, approximately 30% of patients do not improve clinically after CRT. We investigated whether T-wave analysis can improve patient selection. Methods: The study population comprised 335 CRT recipients with baseline 12-lead electrocardiogram recordings. Echocardiographic response after 6-months CRT was defined as a ≥ 5% increase in LV ejection fraction (LVEF). Patients were assessed for HF hospitalization and death separately, as well as both combined with heart transplantation and LVAD implantation (HTLD) at 3 years follow-up. T-wave area was determined in vectorcardiograms (VCGs), constructed from digital 12-lead ECGs using an adapted Kors method. Results: Logistic regression models indicated repolarization variables as good predictors of CRT response. The VCG-derived T-wave area predicted CRT response (odds ratio (OR) per 10 μVs increase 1.172 (p < 0.001)), even better than QRS-wave area (OR = 1.116 (p = 0.001)). T-wave area had especially predictive value in LBBB patients (OR = 2.77 in LBBB vs. 1.09 in non-LBBB). This predictive value persisted after adjustment for multiple covariates, such as gender, ischemia, age, hypertension, coronary artery bypass graft, and the usage of diuretics and beta-blockers. The table depicts that patients with large T-wave area showed a larger increase in LVEF and a lower occurrence of the end-points HF hospitalization, death and HTLD, as compared to those with a small T-wave area, the difference being significant for LBBB patients. Conclusions: In patients with LBBB morphology of the QRS complex, a larger baseline T-wave area is an important additional predictor of both volumetric and long-term clinical response following CRT.