Prediction of Both Electrical and Mechanical Reverse Remodeling On Acute Electrocardiogram Changes After Cardiac Resynchronization Therapy

Background: The development of both electrical reverse remodeling and mechanical reverse remodeling (ERR+MRR) after cardiac resynchronization therapy (CRT) implantation could reduce the incidence of lethal arrhythmia, hence the prediction of ERR+MRR is clinically important. Methods and Results: Eighty-three patients (54 male; 67±12 years old) with CRT \u3e6 months were enrolled. ERR was defined as baseline intrisic QRS duration (iQRSd) shortening ≥10 ms in lead II on ECG after CRT, and MRR as improvement in LVEF ≥25% on echocardiography after CRT. Acute ECG changes were measure by comparing the pre-implant and immediate post-implant ECG. Ventricular arrhythmia episodes, including ventricular tachycardia and ventricular fibrillation, detected by the implanted device were recorded. Patients were classified as ERR only (n=12), MRR only (n+23), ERR+MRR (n=26), or non-responder (ERR— & Mrr—, n=22). On multivariate regression analysis, difference between baseline intrinsic QRS and paced QRS duration (ΔQRSD) \u3e35 ms was a significant predictor of ERR+MRR (sensitivity, 68%; specificity, 64%; AUC, 0.7; P=0.003), and paced QTc \u3e443 ms was a negative predictor of ERR+MRR (sensitivity, 78%; specificity, 60%; AUC, 0.7; P-0.002). On Cox proportional hazard modeling, ERR+MRR may reduce risk of ventricular arrhythma around 70% compared with non-reponder (HR, 0.29; 95% CI: 0.13-0.65). Conclusions: Acute ECG Changes after CRT were useful predictors of ERR+MRR. ERR+MRR was also a protective factor for ventricular arrhythmia