Killu, Ammar M

Introduction: The T peak - T end interval (Tpe) is a measure of transmural dispersion of repolarisation with prolongation of this interval linked to an increased risk of ventricular arrhythmias and sudden death. Patients with cardiac amyloid experience a high rate of sudden cardiac death. Objective: To determine the prognostic utility of the Tpeak-Tend interval in patients with transthyretin (TTR) cardiac amyloidosis. Methods: Of the 240 patients who underwent evaluation for TTR amyloidosis at our tertiary referral center from 1966 to 2010, 39 met inclusion criteria (65 excluded for AF, 66 BBB/Paced Rhythm, 25 CAD, 21 other). Inclusion criteria were presence of histological diagnosis of TTR amyloid and confirmed cardiac involvement by echocardiogram or biopsy and absence of atrial fibrillation (AF) or bundle branch block/paced rhythm on the index surface ECG, or history of coronary heart disease (CAD). Tpe was measured in leads V3 and V5. Cox proportional hazards model were used to estimate hazard ratios (HR) and 95% confidence intervals (CI). Kaplan-Meier curves were used to estimate overall survival and differences between curves were estimated using log rank. Primary endpoints were death or heart transplantation. Results: Of the 39 patients, 85% were male, and 69% were mTTR. Mean age 66.4 ± 13.9 years. Mean follow up period of 4.2 ± 3.2 years, 25 died and 5 received heart transplants. Median survival was 3.8 years, with 5 year survival 34%. On univariate analysis, Tpe in lead V3 was predictive of adverse outcome, HR per 10msec, 1.195 (1.051-1.370). Further multivariate analysis, in a model accounting for age, gender, Lead V3 Tpe was independently associated with survival, HR per 10msec, 1.207, (1.094-1.411, p=0.009). Conclusions: The Tpe interval in Lead V3 at diagnosis is a novel, noninvasive independent predictor of survival in transthyretin cardiac amyloidosis patients in sinus rhythm.