Prognostic utility of T-wave alternans in a real-world population of patients with left ventricular dysfunction: the PREVENT-SCD study.

BACKGROUND

The predictive value of T-wave alternans (TWA) for lethal ventricular tachyarrhythmia in patients with left ventricular (LV) dysfunction is controversial. Also, long-term arrhythmia risk of patients ineligible for the TWA test is unknown.

METHODS

This was a multicenter, prospective observational study of patients with LV ejection fraction ≤40% due to ischemic or non-ischemic cardiomyopathies, designed to evaluate the prognostic value of TWA for lethal ventricular tachyarrhythmia. The primary end point was a composite of sudden cardiac death, sustained rapid ventricular tachycardia (VT) or ventricular fibrillation (VF), and appropriate defibrillator therapy for rapid VT or VF.

RESULTS

Among 453 patients enrolled in the study, 280 (62%) were eligible for the TWA test. TWA was negative in 82 patients (29%), who accounted for 18% of the total population. The median of follow-up was 36 months. The 3-year event-free rate for the primary end point was significantly higher in TWA-negative patients (97.0%) than in TWA non-negative patients (89.5%, P = 0.037) and those ineligible for the TWA test (84.4%, P = 0.003). Multivariable analysis identified both non-negative TWA [hazard ratio (HR) 4.43; 95% confidence interval (CI) 1.02-19.2; P = 0.047) and ineligibility for the TWA test (HR 6.89; 95% CI 1.59-29.9; P = 0.010) to be independent predictors of the primary end point.

CONCLUSIONS

TWA showed high negative predictive ability for lethal ventricular tachyarrhythmia in patients with LV dysfunction, although the TWA-negative patients accounted for only 18% of the entire population. Those ineligible for the TWA test had the highest risk for lethal ventricular tachyarrhythmia.