Abstract

Nieminen, T., Scirica, B. M., Pegler, J. R., Tavares, C., Pagotto, V. P., Kanas, A. F., Sobrado, M. F., Nearing, B. D., Umez-Eronini, A. A., Morrow, D. A., Belardinelli, L., Verrier, R. L. Relation of T-Wave Alternans to Mortality and Nonsustained Ventricular Tachycardia in Patients With Non-ST-Segment Elevation Acute Coronary Syndrome from the MERLIN-TIMI 36 Trial of Ranolazine Versus Placebo Am J Cardiol. 2014;NA(NA):NA.

We explored the utility of T-wave alternans (TWA) in predicting mortality in patients with non-ST-segment elevation acute coronary syndrome (NSTEACS). Maximum TWA was calculated using Modified Moving Average method from continuous electrocardiographic recordings in patients with left ventricular ejection fraction <40% and ventricular tachycardia (VT) ≥4 beats during index hospitalization or sudden cardiac death during the follow-up year and age- and sex-matched controls in the Metabolic Efficiency with Ranolazine for Less Ischemia in Non-ST Elevation Acute Coronary Syndrome-Thrombolysis In Myocardial Infarction (MERLIN-TIMI) 36 trial. All patients received standard therapy for NSTEACS plus ranolazine (n = 109) or placebo (n = 101). Median follow-up was 1 year. Baseline clinical characteristics did not differ between patients with elevated TWA (≥47 muV) compared with lower levels. Patients with TWA ≥47 muV at admission had increased risk of total mortality (adjusted odds ratio [ORadj] 2.35, p = 0.04) during follow-up and VT ≥4 beats (ORadj 2.70, p = 0.01) during hospitalization with a trend toward increased cardiovascular death risk (ORadj 2.18, p = 0.07) during follow-up. In patients receiving placebo, TWA ≥47 muV on day 6 was associated with increased risk of total mortality (OR 4.12, 95% confidence interval 1.25 to 13.64, p = 0.02) and cardiovascular death (OR 4.73, p = 0.01) during follow-up. No deaths occurred among patients with TWA ≥47 muV assigned to ranolazine. In conclusion, in patients with NSTEACS and left ventricular ejection fraction <40%, TWA ≥47 muV early after admission is associated with increased risk of mortality at 1 year and with nonsustained VT during hospitalization. TWA may be useful in risk estimation in patients with NSTEACS. The possibility that TWA may serve as a therapeutic target deserves further exploration.

Trial: MERLIN-TIMI 36