Abstract 2685: Troponin-T Elevation After Implanted Defibrillator Discharges Predicts Survival - A Prospective Study
Background: Troponin-T (TnT) elevations have been reported to occur after implantable cardioverter defibrillator (ICD) discharges, but their prognostic significance is unknown.
Aim of the study: To prospectively evaluate whether TnT elevations occurring after ICD discharges impact survival.
Methods: We studied 139 consecutive patients: 46 who received spontaneous ICD discharges for tachyarrhythmias and 93 in whom TnT rose after ICD discharges delivered during device testing. There were 112 men and 27 women with mean age 68 ± 12 years. Ischemic cardiomyopathy was present in 84%. The mean LV ejection fraction was 29 ± 10% and mean serum creatinine was 1.2 ± mg/dl. Troponin-T was measured between 12 and 24h after ICD discharge. Patients received between 1 and 19 discharges (mean 2.3 ± 2.1), with total delivered energy ranging from 6 to 288 joules (mean 34 ± 35J).
Results: During a median follow-up period of 19.6 months (range 4–92), 34 patients died. Kaplan Meier survival curves for TnT ≥ 0.05 ng/ml vs TnT ≥ 0.05 ng/ml are shown in Figure⇓. The significant relationship between elevated TnT and survival was retained in Cox multivariable analysis that included age, sex, left ventricular ejection fraction, and serum creatinine. This association was present whether TnT elevation was entered into the multivariable model as a continuous or dichotomized variable.
Conclusion: Elevation of Troponin-T after ICD discharge, even when it occurs following device testing, is not a random event. It is a risk factor for mortality that is independent of other common clinical factors that predict survival in such patients.