Cardiac troponin T as a predictor of cardiac death in patients with left ventricular dysfunction

Abstract

Background: Cardiac troponin T (cTnT) has been reported to be associated with cardiac mortality. In the present study, we evaluated the role of routine assessment of cTnT as a predictor of future cardiac death in patients with left ventricular (LV) dysfunction.

Methods: Patients who were eligible for prophylactic implantable cardioverter defibrillator (ICD) were included from cardiac catheterization database. Inclusion criteria were patients with LV ejection fraction of ≤ 35% and with New York Heart Association (NYHA) ≥class II. Exclusion criteria were patients with acute coronary syndrome, ICD for secondary prevention, NYHA class IV, and lack of data. The final study patients were divided into the following three groups in accordance with two quartile points of serum cTnT levels: low cTnT, intermediate cTnT, and high cTnT groups. The primary endpoint of this study was cardiac death.

Results: A total of 70 patients were included (mean age, 62±13 years; male individuals, 56; ischemic, 36; and non-ischemic, 34). During the observation period of 2.2 years, cardiac death was observed in 17 patients (fatal arrhythmic event, 9; heart failure, 7; myocardial infarction, 1). In the Kaplan-Meier analysis, the high cTnT group showed the highest risk among all the groups (p<0.001). Even in sub-analyses for ischemic and non-ischemic patients, the results were the same, and the high cTnT group showed the highest event rate (p<0.05). In contrast, no cardiac death was observed in the low cTnT group.

Conclusion: The cTnT levels in a stable state were associated with cardiac death in patients with LV dysfunction, even in those with non-ischemic diseases.

Keywords: Cardiac death; Cardiac troponin T; Left ventricular dysfunction; Sudden death.

Fig. 1

Kaplan–Meier estimates of prognoses in the three patient groups with different cTnT levels. This figure shows Kaplan–Meier estimates of prognoses in patient groups with low, intermediate, and high cTnT levels. Panel A presents the results for all patients with cardiac death. The event rate was higher in the high cTnT group than in the other groups. Panel B presents the sub-analysis data for IHD patients. The event rate was higher in the high cTnT group than in the other groups, and no event was observed in the low and intermediate cTnT groups. Panel C presents the sub-analysis data for non-IHD patients. The event rate was higher in the high cTnT group than in the other groups. IHD=ischemic heart disease, cTnT=cardiac troponin T, HR=hazard ratio, 95% CI=95% confidential interval.