The usefulness of serum troponin levels to predict 1-year survival rates in infective endocarditis

Abstract

Infective endocarditis (IE) is associated with increased mortality and morbidity. In this study, we aimed to evaluate the role of troponin levels in predicting long-term survival in patients with IE. A retrospective analysis of the medical database of Yuksek Ihtisas Education and Research Hospital was performed to reach the patients that received the diagnosis of definite IE according to Duke criteria. Out of 84 definite IE cases, 48 patients (mean age 45.6 ± 17.3, 39.6% female) that had troponin T levels measured upon hospital admission were included. The survival status of the study subjects was assessed during a follow-up period of 1 year. A total of 20 (41.7%) patients died during the follow-up. Baseline median troponin T levels were significantly higher in fatal cases (0.08 [0.02-0.24] ng/ml vs. 0.02 [0.01-0.04] ng/ml p = 0.003). The optimal troponin T level to detect mortality was 0.05 ng/ml according to receiver operating characteristic curve (area under the curve 0.75, 95% Confidence Interval (CI) [0.61-0.9], p = 0.003) with 70% sensitivity and 79% specificity. Patient with elevated troponin levels were older, were more likely to be male and tended to have enterococcal infection. These patients had also higher creatinine levels and increased systolic pulmonary pressures. In the multivariate Cox regression analysis, renal failure (hazards ratio (HR) 8.23, CI 95% 2.53-26.9, p < 0.0001), heart failure (HR 4.48, CI 95% 1.73-11.61, p = 0.002) and troponin T ≥ 0.05 ng/ml (HR 3.11, CI 95% 1.13-8.56, p = 0.03) were associated with increased mortality rates. IE has poor outcome and baseline troponin T levels may predict long-term survival rates in these patients.