Interpreting troponin elevation in the setting of infective endocarditis: Causes and prognostic value

Background Measurement of cardiac troponin (cTn) levels in blood is standard for diagnosis and risk stratification in cardiac emergencies. Purpose To investigate the causes, link to underlying coronary artery disease and prognostic value of cTn release in infective endocarditis (IE). Method Eighty-six consecutive patients hospitalized for acute IE, with at least one cTn drawn and a coronary angiogram performed, were reviewed retrospectively. Factors related to the increase of cTn above the 99th percentile or above 10 times normal (> 10N), as well as their prognostic impact, were assessed. Results The mean patient age was 63 + 14 years, the majority were men (n = 68, 79%) with staphylococcus IE (n = 34, 40%). Cardiac troponins were elevated above the 99th percentile for 74 (86%) patients and > 10N for 25 (29%) patients. There was no statistically significant correlation between elevated cTn and the presence of an underlying coronary artery disease ( Table 1 ). Cardiac troponin elevation above the 99th percentile was significantly associated with impaired renal function (P = 0.04) and staphylococcus infection (P = 0.02). A rise of cTn > 10N was significantly associated with acute pulmonary edema (P = 0.001), myocardial abscess (P = 0.01), staphylococcus (P = 0.0004), streptococcus (P = 0.008), and renal function (p = 0.0001). The average follow-up period was 919±816 days, and an elevation of cTn > 10 N had a clear prognostic impact (HR 2.38, 95%CI: 1.18–4.84, P = 0.01) ( Fig. 1 ). Conclusion Troponin elevation in IE is frequent and appears to be related to direct and indirect myocardial injury. It is associated with a poor prognosis.