Context: The prognostic value of mild elevation of cardiac-specific troponin I (cTnI) levels is poorly defined, which can make interpretation of such an elevation difficult.
Objective: To study the prognostic value of transient mild elevation of cTnI levels in the hospitalized patient population.
Design: We performed a case-control study that compared the outcome of patients hospitalized for any cause with at least 2 subsequent transient cTnI measurements of 0.1 ng/mL or higher and less than 1.5 ng/mL with matched controls with cTnI levels less than 0.1 ng/mL. A cohort of 118 patients (mean +/- SD age, 67.4 +/- 14.0 years; 35.6% men) was followed up for an average +/- SD of 11.9 +/- 7.9 months. Seventy-one cases were matched with 37 controls in terms of demographics, coronary artery disease risk factors, and reason for admission. End points were all-cause mortality and major cardiovascular end points, including cardiovascular mortality, myocardial infarction, and revascularization.
Results: The total event rate was significantly increased in the case group compared with the control group at 12, 6, and 3 months (62.0% vs 24.3%, 59.2% vs 16.2%, and 47.9% vs 5.4%, respectively; P < .001). At 12, 6, and 3 months, the cases had a significant increase in all-cause mortality (43.7% vs 16.2%, 40.8% vs 8.1%, and 33.8% vs 0.0%, respectively; P = .005) and major cardiovascular end points (26.8% vs 8.1%, 26.8% vs 8.1%, and 21.1% vs 5.4%, respectively; P = .02) compared with controls.
Conclusion: Transient mild elevation of cTnI levels in hospitalized patients is associated with an increase in all-cause mortality and major cardiovascular complications. Such elevations of cTnI levels can be considered a marker for both all-cause and cardiovascular morbidity and mortality.