Serial High-Sensitivity Troponin T in Post-Primary Angioplasty Exercise Test

BACKGROUND: The kinetics of high-sensitivity troponin T (hscTnT) release should be studied in different situations, including functional tests with transient ischemic abnormalities. OBJECTIVE: To evaluate the release of hscTnT by serial measurements after exercise testing (ET), and to correlate hscTnT elevations with abnormalities suggestive of ischemia. METHODS: Patients with acute ST-segment elevation myocardial infarction (STEMI) undergoing primary angioplasty were referred for ET 3 months after infarction. Blood samples were collected to measure basal hscTnT immediately before (TnT(0h)), 2 (TnT(2h)), 5 (TnT(5h)), and 8 hours (TnT(8h)) after ET. The outcomes were peak hscTnT, TnT(5h)/TnT(0h) ratio, and the area under the blood concentration-time curve (AUC) for hscTnT levels. Log-transformation was performed on hscTnT values, and comparisons were assessed with the geometric mean ratio, along with their 95% confidence intervals. Statistical significance was assessed by analysis of covariance with no adjustment, and then, adjusted for TnT(0h), age and sex, followed by additional variables (metabolic equivalents, maximum heart rate achieved, anterior wall STEMI, and creatinine clearance). RESULTS: This study included 95 patients. The highest geometric means were observed at 5 hours (TnT(5h)). After adjustments, peak hscTnT, TnT(5h)/TnT(0h) and AUC were 59% (p = 0.002), 59% (p = 0.003) and 45% (p = 0.003) higher, respectively, in patients with an abnormal ET as compared to those with normal tests. CONCLUSION: Higher elevations of hscTnT may occur after an abnormal ET as compared to a normal ET in patients with STEMI.