Cardiac troponin I for risk stratification following percutaneous coronary artery intervention in acute coronary syndromes

The cardiac troponins have been shown to provide prognostic information allowing risk stratification of patients with acute coronary syndromes (ACS). The benefit of early percutaneous coronary intervention (PCI) in this setting has been highlighted by the FRISC II study. We assessed the pattern of release of cardiac troponin I (cTnI) following PCI in patients with ACS and evaluated its prognostic value for major adverse cardiac events (MACE): death, Q-wave myocardial infarction (QWMI), and repeat revascularization at follow-up. cTnI was sampled at baseline and 6, 14, and 24 hr following PCI in 73 patients presenting with unstable and post-MI angina. Clinical follow-up was obtained in all 73 patients at a mean period of 43 +/- 19.9 weeks (range, 11-68 weeks). Patients were stratified into two groups according to whether cTnI remained unchanged or fell below baseline 24 hr post-PCI (group 1, n = 47) or increased above baseline 24 hr following PCI (group 2, n = 26). MACE occurred in 4 (8.5%) of patients in group 1 (QWMI = 1, CABG = 1, re-PCI = 2) and in 19 (73%) of patients in group 2 (death = 1, QWMI = 2, CABG = 2, re-PCI = 14; chi-square = 32.34, P < 0.0001). The positive predictive value of rising cTnI within 24 hr following PCI for MACE at follow-up was 0.73 and the negative predictive value was 0.92 (specificity = 83%, sensitivity = 86%; odds ratio = 29.18, 95% CI = 7.62-110.64, P < 0.0001). cTnI is an inexpensive and widely applicable tool that offers reliable prognostic information for the risk stratification of patients undergoing coronary revascularization in the setting of acute coronary syndromes and may identify a group of patients at particular risk of repeat PCI.