Relation of minor cardiac troponin I elevation to late cardiac events after uncomplicated elective successful percutaneous transluminal coronary angioplasty for angina pectoris

There is little information about the relation between mild cardiac troponi n I (cTn-I) increase after coronary interventions and late outcome. We ther efore Focused on the long-term outcome and the clinical, morphologic, and p rocedural correlates of elevation of cTn-I compared with cardiac troponin T , creatine kinase (CK), CK-MB activity and mass, and myoglobin in 105 patie nts with successful elective percutaneous transluminal coronary angioplasty (PTCA) for stable or unstable angina. Patients with myocardial infarction and those with unstable angina who had a detectable increase in serum marke rs before PTCA were excluded. Markers were measured before and after the pr ocedure and for 2 days. Patients were followed up to record recurrent angin a, myocardial infarction, cardiac death, repeat PTCA, or elective coronary artery bypass graft surgery. Procedure success was achieved in all cases. E levation in cTn-I (greater than or equal to 0.1 mu g/L) was observed in 23 of 105 patients (22%) (median peak: 0.25 mu g/L); 18% had cardiac troponin T (cTn-T) release (greater than or equal to 0.1 mu g/L, median peak (0.21); 11.4% CK-MB mass (greater than or equal to 5 mu g/L), and 7.6% myoglobin ( greater than or equal to 90 mu g/L) release. Five and 2 patients had elevat ed CK and CK-MB activity, respectively. Fourteen of 18 patients with cTn-T elevation had a corresponding elevation in cTn-I (kappa 0.68; p = 0.001). P atients positive for cTn-I had more unstable angina (p = 0.042) and heparin before PICA (p = 0.046), and had longest total time (p = 0.004) and single inflation (p = 0.01). By multivariate logistic regression, predictors of p ostprocedure cTnI elevation were maximum time of each inflation (odds ratio 9.2; p = 0.0012), type B lesions (odds ratio 6.6; p = 0.013), unstable ang ina (p = 0.041), and age greater than or equal to 60 years (p = 0.032). Cli nical follow-up was available in 103 patients (98%) (mean 19 +/- 10 months) . Kaplan-Meier survival analysis showed that cTn-I elevation was not an imp ortant correlate of cardiac events (p = 0.34, by log-rank analysis). The in cidence of recurrent angina, myocardial infarction, cardiac death, and repe at revascularization after 12 months was not different in patients positive or negative for cTn-I. We conclude that cTn-I elevation after successful P TCA is not associated with significantly worse late clinical outcome. level s of cTn-I allow a much higher diagnostic accuracy in detecting minor myoca rdial injury after PICA compared with other markers, but there is no associ ation with periprocedural myocardial cell injury and late outcome when cTn- I and other markers are considered. (C) 1999 by Excerpta Medico, Inc.