Introduction and objectives: Troponin I (TnI) is a useful marker of myocardial damage for the diagnosis and prognosis of acute coronary syndrome. The purpose of this study was to analyze the long-term prognostic value of the peak TnI concentration obtained within 48 h of admission to the coronary unit for unstable angina.
Methods: The study included 149 consecutive patients. Serial determinations were made of the MB fraction of creatine kinase (CK-MB) and TnI. Patients without CK-MB elevation were classified into two groups depending on the presence of high (n = 58) or normal (n = 91) troponin I values. We prospectively analyzed the clinical and evolutive factors related to the probability of death, new acute coronary event, or coronary revascularization at one-year of follow-up.
Results: There were no differences in the clinical characteristics between groups, except that patients in the group with high TnI values were older (69 vs. 64 years, p = 0.01). At one year of follow-up there were no differences in the incidence of new acute coronary events or coronary revascularization procedures; however there was a higher mortality in the group with high TnI (13 vs. 4%; p = 0.01). The independent predictors of mortality were prior myocardial infarction (RR = 3), elevated troponin I (RR = 3.2), left ventricular ejection fraction < 35% (RR = 10), and age > 70 years (RR = 15).
Conclusions: In patients with unstable angina a high troponin I value in the first 48 h of admission was associated with a higher mortality rate at one-year of follow-up.