Incidence and Predictors of Obstructive Coronary Artery Disease and the Role of Cardiac Troponin Assays in Patients with Unstable Angina

In a time when cardiac troponin assays are widely used to detect myocardial injury, data remain scarce concerning the incidence and predictors of substantial obstructive coronary artery disease that causes unstable angina. This retrospective single-center study included consecutive patients hospitalized for unstable angina from January 2015 through January 2016. Patients with troponin I levels above the upper reference limit and those who did not undergo angiography were excluded. Multivariate logistic regression analysis was used to identify predictors of obstructive coronary artery disease that warranted revascularization and of major adverse cardiac events up to 6 months after discharge from the hospital. Of the 114 patients who met the inclusion criteria, 46 (40%) had obstructive coronary artery disease. In the univariate analysis, male sex, white race, history of coronary artery disease, prior revascularization, hyperlipidemia, chronic kidney disease, aspirin use, long-acting nitrate use, and Thrombolysis in Myocardial Infarction score ≥3 were associated with obstructive coronary artery disease. History of coronary artery disease, prior revascularization, hyperlipidemia, and long-acting nitrate use were associated with major adverse cardiac events. Male sex was an independent predictor of obstructive coronary artery disease (adjusted odds ratio=4.82; 95% CI, 1.79-13; P=0.002) in the multivariate analysis. Our results showed that coronary artery disease warranting revascularization is present in a considerable proportion of patients who have unstable angina. The association that we found between male sex and obstructive coronary artery disease suggests that the risk stratification of patients presenting with unstable angina may need to be refined to improve outcomes.