Prevalence and Predictors of Obstructive Coronary Artery Disease in Non-low Risk Acute Chest Pain Patients Who Rule Out for Myocardial Infarction in the High-sensitivity Troponin Era

The best management of chest pain patients who rule out for myocardial infarction (MI) in the high-sensitivity troponin (hsTn) era remains elusive. Patients, especially those with non-low clinical risk scores, are often referred for inpatient ischemic testing to uncover obstructive coronary artery disease (CAD). Whether this cohort, in the hsTn era, has a high enough prevalence of obstructive CAD to justify routine testing is unknown. We conducted a retrospective cohort analysis of 1,517 acute chest pain patients who ruled out for MI by virtue of a stable high-sensitivity troponin T (hsTnT) levels (defined as highest level ≤ 50ng/l with inter-measurements increase < 5 g/l) and were admitted from the emergency department for inpatient testing. 11.9% had an abnormal ischemia evaluation (including 5.9% with fixed wall motion or perfusion defects). Of those undergoing invasive angiography (n=298), obstructive CAD (≥70% or unstable lesions) and multivessel disease occurred in 16.8% and 5.4%, respectively. In a multivariate logistic regression model, known CAD, prior MI, chest pain character, mildly elevated hsTnT, and left ventricular ejection fraction < 40% were predictive of an abnormal ischemia evaluation result whereas EKG findings and HEART score were not. Of note, 30-day adverse cardiac events were strikingly low at 0.4% despite a majority of patients (> 90%) having an intermediate or high HEART score. In conclusion, a considerable percentage of acute chest pain patients who rule out for MI by hsTn had evidence of obstructive CAD, and HEART score was not predictive of an abnormal ischemia evaluation in our subjects.