Coronary vasospasm as a possible cause of elevated cardiac troponin I in patients with acute coronary syndrome and insignificant coronary artery disease

Background: Abnormal levels of serum cardiac troponin I (cTnl) are occasionally found in patients presenting with acute coronary syndromes but having insignificant coronary artery disease. Before one concludes that an abnormal cTnl level is a false-positive result, the possibility of coronary vasospasm should be considered. This study investigated whether coronary vasospasm could be a reason for elevated cTnl in this patient population. Methods and Results: This investigation enrolled 93 patients who presented to the emergency department with suspected coronary ischemia and had insignificant coronary artery disease. cTnl was elevated in 23 patients (25%) and was normal in 70 patients (75%). Coronary vasospasm, documented by an ergonovine provocation test, was found in 38 patients (41%). Patients with elevated cTnl levels, compared with those with normal cTnl, were older (63 ± 13 y vs 56 ± 14 y, P = .032), had a higher incidence of males (78% vs 52%, P = .049) and positive ergonovine provocation tests (74% vs 30%, P < .0001), and tended to have a lower incidence of hypercholesterolemia (26% vs 48%, P = .088) and normal electrocardiograms (48% vs 70%, P = .078). Multivariate analysis showed that the variables independently/associated with an elevated cTnl level included coronary vasospasm (odds ratio 2.41, 95% Cl 1.48-3.18, P < .0001) and hypercholesterolemia (odds ratio 0.64, 95% Cl 0.47-0.99, P = .049). Coronary vasospasm (positive ergonovine provocation test) could explain 74% of elevated cTnl levels in patients with insignificant coronary stenosis. Conclusions: In patients with acute coronary syndrome with elevated cTnl and insignificant coronary artery disease, the possibility of coronary vasospasm as a cause of elevated cTnl should be considered.