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.