Safety and usefulness of acetylcholine provocation test in patients with no culprit lesions on emergency coronary angiography.

BACKGROUND

Vasospastic angina (VSA), which often causes acute coronary syndrome (ACS), can be diagnosed by intracoronary acetylcholine (ACh) provocation test. However, the safety and usefulness of ACh provocation test in ACS patients on emergency coronary angiography (CAG) compared to non-emergency settings are unclear.

METHODS

A total of 529 patients undergoing ACh provocation test during emergency or non-emergency CAG were included. Patients with resuscitated cardiac arrest were excluded. The primary endpoint was adverse events defined as a composite of death, ventricular fibrillation or sustained ventricular tachycardia, myocardial infarction, cardiogenic shock, cardiac tamponade, and stroke within 24 h after ACh provocation test.

RESULTS

There were no significant differences of the clinical characteristics between the groups of emergency (n = 84) and non-emergency (n = 445) ACh provocation test. The rate of positive ACh provocation test was similar between the 2 groups (50% vs. 49%, p = 0.81). Similarly, the incidence of adverse events in patients with emergency and non-emergency ACh provocation test did not significantly differ (1.2% vs. 1.3%, p = 1.00).

CONCLUSION

ACh provocation test can be safely performed in ACS patients with no obstructive culprit lesions on emergency CAG, and may be useful to diagnose VSA in those patients.