Introduction: Intracoronary acetylcholine (ACh) provocation test is useful to diagnose vasospastic angina, which causes myocardial infarction, ventricular arrhythmia, or sudden cardiac arrest.
Hypothesis: Although outpatient coronary angiography has been widely performed in the current clinical settings, feasibility and safety of ACh provocation test in an outpatient department are unclear.
Methods: A total of 326 patients who electively underwent ACh provocation test in the hospitalization and an outpatient department were included. Coronary angiography was performed after insertion of a temporary pacing electrode in the right ventricle. The positive diagnosis of intracoronary ACh provocation test was defined as total or subtotal coronary artery narrowing accompanied by chest pain and/or ischemic electrocardiographic changes. Cardiac complications defined as composite of death, ventricular fibrillation or sustained ventricular tachycardia, myocardial infarction, cardiogenic shock and cardiac tamponade. In addition, stroke, paroxysmal atrial fibrillation during the test, and unexpected or extended hospitalization were also evaluated.
Results: There were 201 patients (62%) in the hospitalization group and 125 patients (38%) in the outpatient group. The incidence of positive ACh provocation test was similar among the 2 groups (47% vs. 54%, p=0.23). All subjects in the outpatient group were approached by radial artery, mostly (98%) with 4F sheath. Venous access site was not significantly different among the 2 groups, and all venous sheath size was 5F. There were 2 cases (1.0%) of cardiac complications in the hospitalization group, whereas 1 case (0.8%) which led to the unexpected hospitalization in the outpatient group (Table).
Conclusion: Intracoronary ACh provocation test for diagnosing vasospastic angina in an outpatient department was feasible and safe in the selected patients.