Prognosis of patients diagnosed with vasospastic angina by acetylcholine provocation testing with and without resuscitated cardiac arrest

Backgrounds Although the prognosis of patients with vasospastic angina (VSA) is generally considered favorable, patients who experience cardiac arrest presumed to be caused by coronary artery spasm, while rare, are thought to have poor outcomes. However, detailed data on the prognosis of these patients remain limited. Purpose In this study, we examined differences in clinical outcomes between patients with VSA diagnosed by acetylcholine (ACh) provocation testing, stratified by the presence or absence of resuscitated cardiac arrest. Methods From April 2012 to October 2025, a cohort of 1,191 patients who underwent ACh provocation testing in our institution was screened. Among them, patients with a positive ACh provocation test were included and were divided into two groups according to the presence or absence of cardiac arrest. In our institution, ACh provocation testing is routinely performed in clinically stable post-resuscitation patients with favorable neurological status in whom no identifiable cause of cardiac arrest is identified. The primary endpoint was a composite outcome of all-cause death or cardiac arrest during the follow-up period. Secondary endpoints included cardiovascular death, resuscitated cardiac arrest, non-fatal myocardial infarction, coronary revascularization, hospitalization for heart failure and hospitalization for chest pain. Results Among 597 patients diagnosed with VSA, 24 patients (4%) had undergone ACh provocation testing following resuscitated cardiac arrest. Compared with the no cardiac arrest group, patients in the cardiac arrest group were younger, more likely to be male, and had a significantly lower body mass index and lower prevalence of dyslipidemia. Left ventricular ejection fraction was also significantly lower in the cardiac arrest group. (Table) During a median follow-up of 2.8 years, the primary composite endpoint of all-cause death or cardiac arrest occurred significantly more frequently in the cardiac arrest group than in the no cardiac arrest group (16.7% vs. 3.1%, Log rank p = 0.017). (Figure) Hospitalization for heart failure was also significantly higher in the cardiac arrest group (12.5% vs. 0.3%, p = 0.001). In contrast, no significant differences were observed between the two groups with respect to other clinical events. Notably, no patients in the cardiac arrest group were admitted to the hospital with chest pain during follow-up. (Table) Conclusions Patients diagnosed with VSA by ACh provocation testing after resuscitated cardiac arrest had a significantly higher risk of recurrent cardiac arrest compared with those without a history of cardiac arrest. These findings suggest that patients who experienced cardiac arrest may require more intensive medical therapy than those without such a history.