Characteristics and Prognosis of Patients with Vasospastic Angina Diagnosed by a Provocation Test with Secondary Prevention Implantable Cardioverter Defibrillator: Comparison with Organic Coronary Stenosis

This study aimed to evaluate the characteristics and prognosis of patients with vasospastic angina (VSA) diagnosed by a provocation test with a secondary prevention implantable cardioverter defibrillator (ICD), compared with patients with organic coronary stenosis. We retrospectively evaluated 309 consecutive patients who received an ICD implantation between January 2010 and March 2018 in our institutions. Of these patients, 206 were implanted with an ICD for secondary prevention. In these 206 patients, 40 with VSA and 72 with organic coronary stenosis were evaluated. Patients with VSA were characterized by younger age (56.1 ± 13.1 versus 69.2 ± 9.5 years, respectively), and a lower prevalence of diabetes (15.0% versus 40.3%, respectively) and heart failure (2.5% versus 26.4%, respectively) than patients with organic coronary stenosis (P < 0.001). Using the Kaplan-Meier analysis, with the VSA group as the reference, the incidence of appropriate ICD shock was similar between the two groups (hazard ratio, 0.85; 95% confidence interval, 0.341-2.109; P = 0.722). The incidence of ventricular fibrillation was significantly higher in the VSA group (hazard ratio, 0.22; 95% confidence interval, 0.057-0.814; P = 0.024), whereas the incidence of major adverse cardiac events, including cardiac death, nonfatal myocardial infarction, hospitalization for unstable angina pectoris, and heart failure, was significantly higher in the organic coronary stenosis group (hazard ratio, 13.1; 95% confidence interval, 1.756-98.17; P = 0.012). In conclusion, patients with VSA with an ICD implanted for secondary prevention have a higher risk of ventricular fibrillation and lower risk of major adverse cardiac events than patients with organic coronary stenosis.