Abstract Body: Background:
Although patients who have experienced sudden cardiac arrest (SCA) due to vasospastic angina (VSA) are at high risk of recurrent life-threatening arrhythmias, the benefit of implantable cardioverter-defibrillators (ICD) implantation in these patients remains inconclusive. Furthermore, the acetylcholine (ACh) provocation test, which is the gold standard for diagnosing VSA, is rarely performed on post-resuscitation patients. Consequently, the prognosis of post-resuscitation VSA patients with positive ACh provocation test has not been fully elucidated. Thus, we aimed to investigate the long-term clinical prognosis of VSA patients, diagnosed using the ACh provocation tests, who received an ICD implantation for secondary prevention.
Methods:
From January 2012 to March 2024, a cohort of 222 patients who were resuscitated from SCA and received an ICD as secondary prophylaxis of sudden cardiac death in our institution were retrospectively analyzed. The patients were divided into two groups according to the presence of VSA. In this study, VSA was defined by meeting all of the following criteria; (1) a positive ACh provocation test, (2) normal left ventricular ejection fraction (LVEF) and no wall motion abnormality (3) absence of identifiable or reversible causes of lethal ventricular arrhythmias. The primary endpoint was a composite of all-cause mortality and appropriate ICD shock therapy. Additionally, we evaluate an incidence of appropriate ICD shock therapy and all-cause mortality, respectively.
Results:
Overall, patients with VSA were younger and more likely to be current smoker than those without. Also, the level of brain natriuretic peptide was lower and LVEF was better in the VSA group than in the non-VSA group. (Table) However, the incidence of appropriate ICD shock therapy was equivalent between patients with and without VSA during a median follow-up period of 3.7 years. (11.8% vs. 13.7%, p=1.000) Kaplan-Meier curve analysis showed no significant difference in the incidence of composite of all-cause mortality and appropriate ICD shock. (Log rank p=0.286) (Figure)
Conclusions:
In a cohort of patients who received an ICD for secondary prophylaxis, long-term clinical outcomes in patients with VSA who were diagnosed by ACh provocation tests and preserved LVEF were similar to those without. This result suggests that patients with VSA following cardiac arrest may have a high risk for lethal arrhythmias and an unfavorable prognosis.