Differential prognosis of vasospastic angina according to presentation with sudden cardiac arrest or not: Analysis of the Korean Health Insurance Review and Assessment Service

Background: The long-term prognosis of vasospastic angina (VSA) patients presenting with aborted sudden cardiac death (ASCD) is still unknown. We sought to compare the long-term clinical outcomes between VSA patients presenting with and without ASCD by retrospective analysis of a nationwide population-based database. Methods: A total of 6972 patients in the Health Insurance Review and Assessment database who were hospitalized in the intensive care unit with VSA between July 1, 2007 and May 31, 2015 were enrolled. Primary outcome was the composite of cardiac arrest and acute myocardial infarction after discharge. Results: Five hundred ninety-eight (8.6%) VSA patients presented with ASCD. On inverse probability of treatment weighting, ASCD patients had a significantly increased risk of the composite of cardiac arrest and acute myocardial infarction (adjusted hazard ratio, 2.52; 95% confidence interval, 1.72–3.67; p < 0.001) during the median follow-up duration of 4 years. The association of ASCD presentation with a worse outcome in terms of primary outcome was consistent across various subgroups, including comorbidity type and use of vasodilators (all p-values for interaction: non-significant). ASCD patients treated with an implantable cardioverter defibrillator (ICD) had a lower incidence of the composite of cardiac arrest and acute myocardial infarction during follow-up than those without an ICD (p = 0.009). Conclusions: VSA patients that present with ASCD are at increased risk of cardiac arrest or myocardial infarction during long-term follow-up despite adequate vasodilator therapy. An ICD is a potential therapeutic option for secondary prevention.