Abstract 9877: Novel Clinical Risk Score for the Prediction of Cardiac Events in Patients with Vasospastic Angina -A Report from the Nationwide Multi-Center Registry by the Japanese Coronary Spasm Association

Abstract

Background: Previous studies demonstrated various predictive factors of cardiac events (e.g., out-of-hospital cardiac arrest) in patients with vasospastic angina (VSA). However, the useful score to predict cardiovascular events in VSA patients needs to be developed. We thus aimed to develop a novel clinical risk prediction score for VSA patients. Methods: The VSA database of the nationwide multi-center registry study by the Japanese Coronary Spasm Association (n=1,429; median 66 years; median follow-up of 32 months) was utilized for score derivation. Multivariable Cox proportional hazard model was used to select the correlated factors of major adverse cardiac events (MACE) including cardiac death, non-fatal myocardial infarction, unstable angina and heart failure. They were subsequently weighted according to the adjusted hazard ratio (HR) and integrated into the scoring system. Results: Six variables selected following Cox model were weighted; smoking (2 points), angina at rest alone (2 points), life-threatening arrhythmia during angina (2 points), multivessel spasm (2 points), organic coronary stenosis >50% (2 points) and ST elevation during angina (1 point). According to the total score, 3 strata of risk were defined; low (score 0-3, n=713), intermediate (score 4-6, n=666) and high (score 7-9, n=50). The incidence of MACE in the low-, intermediate- and high-risk patients were 2.8%, 8.3% and 20.0%, respectively (P<0.001). Kaplan-Meier curve for MACE among the 3 risk groups showed prognostic utility of the scoring system throughout the follow-up period (low vs. intermediate, HR 3.04, 95% CI 1.82-5.07, P<0.001; low vs. high, HR 8.13, 95% CI 3.80-17.37, P<0.001) ( Figure ). The C-statistic for the score predicting MACE was 0.67. Conclusions: We developed a novel scoring system that provides the stratification of cumulative risk of cardiac events in VSA patients, which is clinically relevant in the triage and management of the disorder.