Risk Prediction of Coronary Artery Spasm in Patients Without Obstructive Coronary Artery Disease Using a Comprehensive Clinical, Laboratory and Echocardiographic Diagnostic Score

BACKGROUND The lack of an accurate coronary artery spasm (CAS) risk prediction model highlights the failure to consider the dynamic coronary health and a gap in understanding CAS. METHODS A total of 913 Taiwanese patients (460 women and 453 men) with suspected ischemic heart disease but without angiographic obstructive coronary artery disease were subjected to intracoronary methylergonovine testing during the period 2008-2025. RESULTS The study included 645 CAS cases (70.6%) and 268 non-CAS controls (29.4%). The proportion of men was higher in the CAS than non-CAS group (54.6% vs. 37.7%, p<0.001). The multivariable logistic regression model identified 10 variables significantly associated with CAS (p<0.05): male, smoking, low systolic and diastolic blood pressure, reduced B-type natriuretic peptide levels, elevated low-density lipoprotein levels, increased relative wall thickness at end-systole, high left ventricular mass index, low e’(l) values and high Tei index. Notably, concentric remodeling might promote CAS development. Discrimination performance was moderate, with an AUC value of 73.8% that dropped to 72.4% after bootstrapped internal validation, suggesting the potential generalizability of the derived model. The scoring system ranged from 36 to 98, representing predicted probabilities between 12% and 98%, respectively. CONCLUSIONS While a total score of ≥58 with the probability of CAS exceeding 50% indicates a significant chance of undiagnosed CAS, for those with a total score ≥69 with a very high probability of CAS ≥75%, coronary catheterization with CAS provocation tests is strongly recommended for a definite diagnosis. The simple 10-variable scoring model allows ranking at-risk population and diagnostic resource allocation. Abstract Figure CLINICAL PERSPECTIVE What Is New? A simple comprehensive 10-variable scoring model (sex, smoke, systolic and diastolic blood pressure, B-type natriuretic peptide, low-density lipoprotein, left ventricular mass index, relative wall thickness at end-systole, e’(l) and Tei) could offer a non-invasive means of identifying patients at earlier stages of developing coronary artery spasm (CAS). While the probability of CAS was <25% when the total score was ≤45, for those with a total score ≥69 with a very high probability of CAS ≥75%, coronary catheterization with CAS provocation tests is strongly recommended for a definite diagnosis. What Are the Clinical Implications? This well-calibrated CAS risk score model has good discrimination, which allows for early allocating diagnostic coronary catheterization effectively, individualized treatments, and better outcomes.