A Simple Risk Score to Differentiate Between Coronary Artery Obstruction and Coronary Artery Spasm of Patients With Acute Coronary Syndrome Without Persistent ST-Segment Elevation

BACKGROUND: The aim of this study was to create a risk scoring model to differentiate obstructive coronary artery (CA) from CA spasm in the etioology of acute coronary syndrome (ACS). METHODS AND RESULTS: We included 753 consecutive patients with ACS without persistent ST-segment elevation (p-STE). The exclusion criteria were: (1) out-of-hospital cardiac arrest; (2) cardiogenic shock; (3) hemodialysis; (4) atrial fibrillation/flutter; (5) severe valvular disease; (6) no coronary angiography; (7) non-obstructive coronary artery without "definite" vasospastic angina definition; and/or (8) missing data. From the multivariate logistic regression analysis for prediction of obstructive CA, an integer score of 2 to each 0.5 increment in odds ratio was given, and values were divided into quartiles according to the total score. The scores were as follows: age >70 years (6 points), non-STE myocardial infarction (9 points), diabetes mellitus (5 points), B-type natriuretic peptide >90 pg/mL (7 points), neutrophil to lymphocyte ratio >2 (5 points), and high-density lipoprotein cholesterol <50 mg/dL (5 points). CA spasm-induced ACS occurred in 50.0% in Quartile 1 (total score: 0-13), 20.5% in Quartile 2 (total score: 14-19), 4.9% in Quartile 3 (total score: 20-26), and 2.2% in Quartile 4 (total score: 27-37) (P<0.001), indicating that a total score of <20 was a potential clinical indicator of CA spasm-induced ACS. CONCLUSIONS: CA spasm-induced ACS should be suspected if a total score of <20, and a spasm provocation test was being considered.