Dual antithrombotic treatment in chronic coronary syndrome: European Society of Cardiology criteria vs. CHADS-P2A2RC score

Aims: According to the 2019 European Society of Cardiology (ESC) guidelines on chronic coronary syndromes (CCS), adding a P2Y12 inhibitor or rivaroxaban to aspirin should be considered in high-risk patients. We estimated the proportion of patients eligible for treatment with the ESC criteria and examined if a recently validated risk score (CHADS-P2A2RC) could improve risk prediction.

Methods and results: We included 61 338 CCS patients undergoing first-time coronary angiography in Western Denmark (2003-16) and classified them according to the ESC criteria and the CHADS-P2A2RC score. The ESC criteria identified 33.9% as high risk, 53.3% as moderate risk, and 12.8% as low risk. The CHADS-P2A2RC score identified 24.9% as high risk (≥4 points), 48.1% as moderate risk (2-3 points), and 27.0% as low risk (≤1 points). Major adverse cardiovascular events per 100 person-years were 4.8 [95% confidence interval (CI) 4.6-5.0] in patients considered high risk with both schemes, 2.1 (95% CI 2.0-2.2) in patients considered high risk with the ESC but low-to-moderate risk with the CHADS-P2A2RC criteria, 3.8 (95% CI 3.6-4.1) in patients considered low-to-moderate risk with the ESC but high risk with the CHADS-P2A2RC criteria, and 1.5 (95% CI 1.5-1.6) in patients considered low-to-moderate risk with both schemes. The CHADS-P2A2RC score enabled correct downward risk reclassification of 5161 patients (8%) without events, yielding an improved specificity of 9.7%, a loss of sensitivity of 4.4%, and an overall net reclassification index of 0.053.

Conclusion: Based on the 2019 ESC guidelines, dual antithrombotic treatment should be considered in one-third of CCS patients. The CHADS-P2A2RC score improved risk classification and may particularly identify low-risk patients with limited benefit from treatment.