Risk stratification of net adverse clinical events using CHADS-PARC and CHADS scores in chronic coronary syndrome patients without atrial fibrillation: Insights from the CLIDAS-PCI.

Background: There are few data verifying the utility of the CHADS-PARC score in comparison with the CHADS score for estimating net adverse clinical events (NACE) in chronic coronary syndrome (CCS) patients without atrial fibrillation (AF) in real-world settings.

Methods: We performed analysis for a total of 3985 CCS patients without AF who underwent percutaneous coronary intervention (PCI) between April 2013 and March 2019 for whom information was obtained from the CLIDAS (Clinical Deep Data Accumulation System)-PCI database. The primary endpoint was NACE defined as the composite of 3-point major adverse cardiovascular events (3P-MACE) (cardiovascular death, non-fatal myocardial infarction, and non-fatal stroke) and GUSTO moderate/severe bleeding events.

Results: Kaplan-Meier analysis showed that both the CHADS-PARC and CHADS scores stratified the risks. The incidences of NACE were stratified well by the very-high-risk category, which was uniquely defined as a CHADS-PARC score of ≥6 (hazard ratio: 2.38, 95 % CI = 1.91-2.97, p-value <0.001). The area under the curve (AUC) in estimating NACE within 3 years was higher when the CHADS-PARC score was used than when the CHADS score was used (0.67 vs. 0.62, p = 0.003). This was mainly due to the accuracy in estimating bleeding events (0.66 vs. 0.60, p = 0.006).

Conclusions: The accuracy in estimating NACE after PCI for CCS patients without AF was higher when the CHADS-PARC score was used than when the CHADS score was used, mainly due to the accuracy in predicting bleeding risk. Higher incidences of endpoints were well-stratified by a very-high-risk category defined as a CHADS-PARC score of ≥6.