The Association of CHADS-P2A2RC Risk Score With Clinical Outcomes in Patients Taking P2Y12 Inhibitor Monotherapy After 3 Months of Dual Antiplatelet Therapy Following Percutaneous Coronary Intervention

Author's summary

It is unclear whether ischemic risk guides the selection of antiplatelet therapy after percutaneous coronary intervention (PCI). Recently, the CHADS-P2A2RC was developed as an ischemic risk prediction model. There was a stepwise increase in the rates of major adverse cardiac and cerebral events and all-cause death according to increased CHADS-P2A2RC in the study population. No significant interactions were observed between the strata of the CHADS-P2A2RC and the antiplatelet strategies for ischemic and bleeding outcomes; the benefits of P2Y12 inhibitor monotherapy were similar even in patients with high ischemic risk. Randomized studies are needed to evaluate the utility of ischemic risk stratification to guide antiplatelet therapy selection after PCI.

Abstract

Background and Objectives

Concerns remain that early aspirin cessation may be associated with potential harm in subsets at high risk of ischemic events. This study aimed to assess the effects of P2Y12 inhibitor monotherapy after 3-month dual antiplatelet therapy (DAPT) vs. prolonged DAPT (12-month or longer) based on the ischemic risk stratification, the CHADS-P2A2RC, after percutaneous coronary intervention (PCI).

Methods

This was a sub-study of the SMART-CHOICE trial. The effect of the randomized antiplatelet strategies was assessed across 3 CHADS-P2A2RC risk score categories. The primary outcome was a major adverse cardiac and cerebral event (MACCE), a composite of all-cause death, myocardial infarction, or stroke.

Results

Up to 3 years, the high CHADS-P2A2RC risk score group had the highest incidence of MACCE (105 [12.1%], adjusted hazard ratio [HR], 2.927; 95% confidence interval [CI], 1.358–6.309; p=0.006) followed by moderate-risk (40 [1.4%], adjusted HR, 1.786; 95% CI, 0.868–3.674; p=0.115) and low-risk (9 [0.5%], reference). In secondary analyses, P2Y12 inhibitor monotherapy reduced the Bleeding Academic Research Consortium (BARC) types 2, 3, or 5 bleeding without increasing the risk of MACCE as compared with prolonged DAPT across the 3 CHADS-P2A2RC risk strata without significant interaction term (interaction p for MACCE=0.705 and interaction p for BARC types 2, 3, or 5 bleeding=0.055).

Conclusions

The CHADS-P2A2RC risk score is valuable in discriminating high-ischemic-risk patients. Even in such patients with a high risk of ischemic events, P2Y12 inhibitor monotherapy was associated with a lower incidence of bleeding without increased risk of ischemic events compared with prolonged DAPT.

Trial Registration

ClinicalTrials.gov Identifier: NCT02079194

Graphical Abstract