Dual antiplatelet therapy in non-ST elevation acute coronary syndromes at Veterans Affairs Hospitals.

ABSTRACT

OBJECTIVE: Current guidelines recommend that patients with non-ST elevation acute coronary syndromes (NSTEACS) receive dual antiplatelet therapy (DAPT) early in hospitalisations. However, observational studies suggest that this rarely occurs. We evaluated site-specific variation and clinical outcomes associated with early DAPT among patients undergoing angiography for NSTEACS. METHODS: In this observational analysis, we identified patients undergoing angiography for NSTEACS in Veterans Affairs hospitals from 2008 to 2016 and assessed characteristics and site variation associated with early DAPT (administration <24 hours of admission). Using propensity matching, we compared time to revascularisation, recurrent myocardial infarction (MI) and mortality between those receiving early DAPT and those not receiving early DAPT (administration ≥24 hours). RESULTS: Of 45 569 patients undergoing angiography for NSTEACS, 15 084 (33%) received early DAPT. Early DAPT was more frequent in patients with non-ST elevation MI, prior surgical revascularisation and among patients undergoing revascularisation. There was a greater than twofold difference in early DAPT across sites, independent of patient characteristics (median OR 2.43, 95% CI 2.28 to 2.55). There was no difference in time topercutaneous coronary intervention (PCI) between groups, but a significant delay to surgical revascularisation with early DAPT (median 4 vs 3 days, p<0.001) without reduction in hazard of death or MI (HR 1.08, 95% CI 1.00 to 1.16) and similar results demonstrated in the subgroup of patients undergoing revascularisation (HR 1.02, 95% CI 0.91 to 1.13). CONCLUSION: Among NSTEACS patients undergoing coronary angiography, early DAPT was not associated with improvement of outcomes but was associated with delays in surgical revascularisation.