Long-Term Outcomes for Patients With Acute Coronary Syndrome and Nonvalvular Atrial Fibrillation

Abstract

Short-term outcomes are worse for patients with acute coronary syndrome (ACS) with a history of nonvalvular atrial fibrillation (NVAF). However, long-term prognosis remains unclear. We linked administrative health databases to identify patients hospitalized with ACS (ST-elevation myocardial infarction [STEMI], non-STEMI [NSTEMI], and unstable angina) between 2008 and 2019 in Alberta, Canada. Patients were stratified according to history of NVAF before hospitalization. The primary outcome was a composite of all-cause mortality, hospitalization for myocardial infarction, or stroke at 3 years. Cox models were constructed to estimate the association between ACS, NVAF, and outcomes. Of 54,309 ACS hospitalizations, 6,351 patients (11.7%) had a history of NVAF. Compared with patients without NVAF, patients with previous NVAF were older (75.6 ± 11.6 vs 64.9 ± 13.4 years), women (35.1% vs 30.0%), had higher comorbid burden (Charlson co-morbidity index 3.0 vs 1.0), and more often presented with NSTEMI (57.5% vs 49.0%). The primary outcome occurred in 37.0% of patients with previous NVAF and 17.4% without (p <0.001). In the multivariable analysis, there was a 1.14-fold (95% confidence interval [CI] 1.09 to 1.20) higher risk of the primary outcome in patients with previous NVAF. There was a significant association with STEMI (adjusted harazard ratio [aHR] 1.24, 95% CI 1.12 to 1.36) and NSTEMI (aHR 1.12, 95% CI 1.06 to 1.19) but not with unstable angina (aHR 1.04, 95% CI 0.90 to 1.22). In conclusion, in this population-based study, we identified that a history of NVAF at ACS presentation is associated with worse long-term prognosis, particularly for STEMI and NSTEMI.