RESUMO
Atrial fibrillation (AF) is a frequent complication of acute coronary syndromes (ACS) and is associated with an increased risk of in-hospital and long-term mortality. Our objective was to determine whether patients with previous AF and those who presented with or developed AF during their ACS hospitalization (new onset) have an associated increased risk of short- and mid-term cardiovascular events, death, or a composite. We included 7,228 patients from the Global Registry of Acute Coronary Events electrocardiogram core laboratory substudy, who presented with an ACS. Associated multivariable-adjusted risk of death and major adverse cardiovascular events (MACE) of death, re-infarction, or stroke in-hospital and at 6 months were estimated. New-onset AF and previous AF patients had higher rates of in-hospital mortality (14.9% and 10.9%, respectively) compared with patients without AF (3.8%; both p < 0.001). New-onset AF and previous AF patients had higher rates of 6-month mortality (22.3% and 21.3%, respectively) compared with patients without AF (7.0%; both p <0.001). After adjustment for clinical prognosticators, including those in the Global Registry of Acute Coronary Events risk model, new-onset AF was associated with higher mortality in-hospital (ORadj 1.87, 95% CI 1.30 to 2.70) and at 6 months (ORadj 1.75, 95% CI 1.29 to 2.39) as well as MACE at 6 months (ORadj 1.43, 95% CI 1.12 to 1.81) compared with patients without AF, but were at similar risk compared to those with previous AF (all p > 0.40). In conclusion, the risk of death and MACE after ACS in patients with new-onset and previous AF appears similar and significantly increased compared with patients without AF.