Prognostic impact of atrial fibrillation in patients with acute myocardial infarction

BackgroundAtrial fibrillation (AF) is the most common supraventricular tachyarrhythmia in patients with acute myocardial infarction (AMI). However, little is known about the impact of AF on in-hospital and long-term mortalities in patients with AMI in the era of primary percutaneous coronary intervention (PCI).MethodsSix hundred ninety-four consecutive patients with AMI admitted within 48 h after symptom onset were analyzed. All patients successfully underwent primary PCI at the acute phase of AMI. Patients were divided into 2 groups according to the presence of AF at admission or during index hospitalization. We retrospectively evaluated the in-hospital and long-term all-cause mortalities between patients with and those without AF.ResultsAF was detected in 38 patients (5.5%) at admission and in 51 patients (7.3%) during hospitalization. Patients with AF were older and had a higher heart rate, lower ejection fraction, higher prevalence of hypertension, worse renal function, higher peak level of creatine phosphokinase, and lower rate of final TIMI flow grade 3 than those without AF. Although patients with AF had a more complicated clinical course and higher in-hospital mortality (11.2% vs. 4.0%, P=0.009), there was no significant association between presenting AF and in-hospital death after adjustment for baseline confounders (odds ratio, 2.63; 95% confidence interval [CI], 0.91–5.47; P=0.076). During the follow-up period of 3.0±1.7 years, patients with AF had a higher all-cause mortality than those without AF (30.3% vs. 22.1%, P=0.004 by log-rank test). However, after adjustment for clinical characteristics, presenting AF was not an independent predictor of all-cause mortality (hazard ratio, 1.15; 95% CI, 0.67–1.88; P=0.588).ConclusionsAF is a common complication of AMI and associated with a more complicated clinical course. However, AF is not an independent predictor of both in-hospital and long-term mortalities in the PCI era.