Clinical characteristics, management and outcomes of patients with acute coronary syndrome and atrial fibrillation: real-world data from two nationwide registries in Italy

Background Atrial fibrillation is common in the setting of acute coronary syndromes (ACS) although its impact on ACS remains controversial. Aim To describe in-hospital management of patients with atrial fibrillation and ACS evaluating the impact of atrial fibrillation on in-hospital and mid-term outcome. Methods We analysed the data of two prospective multicentre nationwide registries (IN-ACS Outcome and MANTRA) to assess clinical characteristics, management, and outcomes of patients with ACS and atrial fibrillation. Study outcomes included death from any cause and a composite end-point of death/re-infarction/stroke/major bleeding within index admission and 6 months' follow-up. Results Out of 12 288 ACS patients, 1236 (10.1%) had atrial fibrillation at admission or developed it during hospitalization. Atrial fibrillation patients were older, more often female, and had higher burden of comorbidities. In-hospital mortality was higher among atrial fibrillation patients (8.7 vs. 2.4%,P < 0.001). Patients with atrial fibrillation had a higher incidence of re-infarction (3.5 vs. 1.7%,P < 0.0001) and ischemic stroke (1.7 vs. 0.4%,P < 0.001) compared with those in sinus rhythm. Major bleedings were also more frequent among atrial fibrillation patients (1.9 vs. 0.9%,P < 0.001). In-hospital and at 6 months' follow-up death from any cause occurred more often in atrial fibrillation patients than in those without atrial fibrillation (9.4 vs. 3.5%,P < 0.0001). At multivariable analysis, atrial fibrillation was an independent predictor of the in-hospital composite end-point (OR 1.67, 95% CI 1.35-2.06,P < 0.0001) but not at 6 months' follow-up. The independent role of atrial fibrillation on the in-hospital composite end-point was also confirmed by propensity score analyses. Conclusion Atrial fibrillation was an independent predictor for adverse in-hospital outcome in ACS. This effect disappeared at mid-term follow-up, whereas noncardiac comorbidities emerged as prognostic factors of adverse outcomes.