New-onset atrial fibrillation (NOAF) during hospitalization is considered a frequent complication associated with worse outcomes in the setting of acute coronary syndromes (ACS)

To assess the predictors and prognosis of NOAF during ACS.

A total of 402 patients who were hospitalized with a diagnosis of ACS were prospectively enrolled. Clinical parameters, echocardiography, biochemical markers were collected. In-hospital mortality and incidence of in-hospital main adverse cardiovascular and cerebrovascular events (MACCE) were compared between NOAF and non-NOAF groups.

In our study population, 39 (9.7%) patients developed NOAF during hospitalization. The patients in NOAF group were significantly older than those in the non-NOAF groups (65±10 years vs 59±10 years, P=0.001). Moreover, the levels of serum uric acid (P=0.001), peak creatinine (P=0.001), CRP (P=0.02), neutrophil to lymphocyte ratio (P=0.04) and mean platelet volume (MPV, P=0.02) were significantly higher in the NOAF group, while left ventricular ejection fraction (LVEF: 43±12% vs 48±10%, P=0.01) and hemoglobin (119±1.8g/l vs 130±1.9g/l, P=0.001) were significantly lower in the NOAF group. Logistic multivariate regression showed that age (OR=1.08; P=0.02), MPV (OR=1.4; P=0.03), LVEF (OR=2; P=0.001) and indexed left atrial volume (OR=1.15; P=0.004) were independent predictors of NOAF after ACS. Patients in the NOAF group had significantly longer hospital stay (4±1.2 days vs 3.6±1 days, P=0.02). The in-hospital mortality (5% vs 0%, P=0.009) and the incidence of bleeding complications (5% vs 0.5%, P=0.04) in the NOAF group were significantly higher. There were no significant differences in stroke between the two groups.

Age, LVEF, MPV and indexed left atrial volume are independent predictors of NOAF during ACS in Tunisian patients. This arrhythmia is associated with higher in-hospital mortality and bleeding complications.