Long term prognosis of atrial fibrillation in ST-elevation myocardial infarction patients undergoing percutaneous coronary intervention.

Background: Atrial fibrillation (AF) is a well-known complication in the setting of ST elevation myocardial infarction (STEMI). Data on the long-term prognostic implications of New-Onset AF (NOAF) complicating STEMI in the era of complete revascularization remains controversial. Our aim therefore was to evaluate the long-term prognosis of prior AF (pAF) and new-onset AF (NOAF) in STEMI patients undergoing percutaneous coronary intervention (PCI).

Methods: We studied 1657 consecutive STEMI patients hospitalized in the cardiac intensive care unit during 2008-2014. We reviewed patient records for the occurrence of pAF and NOAF. NOAF was defined as AF occurring within 30days of the STEMI episode. Patients were followed for a mean period of 3.4±2.1years.

Results: Within our cohort 77 (4.6%) patients had pAF and 47 (2.8%) had NOAF. Patients with any AF were older and had a reduced systolic ejection fraction. Thirty-day mortality and all-cause mortality rates were significantly higher in patients with pAF in comparison to those without AF (9.1% vs. 2.2% p<0.001 and 31.2% vs. 9.4%, p<0.001, respectively). NOAF showed a trend for increased all-cause mortality (17% vs. 9.1%, p=0.07) and 30-days mortality (6.4% vs. 2.1%. p=0.09). In a multivariate regression model, pAF but not NOAF was a predictor of mortality throughout the follow-up period (HR 2.02, 95% CI 1.2 to 3.1, p=0.005 and HR 1.1, 95% CI 0.56 to 2.2, p=0.75, respectively).

Conclusions: Prior AF and not new-onset AF is an independent predictor of both short and long term mortality in patients treated with PCI.