Antithrombotic Therapy and Outcomes of Patients With New-Onset Transient Atrial Fibrillation After ST-Segment Elevation Myocardial Infarction.

Background: Atrial fibrillation (AF) is a common complication of ST-segment elevation myocardial infarction (STEMI), and AF might require anticoagulant treatment in some conditions.

Study Question: There are no clear recommendations about vitamin K antagonist (VKA) use in patients with STEMI who complicated with new-onset transient AF. In this study, we examined the association of concomitant use of VKA and dual antiplatelet therapy (DAPT) with clinical outcomes of this patient population.

Study Design: A total of 4086 patients with STEMI who underwent primary percutaneous coronary intervention retrospectively investigated. Among these patients, a total of 286 patients who developed new-onset transient AF during hospitalization were enrolled. VKA group consisted of 116 patients treated with warfarin, aspirin, and clopidogrel, and DAPT group consisted of 170 patients treated with aspirin and clopidogrel.

Measures And Outcomes: One-year mortality, ischemic stroke, major, and minor bleeding were determined as clinical outcomes.

Results: Although VKA group had proportionally lower mortality (17.2% vs. 20.0%) and ischemic stroke (7.8% vs. 11.8%) compared with DAPT group, the differences did not reach to statistical significance, whereas the 1-year major bleeding had higher rates at VKA group and that had 3.5-times higher major bleeding than DAPT group. This relationship was persisted after multivariable analysis (hazard ratio = 3.37, 95% CI, 1.76-10.04, P = 0.012).

Conclusions: There is not a widely accepted treatment algorithm in patients with STEMI who complicated with new-onset AF in clinical guidelines. The current study indicated that transient form of new-onset AF might not require long-term VKA. Besides, addition of VKA to DAPT therapy may increase the rates of major and minor bleeding.