Effect of current smoking on ischemic events in patients with atrial fibrillation taking vitamin K antagonist

PURPOSE: We investigated the association between current smoking and clinical outcomes in patients with atrial fibrillation (AF) prescribed vitamin K antagonist (VKA). METHODS: We conducted a retrospective study at 71 centers in Japan. The inclusion criterion was taking a VKA for AF. Exclusion criteria were mechanical heart valves or history of pulmonary thrombosis or deep vein thrombosis. Consecutive patients were registered in February 2013 and followed until February 2017. The primary outcomes included ischemic events and major bleedings. The secondary outcomes were ischemic stroke, hemorrhagic stroke, and all-cause mortality. RESULTS: A total of 7826 patients were included, with a mean age of 73 years; 5274 (67%) were men. The adjusted hazard ratios (HRs; 95% confidence intervals [CIs]) of current smokers relative to non–current smokers for ischemic events and major bleedings were 1.64 (1.05–2.57) and 1.09 (0.72–1.65), respectively. The adjusted HRs (95% CIs) of current smokers relative to non–current smokers for ischemic stroke, hemorrhagic stroke, and all-cause mortality were 1.65 (1.03–2.64), 0.52 (0.12–2.15), and 1.26 (0.83–1.92), respectively. CONCLUSIONS: There were significant associations between current smoking and ischemic events or ischemic stroke in patients with AF on VKA.