Epidemiology, anticoagulant treatment and risk of thromboembolism in patients with valvular atrial fibrillation: Results from Atrial Fibrillation in Turkey: Epidemiologic Registry (AFTER)

Abstract

Background: The aim of this study was to perform a multicenter, prospective investigation regarding the epidemiology, the current effectiveness of therapeutic anticoagulation, and the risk of thromboembolism in patients with valvular atrial fibrillation (AF) based on the records of the Atrial Fibrillation in Turkey: Epidemiologic Registry (AFTER) study.

Methods: Patients were selected from a total of 2,242 consecutive admissions that presented with AF diagnosed via electrocardiogram. Those diagnosed with non-valvular AF were excluded from the AFTER study population, which left 497 patients with valvular AF for analysis.

Results: The etiology of valvular AF in patients was either attributed to rheumatic mitral valve stenosis (n = 217) or possessing a prosthetic heart valve (n = 280). Out of all the patients with valvular AF, 83.1% were taking warfarin for anticoagulation. Only 36.1% demonstrated a therapeutic international normalized ratio (INR), and among those patients it was found that 19.1% exhibited a labile INR. Multivariate analysis revealed that age was the only independent predictor of thromboembolic events in patients with valvular AF.

Conclusions: Many valvular AF patients are not maintained at therapeutic INR levels, which poses a threat to patient health as they age and are at greater risk for thromboembolism.