Background : The CHADS₂ score is a well-established predictor for outcomes in patients with atrial fibrillation (AF). The ankle-brachial index (ABI) is a known tool for diagnosing peripheral artery disease and a predictor for cardiovascular diseases ; however, it is unclear whether it can predict cardiovascular death, myocardial infarction [MI], and stroke (major adverse cardiovascular event (MACE)) in patients with AF. The aim of this study was to investigate whether ABI could predict the prognosis in AF patients.
Methods : We measured ABI in 3131 consecutive patients who visited our cardiovascular center from 2005 to 2015, of which 401 had AF, and they were enrolled in this study. Three patients were excluded because their ABI was inadequate or higher than 1.5. The mean age was 68.0±11.3 years old, and mean observation period was 4.6±2.7 years. We examined the relationship between ABI and MACE.
Results : Of 398 patients, 52 (13.1％) had MACE. Patients with ABI <0.92 had an increased incidence of MACE over those with ABI>0.92 (17 of 66 vs. 35 of 332, HR 2.2, 95％ CI 1.3 to 3.6, p＝0.0056). Patients with CHADS₂ score>2 had a statistically insignificant increase in MACE over those with CHADS₂<1 (HR 1.6, 95％ CI 0.92 to 2.73, p＝0.12). Further, a CHA₂DS₂-VASc score>2 showed a significant difference from that<1 (HR 3.0, 95％ CI 1.2 to 7.4, p＝0.0079).
Conclusions : The ABI could predict the prognosis of patients with AF comparable to the CHADS₂ or CHA₂DS₂-VASc scores.