Identification of factors associated with progression of left atrial enlargement in patients with atrial fibrillation.

Left atrial (LA) enlargement frequently occurs in atrial fibrillation (AF) patients, and this enlargement is associated with the development of heart failure, thromboembolism, or atrial functional mitral regurgitation (AFMR). AF patients can develop LA enlargement over time, but its progression depends on the individual. So far, the factors that cause progressive LA enlargement in AF patients have thus not been elucidated, so that the aim of this study was to identify the factors associated with the progression of LA enlargement in AF patients. We studied 100 patients with persistent or permanent AF (aged: 67 ± 2 years, 40 females). Echocardiography was performed at baseline and 12 (5-30) months after follow-up. LA size was evaluated as the LA volume index which was calculated with the biplane modified Simpson's method from apical four-and two-chamber views, and then normalized to the body surface area (LAVI). The deterioration of AFMR after follow-up was defined as a deterioration in severity of mitral regurgitation (MR) by a grade of 1 or more. Multivariate regression analysis demonstrated that hypertension (p = .03) was an independently associated parameter of progressive LA enlargement, as was baseline LAVI. In addition, the Kaplan-Meier curve indicated that patients with hypertension tended to show greater deterioration of AFMR after follow-up than those without hypertension (log-rank p = .08). Hypertension proved to be strongly associated with progression of LA enlargement over time in patients with AF. Our findings provide new insights for better management of patients with AF to prevent the development of AFMR.