Association of left ventricular end-diastolic diameter with incidence of thromboembolism in patients with non-valvular atrial fibrillation: the Fushimi AF Registry

Background Atrial fibrillation (AF) is a common arrhythmia and a risk factor for thromboembolism including ischemic stroke (IS) and systemic embolism (SE). Thrombus formation mainly occurs in the left atrium (LA), but we reported that relative wall thickness (RWT) of left ventricle (LV) was independently associated with IS/SE among patients with non-valvular AF. Little is known about the impact of LV size on thromboembolism in patients with AF. We investigated the relationship between left ventricular end-diastolic diameter (LVDd) and incidence of IS /SE, using data from the Fushimi AF Registry. Methods The Fushimi AF Registry, a community-based prospective survey, was designed to enroll all of the AF patients in the community. Follow-up data were available for 4,472 patients as of November 2020, and the median follow-up period was 1,820 days. Of them, we excluded 226 patients with mitral stenosis or prior cardiac valve surgery. Among 4,246 non-valvular AF patients, follow-up data including LVDd at the baseline from echocardiography were available for 3,311 patients. We divided these patients into three groups according to LVDd tertile (T1:<44.0 mm; n=1,091, T2: 44.0–48.5; n=1,112, T3: 48.5 or above; n=1,108), and compared the clinical characteristics and outcomes. Results Percentage of female (T1 vs. T2 vs T3; 56.5 vs. 37.5 vs. 34.1%; p<0.01), age (76.2±9.9 vs. 72.8±10.7 vs. 71.9±11.1 years; p<0.01), height (156.3±9.9 vs. 160.4±9.4 vs. 163.7±9.5 cm; p<0.01), BMI (21.8±3.9 vs. 23.3±3.6 vs. 24.2±4.4 kg/m2; p<0.01), prevalence of hypertension (58.8 vs. 64.1 vs. 67.7%; p<0.01), vascular disease (7.4 vs. 8.8 vs. 15.2%; p<0.01), CHA2DS2-VASc score (3.59±1.68 vs. 3.27±1.70 vs. 3.31±1.73; p<0.01) and the prescription of oral anticoagulants (OACs) were different among groups. LV ejection fraction (65.9±8.7 vs. 65.0±9.1 vs. 57.7±14.4%; p<0.01), LA diameter (40.7±7.9 vs. 42.8±7.3 vs. 45.8±7.6 mm; p<0.01), LVRWT (0.471±0.090 vs. 0.411±0.064 vs. 0.366±0.063; p<0.01) and LV mass index (79.6±21.4 vs. 93.5±20.4 vs. 117.6±30.3 g/m2; p<0.01) were different. Prevalence of prior stroke/SE and prior major bleeding were comparable among groups. In Kaplan-Meier analysis, the incidence of IS/SE was different among the groups during the median follow-up period of 1,826 days (T1 vs. T2 vs T3; 2.1 vs. 1.9 vs. 1.1 per 100 person-years; p<0.01, by log-rank test) (Figure). LVDd (All age, hazard ratio [95% confidential interval]: T1/T3 1.57 [1.09–2.29]; p=0.02, T2/T3 1.55 [1.11–2.17]; p<0.01: less than 75 years, T1/T3 2.27 [1.24–4.22]; p<0.01, T2/T3 1.54 [0.89–2.70]; p=0.12: 75 years or above, T1/T3 1.33 [0.83–2.14]; p=0.08, T2/T3 1.57 [1.04–2.40]; p=0.03) was an independent predictor of the incidence of IS/SE after adjustment by the components of CHA2DS2-VASc score, LA diameter, LVRWT, type of AF and the prescription of OACs (Table). Conclusion LVDd was independently associated with IS/SE among Japanese patients with non-valvular AF. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): the Practical Research Project for Life-Style-related Diseases including Cardiovascular Diseases and Diabetes Mellitus from Japan Agency for Medical Research and Development