Nonalcoholic fatty liver disease as a predictor of atrial fibrillation: a systematic review and meta-analysis.

Introduction: Numerous epidemiologic studies have investigated the link between nonalcoholic fatty liver disease (NAFLD) and long-term atrial fibrillation (AF) risk, but the results are surprisingly conflicting. Aim: Therefore, we systematically reviewed all published studies assessing the risk of AF in patients with NAFLD and conducted a meta-analysis. Material and methods: We performed a literature search using PubMed, EMBASE and Cochrane Library databases in February 2017 with no restrictions. Two cohort studies and two cross-sectional studies were identified, involving a total of 5150 subjects (NAFLD: 1655; controls: 3495) in this meta-analysis. Data from selected studies were extracted and a meta-analysis was performed using a random effects model. Results: Nonalcoholic fatty liver disease patients had a significantly higher risk of AF compared to controls (relative risk (RR): 2.61; 95% confidence interval (CI): 1.34-5.06, p = 0.00; I-2 = 52.5%, p = 0.097). In a further analysis stratified by presence of type 2 diabetes, the increased risk was present predominantly in patients with type 2 diabetes (RR = 5.10; 95% CI: 2.43-10.7, p < 0.001; I-2 = 0, p = 0.958). However, subjects without type 2 diabetes were at slightly increased risk of AF but the relative risk did not reach statistical significance (RR = 1.68; 95% CI: 0.99-2.82, p = 0.05; I-2 = 0, p = 0.461). Conclusions: Our meta-analysis suggested that ultrasound-diagnosed NAFLD patients have a significantly higher risk for AF after adjustment for numerous important clinical risk factors for AF. These results need to be confirmed in large prospective studies.