Prognostic efficacy of circulating asymmetric dimethylarginine in patients with peripheral arterial disease: A meta-analysis of prospective cohort studies.

Background Asymmetric dimethylarginine is suggested to be a marker of poor prognosis in patients with atherosclerosis. However, the predictive role of circulating asymmetric dimethylarginine for clinical outcome in patients with peripheral arterial disease has not been determined. Aims To quantitatively assess the predictive value of circulating asymmetric dimethylarginine for clinical outcome in patients with peripheral arterial disease in a meta-analysis of prospective cohort studies. Methods Relevant studies were identified by systematically searching of PubMed and Embase databases. A random-effect model was used to synthesize the results. Sensitivity analyses by omitting one study at a time were performed to evaluate the robustness of the results. Results Six studies with 2535 peripheral arterial disease patients were included. Patients with higher circulating asymmetric dimethylarginine at baseline were associated with higher risk of all-cause mortality (adjusted hazard ratio: 1.63, 95% confidence interval: 1.28-2.06, I2 = 16%), and major adverse cardiovascular events (adjusted hazard ratio: 2.01, 95% confidence interval: 1.08-3.73, I2 = 78%) as compared with those with lower circulating asymmetric dimethylarginine at baseline. Specifically, every increment of 0.1 µmol/l of asymmetric dimethylarginine was associated with 18% (adjusted hazard ratio: 1.18, 95% confidence interval: 1.06-1.31) increased risk for all-cause mortality and 14% (adjusted hazard ratio: 1.14, 95% confidence interval: 1.04-1.25) increased risk for major adverse cardiovascular disease. Sensitivity analyses by omitting one study at a time did not significantly change the results. Conclusion Higher circulating asymmetric dimethylarginine at baseline may be associated with higher incidence of cardiovascular events and mortality in patients with peripheral arterial disease.