Background: Circulating soluble urokinase-type plasminogen activator receptor (suPAR), which can reflect immune activation and low-grade inflammation, may be a novel biomarker of cardiovascular disease. Methods: We investigated the potential association between suPAR and the prevalence of atrial fibrillation (AF) by analyzing patients with either sinus rhythm, paroxysmal atrial fibrillation (PAF), or nonparoxysmal atrial fibrillation (NPAF), which indicates either permanent or persistent AF. Results: Among 426 patients enrolled (mean age 71.4±9.2 years; 110 (25.8%) female), 310, 62, and 54 were diagnosed with sinus rhythm, PAF, and NPAF, respectively. NPAF was >10-fold more prevalent in the highest suPAR quartile (>3534 pg/mL; 32 (30.2%) of 106 patients) than in the lowest suPAR quartile (<1802 pg/mL; 3 (2.8%) of 107 patients). Logistic regression analysis showed that, as compared with the lowest suPAR quartile, the highest suPAR quartile was associated with NPAF with an odds ratio of 6.48 (95% confidence interval, 1.71-24.5) after adjustment for sex, age, log(eGFR), C-reactive protein, and systolic blood pressure. In multivariate receiver operating characteristic analysis to predict NPAF, the area under the curve (AUC) for the combination of age, sex, log(eGFR), and C-reactive protein was 0.777 (standard error [SE], 0.036); the addition of log(suPAR) slightly improved the prediction (AUC, 0.812; SE, 0.034, P=0.084). Conclusions: Serum suPAR was associated with AF, particularly NPAF, as demonstrated by multivariate logistic regression analysis. Whether suPAR promotes or maintains AF should be investigated in further studies.
Ichihara, N., Miyamura, M., Maeda, D., Fujisaka, T., Fujita, S. I., Morita, H., … Ishizaka, N. (2017). Association between serum soluble urokinase-type plasminogen activator receptor and atrial fibrillation. Journal of Arrhythmia, 33(5), 469–474. https://doi.org/10.1016/j.joa.2017.05.003