Renalase is associated with adverse left atrial remodelling and disease burden in patients with atrial fibrillation undergoing pulmonary vein isolation.

Abstract

Renalase is a catecholamine-metabolising enzyme, but its possible association with atrial fibrillation (AF) remains unknown. We sought to evaluate plasma renalase concentration in patients with AF undergoing pulmonary vein isolation (PVI) with respect to AF clinical characteristics, left atrial (LA) remodelling, and PVI efficacy. This case-control study included 69 patients (median age 58 years) with either paroxysmal (89%) or persistent (11%) AF, referred for PVI, and a control group consisting of 15 patients without AF, matched for age, sex, and comorbidi-ties. An evaluation of transthoracic echocardiography with LA speckle tracking and plasma renalase concentration using an enzyme-linked immunosorbent assay was performed. AF recurrence was defined as any AF episode on seven-day electro-cardiographic monitoring at six-month follow-up. Renalase level was higher in the study group than in the control group (mean 27.99 vs. 21.48 μg/mL, p = 0.004), but it was lower in patients with persistent AF (19.05 vs. 28.77 μg/mL; p = 0.023) and among patients with AF episodes di-rectly preceding PVI (24.50 vs. 29.66 μg/mL; p = 0.04). Renalase concentration within the first quartile was associated with higher mean heart rate (70 vs. 61 bpm, p = 0.029), greater AF burden (36.9% vs. 9.3%, p = 0.027), greater LA diameter (41.1 vs. 37.9 mm, p = 0.011), and a trend towards less negative global LA strain (-9.4 vs. -13.5, p = 0.082). Logistic regres-sion revealed that global four-chamber LA strain was the only independent predictor of renalase variability (p = 0.0045). Renalase concentration did not predict AF recurrence at six-month follow-up (area under curve [AUC] = 0.614, p = 0.216). Low renalase level may be associated with impaired rate control, higher AF burden, and advanced LA remodel-ling in AF patients undergoing PVI, but it does not predict sinus rhythm maintenance.