Relationship between red blood cell distribution width levels and atrial fibrillation in hypertensive patients

Background Information on the relationship between red blood cell distribution width (RDW) and atrial fibrillation (AF) in patients with essential hypertension are scarce. The study aimed to assess the relationship between AF and RDW in hypertensive patients. Methods We enrolled 432 hypertensive patients, including 350 AF patients and 82 patients as controls. Patients' demographic, clinical, laboratory and echocardiographic characteristics were recorded. The AF patients were further divided into the persistent and paroxysmal AF subgroups. Electrocardiograms were monitored to identify the cardiac rhythm during blood sampling, and based on the rhythm, the paroxysmal AF group was categorized into the presence (with AF rhythm during blood sampling) and absence (with sinus rhythm during blood sampling) groups. Results The AF group had elevated RDW levels than the controls (12.7% +/- 0.8% vs. 12.4% +/- 0.7%, P = 0.002), and the persistent AF subgroup had higher RDW levels than the paroxysmal AF subgroup (12.9% +/- 0.8% vs. 12.6% +/- 0.8%, P = 0.007). Furthermore, in the paroxysmal AF group, the presence group had higher RDW levels than the absence group (13.0% +/- 0.6% vs. 12.5% +/- 0.9%, P = 0.001). There was no significant difference in RDW levels between the persistent AF subgroup and presence group of the paroxysmal AF subgroup (P = 0.533) and between the absence group of the paroxysmal AF subgroup and control group (P = 0.262). In multivariate regression analysis, in hypertensive patients, the presence of AF rhythm is an independent predictor for increased RDW concentration (P = 0.001). Conclusions The RDW may be associated with the presence of AF rhythm, which implies the importance of maintaining the sinus rhythm in hypertensive patients.