Left atrium size and red cell distribution width predict atrial fibrillation progression from paroxysmal or persistent to permanent.

Objective: Stratifying patients with paroxysmal or short-term persistent atrial fibrillation (AF) who are at greater risk of developing permanent AF is challenging. Aim of our prospective study was to evaluate association of laboratory parameters (biochemistry and complete blood count (CBC)) together with standard demographic, clinical and echocardiography parameters, with AF progression.Methods: We prospectively recruited 579 patients with AF and divided them into two groups at index hospitalization: paroxysmal or persistent (non-permanent AF), and long-term persistent or permanent AF patients (permanent AF). Clinical, echocardiographic, and relevant CBC parameters were collected. Non-permanent AF patients were selected for follow-up, with a median follow-up time of 21 months. Endpoint was progression to permanent AF.Results: Out of 409 patients with non-permanent AF, 109 (26.6%) progressed within follow-up. In a multivariate Cox regression model only increased left atrium (LA) diameter (HR 2.16, 95% CI 1.20-3.87, p = 0.010), and increased red cell distribution width (RDW; HR 1.19, 95% CI 1.03-1.39, p = 0.022) showed significant independent association with progression. There were 221/409 patients with both LA ≤45 mm and RDW level ≤14.5% who progressed at a rate of only 17.6%, and showed relative risk of AF progression of 0.47 (95% CI 0.34-0.67; p < 0,001).Conclusion: Together with LA size, RDW was independently associated with AF progression. Patients with both LA size ≤45 mm and RDW level ≤14.5% are most probably the best candidates for rhythm control strategies.