Diastolic wall strain predicts progression from paroxysmal to persistent or permanent atrial fibrillation in structurally normal hearts

Abstract

BackgroundAtrial fibrillation (AF) is characterized by a progression from paroxysmal to persistent or permanent AF. Recent studies have shown that AF progression is related to a worse morbidity and mortality, and poorer outcomes of radiofrequency catheter ablation (RFCA). We previously showed that left ventricular (LV) compliance assessed by diastolic wall strain (DWS) was a strong determinant of prevalent AF. Methods and resultsWe studied 306 paroxysmal AF patients with structurally normal hearts. The DWS was non-invasively measured with echocardiography. During a follow-up of 35±19 months, AF progression occurred in 60 of 172 (35%) patients treated with medications only (medication group), and 3 of 134 (2%) who underwent RFCA (RFCA group) (p<0.001). In the medication group, patients with a DWS <0.38 had a higher incidence of AF progression than those without (log-rank p<0.001), while the AF progression rate was low irrespective of the DWS in the RFCA group. In a multivariate analysis, the DWS and left atrium volume index (LAVI) were independent predictors of AF progression in the medication group (hazard ratio, 1.13 per 0.01 decrease; 95% CI: 1.08–1.18; p<0.001, and 1.04 per 1mm increase; 95% CI: 1.01–1.08; p=0.012, respectively). In the medication group, AF progression occurred in only 5 of 61 (8%) patients with a DWS ≥0.38, whereas 27 of 40 (68%) with a DWS <0.38 and LAVI >34mL/m2 progressed to persistent or permanent AF. ConclusionsThe LV compliance estimated by the DWS was independently associated with AF progression. The DWS would be useful to stratify patients at risk of AF progression who could benefit from an earlier RFCA intervention.