Abstract 505: Stiffness of the Left Atrium Relates to Left Ventricular Diastolic Dysfunction and Late Recurrence After Pulmonary Vein Isolation for Paroxysmal Atrial Fibrillation
Background and Purpose: Stiffness of the left ventricle (LV) is known to relate to myocardial fibrosis and diastolic dysfunction. However, clinical significance of left atrial (LA) stiffness has not been well examined because accurate evaluation is difficult. Evaluation of LA stiffness with reasonable accuracy is now achievable from direct LA pressure and LA strain obtained by speckle tracking imaging (STI) in patients undergoing pulmonary vein isolation (PVI) for atrial fibrillation (AF). This study aimed to measure LA stiffness of patients with AF and to evaluate whether LA stiffness correlates with cardiac function and morphology, serum natriuretic peptides, collagen markers, and late recurrence of AF after PVI.
Methods: We enrolled 114 patients with paroxysmal atrial fibrillation (P-AF) in this study. Patients with systolic dysfunction (LVEF <55%) or significant valve insufficiency were excluded. Plasma levels of BNP, ANP, amino-terminal propeptide of procollagen type III (PIIIP) and carboxy-terminal telopeptide of collagen type I (CITP) were measured just before PVI. Echocardiography was performed simultaneously. LA strain (LAs) during the systolic period was measured by STI. The difference between minimum and maximum LA pressures during the systolic period (ΔLAPs) was directly measured by transeptal puncture. All echocardiographic and hemodynamic data were recorded during sinus rhythm. The ratio of ΔLAPs to LAs strain was used as an index of LA stiffness referencing a previous report with modification.
Results: LA stiffness related to BNP (r = 0.301, p = 0.004), PIIIP (r = 0.186, p = 0.05), left atrial volume index (r = 0.237, p = 0.03), ratio of E/A (r = 0.318, p = 0.003), and ratio of E/e′ (r = 0.312, p = 0.003). During a post-PVI follow-up period of 383±292 days, late AF recurrence occurred in 15 patients (13%). Multivariate logistic regression analysis showed LA stiffness to be an independent predictor of late recurrence of AF after PVI (odds ratio [OR] 36.323, 95% CI 2.390 to 551.976, p = 0.010).
Conclusion: LA stiffness is associated with collagen synthesis, LA dilatation, and LV diastolic dysfunction. LA stiffness reflects progression of LA structural remodeling in patients with P-AF and predicts late recurrence after PVI.