Assessment of Left Atrial Function and Remodeling in Patients With Atrial Fibrillation by Performing Strain Echocardiography: A Prospective Study to Assess the Influence of Renin-Angiotensin System Inhibitors on Atrial Fibrillation

ABSTRACT

BACKGROUND AND OBJECTIVES: Renin-angiotensin system (RAS) inhibitors are likely to reduce the development of atrial fibrillation (AF) by preventing atrial fibrosis. We attempted to assess the relevance of strain echocardiography for quantitative assessment of the left atrial (LA) status in AF, its modification by RAS inhibitors and changes of biochemical markers during cardiac remodeling in AF. SUBJECTS AND METHODS: Strain echocardiography is performed 2 times (baseline and 12 month) in 60 patients with AF (RAS inhibitors-used group 30, non-used group 30). In an apical 4-chamber view, the regional analysis consisted of placing the region of interest cursor at the basal segments of the septal and lateral wall of LA. Mean peak systolic and early diastolic strain/rate are measured with LA end-systolic antero-posterior, longitudinal and transverse dimensions. RESULTS: Six patients of RAS inhibitors-used group (group A, 20%) and three patients of non-used group (group B, 10%) were converted to normal sinus rhythm during the study. LA size, E wave velocity, E/E', strain parameters showed no significant differences between groups at the baseline. There were no significant differences in LA size and E wave velocity between groups at the 12 months, however, peak systolic strain/rate were significantly higher in group A (36.71+/-13.63% and 2.98+/-0.59s(-1), p<0.05, respectively) than group B (27.21+/-10.49% and 2.21+/-0.47s(-1)). In addition, peak early diastolic strain/rate were significantly higher in group A (-1.89+/-3.30% and -2.32 +/-0.77s-1 p<0.05, respectively) than group B (-0.83+/-2.79% and -1.77+/-0.25s(-1)). There were no significant differences in C-reactive protein (CRP) and B-type natriuretic peptide (BNP) at the baseline, but BNP were significantly reduced in group A (822.9+/-798.3 pg/mL, p<0.05) than group B (1481.9+/-209.97 pg/mL) at the 12-month follow-up. CONCLUSION: The increased values of atrial peak systolic and diastolic strain/rate after treatment with RAS inhibitors revealed that passive stretching and shortening of LA wall might improve in some patients with AF even before LA size change possibly because of reduced atrial fibrosis and increased compliance. Our results indicated that strain echocardiography provides clinically useful information of LA function and remodeling and treatment with RAS inhibitors appears to preserve LA reservoir function in AF patients without visible LA structural change.