In patients with atrial cardiomyopathy long-lasting atrial fibrillation is associated with unfavorable structural changes in right chambers and worse outcome

Abstract

Abstract Background The main factor responsible for atrial cardiomyopathy (ACM) is atrial fibrillation (AF). It is known that AF causes remodeling of the left atrium but its effects on the right heart chambers and mortality are not well studied. Purpose To assess the echocardiographic characteristics of patients with atrial cardiomyopathy with long-standing and paroxysmal AF and their impact on survival. Methods From 624 consecutive patients with AF only 173 met the inclusion criteria for atrial cardiomyopathy, defined as severely dilated left atrium with indexed left atrial volume (LAVI) >48 ml/m2, preserved left ventricular systolic function, without significant valvular disease or left ventricular hypertrophy. The mean age of the studied population was 73,7 ± 9,5 years, 59% women. The patients were divided into two groups according to the presence of persistent or permanent AF (long-standing AF) - Group 1 (n = 87) or paroxysmal AF - Group 2 (n = 86). All patients underwent a comprehensive echocardiography with volumetric and speckle tracking analysis on enrollment and were followed for cardiovascular outcomes, including mortality 24 months. Results The group with long-standing AF had more dilated right atrium (indexed right atrial volume- RAVI 41.9 ± 24.4 vs. 33 ± 13.5 ml/m2; P=0.003), lower reservoir strain of the right atrium (13.1% ± 8.6 vs. 19.7% ± 10.6; P<0.001) and lower right ventricular free wall strain (18.1% ±7.3 vs. 21.2% ± 7.1; P=0.006). Over a median follow up of 18 months (7-29) 16 patients (18%) from Group 1 died compared to 6 patients (7%) from Group 2 (P=0.022). The presence of more than mild tricuspid regurgitation (OR 4.53; CI: 2.37-8.67; P<0.001), heart failure (OR 3.44; 95% CI: 1.83-6.48; P<0.001), and long-standing AF (OR 3.00, 95% CI: 1.41-8.09; P=0.028) were associated with worse mid-term survival. Conclusion Patients with ACM and long-standing AF have more advanced structural changes of the right atrium and the right ventricle and worse prognosis. The presence of more than mild tricuspid regurgitation, heart failure, and long-standing AF are predictors of poor outcome.