Abstract 18622: Effects of Percutaneous Mitral Balloon Valvuloplasty on Left Atrial Compliance
Introduction: Percutaneous mitral balloon valvuloplasty (PMV) is the treatment of choice for patients with symptomatic mitral stenosis (MS). Rapid improvement in symptoms and hemodynamic parameters can be observed after increasing mitral valve area and decreasing left atrial pressure. However, left atrial pressure has been shown to be influenced by both MS severity and left atrial compliance (Ca). The effects of PMV on Ca are still relatively unknown. The aim of this study is to define the immediate effects of PMV on Ca and to identify factors influencing the changes in Ca post PMV in patients with MS.
Methods: We enrolled patients in our institution with MS who underwent successful PMV from December 2012 to May 2014. Transthoracic echocardiography was performed in all the patients pre and 24-h post procedure. PMV was performed by the Inoue technique, guided by echocardiography. Gas analyzes of blood samples from aorta and pulmonary artery were obtained and pressure tracings were recorded from aorta, left ventricle and left atrium before and after the balloon dilation in order to calculate cardiac index and the left atrial compliances.
Results: Sixty- one patients were enrolled in the study. The mean age was 45 ± 12 years, 84% were female. The mean mitral valve area (MVA) pre procedure was 0.96 ± 0.25 cm2. After the PMV we observed a significant decrease in mPAP (35.1 ± 12.4 mmHg vs. 29.6 ± 9.7 mmHg, p<0.001) and an increase in cardiac output (4.1 ± 1.3 L/min vs. 4.4 ± 1.3 L/min, p<0.001). The median Ca pre procedure was 6.6 [4.5 - 9.2] mL/ mmHg with increase after PMV to 12.4 [6.6 - 22.5] mL/ mmHg (p<0.001). The change in Ca correlated with changes in mitral transvalvular gradient, pulmonary artery pressure, left atrial pressure and pulmonary vascular resistance pre- and post-PMV. Multivariable analysis revealed that the degree of change post PMV in mPAP (p=0.004), left atrial pressure (p= 0.012) and pulmonary vascular resistance index (p=0.001) were independently associated with changes in Ca.
Conclusions: This study demonstrates that successful PMV can significantly increase Ca, which is associated with improvement in cardiac hemodynamics. These results may also provide potential mechanistic insights into the pathophysiology of the hemodynamic changes seen in MS.
Author Disclosures: G.S. Athayde: None. B.R. Nascimento: None. L. Lodi-Junqueira: None. W.M. Esteves: None. J.R. Soares: None. L.A. Dias: None. T.N. Reis: None. L.F. Barbosa: None. T.C. Tan: None. M.P. Nunes: None.
- © 2014 by American Heart Association, Inc.