Efeito da valvuloplastia mitral percutânea sobre a complacência do átrio esquerdo em pacientes com estenose mitral reumática

Abstract

Introduction: Percutaneous mitral valvuloplasy is the standard treatment option for severe mitral stenosis (MS). Its effects on several prognostic markers of MS such as mitral valve area and transmitral pressure gradient are well known. Recently there has been new evidence about left chambers compliance as an important parameter for prognosis is MS. The effects of the PMV on these parameters are not estabilished. The objective of this study was to determine the response of the left atrial and left atrioventricular compliance to the PMV as well as to define if these changes have any effect on the patients functional capacity. Methods: Ninety-four patients with severe MS and indication for PMV in the Hospital das Clínicas da UFMG were enrolled in the study. All the echocardiographic and hemodynamic parameters were recorded before and after the valvular dilatation. The change in left chambers compliance was correlated with the improvement in functional status. Results: The procedure improved significantly the mitral valve area and the transmitral gradient pressure and we also observed significant reduction of the left atrium pressure and the pulmonary artery pressure. In the overall population, the left atrial and the left atrioventricular compliance improved significantly from 6.79 [4.57- 9.23] to 12.69 [7.34-26.88] (p<0.001) and 2.82 [2.02-4.08] to 3.21 [2.33-4.66] (p<0.001). The left ventricular compliance did not change significantly. These effects were observed only in the patient where the procedure was successful. The improvement in the left atrial compliance correlated with the improvement in the functional capacity (adjusted odds ratio [OR] 0.67; 95% confidence interval [CI95%] 0.45 to 0.97; p=0.036), after adjusting for immediate procedural results, including postprocedural mitral valve area, systolic pulmonary artery pressure, mean transvalvular gradient and mitral regurgitation. Conclusions: The PMV improved significantly the left atrial and left atrioventricular compliance and this was correlated to the improvement of the symptoms in a 6 month follow up. These effects were regardless of the effects on other parameters of the severity of MS.