Left Ventricular Dimension after Mitral Valve Surgery in Rheumatic Mitral Stenosis: the Impact of Myocardial Fibrosis

Abstract

Background: Patients with rheumatic mitral stenosis (MS) experience changes in left ventricular (LV) dimensions after mitral valve surgery. We sought to investigate changes in LV dimensional parameters after mitral valve surgery and find out whether the same changes occurred in different extents of myocardial fibrosis. Methods: This prospective observational study comprised 43 patients with rheumatic MS planned for mitral valve surgery between October 2017 and April 2018 in National Cardiovascular Center Harapan Kita (NCCHK) Jakarta. All the patients underwent cardiac magnetic resonance imaging based on the late gadolinium enhancement (LGE) protocol for myocardial fibrosis assessment prior to surgery. The patients were classified according to the estimated fibrosis volume considered to influence hemodynamic performance (myocardial fibrosis <5% and myocardial fibrosis ≥5%). Serial transthoracic echocardiographic examinations before and after surgery were performed to detect changes in LV dimensional parameters. Results: This study consisted of 31 (72.1%) women and 12 (27.9%) men at a mean age of 46±9 years. The LGE protocol revealed myocardial fibrosis of less than 5% in 32 (74.4%) patients. A significant increase was detected in the LV end-diastolic diameter postoperatively, specifically in the patients with myocardial fibrosis of less than 5% (44.0±4.8 mm vs 46.6±5.6 mm; P value=0.027). A similar significant increase was not found in the other group (45.0±6.6 mm vs 46.7±6.9 mm; P value=0.256). Other changes in echocardiographic parameters showed similar patterns in both groups. Conclusion: Our patients with rheumatic MS who had myocardial fibrosis of less than 5% demonstrated better improvements in terms of increased preload. Myocardial fibrosis of less than 5% is associated with more favorable improvements in LV geometry.