Mitral Valve Replacement and Remodeling of the Left Ventricle in Dilated Cardiomyopathy with Mitral Regurgitation: Initial Results

Abstract

Objective -This study evaluated the effects of a new method of mitral valve replacement on left ventricular (LV) remodeling and heart failure functional class. Methods -Eight patients (6 men) Original ArticleFunctional mitral insufficiency (FMI) is not a rare complication of advanced dilated cardiomyopathy (DCM). It reflects changes in left ventricular (LV) geometry, the subvalvular apparatus, the mitral valve area and transvalvular pressures. Patients with DCM and FMI have refractory congestive heart failure and high mortality when in functional class (FC) III or IV. Blondhein et al 1 reported survival rates over 32 months of 59% in patients with DCM without FMI, 26% in those with DCM and discrete FMI, and 17% in patients with DCM and moderate-to-severe FMI.Although heart transplantation is the standard treatment for advanced DCM, the few available donor hearts are insufficient to supply all patients awaiting the organ. Stevenson et al 2 reported a mortality rate of 46% per year in patients with an indication for cardiac transplantation who were waiting for a donor. Others are excluded from the organ waiting list because of advanced age or clinical contraindications.Alternatives to heart transplantation have been proposed to improve quality of life and decrease mortality in these patients. FMI reflects the worst clinical evolution of DCM, and 2 techniques have been used to correct it. The first technique, mitral valve reconstruction, was proposed by Bolling et al 3 . This technique involves reduction of the dilated mitral annulus, thus, LV remodeling because of a decrease in the base diameter. The second technique, mitral valve replacement, was proposed by Buffolo et al 4 . This technique corrects valvular insufficiency and decreases LV base diameter. It involves implanting a small-diameter prosthesis and anchoring the 2 anterior valve hemileaflets, with their respective chordae tendineae, to the mitral annulus to assist the remodeling process.We used mitral valve replacement to treat patients with DCM and FMI in this study. Our primary objective was to evaluate the short-term effects of valve replacement with new positioning of the chordae tendineae on LV remodeling and FC. First, we altered the subvalvular apparatus to isolate 4 pillars with chordae tendineae, 2 from the anterior leaflet

Substituição valvar mitral com papilopexia cruzada e constrição anular em pacientes com insuficiência cardíaca

“…The absence of operative mortality and mechanical ventricular assistance mechanism presented in this study, compared with the other papers previously mentioned [14][15][16][17][18][19][20][21][22][23], may be explained by the fact that the crossing of the papillary muscles has allowed for left ventricular diastolic containment. Similarly, the annular constriction due to the implantation of an undersized prosthesis promotes the base ventricular remodeling, allowing improvement of cardiac performance.…”

“…The higher survival rates shown in this study compared with other mitral valve approaches forementioned [14][15][16][17][18][19][20][21][22][23] is probably due to the immediate improvement of ventricular performance in short-term (this factor may be considered to be a predictor of increased survival). It is possible that in a long-term follow-up, this improvement of ventricular performance can be a determining factor in increased survival rates.…”

“…A new possibility then arose: surgically approaching the mitral valve in patients with severe left ventricular dysfunction in order to improve ventricular performance. This possibility may be included in the surgical and therapeutic tools to combat advanced heart failure [14][15][16][17][18][19][20][21][22][23].…”

“…Some authors [14][15][16][17][18][19][20][21][22][23] have shown that the correction of mitral valve insufficiency in patients with severe left ventricular dysfunction -whether due to valvuloplasty or to valve replacement with preservation of subvalvar apparatus -was associated with low operative mortality and improves survival in the short-and mid-term.…”

Tratamento cirúrgico de pacientes com insuficiência cardíaca: revascularização miocárdica, reconstrução ventricular, cirurgia valvar mitral

“…Through the implant of prosthesis in A-V position, the mitral insufficiency is repaired, the mitral ring is remodeled and the parallelism of the papillary muscles is restored 20 . This technique has been modified and applied by others 21,22 .…”