Outcomes of complete mitral valve excision and replacement with tilting disc (TTK Chitra) valve for rheumatic mitral valve stenosis

Background: Mitral valve (MV) disease is one of the earliest diseases of the heart, and rheumatic MV disease is one of the first discovered in the world dating back to the 19th century. Rheumatic heart disease (RHD) is declining in other countries, but it is still prevalent in the rural parts of India especially in lower economic group. In our hospital, we have operated 50 cases of rheumatic mitral stenosis for whom mitral valve replacement (MVR) with tilting disc (TTK Chitra valve) was done. Most of the MV cases have MV score >12 and the subvalvular apparatus was severely affected. In all the cases we have operated, we have excised complete valve and no posterior leaflet preservation or chordal tethering and repair was done. Objectives of the study: To study MVR outcomes with tilting disc TTK Chitra valve and to compare pre- and postoperative valve gradient across tilting disc prosthetic valves and also study the left ventricular (LV) dimensions pre and post MVR and to study ejection fraction (EF) pre and post valve replacement and complications arising from posterior leaflet excision. Materials and Methods: Fifty patients with chronic RHD Chronic Rheumatic heart Disease (CRHD) with severe mitral stenosis were taken up for the study who were operated in this department from May 2016 to April 2019. All the patients were evaluated with 2D echo, electrocardiogram, and coronary angiogram (when they were >35 years old). Results: Out of 50 patients operated in our hospital, 34 were females, that is, 68% of the patients, and 16 patients were males, that is, 32%. As per age, 20 patients were between 41 and 50 years of age, that is, 40% belonged to 41–50 years of age; 39 patients were below 50 years, that is, 78% of patients were below 50 years; 4% are below 20 years; and 22% were above 50 years. As per the combined age and sex ratio also among both males and females, most Mitral Stenosis (MS) presumed below 50 years only. As per the valve area, the most common valve by preoperative echo was 66% below and equal to 1 cm2 by Pressure half time (PHT) and Planimetry. About 60% of the patients had preoperative EF of more than 55% and less than 10% had between 36% and 40%. Preoperatively, 40% of the patients had severe pulmonary arterial hypertension (PAH), 30% of the patients had moderate PAH, and 30% of the patients had mild PAH. All these patients had been operated for MV where posterior leaflet was excised and no subvalvular apparatus was conserved and no chordal repair was done, but apparently no postoperative LV dysfunction was found in these patients. All these patients had taken up for MVR and TTK Chitra valve between 27 and 31 was used. In 70% of the patients, 29 and 31 TTK Chitra valve was used. This study is based on the echocardiographic analysis of the preoperative mean gradient across MV and postoperative mean gradient across MV which shows a considerable, comparable, and acceptable mean gradient postoperatively. Conclusion: Whenever rheumatic mitral stenosis is present, complete valve can be reasonably excised without even sparing or preserving the subvalvular apparatus and it does not affect the EF and LV function. Native tilting disc valve, that is, TTK Chitra valve, can be safely used and it can give comparable results with the recent generation valves. Better outcomes are encountered with 29-mm size and above valves. Pulmonary artery hypertension decreases significantly if mitral stenosis is operated regardless of the advancement of disease process. There is no significant change in the LV parameters, and pre- and postoperatively EF remained the same.