A cross-sectional study of patients with prosthetic mitral valves at a tertiary centre in Johannesburg, South Africa

Background. There is a high incidence of rheumatic valvular heart disease involving the mitral valve in Soweto, Johannesburg. Many of these patients go on to have mitral valve replacement (MVR). Data regarding clinical and echocardiographic characteristics of patients with prosthetic mitral valves are scarce in South Africa. Objective. To document the clinical and echocardiographic profiles of contemporary patients with MVR. Methods. Clinical, electrocardiographic and echocardiographic data in these patients were collected prospectively from March 2020 to August 2021 at Chris Hani Baragwanath Academic Hospital prosthetic valve clinic. Results. The study included 186 participants with a median (interquartile range (IQR)) age of 52 (41 - 60) years. Of these, 96% were of black African ethnicity (79% female). The median (IQR) body mass index (BMI) among participants was 27 (23.5 - 30.4) kg/m2, with 29% of participants classified as obese (BMI >30 kg/m2). Eighty-two percent of patients had New York Heart Association class 1 dyspnoea. The most common complications were atrial fibrillation (AF, 39%), heart failure (HF, 25%) and stroke (13%). There were two cases of previously documented prosthetic valve thrombosis, two cases of prosthetic valve endocarditis, two of paravalvular regurgitation and one with structural valve deterioration. Seventy percent of patients had subtherapeutic international normalised ratios (INRs), with a median (IQR) INR of 2.55 (2.03 - 2.92). Forty-seven percent of patients had a left ventricular ejection fraction (EF) of <40%. Seventy-four percent of participants were on some combination of guideline-directed medical therapy for HF with reduced EF, although only 12% were on at least three medications. Pulmonary hypertension was present in 37% of patients, with a median (IQR) pulmonary artery systolic pressure of 28.5 (17 - 41) mmHg. Tricuspid annuloplasty ring was noted in a minority (12 patients). Conclusion. The contemporary patients with MVR were middle-aged obese females with significant AF burden, residual left ventricular dysfunction that was suboptimally managed, and subtherapeutic INR.