CARDIOVASCULAR JOURNAL OF AFRICA • Volume 35, No 1, January – April 2024 AFRICA 17 Rheumatic heart disease (RHD) is endemic in Tanzania; recently published data state the prevalence is around 17.9 per 1 000 population.1 In Tanzania, RHD is the third most common cause of heart failure after hypertension and cardiomyopathies, including idiopathic dilated cardiomyopathy, peripartum cardiomyopathy and endomyocardial fibrosis.2 Rheumatic mitral stenosis (MS) in Africa shows a female predominance with presentation early in life.3,4 Patients usually present in New York Heart Association (NYHA) functional class II–III, with atrial fibrillation (28%) and thromboembolic events (3.2%).4,5 Clinically, patients may present with an irregular pulse, normal blood pressure, elevated jugular venous pulse, left parasternal lift and normal apex impulse. Auscultation reveals a low-pitched rumbling diastolic murmur. Transthoracic echocardiography (TTE) is used to confirm the diagnosis, and assess the severity and prognosis of MS. It is used to describe valve morphology, assess valve function and cardiac chambers, and evaluate the feasibility and indications for intervention.6 Transoesophageal echocardiography (TEE) is done to complement TTE pre-intervention, and specifically to rule out left atrial or left atrial appendage thrombus that may not be visible by TTE. Several two-dimensional (2D) echocardiography scoring systems have been created for evaluation of mitral valve anatomy and suitability for percutaneous balloon mitral valvuloplasty (PBMV) without demonstrating superiority,7 including the most commonly used Wilkins score,8 Echo score revisited9 and Cormier score.10 Limitations of the Wilkins score are the inability to differentiate fibrosis from calcification and the underestimation of commissural/subvalvular involvement.11,12 However, the decision to perform PBMV is not solely dependent on the mitral valve score but also on clinical judgment. Studies have shown that in young patients or patients with fewer co-morbidities, PBMV gave a better survival rate despite a mean Wilkins score of 9.5.13 Guidelines recommend PBMV or mitral valve surgery for the management of clinically significant MS.14,15 However, due to limited access to interventional cardiology and cardiothoracic surgery in low- and middle-income countries (LMICs), most of these patients are likely to be managed conservatively.16 In Uganda, Okello et al.17 demonstrated only 8% of patients requiring surgery and 1% requiring PBMV received those services. Instead, only medical therapy, including diuretics, betablockers, digoxin, calcium channel blockers and angiotensin converting enzymes inhibitors were prescribed. However, most of these medications only alleviate some of the symptoms but do not resolve the obstructive valve pathology.18 Additional medical therapy includes anticoagulation, indicated for the history of systemic embolism, thrombus in the left atrium, atrial fibrillation, dilated left atrium (diameter > 50 mm/indexed volume > 60 ml/m2), and those that receive a prosthetic heart valve.6,19 Secondary antibiotic prophylaxis for the prevention of recurrent attacks of acute rheumatic fever and progression of valve lesions is important.20 To optimise the evaluation andmanagement of rheumaticMS, a heart team including cardiology, anaesthesiology, interventional cardiology and cardiothoracic surgery is a necessity.14,15 To guide the choice of intervention (PBMV or surgery), this multidisciplinary approach incorporates clinical assessment, detailed imaging evaluation, procedural risk assessment and scoring systems. PBMV is a safe and cost-effective procedure, and provides excellent short- and long-term outcomes with improved haemodynamics, and symptomatic improvements in appropriately selected patients.6,19,21,22 Currently, most sub-Saharan African countries, including Tanzania, have access to a cardiac catheterisation laboratory and therefore PBMV is a feasible option. In August 2019, visiting teams from the United States started a mission in Tanzania to initiate, enhance and consolidate PBMV skills in the local cardiac interventional team. This study was conducted to determine the profiles of patients evaluated for PBMV due to rheumatic MS at Jakaya Kikwete Cardiac Institute (JKCI) during those workshop missions. Methods This was a prospective, single-centre, hospital-based, crosssectional study of Tanzanian patients who were screened for PBMV at JKCI, the only institute offering the intervention in the country. All consecutive patients who were scheduled for PBMV due to severe rheumatic MS between August 2019 and May 2022 were enrolled in the study. We excluded patients with unfavourable clinical characteristics and mitral valve morphology and those with other forms of non-rheumatic valvular heart disease or other cardiac diseases. Written, informed consent was obtained from all participants over 18 years. Assent was obtained from minors over 13 years of age in the presence of adult witness. For under 13 years, oral consent was provided by the guardian of the minor. The study was approved by the Directorate of Research and Publications of Muhimbili University of Health and Allied Sciences (P. MUHAS – REC-9-2019-059). Permission to conduct this study was obtained from JKCI (AB.157/334/01’A). The sociodemographic, medical and co-morbidity history were obtained from all patients. NYHA functional class, Wilkins score and mortality information were also collected. All patients were clinically evaluated for the evidence of severe MS according to recognised clinical and echocardiographic criteria.14,15,23 Several echocardiographic (SC 2000 Siemens Echo machine), electrocardiographic (General electronic Mac 400) and laboratory parameters were documented. All of the echocardiographic images were reviewed by a heart team that comprised the local team and several members of the visiting team. All TTE was done with the patient in the left lateral decubitus position and with conventional views (parasternal long-axis, short-axis and apical four-chamber view). Two-dimensional and Doppler echocardiographic studies were performed according to the American Society of Echocardiography (ASE) guidelines.24 TEE was also performed as previously described.25 The team took into consideration the following factors, apart fromMVA ≤ 1.5 cm2, when reaching a consensus on management strategy: clinical assessment, such as symptomatic severity and co-morbidities, scoring systems (by Wilkins score) and procedural risk assessment, for example anatomical favourability and clinical favourability (pulmonary hypertension). We used the European Society of Cardiology (ESC) and the American Heart Association/American College of Cardiology (AHA/ ACC)14,15 definition of unfavourable anatomical characteristics: left atrial thrombus, Wilkins > 8, mitral regurgitation > grade
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