Cardiovascular Journal of Africa: Vol 32 No 5 (SEPTEMBER/OCTOBER 2021)

CARDIOVASCULAR JOURNAL OF AFRICA • Volume 32, No 5, September/October 2021 264 AFRICA followed up for periods of time before presentation to surgery. It is however, postulated that rheumatic valve disease progression in the developing world is characterised by considerably shorter latent phase periods, likely due to recurrent carditis. 9 Several studies reported a predominance of rheumatic heart disease among females, 3,11,12,14,15 with 68% being female in the study by Sliwa et al ., 6 66% in that of Kim et al ., 11 58% in that of Faheem et al . 12 and 81% in the study by Yau et al . 14 Findings from the current study, although reporting only on mitral valvular disease, also showed female predominance, with 58% of the patients being female. The reason for female predominance has not been explored in previous studies, 4,6,15 and may have been coincidental. Outcomes of the current study showed that 75% of study patients were in the black population. Although the finding of predominance in the black population in rheumatic heart disease has been shown before, a direct link between race and high incidence of rheumatic heart disease has not been established. 2,3,16-19 An argument for the influence of poor socio- economic conditions may however be made. This link to low socio-economic status has been made previously. 19 The majority of black South Africans live in impoverished areas of South Africa, which may indicate a link with the high prevalence of rheumatic heart disease in this population. 2,3,16-19 The link between high rheumatic heart disease rates and poor socio-economic status is supported by Hofer et al ., 19 who noted that the highest rates of disease were in Aboriginal Australians from poor indigenous areas. In addition, Gosh et al ., 18 in their review article in 2011, also reported high rheumatic heart disease prevalence in a poor rural region of eastern India. Arrhythmias, congestive cardiac failure, infective endocarditis and pulmonary hypertension are common complications of rheumatic heart disease. 14,19-25 In the current study, 45% of study patients presented with arrhythmias. This was, however, less than that seen in an epidemiological non-surgical Ugandan study in which 64% of patients had arrhythmias at initial presentation. 24 Okello et al . 24 also reported that 35% of their Ugandan study patients presented with decompensated cardiac failure. In the current study, a higher rate (49%) of patients presented for surgery in congestive heart failure. Only 12% of study patients within this study presented with infective endocarditis. This was much lower than those in the study by Koegelenberg et al ., 25 which found 51% of their patients presenting with infective endocarditis at Tygerberg Academic Hospital, Cape Town, South Africa in 2003. The mean (SD) PAP in the current study was 57 (20) mmHg overall and the majority of the analysed and stratified study patients presented with moderate to severe pulmonary hypertension (PHT) (84% in MR and 97% in MS). This has critical clinical implications as peri-operative PHT is linked to increased complications and high rates of mortality peri- operatively. 6,21 Jiang et al. 6 found a gradual but significant increase in in-hospital mortality rates as PAP levels increased in middle- aged and aged patients [mean (SD) age 57 (6) years] diagnosed with rheumatic mitral disease, undergoing valve-replacement surgery. They found that PAP > 52.5mmHg had a sensitivity of 60.3% and specificity of 67.7% in predicting in-hospital death (area under the curve = 0.672, 95%confidence interval: 0.602– 0.743, p < 0.001). They also showed that patients with PAP > 52.5mmHg had higher one-year mortality rates after surgery than those without ( p < 0.001). 6 Pre-operative renal and liver function assessment is important as pre-operative creatinine levels > 2–4 mg/dl (176–352 mmol/l) in patients scheduled for valve procedures have been identified as risk factors for the development of acute renal failure post open- cardiac surgery. 26 Sabzi and Faraji 27 reported an overall hospital mortality rate of 54% in a prospective study carried out on patients who developed liver failure secondary to cardiac failure. The current study found that pre-operative urea and creatinine levels and liver function tests were normal for all study patients who had data. The 2014 (updated in 2017) AHA/ACC guidelines for valvular heart disease include the description of the dominant lesion, left atrial size, pulmonary artery pressures, LVESD and LVEF as echocardiographic parameters for staging of severity in rheumatic valvular heart disease. 9,10 Rheumatic MR appears to be predominant in African countries, as evidenced by studies conducted in the savannah in Nigeria, Soweto in South Africa, and a tertiary institution in Uganda, which reported MR predominance of 37% (the study reported mixed mitral valve as a separate group), 59 and 68%, respectively. 3,24,28 The current study also found MR to be predominant, as 53% of study patients were shown to have this lesion on echocardiography. The decision for early or late surgical intervention in patients with asymptomatic MR remains controversial. 29-31 Tribouilloy et al. 30 noted that ‘early surgical intervention is a reasonable consideration in asymptomatic patients booked for mitral regurgitation correction. However, clinicians are hesitant to recommend surgery in patients with no or minimal symptoms for fear of exposure to operative mortality and morbidity.’ The AHA/ACC guidelines suggest that primary MR, being a mechanical leaflet problem, requires a mechanical surgical solution. ‘The goal of therapy in MR is to correct it before the onset of left ventricular systolic dysfunction and the subsequent adverse effect on patient outcomes’. 9 The overall mean (SD) left atrial size of patients in the current study was severely enlarged at 53 (11) mm, placing them at risk of developing complications. Enlarged left atrial size on echocardiography results in significant complications such as atrial fibrillation, stroke and heart failure. 32-34 Reed et al ., 35 in their study on pre-operative predictors of postoperative cardiac-related mortality concluded that (1) measures of both left ventricular systolic function and left atrial size are equally important in predicting postoperative cardiac-related mortality in patients with symptomatic chronic MR undergoing mitral valve replacement; (2) left atrial size may be important because it reflects the ‘history’ (severity and duration) of MR. 35 LVEF and LVESD are good predictors of postoperative left ventricular function and can be used as objective markers to decide on timing of surgery in patients with MR. 29 In the current study, 49% of MR patients presented with LVEF > 60% and 45% presented with LVESD < 40 mm. Class 1 evidence for primary MR from the AHA/ACC guidelines suggests that the goal of therapy in MR is to correct it before the onset of left ventricular systolic dysfunction and the subsequent adverse effect on patient outcomes. 9 It is deemed ideal to operate prior to indications of systolic dysfunction (LVEF ≤ 60% or LVESD ≥ 40 mm). The