CARDIOVASCULAR JOURNAL OF AFRICA • Volume 35, No 2, May – August 2024 AFRICA 93 shown that rheumatic MVD inherently has a predilection for females.1,18 It is uncertain whether RHD prevalence is due to more vulnerability to developing an auto-immune response after Streptococcus pyogenes infection or whether social factors, such as involvement in parenting, leads to an increased susceptibility.9 RHD often becomes apparent during pregnancy, especially with stenotic lesions, because of its associated higher cardiac output.9 This may explain the younger age of patients with MS in the current study. Risk factors for RHD include age, gender and numerous environmental factors, as reported by Carapetis et al.9 With regard to age, the peak prevalence of RHD occurs in the second and third decades of life.19 This is in contrast to the findings of this study, where the peak prevalence ranged between 30 and 70 years of age. The aforementioned findings can be attributed to the decline in cases of acute rheumatic carditis, which has a predilection for younger patients, as opposed to chronic rheumatic MR, which is now commonly seen in older RHD patients due to a decline in ARF. MR is generally well tolerated with fewer complications than in MS patients and therefore patients can live longer with MR and are likely to have delayed presentation. Furthermore, better access to healthcare and advances in medical therapy for HF serves to stabilise the disease process, therefore prolonging the time to decompensated HF.20 In this study, severe LV systolic dysfunction (LVEF < 40%) occurred in very few MR patients, however 48% of the MR patients had LVEF < 60%, which heralds the onset of LV systolic dysfunction in this subgroup.21 Eighty-two per cent of patients in this research group suffered with moderate to severe MVD. These findings were consistent with studies from developing countries.5,6 In the current African population, MVD was complicated by multiple co-morbidities such as older age, being overweight, RVD reactive and hypertensive, which makes it challenging to assess severity of MVD and aetiology of LV dysfunction in these patients. This is exemplified by cases where a high afterload from hypertensive heart disease results in overestimation of MR severity. In patients with co-existing RVD and chronic severe MR, it can be difficult to elucidate the predominant aetiology of LV systolic dysfunction. Therefore, a careful assessment is required that considers the confounding effects of these co-morbidities on LV function in patients with MVD. The current study had a higher prevalence of myxomatous degenerative MVD (6%). This was greater than previously reported by Sliwa et al.,1 where myxomatous disease of the MV was noted in three cases only. This is likely due to more accurate diagnosis of this condition as a result of evolution in echocardiographic imaging with better image resolution. Furthermore, the older age of the current study patients may partly explain the increase in degenerative myxomatous disease.22 In contrast to the study by Sliwa et al.,1 we did not observe any cases of calcific degenerative disease. In this study, none of the patients who underwent a diagnostic coronary angiography had coronary artery disease (CAD). This is in line with the findings from a recent study by Meel et al.23 In that study, a low prevalence of CAD was reported among patients undergoing valve replacement,23 and the value of routine coronary angiography prior to surgery in VHD patients was also questioned. IE (3%) was rare in this study group. This is likely an underrepresentation as the majority of these patients are sick and undergo emergency or urgent surgery soon after admission and therefore are not seen in an out-patients clinic setting. Most of the patients were in the NYHA II functional class (54%). Patients suffering with chronic HF and NYHA III and IV functional class have poorer outcomes.24,25 Eighty-one per cent of patients in this research group had a preserved LVEF and all were on HF therapy. The majority of patients with MVD were on loop diuretics (95%), beta-blockers (76%) and angiotensin converting enzyme (ACE) inhibitors (43%) compared to the findings of Sliwa et al.1 Cardiac-specific treatment was better prescribed compared to the findings of the aforementioned study,1 where loop diuretics, ACE inhibitors, beta-blockers and aldosterone inhibitors were prescribed in 57, 26, 22 and 14% of cases. Despite being on medical therapy, a large proportion of patients in this study were symptomatic. This brings to the fore the advanced nature of disease in this population, likely a result of delayed medical attention, delayed diagnosis and limited resources. Twenty-two per cent of the patients had more than one HF-related admission. This translates into increased morbidity and mortality rates associated with HF secondary to VHD.26 There is also an associated economic burden with repeated HF admissions to CHBAH. Facility fees for a patient at CHBAH, besides all other costs related to the HF admission, can range anywhere between ZAR135 and ZAR733 per night.27 In a study by Ogah et al.,28 the total cost for one HF patient per year equated to US$1 260. Interestingly, despite a large burden of RHD, no cases of ARF were reported in this study. Only 11% of patients took penicillin prophylaxis. This is likely due to their older age and patients were therefore past the window period for ARF prophylaxis.14 The decline in ARF is largely related to the general epidemiological transition to more degenerative diseases in our society and improved socio-economic status with better access to healthcare.29 The other possible explanation of this perceived decline in rates of rheumatic fever may be due to under-reporting of rheumatic fever in South Africa.30 In this study group there was a significant time delay prior to surgical intervention. Currently, all state patients are being operated on at a single tertiary hospital in Gauteng with limited resources. This results in delayed definitive surgical management of these patients, with the resultant increase in morbidity and mortality rates, and further burdening of an under-resourced healthcare system. This highlights the dire need for an on-site cardiothoracic surgery service at CHBAH, the largest healthcare facility in the southern hemisphere.1 Study limitations The main limitation of this study was its short duration and, in part, reliance on collection of data from patient files. Some patients were excluded from the study due to missing information or incomplete data-collection sheets. It was not possible at times to get the missing patient information as the files are kept with the patients themselves. In severe MR, a LVEF < 60% is an indication for surgery in symptomatic patients. Therefore, the EF classification used in this study is a limitation as some MR patients, classified as a preserved LVEF of > 50%, actually qualified for surgery. Few patients had systematically documented coronary angiography findings. The
RkJQdWJsaXNoZXIy NDIzNzc=