Cardiology

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The changing spectrum of coronary artery disease in black African patients at a tertiary institution : a one year experience.
(2014) Dela, Sapna Shivani.; Naidoo, Datshana Prakesh.
The spectrum of coronary artery disease among Black African patients in South Africa is not completely known. Previous reports have described acute coronary syndrome (ACS) in Blacks as uncommon. Studies have shown that Blacks have milder coronary artery disease compared to other population groups. More recently, reports are showing a rising number of cardiovascular risk factors and myocardial infarction in this population group. There is currently a paucity of local data looking at the growing burden of this disease and the spectrum of presentation in Black African populations. The aim of this study was to describe the spectrum of coronary artery disease in Blacks and determine if there were significant differences in severity and outcome as compared to more usually affected population groups with coronary artery disease. A retrospective chart review of Black African patients with acute coronary syndrome was conducted at Grey’s Hospital, with data obtained over a twenty month period at our tertiary referral centre. Blacks were compared with an equivalent number of Indian and Caucasian subjects presenting with acute coronary syndrome during the same period. The clinical presentation, biochemistry and angiographic findings were examined. The prevalence of acute coronary syndrome in Blacks was similar to Caucasians (17% v. 19%) but lower than Indians (64%). Except for family history (5%), traditional risk factors occurred as frequently in Blacks as in Indians and Caucasians. The prevalence of diabetes mellitus in Blacks (46.8%) was almost identical to Indians (50%). Hypertension (67%) was similar to Indians and Caucasians, but dyslipidaemia (56%) and smoking (41%) was lower among Blacks. Metabolic syndrome occurred as frequently in Blacks as in Indians. Black African patients had comparable coronary vessel involvement to Caucasians (single and double vessel disease), but less three vessel disease (18%). They were more likely to present, ab initio, at a younger age compared to Caucasians, with less preceding angina and with anterior ST segment elevation myocardial infarction. In conclusion, the study shows that Black African patients have become a high risk group with coronary artery disease than previously thought. It shows that coronary artery disease in Blacks is no longer an uncommon problem and that they should be considered a high risk group of patients with a cardiovascular risk that is comparable to Indians and Caucasians. Aggressive screening and treatment of cardiovascular risk factors should be undertaken with the same seriousness as in other usually affected population groups.
Does blood cardioplegia solution cause deterioration in clinical pulmonary function following coronary artery bypass graft surgery?
(2006) Farlane, Tamara Cindy.; Kleinloog, Robert.; Robbs, John Vivian.
Pulmonary dysfunction following cardiopulmonary bypass surgery is a widely explored complication and a multitude of factors have been implicated, including but not limited to: operative trauma; the cardiopulmonary bypass circuit; cardioplegia; the type of donor grafts utilised; anaesthesia and fluid administered. There is a paucity of information regarding the effect of cardioplegia on the lungs. No studies have previously investigated whether allowing cold-blood cardioplegic solution to enter the lung parenchyma, during the period of cardioplegia delivery, has an effect on the clinical outcome of lung function following cardiopulmonary bypass surgery. For this reason an original study was done to determine the effect of preventing cardioplegia from entering the lungs, by evacuating overflow of cardioplegia not drained via the atriocaval cannula, by using a pulmonary artery vent. A total of 403 patients admitted to undergo full cardiopulmonary bypass were screened and 142 patients who fitted the criteria for inclusion and provided informed consent took part in this prospective double blind randomised clinical trial. The control group underwent routine cardiopulmonary bypass grafting. The study group had the intervention of a pulmonary artery vent sutured in position at the time the heart was cannulated for bypass. During cardioplegia delivery the cardioplegia was removed via the atriocaval cannula in the control group (A) and via the atriocaval cannula and the pulmonary artery vent in the study group (B). Aside from this difference, the two groups were managed identically intra- and post-operatively. Outcomes which were compared included eight time measures of arterial blood gases; electrolytes and shunt fraction; bedside lung spirometry measures over five time periods; radiographic measures of atelectasis and effusion over three time points; as well as physiotherapy and hospitalisation requirements. Numerous other potentially extraneous variables were measured and compared in order to monitor homogeneity of the study samples. The consistency of the results within each group throughout the study provides strong evidence that the measurements taken were accurate. The use of standardised equipment and vigilant adherence to the protocol ensured no extraneous deviation. The internal validity of this study was therefore good and accurate. The findings of the study however brought into question a previously accepted belief that the pulmonary artery vent prevents the overflow of cardioplegia, not drained from the right atrium, from entering the lungs. There was no literature or previous studies to confirm or dispute this accepted ‘observation’ by cardiac surgeons that the cardioplegia does enter the lung parenchyma. To therefore validate the findings of the study a further four original studies were designed and initiated. The objective of these studies was to establish the efficacy of the pulmonary artery vent and to determine whether cardioplegia indeed circulates through the lung parenchyma or merely accumulates and ‘pools’. Technetium (Tc-99m), a radio labelled isotope was added to the cold blood cardioplegia solution prior to delivery in order to determine this. In the four sub-studies it was confirmed that the pulmonary artery vent is 90-100% effective in retrieving any cardioplegic solution not drained by the atriocaval cannulae, thus confirming the effectiveness of the pulmonary artery vent in preventing cold blood cardioplegic solution from entering the lungs. The findings of the main study confirmed that respiratory impairment after uncomplicated cardiopulmonary bypass, even in low risk patients, is relatively common, as within each group there was a significant change in outcome measures over time. Inter-group comparisons however showed these changes were not significant, with both groups deteriorating by the same degree post-operatively, therefore establishing that these changes were independent of the intervention of the pulmonary artery vent. In the control group, the cold blood cardioplegia solution that did not drain from the atriocaval cannula entered the lungs and circulated the lung parenchyma during cardiopulmonary bypass. The study group made certain that none, or very little, of the cold blood cardioplegia solution entered the lungs. The main findings of this study are therefore that pulmonary function and gas exchange, although markedly reduced following cardiac surgery, are not affected by placement and suctioning via a pulmonary artery vent during the time of cardioplegia delivery intraoperatively. Furthermore, these studies strongly suggest that cold blood cardioplegia solution is innocuous to the lungs
Echocardiographic features of the complications of infective endocarditis, with special reference to patients with HIV.
(2008) Nel, Samantha Heidi.; Naidoo, Datshana Prakesh.
Purpose: The aim was to determine the echocardiographic features of patients with infective endocarditis, and to compare the findings in HIV positive versus HIV negative patients. Methods: This was a prospective study, conducted over three years using the modified Duke criteria in diagnoses. A control group of age-matched patients with clinical and echocardiographic evidence of valvular regurgitation, who did not satisfy the criteria and who underwent surgery was used in comparison. Results: During this period 91 patients were screened for infective endocarditis. 77 satisfied the criteria for a definite diagnosis of IE. Blood cultures were positive in 46% cases. The commonest organism was S. aureus. Most patients had advanced valve disruption with heart failure and a high peri-operative mortality. The clinical features in the two groups of patients was similar. The incidence of echocardiographic complications was 50.6% in the whole group. Except for leaflet aneurysms in four HIV positive cases, complications were not more frequent in this group. Conclusion: There was a high rate of culture negative cases in this study, probably related to prior antibiotic usage; in this setting the modified Duke criteria have diagnostic limitations. There was no difference in the clinical presentation of infective endocarditis between HIV positive and HIV negative patients. Leaflet aneurysms were more common in the HIV positive patients.
The echocardiographic manifestations of an urban, working class community with a high cardiovascular risk profile.
(2013) Prakaschandra, Dorcas Rosaley.; Naidoo, Datshana Prakesh.; Gordon, Michelle Lucille.
The metabolic syndrome (MS), consequent upon the pandemic of obesity and diabetes, is associated with an increased risk for cardiovascular (CV) disease. Development of sub-clinical cardiac structural and functional changes associated with CV disease risk factors may be detected on echocardiography. The extent to which these structural changes and CV risk factors are dependent on genetic factors is not clearly established. This project was designed to investigate the relationship between CV disease risk factors, cardiac structural and functional changes and underlying genetic abnormalities. Specifically, the risk factor profile and the presence of the MS were determined. This was then correlated with the echocardiographic findings and gene polymorphisms. Method: A randomly selected cohort of 1428 subjects from the Phoenix community was studied. Demographic data was collected using the WHO STEPS instrument. Blood samples for biochemistry and genetic analysis, together with anthropometric measurements, were collected. Blood pressure and echocardiography was performed on all subjects. The metabolic syndrome was classified according to the National Cholesterol Education Panel (NECP) Adult Treatment Panel III (ATP III) and International Diabetes Federation (IDF) criteria. The Lipoprotein Lipase and Human Paraoxonase-1 genes were genotyped on a Light Cycler 480 Real-Time PCR instrument, using allele-specific probes and sequencing. Results: There was a high prevalence of CV risk factors in this sample; particularly increased waist circumference (79%), obesity (64%) insulin resistance (58%) and hypertension (50%) across the age groups. This translated into a high prevalence of MS (38% using NCEP ATPIII and 46% using IDF criteria). There were significant echocardiographic differences between subjects with and without MS for chamber dimensions (p<0.001), left ventricular wall thickness (p<0.001) and mass (p<0.001), diastolic indices (E-wave {p<0.001}, trans-mitral ratio {p=0.017}) and sub-epicardial adipose tissue (SEAT) thickness (p<0.001). Stepwise multivariate analysis identified age (95% CI 0.975; 0.998), gender (95%CI 0.48; 0.9) and hypertension (95% CI 0.53; 0.99) as independent risk factors for diastolic abnormalities. Logistic regression identified age as the most significant contributor to diastolic abnormalities (OR=1.02; 95%CI 1.009; 1.03; Wald=13.4), followed by the waist circumference (OR=1.025; 95%CI 1.014; 1.037) and BMI (OR=1.075; 95% CI 1.035; 1.117). Genetic analysis showed significant associations between the heterozygous variant of Q192R genotype (PON-1 gene) and elevated HDL levels and also between this variant and obese women (p= <0.05). Conclusion: The high prevalence of CV risk factors and MS in this community has reached epidemic proportions. Although the MS was associated with significant remodelling of cardiac structure, alteration of diastolic indices and increased sub-epicardial adipose tissue thickness, BMI and waist circumference were stronger promoters of altered cardiac physiology. This augurs poorly for this population group unless intervention is introduced to address the markedly high prevalence of these culprit drivers.
The effects of HIV/AIDS on the clinical profile and outcomes post pericardectomy of patients with constrictive pericarditis : a retrospective review.
(2016) Laurence, Graham.; Naidoo, Datshana Prakesh.
Constrictive Pericarditis (CP) is an uncommon condition which is a known treatable cause of heart failure. It is a condition that affects people from both developed and developing countries. In developed countries the aetiology of CP has undergone a paradigm shift away from infectious causes such as tuberculosis to acquired causes such as previous cardiac surgery and mediastinal radiotherapy for cancer. In the developing world by far the commonest cause remains tuberculosis. All aspects of CP have been widely studies in developed countries however there is limited data and studies on the condition from developing countries and more specifically African countries where tuberculosis is endemic. In South Africa the HIV/AIDS pandemic in association with persistent widespread poverty and poor socio-economic conditions has ensured that the incidence of tuberculosis infection remains exceedingly high. There have been numerous studies done evaluating the incidence, pathophysiology and treatment of tuberculous pericarditis in the HIV era. There however very limited data available describing CP in a South African setting. The objectives of this single centre study are to contrast the clinical profiles; surgical outcomes and short term follow up of patients diagnosed with CP at Inkosi Albert Luthuli Hospital. Through this study we hope to gain insight into the effects of HIV on patients with CP and determine whether it has any influence on the natural history and outcomes when compared to HIV uninfected individuals. It is hoped that information gained from this study will serve to further assist medical professionals in their understanding of CP and aim to improve both our management of patients with this debilitating condition and ultimately there life expectancy. In addition it is hoped that that study might serve as a catalyst for larger prospective studies in this field. Results missing (abstract) i.e aim, method, conclusion.
Genetic contribution to the risk for metabolic syndrome : an investigation of candidate gene polymorphisms related to lipid and carbohydrate metabolism.
(2015) Maistry, Tanya.; Gordon, Michelle Lucille.; Naidoo, Datshana Prakesh.
Abstract available in PDF file.
Observations on the effects of some environmentally induced mental stresses on the heart.
(1973) Meeran, Mooideen Kader.
No abstract available.
The outcome of patients undergoing simultaneous tricuspid and left-sided valve surgery in a rheumatic population.
(2014) Munasur, Mandhir.; Naidoo, Datshana Prakesh.
Background In the context of endemic left-sided rheumatic heart disease, tricuspid valve disease requiring surgical intervention merits closer scrutiny in order to analyse surgical outcomes with presently employed techniques. Aims To evaluate the results of simultaneous tricuspid valve surgery for severe functional tricuspid regurgitation in rheumatic heart disease at the time of left-sided valve surgery. Materials and methods A retrospective analysis of the perioperative and follow-up data of 30 patients who underwent tricuspid valve surgery with concomitant mitral and/or aortic valve replacement between July 2003 and December 2011 was undertaken. Patients referred for left-sided valve replacement surgery with clinically and echocardiographically documented severe functional tricuspid regurgitation in the presence of tricuspid annular dilatation, were submitted for combined valvular procedures. Outcomes were analysed by evaluation of the perioperative and 2-year follow-up clinical and echocardiographic data. Results There was a statistically significant improvement in the following parameters at 6 weeks postoperatively: New York Heart Association functional class, tricuspid annular diameter (p 0.001), pulmonary artery systolic pressure (p 0.001), severity of tricuspid regurgitation (p<0.001) and tricuspid transvalvular gradient (p 0.004). Preoperative (p 0.013) and postoperative pulmonary hypertension (p<0.002) were demonstrated to be associated with the development of major adverse cardiovascular events. There were no identifiable predictors for the development of severe residual postoperative tricuspid regurgitation. The development of severe residual postoperative tricuspid regurgitation was not associated with the occurrence of major adverse cardiovascular events. The technique of tricuspid valve repair did not impact on the occurrence of major adverse cardiovascular events or on the development of severe residual postoperative tricuspid regurgitation. A satisfactory outcome was observed in 40% of the study population. Conclusion The immediate results of tricuspid valve surgery for severe functional tricuspid regurgitation in rheumatic heart disease favour surgical intervention. However, the persistence of severe tricuspid regurgitation adversely influenced long-term outcomes. Therefore, the management of rheumatic patients with functional tricuspid regurgitation should encompass surgical strategies which result in a lower incidence of severe residual postoperative tricuspid regurgitation.
Relationship of body anthropometry with cardiovascular risk factors in a random community sample in Phoenix, KwaZulu-Natal.
(2014) Duki, Yajna.; Naidoo, Datshana Prakesh.
Abstract available in print copy.
The role of genetic factors in early onset coronary heart disease in the Natal Indian.
(2000) Naidoo, Datshana Prakesh.; Chetty, R.; Sharma, Arya.
Objective: To determine the role of candidate gene polymorphisms in patients who sustained myocardial infarction at a young age and examine their relationship, if any, to risk factors. Since angiotensin II is known to play a pathophysiological role at the myocardial and vascular level, the genes to be studied are those regulating the renin angiotensin system and tissue metabolism. Design: The risk factors and genetic profile is described in 117 young Indians with myocardial infarction recruited over a period of thirty months (Dec 1997 - Jun 1999). Controls comprised 80 normal subjects with no clinical evidence of coronary heart disease (CHD) and with a normal effort response. The key features of this study are the selection of young subjects with myocardial infarction, (mean age 43 ± 6.8 years) in whom the possibility of a genetic basis for the disease was felt to be more likely since the confounding effect of age as a risk factor was reduced. Setting: Patients recruited 3 -12 months after myocardial infarction from Addington Hospital, Durban. This hospital subserves the Indian community in the north of Durban. The majority of patients were from the Phoenix settlement area. Results: 1. The clinical profile of the young Indian with myocardial infarction is a young man, slightly overweight with a high prevalence of risk factors, particularly smoking and diabetes, coupled with sedentary behaviour and risk-prone dietary patterns characterised by high red meat intake and low fruit and vegetable consumption, resulting in increased BMI and W/H ratios. 2. There were no differences in the patterns of gene polymorphism in the reninangiotensin system between the study and control groups. This finding extended across all candidate gene loci studied i.e. those involving aldosterone, G-protein, TGF-B and homocysteine metabolism. Serum triglycerides, haemoglobin AlC and urine microalbumin levels were elevated in the probands together with low HDL-C levels (p = 0.001). 3. A striking finding of this study was the substantial proportion of patients found to have diabetes mellitus, totalling 47% of the proband group. Of the 53 diabetic patients, (45 males and 8 females) four (3 males, 1 female) had impaired glucose tolerance. Cigarette smoking, a positive family history of hypertension/diabetes and a family history for premature CHD emerged as important risk predictors for MI. Conclusion: This study, the first to report candidate gene polymorphisms in young Indians with coronary heart disease, has shown no obvious association between the genetic loci studied and acute myocardial infarction. Instead a high prevalence of risk factors, particularly smoking and diabetes mellitus, coupled with coronary-prone behavioural patterns was observed. In the light of these findings, genome-wide screening of unaffected siblings of subjects with early onset CHD cannot be recommended in this population until common polymorphisms can be clearly identified as risk factors. Indeed this study again supports the dire need for early, school level, education in behavioural lifestyle patterns and disease predisposition. The Indian community is a very high-risk group who should be targeted, not for secondary, but for primordial disease prevention measures. The study does not rule out the role of other candidate gene polymorphisms in the pathogenesis of CHD in these subjects. The high prevalence of diabetes and insulin resistance suggests that studies of genes regulating glucose and lipid metabolism should be pursued. Such candidate genes should include genes for lipoprotein lipase and paraoxonase polymorphisms which may explain the dyslipidaemia patterns in this group.

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