Browsing by Author "Doubell, Anton"

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    The 12-month period prevalence and cardiac manifestations of HIV in patients with acute coronary syndrome at a tertiary hospital in Cape Town, South Africa : a retrospective cross-sectional study
    (BMC (part of Springer Nature), 2021) Pennefather, Camilla; Esterhuizen, Tonya; Doubell, Anton; Decloedt, Eric H.
    Background: HIV-positive patients are increasingly being affected by non-communicable diseases such as coronary artery disease (CAD). Data from high-income countries (HICs) indicate that HIV-positive patients have different riskfactor profiles for acute coronary syndrome (ACS) as well as different cardiac manifestations of this syndrome compared to HIV-negative patients. There is limited data from Sub-Saharan Africa (SSA), and particularly from South Africa with the biggest HIV epidemic in the world. The objective of this study was to determine the 12-month period prevalence of HIV in patients with ACS and to compare the risk-factor profile, ACS presentation and management between HIV-positive and HIV-negative adults. Methods: We included all patients hospitalised with ACS from 01 January to 31 December 2018 in a tertiary hospital, Tygerberg Hospital, in Cape Town, South Africa. The HIV-status of all patients was determined using routine clinical records. We performed multiple conditional logistic regression on HIV-positive and HIV-negative patients (1:3 ratio) to compare the risk factor profile, ACS presentation and management between the groups. Results: Among 889 patients, 30 (3.4%) were HIV-positive (95% confidence interval (CI): 2.3–4.8). HIV-positive patients were younger, more frequently men, and had a lower prevalence of medical comorbidities and a family history of CAD. They were more likely to present with ST-elevation myocardial infarction (STEMI) [odd’s ratio (OR) (95% CI): 3.12 (1.2–8.4)], and have single-vessel disease [OR (95% CI): 3.03 (1.2–8.0)]. Angiographic and echocardiographic data, as well as management, did not differ between the groups. Among HIV-positive patients, 17 (65%) were virally suppressed (HIV viral load < 200 copies/mL) with a median CD4+ count of 271 cells/mm3. The majority (20, 67%) of HIV-positive patients were receiving antiretroviral therapy at the time of the ACS. Conclusions: We found an HIV-prevalence of 3.4% (95% CI 2.3–4.8) in adults with ACS in a high endemic HIV region. HIV-positive patients were younger and more likely to present with STEMIs and single-vessel disease, but had fewer CAD risk factors, suggesting additional mechanisms for the development of ACS.
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    Cardiology training in South Africa – on the brink?
    (South African Heart Association, 2016) Doubell, Anton
    ENGLISH ABSTRACT: More often than not, when we use the expression “on the brink”, we are referring to an impending bad situation. On the edge of a cliff without wings so to speak…, on the brink of disaster…, on the brink of ruin…, on the brink of collapse…, on the brink of extinction…. In the broad sense, “on the brink” refers to the point where a new or different situation is about to begin and it may not necessarily signal impending doom. On the contrary, it may refer to a sense of anticipation, of being primed, a state of readiness, champing at the bit. It may signal that it is all systems go.
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    COVID-19 and cardiovascular imaging : a guide for the practising clinician
    (South African Heart Association, 2020) Meel, Ruchika; Cupido, Blanche; Pecoraro, Alfonso; Doubell, Anton; Lubbe, Wayne; Ntusi, Ntobeko A. B.
    ENGLISH ABSTRACT: In the ongoing COVID-19 pandemic, patients with cardiac disease have been the worst affl icted with a high mortality. Cardiac imaging forms an integral part of the armamentarium in the management of these patients. This review focuses on providing a general guide to cardiac imaging in the COVID-19 context for the practising clinician in Africa. These recommendations are likely to be modifi ed as further data emerge on the effect of the SARS-CoV-2 virus on the cardiovascular system.
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    Developing a new electrophysiology service and training platform - narrowing the gap
    (South African Heart Association, 2020) Moses, Jane; Doubell, Anton
    No abstract available.
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    Has preventive medicine entered the realm of the interventional cardiologist?
    (South African Heart Association, 2013) Doubell, Anton
    The result of the Preventive Angioplasty in Acute Myocardial Infarction (PRAMI) trial(1) released at the recent ESC meeting held in Amsterdam has attracted enormous interest and rightly so: if the conclusions drawn by the researchers prove correct, the management of patients presenting with a ST segment elevation myocardial infarction (STEMI) is about to undergo a major change. The authors provide evidence to support “preventive PCI” in non-infarct related coronary arteries in patients with multivessel disease undergoing angiography with the objective of opening the infarct related coronary artery. These findings challenge the long-held view, reflected in international guidelines, that PCI in this setting should be aimed only at the so-called culprit lesion. It also challenges the view that the likelihood of atheromatous plaque rupture is primarily related to the properties of the plaque (degree of inflammation, cap thickness, cholesterol content) and not the degree of stenosis.
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    The hidden continuum of HIVassociated cardiomyopathy : a focussed review with case reports
    (South African Heart Association, 2021) Robbertse, Pieter-Paul; Doubell, Anton; Nachega, Jean; Herbst, Philip
    ENGLISH ABSTRACT: HIV-associated cardiomyopathy (HIVAC) is a poorly understood group of diseases with a poor prognosis once ventricular dysfunction is present. Cardiovascular magnetic resonance has revealed a previously unappreciated burden of asymptomatic myocardial abnormalities in people living with HIV, including abnormalities already present at the time of HIV diagnosis. These abnormalities include thickened, inflamed ventricles that bear resemblance to cases of symptomatic HIVAC that are reported on in this article. Our understanding and the significance of asymptomatic HIV-associated myocardial pathology will be explored as early disease on a continuum towards more advanced cardiomyopathy. The need for prospective research in persons naïve to anti-retroviral therapy is emphasised as it may provide key findings to better understand this elusive disease process.
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    The left atrial appendage - a design flaw or an essential structure
    (South African Heart Association, 2018) Doubell, Anton
    ENGLISH ABSTRACT: The left atrial appendage (LAA) is considered to be a vestigial remnant of the primitive foetal atrium. It has also been identified as the source of the majority of left atrial thrombi in nonvalvular atrial fibrillation (AF). Not having a clearly defined and recognised function, and having the reputation of being the villain in thrombotic stroke in patients with non-valvular AF, has led to a number of rather aggressive interventions targeted at dealing with the scourge of AF.
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    Persistant left superior vena cava – the value of an agitated saline contrast study
    (South African Heart Association, 2014) Moses, Jane; Kyriakakis, Charles; Weich, Hellmuth; Rossouw, Pieter; Herbst, Philip; Doubell, Anton
    A persistant left superior vena cava (PLSVC) draining to the coronary sinus (CS) is the most common venous anomaly of the thorax, affecting approximately 0.5% - 2% of the general population, and is present in up to 10% of patients with other congenital cardiac anomalies.(1) The embryological development of the thoracic venous system is complex and subject to significant variation. Usually, most of the left cardinal system involutes, leaving only the coronary sinus, which drains the cardiac veins, and the ligament of Marshall (a remnant of the left superior vena cava).(2) The presence of a PLSVC is usually an incidental finding at either echocardiography, cardiac catheterisation or device implantation.(1) The typical echocardiographic findings are that of a dilated CS, which can be appreciated on the parasternal long axis view, the parasternal short axis at mitral valve level, the apical 2 chamber view and a modified apical four chamber view scanning down to visualise the CS (Figure 1). A contrast study with agitated saline (“bubble study”) done via the left brachial vein will demonstrate the dilated CS draining into the right atrium (Figure 2).
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    Prevention of infective endocarditis associated with dental interventions : South African Heart association position statement, endorsed by the South African Dental Association
    (South African Heart Association, 2017) Jankelow, David; Cupido, Blanche; Zuhlke, Liesl; Sliwa, Karen; Ntsekhe, Mpiko; Manga, Pravin; Doubell, Anton; Lawrenson, John; Essop, Mohammed Rafique
    ENGLISH ABSTRACT: Infective endocarditis (IE) is associated with significant morbidity and mortality. Prevention is therefore an important clinical entity. The maintenance of optimal oral health is likely to play the most important role in protecting those at risk for IE. Both patients and health care practitioners must be educated in this regard. Guidelines have recommended that antibiotic prophylaxis should be limited to individuals (undergoing certain high-risk dental procedures) with underlying cardiac conditions that are associated with the greatest risk of an adverse outcome from IE. These conditions include prosthetic valves, congenital heart disease and previous IE. In South Africa, and other developing countries, IE is often a disease of young patients with rheumatic heart disease (RHD) and carries a very poor prognosis. In contrast, IE in Europe/North America, where guidelines and indications for antibiotic prophylaxis have been reduced, has a different spectrum of factors. These patients are older with degenerative valve disease. IE may also occur as a result of invasive health care associated procedures or in the setting of prosthetic valves and implantable cardiac devices. Recently published international guidelines cannot be automatically applied to countries where RHD is common and oral hygiene is poor. We therefore recommend that patients with RHD should also receive antibiotic prophylaxis prior to the listed dental procedures. Antibiotic prophylaxis should be prescribed after stressing the role of good oral health and why the approach differs in South Africa. There should be close cooperation between the dental practitioner and clinician as to who should receive prophylaxis and who should not.
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    A retrospective analysis of mitral valve pathology in the setting of bicuspid aortic valves
    (BioScientifica, 2017) Van Rensburg, Annari; Herbst, Philip; Doubell, Anton
    The therapeutic implications of bicuspid aortic valve associations have come under scrutiny in the transcatheter aortic valve implantation era. We evaluate the spectrum of mitral valve disease in patients with bicuspid aortic valves to determine the need for closer echocardiographic scrutiny/follow-up of the mitral valve. A retrospective analysis of echocardiograms done at a referral hospital over five years was conducted in patients with bicuspid aortic valves with special attention to congenital abnormalities of the mitral valve. One hundred and forty patients with a bicuspid aortic valve were included. A congenital mitral valve abnormality was present in eight (5.7%, P = 0.01) with a parachute mitral valve in four (2.8%), an accessory mitral valve leaflet in one (0.7%), mitral valve prolapse in one, a cleft in one and the novel finding of a trileaflet mitral valve in one. Minor abnormalities included an elongated anterior mitral valve leaflet (P < 0.001), the increased incidence of physiological mitral regurgitation (P < 0.001), abnormal papillary muscles (P = 0.002) and an additional chord or tendon in the left ventricle cavity (P = 0.007). Mitral valve abnormalities occur more commonly in patients with bicuspid aortic valves than matched healthy individuals. The study confirms that abnormalities in these patients extend beyond the aorta. These abnormalities did not have a significant functional effect.
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    The South African SHARE-TAVI registry : incidence and risk factors leading to conduction disturbances requiring permanent pacemaker implantation
    (South African Heart Association, 2021) Du Toit, Rudolf; Doubell, Anton; Abelson, Mark; Hellig, Farrel; Horak, Adie; Mabin, Thomas; Klug, Eric; Schaafsma, Elizabeth; Van Wyk, Jacques; Scherman, Jacques; Ntsekhe, Mpiko; Weich, Hellmuth
    Background: One of the most common complications post transcatheter aortic valve implantation (TAVI) is the development of heart block requiring permanent pacemaker implantation (PPM). The incidence of PPM in international registries ranges from 13% - 17.5%. Methods: The aim of this observational study was to report the PPM rate in the SHARE-TAVI registry and determine the clinical, electrocardiographic and procedural predictors of PPM as well as the effect of PPM on clinical outcomes. Results: Three hundred and fi ve subjects were analysed. The PPM rate was 9%. Third degree atrioventricular block at the time of implant was the most common indication for PPM. Self-expanding valves (PPM rate 14% vs. 6% for balloon-expandable valves, p=0.02) were correlated with the need for PPM. Baseline ECG predictors of PPM were axis deviation, QRS duration and conduction delay, most notably a pre-existing right bundle branch block (OR 15.88, p<0.01). PPM infl uenced functional class at 30 days, but not the need for repeat hospitalisation or mortality at 30-day and 1-year follow-up. Conclusions: A PPM rate lower than that reported in large international registries was found. Predictors of PPM and the infl uence of PPM on outcomes were similar to those reported in the international data.
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    Tri-leaflet mitral valves – when lightning strikes thrice
    (South African Heart Association, 2016) Van Rensburg, Annari; Pecoraro, Alfonso; Kyriakakis, Charles; Herbst, Philip; Doubell, Anton
    ENGLISH ABSTRACT: Mitral valves are well known to be bi-leaflet structures with attachments from both leaflets (anterior and posterior) to both papillary muscles (anterolateral and posteromedial). Congenital abnormalities of the mitral valve, although well described, are quite rare. These abnormalities can involve either the leaflet (cleft mitral valve) or the subvalvular apparatus (parachute mitral valve) or even occur as accessory mitral valve tissue (accessory mitral valve leaflet). These can occur in isolation, or in association with other congenital abnormalities. A tri-leaflet mitral valve is a novel echocardiographic finding that has only been described in 6 patients in 4 different case reports.(1-4) We report on 3 patients recently found to have trileaflet mitral valves in the setting of atrioventricular concordance and normal offset of the AV valves at our out-patient clinic.