Hellmuth Weich

Founder mutations in the LDL receptor gene contribute significantly to the familial hypercholesterolemia phenotype in the indigenous South African population of mixed ancestry

The South African population harbors genes that are derived from varying degrees of admixture between indigenous groups and immigrants from Europe and the East. This study represents the first direct mutation‐based attempt to determine the impact of admixture from other gene pools on the familial hypercholesterolemia (FH) phenotype in the recently founded Coloured population of South Africa, a people of mixed ancestry. A cohort of 236 apparently unrelated patients with clinical features of FH was screened for a common mutation causing familial defective apolipoprotein B‐100 (FDB) and seven low‐density lipoprotein receptor (LDLR) gene defects known to be relatively common in South Africans with FH. Six founder‐type ‘South African mutations’ were responsible for FH in ∼20% of the study population, while only 1 patient tested positive for the familial defective apolipoprotein B‐100 mutation R3500Q. The detection of multiple founder‐type LDLR gene mutations originating from European, Indian and Jewish populations provides direct genetic evidence that Caucasoid admixture contributes significantly to the apparently high prevalence of FH in South African patients of mixed ancestry. This study contributes to our knowledge of the biological history of this unique population and illustrates the potential consequences of recent admixture in populations with different disease risks.

Transjugular Tricuspid Valve-in-Valve Replacement

The patient is a 38-year-old woman with rheumatic heart disease requiring surgery 21 years ago. She received a St. Jude mechanical prosthesis in the mitral position and a Carpentier-Edwards Perimount bioprosthesis (size 31) in the tricuspid position. Over the past 2 years, she has become progressively more short of breath with regular admissions for congestive heart failure despite medical treatment. Transthoracic echocardiography showed a severely dilated right atrium and a calcified tricuspid prosthesis with a mean gradient across the valve varying between 9 and 12 mm Hg (Figures 1 and 2). The mitral valve prosthesis functioned well. Figure 1. The continuous wave spectral Doppler of the degenerate tricuspid prosthesis before the procedure showing a profile of severe tricuspid stenosis with averaged (because of atrial fibrillation) peak and mean gradients of 12 and 9, respectively. Vmax indicates maximum flow velocity; Vmean, mean flow velocity; Pmax, maximal pressure gradient: Pmean, mean pressure gradient; Env Ti, duration of measured envelope; VTI, velocity time integral; HR, heart rate. Figure 2. Pressure half-time (PHT) measured over the tricuspid valve confirms severe tricuspid stenosis with a value of 461 ms. A decision was made to replace the tricuspid valve, but in consultation with the heart team, it was agreed that, given that the mitral valve prosthesis was functioning well, the risk of a second sternotomy to replace only the tricuspid valve was difficult to justify if an alternative option was available. Given the limited lifespan of a bioprosthesis in a young person, she would then require her third (and likely final) sternotomy at a young age. A joint decision was therefore made to offer the patient a minimally invasive tricuspid valve replacement by a transcatheter procedure. The risks of a transcatheter procedure were discussed with her, and she provided written informed consent. The option of a …

SASCI/SCTSSA joint consensus statement and guidelines on transcatheter aortic valve implantation (TAVI ) in South Africa : consensus guidelines

The South African Heart Association (SA Heart) together with two of its special-interest groups, the South African Society of Cardiovascular Intervention (SASCI) and the Society of Cardiothoracic Surgeons in South Africa (SCTSSA), represent the scientific, educational and professional interests of South African cardiac specialists, with a combined membership of over 200 members. These two interest groups exclusively represent practicing cardiologists and cardiothoracic surgeons in South Africa. SASCI and SCTSSA are dedicated to maintaining the highest standards of specialist practice and the highest quality of patient care. As a result, SASCI and SCTSSA seek to serve as a knowledge resource for patients and funders in matters related to new technology used in the cardiac interventional and surgical disciplines.

A new window of opportunity for TAVI

This short report features the role of multi detector computer tomography (MDCT) in imaging the ascending aorta to assess the feasibility of a transaortic access route for transcatheter placement of an Edwards SAPIEN XTTM aortic valve.

Joint consensus statement and guideline on transcatheter aortic valve implantation (TAVI) in South Africa - October 2016

The South African Heart Association (SA Heart), together with 2 of its special interest groups, South African Society of Cardiovascular Intervention (SASCI) and Society of Cardiothoracic Surgeons of South Africa (SCTSSA) represent the scientific, educational, socio-economic, ethical and professional interests of South African cardiac specialists, with a combined membership of over 200 members.

First experience with the Edwards SAPIEN transcatheter aortic valve implantation (TAVI). Data from the Western Cape, South Africa

Background: Transcatheter aortic valve implantation (TAVI) is an exciting new technology that was launched in South Africa in October 2009 for the treatment of aortic stenosis in patients at high risk for conventional surgery. We report our initial experience with TAVI in the Western Cape, South Africa. Methods: 70 patients with severe symptomatic aortic stenosis underwent TAVI with the Edwards SAPIEN device (26 via transapical approach and 44 via transfemoral) at Panorama and Vergelegen Mediclinic hospitals in the Western Cape. All implants were performed by a team consisting of 2 cardiothoracic anaesthesiologists, 2 cardiothoracic surgeons, 2 cardiologists and an echo expert. Results: Patients were at high risk with a mean age of 80 years and a mean logistic EuroSCORE of 26. The acute procedural success rate was 97% with two acute deaths. At 30 days, there were a total of 5 deaths. Major vascular complications were seen in 6 cases (9%). Only one stroke was seen during the follow-up period. Conclusions: With a multidisciplinary team approach and careful patient selection, TAVI can be performed by a high volume centre in South Africa with results comparable to international published outcomes.

Intervention for congenital and structural heart disease: Beyond the cradle

During the last four decades we have seen an exponential growth in interventions (both medical and invasive) to diagnose and treat adult cardiac disorders. Coronary stents are in their fourth generation and the developments in cardiac pacing and electrophysiology has shown the same rapid growth. Large numbers of patients at risk who require these treatment modalities have driven these developments and the interventions have made a difference to the lives of hundreds of thousands of patients across the globe.

Closure of pulmonary arterio-venous malformations in a patient with a novel form of Hereditary Haemorrhagic Telangiectasia

CITATION: Weich, H. & Ackermann, C. 2014. Closure of pulmonary arterio-venous malformations in a patient with a novel form of Hereditary Haemorrhagic Telangiectasia. SA Heart, 11(1):34-35, doi:10.24170/11-1-1770.

Persistant left superior vena cava – the value of an agitated saline contrast study

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).

Balloon aortic valvuloplasty in the era of transcatheter aortic valve implantation (TAVI): an opportunity to revisit a previously discouraged treatment option

Balloon aortic valvuloplasty (BAV) was described in the 1980’s but early enthusiasm was kerbed by results indicating risk of stroke and early restenosis. It therefore fell out of favour and is only indicated as a bridge to defi nitive treatment in the majority of cases. With the advent of transcatheter aortic valve implantation (TAVI) as a new form of defi nitive treatment in high risk patients with aortic stenosis, there may be a new role for BAV.