Browsing by Author "Du Toit, Rudolf"

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    Integrated positron emission tomography/computed tomography for evaluation of mediastinal lymph node staging of non-small-cell lung cancer in a tuberculosis-endemic area : a 5-year prospective observational study
    (Health & Medical Publishing Group, 2015) Shaw, Jane A.; Irusen, Elvis M.; Von Groote-Bidlingmaier, Florian; Warwick, James M.; Jeremic, Branislav; Du Toit, Rudolf; Koegelenberg, Coenraad F. N.
    Background. Integrated positron emission tomography/computed tomography (PET-CT) is a well-validated modality for assessing mediastinal lymph node metastasis in non-small-cell lung cancer (NSCLC), which determines management and predicts survival. Tuberculosis (TB) is known to lead to false-positive PET-CT findings. Objectives. To assess the diagnostic accuracy of PET-CT in identifying mediastinal lymph node involvement of NSCLC in a high TB-endemic area. Methods. Patients who underwent both PET-CT and lymph node tissue sampling for the investigation of suspected NSCLC were prospectively included in this observational study. Results were analysed per patient and per lymph node stage. A post-hoc analysis was performed to test the validity of a maximum standardised uptake value (SUV­max) cut-off for lymph node positivity. Results. PET-CT had a sensitivity of 92.6%, specificity of 48.6%, positive predictive value of 56.8% and negative predictive value (NPV) of 90.0% in the per-patient analysis. Diagnostic accuracy was 67.2%. Similar values were obtained in the per-lymph node stage analysis. TB was responsible for 21.1% of false-positive results. A SUVmax cut-off of 4.5 yielded an improvement in diagnostic accuracy from 64.0% to 84.7% compared with a cut-off of 2.5, but at the cost of decreasing the NPV from 90.6% to 83.5%. Conclusion. In a high TB-endemic area, PET-CT remains a valuable method for excluding mediastinal lymph node involvement in NSCLC. Patients with a negative PET-CT may proceed to definitive management without further invasive procedures. However, PET-CT-positive lymph nodes require pathological confirmation, and the possibility of TB must be considered.
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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.