Article Text

PDF
Predisposing factors and incidence of newly diagnosed atrial fibrillation in an urban African community: insights from the Heart of Soweto Study
  1. Karen Sliwa1,2,
  2. Melinda Jane Carrington2,3,
  3. Eric Klug4,
  4. Lionel Opie1,
  5. Geraldine Lee2,
  6. Jocasta Ball3,
  7. Simon Stewart2,3
  1. 1Hatter Cardiovascular Research Institute, Faculty of Health Sciences, University of Cape Town, South Africa
  2. 2Soweto Cardiovascular Research Unit, Chris Hani Baragwanath Hospital, University of the Witwatersrand, Johannesburg, South Africa
  3. 3Baker IDI Heart and Diabetes Institute, Melbourne, Australia
  4. 4Division of Cardiology, Heart Failure Clinic, Johannesburg Hospital, University of the Witwatersrand, Johannesburg, South Africa
  1. Correspondence to Professor Simon Stewart, Preventative Health, Baker IDI Heart and Diabetes Institute, PO Box 6492, St Kilda Rd Central, Melbourne, Vic 8008, Australia; simon.stewart{at}bakeridi.edu.au

Abstract

Background Little is known about the incidence and clinical characteristics of newly diagnosed atrial fibrillation/flutter (AF) in urban Africans in epidemiological transition.

Methods This observational cohort study was carried out in the Chris Hani Baragwanath Hospital in Soweto South Africa. A clinical registry captured detailed clinical data on all de novo cases of AF presenting to the Cardiology Unit during the period 2006–2008.

Results Overall, 246 of 5328 cardiac cases (4.6%) presented with AF (estimated 5.6 cases/100 000 population/annum). Mean age was 59±18 years and the majority were of African descent (n=211, 86%) and/or female (n=150, 61%). Men were more than twice as likely to smoke (OR 2.88, 95% CI 1.92 to 4.04) than women, but women were twice as likely to be obese (OR 1.80, 95% CI 1.28 to 2.52) than men. Lone AF occurred in 22 (8.9%) cases, while concurrent valve disease and/or functional valvular abnormality occurred in 107 cases (44%). Overall, 171 cases (70%) presented with uncontrolled AF (ventricular rate >90 beats/min) with no sex-based differences. Common co-morbidities were any form of heart failure (56%) and rheumatic heart disease (21%). Women with AF were more likely to present with hypertensive heart failure (OR 2.37, 95% CI 1.24 to 4.54) but less likely to present with a dilated cardiomyopathy (OR 0.42, 95% CI 0.23 to 0.76) or coronary artery disease (OR 0.38, 95% CI 0.14 to 1.02) than men. Mean overall CHADS2 score (in 195 non-rheumatic cases) was 1.51±0.91 and, despite a similar age profile, women had higher scores than men (1.73±0.94 vs 1.24±0.78; p<0.0001).

Conclusions These unique data suggest that urban Africans in Soweto develop AF at a relatively young age. Conventional strategies used to manage and treat AF need to be carefully evaluated in this setting.

  • Africa
  • atrial fibrillation
  • valve disease
  • epidemiological transition
  • cardiovascular disease
  • epidemiology

Statistics from Altmetric.com

Footnotes

  • Funding The Heart of Soweto Study registry was supported by the University of the Witwatersrand and unconditional research grants from Adcock-Ingram, the Medtronic Foundation USA, Servier, Bayer-Schering and BHP Billiton. SS and MJC are supported by the National Health & Medical Research Council of Australia.

  • Competing interests None.

  • Ethics approval This study was conducted with the approval of the University of Witwatersrand.

  • Provenance and peer review Not commissioned; externally peer reviewed.

Request permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.