Types of heart disease and its associated risk factors traditionally associated with only high-income countries are steadily increasing in African people, increasing the threat to these populations and broadening the challenges faced by governments and doctors. These are the conclusions of authors of an Article in this week's edition of The Lancet.
The causes and consequences of an epidemic of cardiovascular disease (CVD) and its major component, heart disease, in developed countries have been well documented. However, few data exist in low-income and middle-income countries to describe the effect of CVD emerging as a threat in addition to malnourishment and infectious disease.
Professor Simon Stewart, Cardiovascular Research Unit, Chris Hani Baragwanath Hospital, University of the Witwatersrand, Johannesburg, South Africa, and Baker Heart Research Institute, Melbourne, Australia, and colleagues did the Heart of Soweto Study, which aimed to investigate the clinical range of disorders related to CVD in patients presenting for the first time to a cardiology unit at Chris Hani Baragwanath Hospital in a single year. They recorded data for 4162 patients with confirmed CVD, 1593 of whom were newly diagnosed and 2569 previously diagnosed and under treatment. They also developed a registry for the newly diagnosed patients containing relevant data.
The authors found that 1359 (85%) of the newly diagnosed study population were black Africans, and 939 (59%) were women. The women in the population, mean age 53 years, were younger than the men, mean 55 years. Around 25% of the patients were under 40 years. Heart failure was the most common primary diagnosis, in 44% of patients. Black Africans were 46% more likely to be diagnosed with heart failure than the rest of the cohort, but only one tenth as likely to be diagnosed with coronary artery disease. Presence of CV risk factors was very high, with 56% of patients having high blood pressure (hypertension); 44% of these patients with hypertension were obese. Only 209 of the 1593 newly diagnosed patients had no identifiable risk factors, whereas 933 (59%) had several risk factors.
The authors say their paper has important health implications for the prevention and treatment of heart disease both within Soweto and for other urban communities in Africa undergoing the similar changes to their disease profile (epidemiological change). The present spectrum of heart disease in Soweto now encompasses a broad range of advanced conditions. The so-called traditional forms of infectious diseases (rheumatic valvular diseases, cardiomyopathies, tuberculous pericardial effusion -- exacerbated by HIV incidence) that are usually expected in African populations are included, as are newer non-communicable diseases (hypertensive heart disease and coronary artery disease) -- predominantly associated with advanced clinical presentations -- that are often reported in high-income countries.
The authors highlight their concern that black African women were most likely to be obese both in this hospital cohort and the general community, and that they represented a greater proportion of the whole than black African men. They say: "[This] is especially noteworthy in view of the typical male dominance seen in cohorts from developed countries."
They conclude: "The combination of common preventable risk factors and late clinical presentations -- especially heart failure -- represents a particular challenge to improve primary and secondary prevention strategies to not only reduce the number of new cases of cardiovascular disease but also improve health outcomes for those with pre-established disease."
In an accompanying Comment, Dr Harvey White, Auckland City Hospital, New Zealand, and Dr Anthony Dalby, Milpark Hospital, Johannesburg, South Africa, say: "The major challenge is how to increase health resources. A recurring theme in Africa is the lack of reliable statistics. This registry, from one of the largest urban populations of black Africans, goes a long way to correcting that deficit in Soweto."
Professor Simon Stewart, Cardiovascular Research Unit, Chris Hani Baragwanath Hospital, University of the Witwatersrand, Johannesburg, South Africa, and Baker Heart Research Institute, Melbourne, Australia T) +61 3 8532 1640 / +61 438 302 111 E) simon.stewart@baker.edu.au
Dr Harvey White, Auckland City Hospital, New Zealand T) +64 21756244 E) harveyw@adhb.govt.nz
PDF OF ARTICLE: http://multimedia.thelancet.com/pdf/press/Southafrica.pdf
Journal
The Lancet