Evidence to Support the Emergence of New Forms of Heart Failure in Africa: The Heart of Soweto Study

Background: The Heart of Soweto Study is the largest study of emergent heart disease (HD) in Africa. Methods: Baragwanath Hospital in Soweto provides health care to a population of 1.1 million mainly black Africans. We registered detailed demographic, clinical anddiagnostic data fromall denovopresentations of heart disease (HD) in 2006. Results: In 2006, 844 patients presented with de novo heart failure HF. Women (57%) and black Africans (88%) predominated: 90%had≥1 risk factor, includinghypertension and obesity (34%). Mean left ventricular ejection fraction was 45± 18%, 53% and 27%, respectively had systolic and diastolic dysfunction. The most common forms of HF were dilated CMO (35%), hypertensiveHF (33%), right HF (27%), ischaemic CMO (9%) and valvular HF (8%). Adjusting for age, race and risk factor profile, women had less ischaemic CMO (OR 0.49, 95% CI 0.28–0.85: p= 0.011) but more right HF (OR 1.40, 95% CI 0.99–1.98: p= 0.051) comlarge bowel cancer (25,722 men and 25,992 women) and lung cancer (21,636 men and 12,945 women) were compared. Results: The ratio of patients with HF compared to the six most common forms of cancer (large bowel, lung, prostate, breast, bladder, and ovarian) was 1.5:1 (321,951 vs. 218,664 cases). For patients aged 60 years, the rate of 5year survivalwas 70%and75% inmenandwomenwithHF compared to 57%and61%, respectively, in thosewith large bowel cancer and 18%and 20%, respectively for thosewith lung cancer. Odds ratios for a one-year increment of calendar year, showed that 5-year survival had significantly increased by 7.1% (95% CI 6.8–7.4%) and 6% (5.7–6.4%) per year for men and women with HF and 3.2% (2.4–3.9%) and 2.6% (1.8–3.3%), respectively, per year for large bowel cancer. Five-year survival in both men (odds ratio of 1.01: 0.99–1.02) and women (odds ratio of 1.00: 0.98–1.01) with a first-time diagnosis of lung cancer remained static. Conclusion: These preliminary data suggest that heart failure has become less malignant than many common forms of cancer in Sweden.