Aetiology, management, and outcomes of acute heart failure in 17 African countries (THESUS-HF II): a prospective, multicentre, observational cohort study.

Contemporary data on the aetiology, management, and outcomes of acute heart failure across Africa are scarce. We aimed to conduct a contemporary assessment of acute heart failure aetiology, treatment patterns, presentation rates, and 180-day outcomes across Africa. THESUS-HF II was a prospective, multicentre, observational cohort study in 50 hospitals across 17 African countries. Adults aged 18 years or older with acute heart failure were enrolled during seven 24 h surveillance periods within an 8-week, site-specific window. Acute heart failure was identified by acute dyspnoea and congestion, supported by electrocardiography, chest radiography, and point-of-care echocardiography. We assessed presentation rates per 10 000 people in the adult catchment population per week, treatment patterns (including medication use at discharge), readmission, and all-cause mortality through to 180 days. This study was registered with the Pan African Clinical Trial Registry (PACTR202410553810557) and is completed; however, substudies are ongoing. Between July 1, 2024, and July 31, 2025, 1741 patients were assessed for eligibility at participating hospitals and 1578 were included in the study cohort. 793 (50·5%) of 1570 participants were female, 777 (49·5%) were male, and 1533 (97·8%) of 1567 were of African descent; median age was 56·0 years (IQR 40·0-69·0). The weekly acute heart failure presentation rate was 0·03 per 10 000 people (95% CI 0·02-0·05) overall and 0·02 per 10 000 people (0·01-0·04) for de novo acute heart failure. De novo acute heart failure accounted for 1007 (64·2%) of 1568 presentations. The leading aetiologies were hypertensive heart disease (576 [36·5%] of 1578), cardiomyopathy (370 [23·4%]), and ischaemic heart disease (367 [23·3%]). Median hospital ward stay was 6·0 days (IQR 4·0-10·0), and in-hospital mortality was 8·7% (95% CI 7·3-10·2; 134 of 1542 patients). At discharge, renin-angiotensin-aldosterone system inhibitors were prescribed in 1014 (73·9%) of 1373 patients, β blockers in 1053 (76·9%) of 1369 patients, mineralocorticoid receptor antagonists in 982 (71·9%) of 1366, and SGLT2 inhibitors in 743 (54·7%) of 1359; target doses were reached in fewer than half of patients. Of 1567 patients included in time-to-event analyses, 528 (33·7%) were lost to follow-up before 180 days. All-cause mortality was 11·1% (95% CI 9·6-12·9; 160 deaths) at 30 days and 20·6% (18·4-23·0; 255 deaths) at 180 days. All-cause mortality did not differ across aetiological groups over 30 days (log-rank p=0·39), but differed over 180 days (p=0·019). Compared with THESUS-HF, THESUS-HF II suggests an evolving aetiological profile of acute heart failure in Africa, although differences in ascertainment and diagnostic capability might have contributed to the apparent aetiological shift. High mortality in this relatively young cohort highlights the importance of heart failure prevention, access to cardiac care, guideline-directed therapy, and post-discharge follow-up. These findings suggest that short-term acute heart failure outcomes are not driven by its demographic, aetiological, and echocardiographic factors. Cape Heart Institute, University of Cape Town; Hippocrate Foundation; The Heart Initiative; and Pan African Society of Cardiology.