Researchers who conducted a large-scale review of heart failure data in low- and middle-income countries say the issue is a major public health burden and many patients are not receiving appropriate treatment.

The study, led by Kazem Rahimi and colleagues from the George Institute for Global Health, which receives support from the Oxford Martin School, is published in this week's PLOS Medicine and comprises data from more than 237,000 cases across 31 countries. It found there was significant variation in the causes, management and outcomes of heart failure across different low- and middle-income countries, and that a large proportion of patients were not receiving officially-recommended drug treatments.

By pooling the data from more than 50 studies, they found that the average age of patients admitted for acute heart failure was 63 years, which ranged from 42 years in Cameroon and Ghana to 75 years in Argentina, and correlated with the human development index (a measure of national well-being) of individual countries. The leading causes of heart failure differed across countries, with ischemic heart disease the most common cause in countries outside of Africa and the Americas, hypertension the most dominant cause in Africa (46%), and hypertension and ischemic heart disease similarly common in the Americas (31 and 33%, respectively). While 69% of heart failure patients were prescribed diuretics, the three main treatments currently recommended in guidelines for managing heart failure - angiotensin converting enzyme inhibitors, beta-blockers, and mineralocorticoid receptor agonists - were prescribed at lower rates.

The researchers say that while the findings indicate that the burden of heart failure is substantial in low- and middle-income countries, data from all relevant countries was not available and the estimates are mostly derived from urban tertiary referral hospitals, and that therefore these findings may not reflect the broader picture of heart failure in the community. The limited available data on and substantial impact of heart failure in low- and middle-income countries emphasises the need for more research attention in this area, they add.

“This review shows that heart failure places a considerable burden on health systems in low- and middle-income countries, and affects a wide demographic profile of patients in these countries.” Dr Kazem Rahimi

In an article commenting on the research, PLOS Medicine consulting editor Druin Burch examines how inconsistencies in diagnosis and selection of patients for clinical trials may contribute to treatment burden of heart failure in low- and middle-income countries.

“The gap between suboptimal treatment of heart failure and what is achievable represents not just a failure to practice evidence-based medicine but a greater gap in knowledge and the research agenda.” Darin Burch