Cardiovascular Risk and Events in 17 Low-, Middle-, and High-Income Countries
Salim Yusuf, M.B., B.S., D.Phil., Sumathy Rangarajan, M.Sc., Koon Teo, M.B., Ph.D., Shofiqul Islam, M.Sc., Wei Li, Ph.D., Lisheng Liu, M.D., Jian Bo, B.Sc., Qinglin Lou, M.Sc., Fanghong Lu, B.Sc., Tianlu Liu, B.Sc., Liu Yu, B.Sc., Shiying Zhang, B.Sc., Prem Mony, M.D., Sumathi Swaminathan, Ph.D., Viswanathan Mohan, M.D., Rajeev Gupta, M.D., Ph.D., Rajesh Kumar, M.D., Krishnapillai Vijayakumar, M.D., Scott Lear, Ph.D., Sonia Anand, M.D., Ph.D., Andreas Wielgosz, M.D., Ph.D., Rafael Diaz, M.D., Alvaro Avezum, M.D., Ph.D., Patricio Lopez-Jaramillo, M.D., Ph.D., Fernando Lanas, M.D., Khalid Yusoff, M.B., B.S., Noorhassim Ismail, M.D., Ph.D., Romaina Iqbal, Ph.D., Omar Rahman, M.D., M.P.H., D.Sc., Annika Rosengren, M.D., Afzalhussein Yusufali, M.D., Roya Kelishadi, M.D., Annamarie Kruger, Ph.D., Thandi Puoane, M.P.H., Ph.D., Andrzej Szuba, M.D., Ph.D., Jephat Chifamba, M.Phil., Aytekin Oguz, M.D., Matthew McQueen, M.B., Ch.B., Martin McKee, D.Sc., and Gilles Dagenais, M.D. for the PURE Investigators
N Engl J Med 2014; 371:818-827
August 28, 2014DOI: 10.1056/NEJMoa1311890
Background
More than 80% of deaths from cardiovascular disease are estimated to occur in low-income and middle-income countries, but the reasons are unknown.
Methods
We enrolled 156,424 persons from 628 urban and rural communities in 17 countries (3 high-income, 10 middle-income, and 4 low-income countries) and assessed their cardiovascular risk using the INTERHEART Risk Score, a validated score for quantifying risk-factor burden without the use of laboratory testing (with higher scores indicating greater risk-factor burden). Participants were followed for incident cardiovascular disease and death for a mean of 4.1 years.
Results
The mean INTERHEART Risk Score was highest in high-income countries, intermediate in middle-income countries, and lowest in low-income countries (P<0.001). However, the rates of major cardiovascular events (death from cardiovascular causes, myocardial infarction, stroke, or heart failure) were lower in high-income countries than in middle- and low-income countries (3.99 events per 1000 person-years vs. 5.38 and 6.43 events per 1000 person-years, respectively; P<0.001). Case fatality rates were also lowest in high-income countries (6.5%, 15.9%, and 17.3% in high-, middle-, and low-income countries, respectively; P=0.01). Urban communities had a higher risk-factor burden than rural communities but lower rates of cardiovascular events (4.83 vs. 6.25 events per 1000 person-years, P<0.001) and case fatality rates (13.52% vs. 17.25%, P<0.001). The use of preventive medications and revascularization procedures was significantly more common in high-income countries than in middle- or low-income countries (P<0.001).
Conclusions
Although the risk-factor burden was lowest in low-income countries, the rates of major cardiovascular disease and death were substantially higher in low-income countries than in high-income countries. The high burden of risk factors in high-income countries may have been mitigated by better control of risk factors and more frequent use of proven pharmacologic therapies and revascularization. (Funded by the Population Health Research Institute and others.)
