Paris, France – 3 Sept 2019: Cardiovascular disease remains the main cause of death globally, but cancer has overtaken it to become the leading cause of death in some high-income and upper-middle-income countries. The late breaking results from the PURE study are presented in a Hot Line Session today at ESC Congress 2019 together with the World Congress of Cardiology(1).
Co-primary author Dr Darryl Leong of the Population Health Research Institute, McMaster University, Hamilton, Canada said: “If the pattern of declining cardiovascular deaths seen in the last few decades in high-income countries continues and the same pattern is followed by some middle- and low-income countries, then it is possible that cancer will become the most common cause of death worldwide in a few decades. The high cardiovascular mortality seen in the PURE study in middle- and low-income countries is likely related to low access to effective healthcare.”
Patterns of disease and death across the world are shifting as communicable disease rates fall in low-income countries and prevention and treatments for cardiovascular disease improve in high-income countries. Developing effective strategies to improve global health requires a contemporary understanding of these trends. Substantial further reductions in cardiovascular disease are possible by wider adoption of proven prevention strategies and treatments in all countries.
“Existing data are limited because they were typically collected from one country or countries within a single or a few regions, making our ability to compare regions at different economic levels potentially unreliable,” said Dr Leong. “Also, advances in the prevention and treatment of cardiovascular disease that have impacted populations were not captured in data collected more than 15 to 20 years ago.”
The PURE study(2) was conducted in 21 countries (4 high-income [HIC], 12 middle-income [MIC], and 5-low-income [LIC]) and included urban and rural sites across five continents. Households were selected to broadly represent the sociodemographic composition of their community. This analysis included 162,534 community-dwelling adults aged 35 to 70 years. Participants were contacted at least every three years to ascertain their vital status and the occurrence of incident diseases and hospitalisations. Participants were followed for nearly ten years.
Overall mortality was highest in LIC, intermediate in MIC, and lowest in HIC. This pattern was observed for all common causes of death except cancer where the mortality rates in LIC, MIC, and HIC were similar.
Cardiovascular disease was the most common cause of death overall. But in HIC, cancer deaths occurred twice as often as cardiovascular deaths. In contrast, in LIC, cardiovascular deaths were three times more frequent than cancer deaths, with MIC being in between HIC and LIC. Put another way, the ratio of cardiovascular deaths to cancer deaths was 0.4 in HIC, 1.3 in MIC, and 3.0 in LIC.
“This epidemiologic transition may be partly due to improved strategies to prevent and treat cardiovascular disease in high-income countries,” said co-primary author Dr Gilles Dagenais of the Quebec Heart and Lung Institute, Canada. “Alongside this, apart from tobacco control, effective strategies to prevent and treat cancer have yet to yield large reductions in the incidence of most cancers or deaths from common cancers as it was documented for cardiovascular disease. While very recent advances in cancer treatment will be expected to ultimately deliver impactful improvements in cancer survival, this will require improved access and wider use of such treatments.”
Participants in HIC with cardiovascular disease were less likely to die from their disease compared to MIC and LIC. This paralleled the higher rates of medication use and hospitalisation for cardiovascular disease in HIC.
Professor Salim Yusuf, senior author of the study and Principal Investigator of PURE2, said: “The high rates of cardiovascular disease and related mortality in low-income countries are likely related to gaps in access to, or availability of, healthcare. This was shown by the lower use of preventive medications and less frequent hospitalisation for cardiovascular disease. Improving access to quality healthcare is key to reducing deaths from cardiovascular and other diseases in low- and middle-income countries.”
He concluded: “As cardiovascular disease declines in many countries, cancer mortality is likely to become the leading cause of death in the future.”