Despite more than 80% of the global burden of cardiovascular diseases now occurring in low- and middle-income countries,1 most of what we know about the causes of these diseases comes from studies of populations in North America and Western Europe. Many of the resulting clinical and public health policies in these high-income regions are being applied in lower-income regions, but perhaps sometimes inappropriately, since many lower-income countries have physical, social and economic environments that are substantially different from those in richer parts of the world. Helping to close this gulf in cardiovascular knowledge is the INTERHEART case–control study. Spread across one-quarter of the world’s countries, including 30 or so lower- and middle-income countries, the study is a unique resource for assessing causes of coronary heart disease in different contexts.2 3 4 5 For this reason, and because of its sheer size (12 000 cases of acute myocardial infarction (AMI) and 15 000 controls), INTERHEART has rightly become a landmark study.

New INTERHEART findings for China are unveiled in this edition of the journal (see page 1857).6 The 12 000 INTERHEART cases included 3000 in China, and the results for this subgroup are compared with those for the other 51 countries taken together. While all nine main INTERHEART cardiovascular risk factors were associated with MI in the China subgroup, there was significant heterogeneity in the strength of the association for some of these factors between China and the rest. The results suggest that the effects of diabetes and of psychosocial stress may be unusually strong in China, that the effects …