Prevalence of CHD is decreasing in the US, Western Europe. It stabilises in Central Europe. It increases in Eastern Europe, China (well documented) South-East Asia, Africa and Latin America. So, difficult answer to an apparently simple question
Thanks for voting up. You should find the recent 2015 article in Chest by Guo et al. Greg Lip is the main author and I am sure you see him sometimes in B'ham as well. In this article the authors describe secular trends in incident atrial fibrillation in South-West China, which may be seen as a proxy for CHD as the risk factors are quite similar.