Atlanta, GA - From 1980 to 2000, deaths from coronary heart disease (CHD) in the US fell by more than 40%, and almost half of this drop (44%) was due to reductions in major risk factors, a new study reveals [1]. The findings will come as a surprise, says one of the researchers, because it has been widely assumed that any drop in CHD deaths is all due to better treatment.

Dr Earl S Ford (National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control, Atlanta, GA) and colleagues report their research in the June 7, 2007 issue of the New England Journal of Medicine. The researchers show that modification of risk factors such as blood pressure, lipid levels, and smoking by nonmedical means has had a much larger impact on deaths than technologies such as angioplasty.

Senior author Dr Simon Capewell (University of Liverpool, UK) told heartwire: "There is an important message here for planners and policy makers, particularly in the US. This corrects the assumption made by a lot of people—both professionals and lay people—that the drop in deaths must be due to modern medicine. There has been a huge amount of money spent on angioplasty and CABG, with the prevailing understanding that it prevents deaths, but this is the flashy stuff and it doesn't make a great deal of difference," he said.

This corrects the assumption made by a lot of people . . . that the drop in deaths must be due to modern medicine.

Ford et al applied a statistical model, IMPACT, to data on the use and effectiveness of specific cardiac treatments and on changes in risk factors between 1980 and 2000 among US adults aged 25 to 84 years old. The IMPACT mortality model has previously been validated in Europe, New Zealand, and China and was updated for this US study.

During the two decades in question there was a rapid growth in costly medical technologies and pharmaceutical treatments for coronary heart disease as well as substantial public-health efforts to reduce the prevalence of major cardiovascular risk factors. "Establishing the relative contributions of these two approaches is therefore of considerable interest," they observe.

They found that the age-adjusted death rate for CHD fell from 542.9 to 266.8 deaths per 100 000 population among men and from 263.3 to 134.4 deaths per 100 000 population among women.

Approximately 47% of this decrease was attributed to treatments, with the largest contributions from secondary preventive therapies after MI or revascularization (11%), followed by treatments for acute coronary syndromes (10%), heart failure (9%), and revascularization by CABG or angioplasty for stable or unstable disease, which together accounted for just 7% of the overall drop in deaths from CHD.

In contrast, reducing blood pressure and lipids by nonmedical means—primarily by dietary improvements—accounted for a much larger proportion of the drop in deaths: 20% and 24%, respectively, Capewell told heartwire. Other changes in risk factors that contributed to the fall in deaths were reductions in smoking prevalence (12%) and improvements in physical activity (5%).

The drop in deaths attributed to changes in risk factors was partially offset, however, by increases in body-mass index (BMI) and the prevalence of diabetes, which accounted for an increased number of deaths (8% and 10%, respectively), he added.

"Recent trends [in obesity] in the US are very alarming—the deaths could have been 20% lower if it hadn't been for BMI and diabetes," Capewell says. "And if this had not happened, we would have seen a situation where improvements in risk factors would have accounted for two thirds of the reduction in CHD deaths and treatment only one third."

The deaths could have been 20% lower if it hadn't been for BMI and diabetes.

Capewell told heartwire that there have been signals from other published studies showing that expensive technologies and treatments do not necessarily save as many lives as other, simpler measures, but the message does not seem to have gotten through to those on the ground.

He says the US, in particular, is guilty of intervening too much. "On the one hand, you have 50 million people who have no insurance, but on the other, you have a lot of wealthy people who get extra treatment that they probably don't need."

Capewell believes that government must intervene. "It's one thing to give advice to people in GPs' offices or outpatient clinics, but this lecturing of people has only a small effect. However, simple bits of regulation—such as banning junk-food commercials on children's television—can make a huge difference," he concludes.