The WHO MONICA Project - an international collaboration of researchers from 21 countries (2) - studied more than 30 populations, mainly from Europe, over a period of ten years, from the mid-1980s to the mid 1990s. More than seven million men and women aged between 35 and 64 years of age were monitored to examine if and how certain coronary risk factors and new treatments for heart disease contribute to the decline or rise of heart disease rates in these communities.

The risk factors studied by MONICA included cigarette smoking, blood pressure, blood cholesterol and body weight. Treatments taken into consideration included aspirin, beta blockers, ACE-inhibitors, thrombolytics (clot-busters) and coronary artery surgery. All of these are known from other research studies to determine risk or survival from heart disease in individuals.

Heart disease rates fell in most of the populations studied, as did cigarette smoking in men, blood pressure and blood cholesterol. Smoking in women showed a mixed picture and weight rose in both men and women in most populations. According to WHO, most of the trends are moving in the right direction. However, the increase in obesity, and in smoking among women, requires immediate public health action.

Taking all populations as a whole, decline in smoking seems to have contributed most to the reduction in the risk of heart disease in men. In women, decrease in blood pressure emerged as the strongest determinant.

Overall, it was found that the relation between the fall in heart disease rates and the change in risk factors was more apparent in men than in women.

Countries where large reductions in several risk factors have taken place are experiencing remarkable declines in heart attacks: in men, for example, Finland and New Zealand showed a reduction of 7% per year, USA 6%, and Australia 5%. On the other hand, populations mainly from Eastern Europe and China, where the risk factors have been found to be rising, have experienced increases in heart disease.

Dr Kari Kuulasmaa, lead author of the risk factor report and head of the MONICA Data Centre in Helsinki, Finland, commented: "The results underline that important changes in risk factors are happening across countries. But they also show that many of the trends in heart disease over a ten-year period cannot be fully attributed to the risk factor changes that occur at the same time. More work is needed to understand better how risk factor changes over time impact on heart attack rates in whole communities."

The second report shows that advances in medical treatment in the 1980s and in the 1990s were related to heart disease rates and survival. However, improvements in heart disease rates and treatment varied greatly across countries.

"When the MONICA study was started, there was little evidence that treatment had a real impact on outcomes in heart disease. The recent results are very positive, but we cannot definitely attribute the benefits to specific drugs. These papers will initiate considerable discussion among medical experts and are likely to generate further research in this field", states Professor Hugh Tunstall-Pedoe, University of Dundee, United Kingdom, lead author of the coronary care report. "Take care of your risk factors whether or not you have heart disease. If you have heart disease or are at high risk, be sure to follow your treatment", he added.

According to WHO, the study clearly demonstrates that many of the countries involved are approaching the problem appropriately by combining strong preventive efforts with provision of essential medical treatment.

"This has implications especially in developing countries where heart disease and stroke epidemics are rapidly advancing. In the long run, a preventive approach with emphasis on better diet, more exercise and reduction in smoking will also prevent other noncommunicable diseases, such as diabetes, certain cancers and chronic lung diseases", she adds.

(1) Monitoring trends and determinants in cardiovascular diseases

(2) Australia, Belgium, Canada, China, Czech Republic, Denmark, Finland, France, Germany, Iceland, Italy, Lithuania, New Zealand, Poland, Russia, Spain, Sweden, Switzerland, United Kingdom (Northern Ireland and Scotland), USA, Yugoslavia.

For further information from WHO, journalists can contact Ms Susanna Gorga, WHO, Geneva, tel (+41 22) 791 2592, fax (+41 22) 791 4755. E-mail: gorgas@who.int or Dr Ingrid Martin, Coordinator, NCD/CVD, WHO, Geneva, tel (+41 22) 791 3441, fax (+41 22) 791 4151. E-mail: martini@who.int. All WHO Press Releases, Fact Sheets and Features can be obtained on Internet on the WHO home page http://www.who.int