Editorial: The cardiovascular disease epidemic: global, regional, local

‘The challenge of the cardiovascular disease epidemic is not whether it will occur at all in the developing countries but whether we respond in time to telescope the transition and avoid the huge burden in young and middle age adults. The question is not whether we can afford to invest in cardiovascular disease prevention in the developing countries, but whether we can afford not to’ (Ruth Bonita). This statement by the director for the surveillance of non-communicable diseases at the World Health Organization (WHO) forcefully summarizes critical issues related to cardiovascular disease (CVD) in developing countries: the upsurge of the CVD epidemic and the need for an urgent response to prevent an impending additional burden that can hardly be afforded by low and middle-income countries already plagued with scarce resources and a large burden of infectious diseases. Global–regional–local interrelations are central to these considerations. Globalization fuels the epidemic even to the remotest communities by spreading many unhealthy behaviours and environments conducive to CVD. However, globalization can also provide powerful means to tackle CVD at broad and local levels. The rise in CVD in developing countries can be best understood in the light of the ‘epidemiological transition’ (Omran 1971; Reddy Sacks et al. 2001; Tuomilehto et al. 2001). From a strategic perspective, it must be recognized that interventions targeting only high-risk individuals (e. g. hypertensive or diabetic patients) will have very limited impact on the total CVD burden at the population level because most CVD cases in a population arise from the many individuals who have only moderately elevated risk factor levels – the so called ‘prevention paradox’ (Rose 1981). Population-wide intervention makes sense: it is estimated that a reduction in diastolic BP of only 3 mmHg in the entire population would reduce stroke deaths by about 1 million in the Asia/Pacific region by 2010 (Eastern Stroke and CHD Collaborative Research Group 1998). Overall, enough knowledge is now available for rational and effective prevention and control of CVD, even in developing countries (Beaglehole 2001). The rapidly escalating prevalence of risk factors in many developing countries points to several detrimental effects of globalization. Globalization can be characterized by intensified human interactions in a wide range of spheres (social, political, economic, environmental). The formidable spread of communication technologies has brought about an unprecedented flow of information across geographical, political and cultural boundaries via the mass media, advertising agencies and electronic channels. Unleashed trade liberalization has resulted in profound changes in consumption patterns worldwide, which parallel a concentration of the food production and expanded markets at an intercontinental scale. Remarkable examples of increased consumption of unhealthy products resulting from global marketing campaigns and trade liberalization include cigarettes, carbonated drinks (‘coca-colonization’) and cheap energy dense foods – the latter replacing locally produced low-fat and fibre-rich foods. In this respect, CVD can be appropriately considered as a communicated disease. By fuelling ‘vectors’ that can alter people's lifestyles, particularly with regards to tobacco use and unhealthy dietary patterns, globalization is certainly an important factor for the increasing prevalence of overweight, high blood pressure, dyslipidaemia, type II diabetes, and ultimately CVD. However, globalization also offers a range of potentially powerful opportunities for improving public health, including the prevention of CVD. On a general note, globalization can benefit health through improved economic growth and incomes, including the poor (Feachem 2001). More specifically, electronic information technologies permit expeditious and inexpensive dissemination of evidence-based knowledge to individuals, health professionals and policy-makers. This provides unprecedented opportunities for training in the remotest places and it facilitates network-building and information-sharing at regional, national or international levels. Global mechanisms can also be created to counter transnational political or economical influences. An example is the Framework Convention for Tobacco Control (FCTC), which is currently being drafted by the member states of the WHO. This legally binding international treaty will be a powerful global public health instrument for improving and harmonizing tobacco control measures and legislations in most countries. The ‘power of the process’ of negotiating this global treaty is already galvanizing new mechanisms of multisectoral collaboration at both national and continental levels. The influence of globalization on trade can also be positive. In Hungary, liberalization of trade in 1989 (alongside an unchanged health budget) resulted in substantially improved dietary patterns (e. g. fewer animal products and more fresh fruit and vegetables) that are believed to have largely accounted for the 25% decrease of the CVD mortality from 1989 to 1995 (Zatonski et al. 1998). The large contribution of the main risk factors to the CVD epidemic is well established and the need to reduce these risk factors is clearly a common goal of any prevention and control strategy. Generally, a dual approach is considered: screening and treatment of high-risk individuals while fostering population-wide preventive activities, starting in childhood, to reduce risk factor levels in the entire population. However, the appropriate mix in public health interventions and high-risk interventions is likely to differ widely between western and developing countries. Indeed, the CVD epidemic in western countries has largely relied on high-risk strategies (e. g. screening and treatment of hypertension, diabetes and dyslipidaemia) and clinical management of symptomatic CVD (e. g. coronary bypass, angioplasty). This predominant use of clinical approaches in western countries has taken place largely because the knowledge to tackle CVD has developed in parallel with the rise of the epidemic and because these wealthy countries could afford the considerable costs of such approaches. In contrast, the CVD epidemic is still in its upswing in developing countries. Therefore, there is a window of opportunity for primary prevention in these countries. Primary prevention has not only the potential to decrease the number of new cases of CVD (i. e. to short-cut the epidemic) but interventions aimed at promoting healthy lifestyles among populations are also likely to necessitate far fewer resources. The cost of treatment for chronic diseases, from 5–30 for the annual cost of the simplest antihypertension medication to > 5000 for coronary revascularization, should indeed be weighed against the available resources. In low-income countries, health expenses can amount to as little as 10–20 per head of population per year – memorably compared with the cost of a ‘meal at McDonald's (Montgomery 1998) – against 1000–4000 in western countries. These different constraints are also well illustrated by the actual number of cardiac surgery cases: less than 30 cardiac surgery cases per 1 million people in Africa and Asia compared with around 1000 cases per 1 million people in USA (Cox 2001). The control of the CVD epidemic in developing countries should therefore rely largely on primary prevention, as emphasized in various policy documents (Chockalingam et al. 2000; WHO 2000a, b; Lenfant 2001; Nissinen et al. 2001; van der Sande et al. 2001). This includes, on one hand, community empowerment through mass and targeted education. Although there has been some controversy (Ebrahim Sachs 2002). In view of the large impact of CVD on the health of economically active adults, on whom young and old members of the population are often dependent, investment in CVD prevention is likely to improve the productivity of the workforce, speed up economic growth and foster social stability. Inversely, ignoring non-communicable diseases in the health agenda of developing countries will inevitably lead to an increase in their burdens. A ‘no-priority’ approach would also allow the provision of health services for CVD to be largely undirected by issues of cost effectiveness, and their treatment and prevention would be left to the mercy of local and global commercial interests (Unwin et al. 2001). Not only would such a ‘no-priority’ approach provide an ineffective response to the CVD epidemic but also it would ignore issues of equity in providing care for people with these conditions. CVD prevention in the developing countries is necessary, feasible, and affordable. Now is the time to act. I thank Prof Fred Paccaud (University of Lausanne, Switzerland) and Dr Conrad Shamlaye (Ministry of Health, Seychelles) for pertinent comments and suggestions on previous versions.