The limits of antihypertensive therapy--lessons from Third World to First.

A rapidly developing 'second-wave epidemic' of cardiovascular disease is flowing through developing countries and the former socialist republics. It is now evident from World Health Organisation data that coronary heart disease and cerebrovascular disease are increasing so rapidly that they will rank as numbers 1 and 5 respectively as causes of global burden of disease by the year 2020. In spite of the current low prevalence of hypertension in some countries, the total number of hypertensive subjects in the developing world is high, and a cost-analysis of possible antihypertensive drug treatment indicates that developing countries cannot afford the same treatment as developed countries. In the USA only 20% of cases of hypertension are adequately controlled (blood pressure < 140/90 mmHg), and in the developing world the figure falls to 5 - 10%. Black hypertensives have varying responses to antihypertensive therapy. They respond well to thiazide diuretics, calcium channel blockers, vasodilators such as alpha-blockers, hydrazine and reserpine, and poorly to beta-blockers, angiotensin-converting enzyme (ACE) inhibitors and angiotensin II-receptor antagonists unless these drugs are combined with a diuretic. A comprehensive cardiovascular disease (CVD) programme is necessary. There are social, economic and cultural factors that impair control of hypertension in developing countries. Hypertension control should ideally be the initial component of an integrated CVD control programme that needs to be implemented in developing countries. Primary prevention through a population-based lifestyle-linked programme, as well as cost-effective methods of detection and management, are synergistically linked. The existing health care infrastructure needs to be orientated to meet the emerging challenge of CVD, while empowering the community through health education.