Spectrum of Hypertensive Target Organ Damage in Africa: a Review of Published Studies

This paper reviews the evidence of hypertensive target organ damage (HTOD) in Africa, and the difficulties of its assessment, with a focus on implications for further research and prevention. Specific examples of HTOD reviewed include left ventricular hypertrophy, heart failure, ischaemic heart disease, arrhythmias and sudden death, kidney failure, cerebrovascular accidents, retinopathy and central as well as peripheral vascular disease. There is evidence that the prevalence of hypertension is increasing in some parts of Africa, thus increasing the number of people who suffer from fatal and nonfatal complications. Analysis of the type, frequency and distribution of HTOD is critical to the design of interventions to prevent and manage hypertension, and in the design of future clinical research. As would be expected, the frequency of atherosclerotic complications, particularly involving the heart, is lower in Africa than in developed countries. Stroke, renal failure and heart failure appear to be the principal adverse outcomes and are likely to be associated with a high case fatality rate. Community-based data on these issues are limited, however, and hospital series cannot estimate the population burden and may be unreliable in describing the case mix. Improved data on HTOD will more accurately reflect the health impact of hypertension, provide the basis for aggressive efforts at prevention, detection and control of high BP and establish their relevance in the overall scheme of resource allocation during fiscal austerity and limited healthcare spending. Additionally, knowledge of the prevalence and relative frequencies of HTOD has direct and important implications for clinical outcomes research in hypertension.