HYPERTENSION AND AGE-RELATED-CHANGES IN THE HEART - IMPLICATIONS FOR DRUG-THERAPY

Heart disease in older individuals can be characterised as the result of 2 processes, hypertension and atherosclerosis, which are the major causes of heart failure in the elderly population. The aging heart und ergoes changes at the molecular, cellular and organ levels. These age- related changes may then be modulated by pathological conditions, such as hypertension, and by the reduction of blood pressure. One characte ristic of the aged heart is a limited capacity for adaptation, by hype rtrophy, to increased mechanical load. This age-related attenuation of the hypertrophic response may be attributed to the diminished inducti on of proto-oncogenes such as c-fos, c-myc and c-jun. This diminution results from aging of the heart per se and may be modulated by extraca rdiac factors. With regard to the coronary vasculature, the age at whi ch hypertension develops seems to be an important factor for determini ng the vascularity of hypertrophied hearts. Late-onset hypertension is not accompanied by coronary angiogenesis, and it decreases dilator re serve in spite of the absence of myocardial hypertrophy. In contrast, mechanical overload in infant hearts is accompanied by angiogenesis an d normal dilator reserve. In principle, the normalisation of hypertens ion results in the regression of myocardial hypertrophy and decreased coronary dilator reserve. In aged hearts, it is not clear how hyperten sion-induced myocardial hypertrophy or coronary vascular changes regre ss. Although antihypertensive treatment is clearly associated with an improvement of cardiovascular mortality and morbidity in hypertensive elderly individuals, it remains unclear how treatments ameliorate the hypertension-induced alterations.