[Arterial ageing and coronary artery disease: physiopathological and epidemiological data]

Abstract

Vascular remodelling describes any change in arterial structure or function during physiological (ageing) and pathological processes such as atherosclerosis and hypertension. Adaptive changes in the short-term may carry pathological consequences in the long-term. The effects of ageing are additive with those of hypertension. The consequences are different according to whether the small resistance arteries or the large arteries of conduction are taken into consideration. The resistance arteries undergo three types of changes: (1) concentric or entrophic remodelling; this is a reorganisation of the same amount of tissue around a smaller diameter; (2) a rarefaction of the arteriolar bed; this is a smaller density of arterioles per unit weight of tissue perfused; (3) early disease of endothelial function with a reduced bio-availability of NO. The global result is an increase in peripheral resistance, a reduced capacity for vasodilatation and tissue ischaemia under critical conditions of perfusion. The methods of investigation of these different factors are not sufficiently well developed for use in routine clinical practice. Disease of the large arteries is principally an excentric hypertrophy, an increase in rigidity and loss of compliance. The increase in rigidity depends on the arterial territory: it is important in the aorta, moderate for elastic arteries but paradoxically decreased for muscular arteries, reflecting the combined effect of vascular smooth muscle hypertrophy ( mainly in the periphery) and changes in the extracellular matrix (mainly in the elastic arteries). The increased arterial rigidity is accompanied by an increase in cardiac work, hypertrophy, decreased coronary perfusion, favourising myocardial ischaemia. Peripheral artery remodelling also occurs in the coronary network. Therefore, the predictive positive value of hypertrophy and, above all, of aortic rigidity for coronary artery disease has now been well established in many populations. This predictive value is a complement to risk algorithms (SCORE, Framingham) and further predicts the coronary risk. Remodelling and arterial rigidity constitute disease of the artery as a target organ. Arch Mal Coeur Vaiss