Regression of structural alterations of hypertension with calcium antagonists--vascular hypertrophy

Structural vascular changes in the precapillary arterioles are a cardinal feature of established hypertension, and have been described in several vascular beds. In brief, the wall:lumen ratio becomes increased due to hypertrophy of the vascular smooth muscle cells. This results in a reduction of the inner radius in the precapillary vessels, which causes a structurally based vascular hyperreactivity and accentuates the increase in systemic vascular resistance, another hallmark of established hypertension. Much interest has been devoted to the possibility of obtaining a regression of these structural vascular changes. Previously, the emphasis was on obtaining a fall in blood pressure, but more recently additional factors have also been considered, in particular the so-called trophic factors. In this context the calcium antagonists of the dihydropyridine type appear to be of particular interest, since these are markedly effective in lowering elevated arterial pressure, while at the same time they do not cause reflex-mediated elevations of trophic factors during long-term treatment. Few clinical data are yet available to show whether calcium antagonists can cause a regression of structural vascular changes, but some recent animal work suggests that they are clearly useful in this respect.