Although clinical trials of the efficacy of
antihypertensive treatment have demonstrated impressive reductions in the incidence of
stroke, the reduction in
coronary artery disease mortality has been less impressive. It may be that the
antihypertensive drugs used in these trials induced metabolic disturbances, or produced inadequate regression of
left ventricular hypertrophy, thus blunting the reduction in risk of
coronary artery disease expected with blood pressure-lowering.
Isradipine, a
dihydropyridine calcium antagonist known to be an effective
antihypertensive agent, has also displayed pronounced antiatherogenic effects in animals. Thus, a reasonable hypothesis could be that
isradipine not only reduces the level of blood pressure, but also may have a positive effect on the evolution of
atherosclerotic plaque in coronary and carotid arteries, thereby leading to prevention of clinical sequelae of
atherosclerosis. On this basis, a 3-year clinical trial is being carried out in the United States--the Multicenter
Isradipine/
Diuretic Atherosclerosis Study (MIDAS)--to establish the efficacy of
isradipine in inhibiting
atherogenesis and retarding the progression of
atherosclerosis in carotid arteries of hypertensive patients. The primary end point of the study is intima-media thickness and the extent of
atherosclerotic plaque in the carotid arteries, as measured by B-mode ultrasonography.