PROGRESSIVE IMPROVEMENT IN THE STRUCTURE OF RESISTANCE ARTERIES OF HYPERTENSIVE PATIENTS AFTER 2 YEARS OF TREATMENT WITH AN ANGIOTENSIN-I-CONVERTING ENZYME-INHIBITOR - COMPARISON WITH EFFECTS OF A BETA-BLOCKER

To investigate the effects of antihypertensive drugs on resistance art ery structure, 17 essential hypertensive patients were randomly assign ed to be treated with an angiotensin I-converting enzyme inhibitor, ci lazapril, or a beta-blocker, atenolol, for 2 years. Blood pressure was well controlled throughout the 2 years. Before starting treatment, at the end of the first year and at the end of the second year, patients were subjected to gluteal subcutaneous fat biopsies, from which resis tance-size arteries were dissected to be studied. The media width to l umen diameter ratio of arteries from patients in the cilazapril group was 7.5 a 0.3% before starting treatment, and decreased significantly (P < .05) to 6.3 +/- 0.2% at the end of the first year, and to 5.8 +/- 0.2% at the end of the second year, at which time it was not differen t from that of arteries from normotensive subjects (5.2 +/- 0.2%). In patients treated with atenolol, resistance arteries exhibited a media- to-lumen ratio of 8.0 +/- 0.6% before treatment, 8.1 +/- 0.5% after 1 year of treatment, and 7.9 +/- 0.3% at the end of the second year of t reatment, all significantly higher (P < .01) than that of arteries fro m normotensive subjects. Thus, treatment for 2 years with the angioten sin I-converting enzyme inhibitor cilazapril resulted in progressive n ormalization of the structure (media-to-lumen ratio) of gluteal subcut aneous fat resistance arteries of essential hypertensive patients, whe reas there was no change in patients treated with the beta-blocker ate nolol. The extent to which resistance vessels in other more critical b ut less accessible vascular beds are similarly affected, and potential benefits to hypertensive patients with respect to morbidity and morta lity resulting from elevated blood pressure, remain to be established.