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 artery structure, 17 essential hypertensive patients were randomly assigned to be treated with an angiotensin I-converting enzyme inhibitor, cilazapril, 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 resistance-size arteries were dissected to be studied. The media width to lumen 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 different 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 treatment, all significantly higher (P < .01) than that of arteries from normotensive subjects. Thus, treatment for 2 years with the angiotensin I-converting enzyme inhibitor cilazapril resulted in progressive normalization of the structure (media-to-lumen ratio) of gluteal subcutaneous fat resistance arteries of essential hypertensive patients, whereas there was no change in patients treated with the beta-blocker atenolol. The extent to which resistance vessels in other more critical but less accessible vascular beds are similarly affected, and potential benefits to hypertensive patients with respect to morbidity and mortality resulting from elevated blood pressure, remain to be established.