VASCULAR REMODELING AND ENDOTHELIAL FUNCTION IN HYPERTENSIVE PATIENTS- EFFECTS OF ANTIHYPERTENSIVE THERAPY

Objective: To review studies of effects of antihypertensive agents on alterations in structure and function of small (resistance-size) arter ies in hypertensive patients and in experimental hypertensive models, since these vessels may contribute to blood pressure elevation or to t he complications of hypertension. Main outcome measures: The structure and endothelium-dependent relaxation of small arteries obtained in hy pertensive humans from gluteal subcutaneous biopsies, and from differe nt vascular beds in hypertensive rats, without and after antihypertens ive treatment, and studied on a wire-myograph or as pressurized arteri es, are described as reported in different studies. Results: Treatment of spontaneously hypertensive rats (SHR) with angiotensin converting enzyme (ACE) inhibitors, calcium channel antagonists, angiotensin rece ptor antagonists and novel beta blockers such as carvedilol, has been shown to result in regression of the altered structure of small arteri es in different vascular beds, in addition to improved endothelium-dep endent relaxation. Several studies in hypertensive patients have now s hown that treatment with some ACE inhibitors (cilazapril and perindopr il) or extended release calcium channel antagonists (nifedipine GITS) induces similar effects in small arteries obtained from gluteal subcut aneous biopsies: both structure and endothelium-dependent relaxation i mprove under treatment. In contrast, hypertensive patients with equall y well-controlled blood pressure but treated with the beta blocker ate nolol did not in any of three studies exhibit any improvement in the s tructure of small arteries or in endothelial function. Conclusion: Alt hough treatment for at least one year with some ACE inhibitors and ext ended release calcium channel antagonists corrects the structure and e ndothelium-dependent relaxation of gluteal subcutaneous small arteries , it still remains to be determined whether this apparently beneficial effect beyond blood pressure lowering of these and other agents with vascular protective properties will result in reduced morbidity and mo rtality in hypertensive patients.