Remodeling of resistance arteries in essential hypertension and effects of antihypertensive treatment

Essential hypertension is characterized by increased peripheral vascular resistance to blood flow. This resistance results mostly from energy dissipation in small arteries and arterioles. Small decreases in the lumen of these arteries significantly increase resistance. Resistance arteries may play an important role in the development, and may contribute to the complications, of hypertension. Recent studies have demonstrated that the media-lumen ratio of small arteries has prognostic significance in relation to cardiovascular events in hypertensive subjects. Almost all hypertensive patients have vascular-structure remodeling; however, only some exhibit endothelial dysfunction. In particular, endothelial dysfunction is less common in mild hypertension. In both experimental models and humans with hypertension, antihypertensive treatment may partially correct the remodeling of small arteries and arterioles. Some antihypertensive drugs can correct small artery structure and impaired endothelial function. Because the degree of remodeling predicts events in hypertensive subjects, and endothelial dysfunction results from the oxidative stress that may also predict events, correction of small artery structure and function may favorably affect outcomes in hypertension. This improvement in morbidity and mortality end points could be a long-term effect, however, making it difficult to prove in trials lasting 3 to 5 years. Nevertheless, many patients with hypertension will be treated for decades; therefore, the potential long-term benefits of vascular protection might be quite important.