Conventional Therapy and Newer Drug Classes for Cardiovascular Protection in Hypertension

Recently published actively controlled outcome trials in hypertension compared conventional therapy (diuretics and beta-blockers) with newer antihypertensive drug classes, including angiotensin-converting enzyme inhibitors, calcium channel blockers, alpha-blockers, and angiotensin II antagonists. In a quantitative overview of nine trials including 62,605 randomized patients, it was found that conventional therapy and newer drug classes had similar long-term efficacy in preventing cardiovascular complications of hypertension. BP lowering largely accounted for most, if not all, of the observed benefits in cardiovascular outcome. These findings emphasize the desirability of lowering BP as much as possible to maximize the reduction in cardiovascular complications. Furthermore, several clinical trials have been specifically designed to highlight specific mechanisms of action of the newer drugs by measuring intermediate end points, such as carotid intima-media thickening or renal dysfunction, or by studying subgroups of patients with specific disorders, such as diabetes mellitus. In these trials, calcium channel blockers were more effective than conventional therapy in preventing carotid intima-media thickening and mild renal dysfunction, whereas use of calcium channel blockers or angiotensin-converting enzyme inhibitors was associated with a lower incidence of diabetes mellitus in some studies. However, whether or not these specific effects of the newer drugs on intermediary and/or metabolic end points in the long run also lead to fewer cardiovascular complications remains to be proved.