CHICAGO — Monotherapy with the cardioselective beta-1 blocker nebivolol improved vascular function and significantly reduced blood pressure in high-risk, obese African Americans with recently diagnosed stage 1 hypertension, in an open-label study of 43 patients.
The findings are encouraging because the observed vasodilatory effects may be protective against cardiovascular and renal disease in African Americans, a group at high risk of these diseases and in whom hypertension treatment with conventional beta blockers is often suboptimal, Nadya Merchant, Ph.D., and associates reported at a meeting sponsored by the International Society on Hypertension in Blacks.
Mean systolic blood pressure decreased from 143.8 mm Hg at baseline to 133.0 mm Hg in 33 patients who completed 8 weeks of treatment with nebivolol (Bystolic). Diastolic blood pressure decreased from 90.4 mm Hg to 83.6 mm Hg. Significant improvements were seen in aortic augmentation index, from 16.6% to 11.1% post treatment, and in time to wave reflection, from 164 milliseconds to 137 milliseconds. These findings suggest nebivolol improves arterial compliance, said Dr. Merchant, a research fellow in the cardiology department at Emory University in Atlanta.
She noted there was also a significant jump in flow mediated dilation, from 3.4% before treatment to 11% post treatment. Finally, levels of erythrocyte extracellular superoxide dismutase increased with nebivolol treatment from 465.2 units/mL to 537.4 units/mL, suggesting increased bioavailability of nitric oxide.
“These findings imply that nebivolol, if used by obese hypertensive African Americans, can … decrease blood pressure significantly,” she said, adding that “there may be some positive vascular changes and therefore protection against the development of cardiovascular and renal disease.” In the current trial, patients received nebivolol 5 mg per day and were titrated to 10 mg/day if at week 2 there was no change in blood pressure. Their average body mass index was 36.5 kg/m
Forest Pharmaceuticals Inc., which markets nebivolol, provided an unrestricted grant and the study drug. Dr. Merchant is director of investor relationships for InVasc Therapeutics Inc., a company in Tucker, Ga., that develops drugs for diabetes and cardiovascular diseases.