Background: The vasodilating beta-blocker nebivolol is thought to be superior in lowering wave reflection and central blood pressure (BP) compared to nonvasodilating beta-blockers. The results from studies comparing nebivolol with either metoprolol or atenolol, with or without hydrochlorothiazide (HCTZ), are not unequivocal.
Methods: We examined the effects of nebivolol 5 mg and metoprolol 100 mg with HCTZ 12.5 mg on aortic wave augmentation, central BP and hemodynamics using a randomized, double-blind, crossover design. We included 22 patients (17 men, age 59.9 ± 6.4 years) with office SBP of 155 ± 16 mmHg and DBP of 93 ± 10 mmHg. Radial applanation tonometry and noninvasive, continuous finger arterial BP measurement was performed at baseline and after 4 weeks of treatment with either drug regimen, separated by a 4-week washout period.
Results: Neither treatment affected aortic wave augmentation significantly. Augmentation index increased 1.0 ± 7.8% (P = 0.5) for nebivolol/HCTZ and 2.4 ± 6.6% (P = 0.07) for metoprolol/HCTZ. Nebivolol/HCTZ lowered central SBP by 15.8 ± 14.9 mmHg and DBP 10.5 ± 8.4 mmHg, and with metoprolol/HCTZ by 13.5 ± 12.3 mmHg for SBP and 9.5 ± 6.8 mmHg for DBP (all P < 0.001). Heart rate was lowered 8.1 ± 5.4 beats/min by nebivolol/HCTZ and 8.6 ± 4.9 beats/min by metoprolol/HCTZ. Peripheral BP was reduced to a similar extent as central BP. Peripheral BP decreased by 16.3 ± 14.9 mmHg systolic and 10.1 ± 8.2 mmHg diastolic with nebivolol/HCTZ, and by 15.2 ± 13.0 mmHg systolic and 9.1 ± 6.9 mmHg diastolic with metoprolol/HCTZ. Both treatment modalities had a similar effect on stroke volume, cardiac output, left-ventricular contractility and peripheral resistance.
Conclusion: Nebivolol was not superior to metoprolol in reducing aortic wave augmentation or central BP when combined with HCTZ.