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.
aDepartment of Vascular Medicine, Academic Medical Center
bEdwards Lifesciences BMEYE
cLaboratory for Clinical Cardiovascular Physiology, Heart Failure Research Center, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
Correspondence to Daan W. Eeftinck Schattenkerk, MD, Academic Medical Center, Department of Vascular Medicine, Meibergdreef 9, Room F4-121, 1105 AZ Amsterdam, The Netherlands. Tel: +31 205666612; fax: +31 205669343; e-mail: email@example.com
Abbreviations: AIx, augmentation index; AIx@hr75, heart rate-adjusted AIx; BP, blood pressure; CO, cardiac output; HCTZ, hydrochlorothiazide; HOMA, Homeostatic Model Assessment; HR, heart rate; MAP, mean arterial pressure; SV, stroke volume; SVR, systemic vascular resistance; xBRS, cross-correlation time-domain baroreflex sensitivity
Received 5 April, 2013
Revised 12 June, 2013
Accepted 10 July, 2013
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