Effects of Nebivolol on Skeletal Muscle During Exercise in Hypertensive Patients

October 9, 2018 updated by: Wanpen Vongpatanasin, University of Texas Southwestern Medical Center

Effects of Nebivolol on Microvascular Perfusion in the Skeletal Muscles During Exercise in Hypertensive Patients

The purpose of this study is to determine if Nebivolol improves microvascular perfusion in skeletal muscle during exercise in hypertensive patients and whether this improvement is accompanied by reduction in vascular oxidative stress or increased endothelial nitric oxide synthase (eNOS) expression in humans.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

In 32 untreated stage 1 hypertensive subjects, the investigators will measure blood pressure; noninvasive cardiac output by thoracic electrical bioimpedance (Bioz, Cardio Dynamics); forearm mediated vasodilation (FMD), which is a non-invasive assessment of endothelial function; collect venous endothelial cells; and measure microvascular perfusion using an Octafluoropropane microbubble contrast agent (Definity).

To obtain FMD, the brachial artery will be imaged using ultrasound. After a clear picture has been obtained, the cuff on the same arm will be inflated until it is tight for five minutes. During and following this, the subject's arm will continue to be imaged to monitor maximal increase in the brachial artery diameter.

To collect endothelial cells, a thin wire will be inserted in the vein to collect cells from the inner lining of the vein. The cells collected will be processed and stained for several proteins involved in endothelial cell function, using immunofluorescent technique.

To assess the microvascular perfusion in the skeletal muscle, a contrast agent (Definity) will be administered at baseline and after 5 minutes of rhythmic hand grip exercise at 30% of maximal voluntary contraction.

The investigators will then randomize our subjects to receive 12 weeks of Metoprolol or Nebivolol, using a cross over design. There will be a 4 week washout period between the two treatments. During the washout period, subjects will be followed after 2 weeks of drug withdrawal. Subjects found to have BP > 140/90 mmHg then, will be started on hydrochlorothiazide (HCTZ) at 25 mg once daily. Then subjects will be asked to return in 2 weeks. At that time HCTZ will be stopped if started in the earlier visit, and subject will be switched to the remaining treatment (Nebivolol or Metoprolol). Then, the investigators will assess microvascular perfusion in the skeletal muscle at rest and during handgrip exercise, endothelial function (FMD), and changes in endothelial cell protein expression after 12 weeks of Nebivolol and after 12 weeks of Metoprolol treatment in the same subjects.

Study Type

Interventional

Enrollment (Actual)

32

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Texas
      • Dallas, Texas, United States, 75390-8586
        • UT Southwestern Medical Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 65 years (ADULT, OLDER_ADULT)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Men and women with stage I primary untreated hypertension (BP between 140-159/90-99 mmHg)
  • Age 18-65

Exclusion Criteria:

  • Congestive heart failure
  • Coronary artery disease
  • Left ventricular hypertrophy by echocardiography or ECG
  • History of stroke
  • Average blood pressure >159/99 mmHg
  • Bradycardia with a resting heart rate <55 bpm
  • Chronic kidney disease with a serum creatinine > 1.4 mg/dL
  • Asthma or chronic obstructive pulmonary disease
  • Women who are pregnant or planning to become pregnant
  • Hypersensitivity to beta blockers, hydrochlorothiazide, or Definity
  • Any history of substance abuse (other than tobacco)
  • Concomitant drug treatment which raises endogenous nitric oxide levels, including nitrates or phosphodiesterase V inhibitors (Viagra, Levitra)
  • History of symptomatic bradycardia or heart block
  • Patients with Right-to-left, bidirectional, or transient right-to-left cardiac shunts
  • Hypersensitivity to perflutren, blood, blood products or albumin.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: DIAGNOSTIC
  • Allocation: RANDOMIZED
  • Interventional Model: CROSSOVER
  • Masking: NONE

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
ACTIVE_COMPARATOR: Initial treatment with metoprolol
The subject will be started on metoprolol succinate (Toprol XL) 100-300mg daily, which he/she will continue for a period of 12 weeks. Following the 12-week treatment period, the procedures listed below will be performed. After completion of the study procedures, the medication will be discontinued. If necessary, 2 weeks after drug withdrawal, subjects will be started on HCTZ if BP > 140/90 mmHg and will continue HCTZ for a 2-week period, after which the subject will be transitioned to nebivolol (Bystolic) 5-20mg daily, which he or she will continue for a period of 12 weeks. Following the 12-week treatment period, the procedures listed below will be performed. After completion of the study procedures, the medication will be discontinued.
Drug: Metoprolol succinate
The subject will be started on metoprolol succinate (Toprol XL) 100-300mg daily, which he or she will continue for a period of 12 weeks. Following the 12-week treatment period, the procedures listed below will be performed. After completion of the study procedures, the medication will be discontinued.
Other Names:
  • Toprol XL
Drug: Nebivolol
The subject will be started on nebivolol (Bystolic) 5-20mg daily, which he or she will continue for a period of 12 weeks. Following the 12-week treatment period, the procedures listed below will be performed. After completion of the study procedures, the medication will be discontinued.
Other Names:
  • Bystolic
Procedure: Non-invasive measurement of Cardiac Output (CO)
Cardiac Output (CO) will be measured non-invasively at rest and during exercise by thoracic electrical bioimpedance. Stroke volume will be derived from change in impedance/time measured during electrical systole. Cardiac output will be determined as the product of stroke volume and heart rate.
Other Names:
  • Cardiac output by thoracic electrical bioimpedance
  • Bioz, Cardio Dynamics International Corporation
Procedure: Endothelial cell collection
We will collect endothelial cells from a superficial vein, usually in the arm. Following insertion of a peripheral intravenous (IV) catheter, we will collect cells from the inner lining of the vein using a thin, flexible J-tipped wire. The wire will be inserted through the IV into the vein and then removed, along with a sampling of endothelial cells. The cells collected will be processed and stained for several proteins involved in endothelial cell function, using immunofluorescent technique.
Other Names:
  • Endocell collection
Procedure: Microvascular perfusion assessment using Definity
Using high-resolution ultrasound, we will measure skeletal muscle blood flow during infusion of a solution containing the octafluoropropane microbubble contrast agent, Definity. The solution will be a dilution of 1 vial of Definity to 30 cc of normal saline. The ultrasound probe will be placed over the forearm to obtain images while octafluoropropane microbubbles (Definity) are infused intravenously at the rate of 0.20 to 0.27 ml/min, not to exceed a maximum dose of 2 vials per study subject per day or visit. The microvascular perfusion assessment using Definity be performed at rest as well as during slow and fast handgrip exercises.
ACTIVE_COMPARATOR: Initial treatment with nebivolol
The subject will be started on nebivolol (Bystolic) 5-20mg daily, which he or she will continue for a period of 12 weeks. Following the 12-week treatment period, the procedures listed below will be performed. After completion of the study procedures, the medication will be discontinued. If necessary, 2 weeks after drug withdrawal, subject will be started on HCTZ if BP > 140/90 mmHg and will continue HCTZ for a 2-week period, after which the subject will be transitioned to metoprolol succinate (Toprol XL) 100-300mg daily, which he or she will continue for a period of 12 weeks. Following the 12-week treatment period, the procedures listed below will be performed. After completion of the study procedures, the medication will be discontinued.
Drug: Metoprolol succinate
The subject will be started on metoprolol succinate (Toprol XL) 100-300mg daily, which he or she will continue for a period of 12 weeks. Following the 12-week treatment period, the procedures listed below will be performed. After completion of the study procedures, the medication will be discontinued.
Other Names:
  • Toprol XL
Drug: Nebivolol
The subject will be started on nebivolol (Bystolic) 5-20mg daily, which he or she will continue for a period of 12 weeks. Following the 12-week treatment period, the procedures listed below will be performed. After completion of the study procedures, the medication will be discontinued.
Other Names:
  • Bystolic
Procedure: Non-invasive measurement of Cardiac Output (CO)
Cardiac Output (CO) will be measured non-invasively at rest and during exercise by thoracic electrical bioimpedance. Stroke volume will be derived from change in impedance/time measured during electrical systole. Cardiac output will be determined as the product of stroke volume and heart rate.
Other Names:
  • Cardiac output by thoracic electrical bioimpedance
  • Bioz, Cardio Dynamics International Corporation
Procedure: Endothelial cell collection
We will collect endothelial cells from a superficial vein, usually in the arm. Following insertion of a peripheral intravenous (IV) catheter, we will collect cells from the inner lining of the vein using a thin, flexible J-tipped wire. The wire will be inserted through the IV into the vein and then removed, along with a sampling of endothelial cells. The cells collected will be processed and stained for several proteins involved in endothelial cell function, using immunofluorescent technique.
Other Names:
  • Endocell collection
Procedure: Microvascular perfusion assessment using Definity
Using high-resolution ultrasound, we will measure skeletal muscle blood flow during infusion of a solution containing the octafluoropropane microbubble contrast agent, Definity. The solution will be a dilution of 1 vial of Definity to 30 cc of normal saline. The ultrasound probe will be placed over the forearm to obtain images while octafluoropropane microbubbles (Definity) are infused intravenously at the rate of 0.20 to 0.27 ml/min, not to exceed a maximum dose of 2 vials per study subject per day or visit. The microvascular perfusion assessment using Definity be performed at rest as well as during slow and fast handgrip exercises.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Endothelial Cell Protein Expression p47phox From Endothelial Cell Collection
Time Frame: 12 weeks
Endothelial cell (EC) was collected after a 20-guage angiocatheter was inserted into the contralateral forearm vein under sterile conditions. Three J-shaped vascular guidewires (St. Jude, St. Paul, MN) were advanced sequentially into the vein up to 10 cm. Endothelial cells were collected by gentle abrasion and placed into a dissociation buffer (0.5% bovine serum albumin, 2mM EDTA, and 100 ug/ml heparin in PBS). Endothelial cells were recovered from the tips of guide wires by repeated washing into collection tubes and subsequent centrifugation. EC were incubated with monoclonal antibodies against the polyclonal antibodies against NADPH oxidase p47 subunit. The intensity of staining was measured using fluorescence microscopy.
12 weeks
Microvascular Blood Flow
Time Frame: 12 weeks
Microvascular perfusion of skeletal muscle were measured during handgrip at 20 cycle per minute after 12 weeks of metoprolol, and after 12 weeks of nebivolol
12 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Texas Southwestern Medical Center

Collaborators

Forest Laboratories

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

August 1, 2010

Primary Completion (ACTUAL)

December 1, 2015

Study Completion (ACTUAL)

December 1, 2015

Study Registration Dates

First Submitted

November 29, 2011

First Submitted That Met QC Criteria

December 29, 2011

First Posted (ESTIMATE)

December 30, 2011

Study Record Updates

Last Update Posted (ACTUAL)

November 6, 2018

Last Update Submitted That Met QC Criteria

October 9, 2018

Last Verified

May 1, 2018

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • Bystolic MD52

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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