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HypertensionNCT00353925

Genetic Analysis of African-Americans With High Blood Pressure

An observational study of Hypertension, run by National Heart, Lung, and Blood Institute (NHLBI) at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

The purpose of this study is to learn if kinase, a protein found in the heart, contributes to thickening of the heart muscle in people with high blood pressure. A protein called myosin causes the heart to contract and relax. It is thought that kinase changes myosin to make it work better at different heart rates. Read more about this study

Who is it for?
Ages 21 years and older
Conditions the study is for
Hypertension
How many people
1,000 participants
Where
1 siteUnited States
Study dates
5 Oct 1999to 10 Dec 2007
Phase
Observational
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 21 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Afro-American patients with a history of hypertension
  • Age greater than or equal to 21 years old
  • Presence of the kinase allele (homo or heterozygous)
  • Ability to give informed consent.
  • All of the above as well as:
  • Left ventricular ejection fraction of less than 35% by any imaging technique.

Who cannot join

  • For subjects with Kinase Allele:
  • There will be no exclusion criteria. Patients will be evaluated even if they are only able to participate in part of the study.
  • For Subjects without the kinase allele and Myopathy Cohort:
  • History of myocardial infarction
  • History of significant valve disease
  • History of primary hyperthropic or infiltrative cardiomyopathy
Show all 11Show fewer
  • History of rheumatic heart disease
  • Chronic atrial arrhythmia, bundle branch block intraventricular conduction defect or definite myocardial infarction on EKG
  • Inability to perform a metabolic stress test
  • Inability to perform a cMRI
  • Poor echocardiographic windows precluding accurate analysis

Trial locations and contacts

1 site in 1 country.

United States1 site
  • University of Maryland, Baltimore

    Baltimore, Maryland, 21201-1595

Other trials in United States

About this study

Official title: Genetic Analysis of African-American Hypertensives

The purpose of this study is to learn if kinase, a protein found in the heart, contributes to thickening of the heart muscle in people with high blood pressure.

A protein called myosin causes the heart to contract and relax. It is thought that kinase changes myosin to make it work better at different heart rates. This study will try to determine if, in some people with high blood pressure, the different forms of this protein cause changes in the heart. If the protein affects the size of the heart, it might be possible to use it to improve heart function after an injury, such as a heart attack.

African-Americans with high blood pressure will be eligible for this study. Current data show that of almost 900 multi-ethnic individuals, the particular form of kinase under study in this project is found exclusively in the African-American population. Study participants will have two tubes of blood drawn for DNA testing to determine what form of kinase is present. An electrocardiogram will also be done if a recent one is not available. Some people may also have an echocardiogram, an ultrasound test to image the heart.

Read the detailed description

Genetic and in vitro mechanical studies in our laboratory have suggested that the perturbations in the phosphorylation of the cardiac myosin regulatory light chain (RLC) can modulate cardiac function and produce a compensatory hypertrophic response. We have cloned a novel human cardiac kinase (MLCK) that targets the cardiac RLC and identified a common allele unique to the African-American population. The purpose of this protocol is to evaluate a large group of African-American individuals with hypertension and/or cardiac disease, a portion of who will possess this allele. It is well documented that hypertensive African-Americans have an increased prevalence of left ventricular hypertrophy (LVH). We expect that, in this population of hypertensive individuals, we will find an increased left ventricular mass in individuals who are heterozygous or homozygous for this kinase allele.

In this study, patients with the allele can be matched to others in the cohort without the allele and evaluated by echocardiography and cardiac MRI to evaluate cardiac function and chamber size. In addition, metabolic stress testing will be performed to assess the implications of this allele on clinical performance. Another group of 75 Afro-Americans with dilated cardiomyopathy will be referred from local heart failure clinics and evaluated in a similar fashion. Allele prevalence and associated cardiac findings will also be compared with hypertensive patients matched for age and gender. In a parallel experiment, mice over-expressing this kinase, are being generated and will provide us with tissue samples with which to pursue the biophysical basis of the mechanical changes in muscle function.

Conditions
Hypertension
Keywords
Hypertrophy, LVH, Cardiac, Blood Pressure, Papillary Muscle
Medical subject headings
Hypertension, Hypertrophy

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted19 Jul 2006 (estimated)
  2. Study start5 Oct 1999
  3. Study completion10 Dec 2007

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Enrolment
1,000 participants
IDs, dates and publications
ClinicalTrials.gov ID
NCT00353925
Sponsor's protocol ID
000003
Other IDs
00-H-0003
Status last verified
10 Dec 2007
First submitted
18 Jul 2006
Last updated
2 Jul 2017
Results posted
No

Publications

  • Sahn DJ, DeMaria A, Kisslo J, Weyman A. Recommendations regarding quantitation in M-mode echocardiography: results of a survey of echocardiographic measurements. Circulation. 1978 Dec;58(6):1072-83. doi: 10.1161/01.cir.58.6.1072.

    PubMed 709763

Questions about this trial

What is this clinical trial studying?

An observational study of Hypertension, run by National Heart, Lung, and Blood Institute (NHLBI) at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 6 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 2 Jul 2017. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT00353925, which also lists 1 linked publication.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Jul 2017.

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