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Acute Microvascular Changes With LDL Apheresis

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT02388633
Recruitment Status : Completed
First Posted : March 17, 2015
Last Update Posted : August 23, 2018
Information provided by (Responsible Party):
Jonathan R. Lindner, MD, Oregon Health and Science University

Brief Summary:
Severe hypercholesterolemia produced by conditions such as heterozygous familial hypercholesterolemia is associated with multiple complications including premature atherosclerotic disease. There is evidence that microvascular perfusion, particularly flow reserve, in critical organs is limited due to abnormalities in plasma viscosity, abnormal RBC deformability, and an imbalance between vasodilators and vasoconstrictors. There is little is currently known about acute changes in microvascular blood flow and microvascular rheology that occur in response to plasmapharesis which is used in some patients to lower critically elevated cholesterol levels. Our research group has pioneered CEU methods for assessing myocardial and skeletal muscle perfusion, and has previously demonstrated in pre-clinical models that acute hyperlipidemia produces a reduction in microvascular RBC transit rate. In this study, the investigators will assess acute changes in microvascular perfusion in patients undergoing clinically-indicated plasmapharesis.

Condition or disease Intervention/treatment
Hyperlipidemia Procedure: Plasmapharesis

Detailed Description:
Subjects who are scheduled to have planned apheresis treatment for severe hypercholesterolemia will be recruited into the study. They will undergo a screening evaluation, including a medical history, physical examination, ECG, and limited echocardiogram to evaluate for exclusion criteria. Before the apheresis procedure, blood samples will be obtained for plasma markers of inflammation, erythrocyte deformability, and plasma viscosity. Contrast enhanced ultrasound perfusion imaging will be performed to evaluate blood flow in the myocardium at rest, as well as in the forearm skeletal muscle before and after mild isometric exercise (50% maximal grip, 0.2 Hz). Flow mediated vasodilation will be performed. The subjects will then undergo their planned apheresis procedure. Within 2 hours of completion of apheresis, blood collection and CEU will be repeated. Plasma lipids will be available as part of the standard apharesis protocol.

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Study Type : Observational
Actual Enrollment : 8 participants
Observational Model: Cohort
Time Perspective: Prospective
Actual Study Start Date : March 1, 2015
Actual Primary Completion Date : July 1, 2018
Actual Study Completion Date : July 1, 2018

Group/Cohort Intervention/treatment
Patients undergoing apheresis for elevated LDL. Patients will undergo contrast ultrasound perfusion imaging at rest and during forearm exercise at before and immediately after apheresis.
Procedure: Plasmapharesis
Clinically-indicated LDL apheresis

Primary Outcome Measures :
  1. Skeletal Muscle Perfusion at Rest [ Time Frame: 10 min ]
    Contrast ultrasound assessment of microvascular perfusion of forearm skeletal muscle

  2. Skeletal Muscle Perfusion at Rest [ Time Frame: 10 min ]
    Contrast ultrasound assessment of microvascular perfusion of forearm skeletal muscle during contractile exercise.

Secondary Outcome Measures :
  1. RBC Deformability [ Time Frame: 10 min ]
    RBC deformability measured by elongation index.

Information from the National Library of Medicine

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Ages Eligible for Study:   19 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population
Patients with hyperlipidemia undergoing clinically indicated LDL apheresis

Inclusion Criteria:

  • hypercholesterolemia (LDL >200 mg/dL)
  • clinically-indicated aphersis for hyperlipidemia
  • age >18 y.o.

Exclusion Criteria:

  • pregnant or lactating females
  • hypersensitivity to ultrasound contrast agents
  • evidence for right to left or bidirectional shunt
  • on anticoagulants

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT02388633

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United States, Oregon
Oregon Health & Science University
Portland, Oregon, United States, 97239
Sponsors and Collaborators
Oregon Health and Science University
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Principal Investigator: Jonathan Lindner, MD OSHU

Publications automatically indexed to this study by Identifier (NCT Number):
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Responsible Party: Jonathan R. Lindner, MD, Professor, Oregon Health and Science University Identifier: NCT02388633    
Other Study ID Numbers: LDL Apheresis
First Posted: March 17, 2015    Key Record Dates
Last Update Posted: August 23, 2018
Last Verified: August 2018
Additional relevant MeSH terms:
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Lipid Metabolism Disorders
Metabolic Diseases