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The IMPULSE Study: Pilot (IMPULSE)

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: NCT02044471
Recruitment Status : Completed
First Posted : January 24, 2014
Last Update Posted : April 28, 2017
Thoratec Corporation
Information provided by (Responsible Party):
Gilberto Defreitas, Baylor College of Medicine

Brief Summary:

Continuous-flow (CF) left ventricular assist devices (LVADs) are an important tool in the treatment of end-stage heart failure, affording patients significantly improved quantity and quality of life. In recent years, tens of thousands of LVADs have been implanted worldwide, with nearly 1,000 at the Texas Heart Institute (THI). Despite the benefits from LVAD therapy, one major weakness is the high frequency of late strokes, reported up to 19%. CF LVADs minimize or remove the pulsatility within the blood system, introducing a new and incompletely understood physiology.

Increased sympathetic ("fight or flight" nervous system) tone secondary to lack of pulse in the blood system can cause high blood pressure, with subsequent hemorrhaging strokes (bleeding into the brain) are one possible explanation for this high adverse event rate in CF LVAD patients. A simple intervention to decrease the increased sympathetic tone is called "ischemic conditioning"; a sphygmomanometer (blood pressure cuff) is placed on the patient's arm to compress a major artery (ischemia) with subsequent release of the cuff (reperfusion) for set periods of time. This has been shown to reduce blood pressure and major adverse cardiovascular events in other patient populations.

We plan to conduct a trial to evaluate this intervention, ischemic conditioning, in patients with CF LVADs. We hypothesize that IC will cause a reduction in blood pressure and strokes in this patient population.

Condition or disease Intervention/treatment Phase
Chronic Heart Failure Other: Remote Ischemic Conditioning (using Sphygmomanometer) Not Applicable

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 20 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single (Outcomes Assessor)
Primary Purpose: Prevention
Official Title: The IMPULSE Pilot Study-- Investigating a Novel Synergy: Applying Ischemic Conditioning to Modulate the Altered Physiology From Contemporary continUous Flow Left Ventricular Assist Devices, to Reduce Stroke and Other Adverse Effects
Study Start Date : August 2014
Actual Primary Completion Date : April 2016
Actual Study Completion Date : December 2016

Arm Intervention/treatment
Experimental: Intervention

Our intervention will be ischemic conditioning (IC) remotely applied using a sphygmomanometer. We will use the standard, validated protocol, which is inflation of the sphygmomanometer to 200 mmHg for 5 minutes, then deflation with 5 minutes of reperfusion, repeated for 3 cycles (total 30 minutes). This will be done in the dominant arm, twice daily.

Once patients are discharged home on a stable pharmacotherapy regimen, they will be expected to follow the above intervention for 6 weeks, followed by another 6 weeks in the control (no intervention) phase. Patients will be randomized as to which phase they begin the study.

Other: Remote Ischemic Conditioning (using Sphygmomanometer)

Patients in experimental arm will have validated protocol of Remote Ischemic Conditioning (using Sphygmomanometer): 5 minutes with blood pressure cuff inflated at 200 mmHg, then deflated for 5 minutes; repeated for 3 cycles.

Patient in control group will not perform this.

No Intervention: Control
standard care

Primary Outcome Measures :
  1. Change in mean doppler blood pressure [ Time Frame: 6 weeks ]
    Patients will follow a standard, validated protocol for this non-invasive technique for 6 weeks, followed by 6 weeks in the control phase (or vice versa based on randomization of order). Each week, they will have Doppler blood pressure measurements and blood samples drawn for analysis.

Secondary Outcome Measures :
  1. change in mean levels of inflammatory markers (TNFa, IL6, IL8, IL10) and endothelial function (adenosine, acetylcholine, bradykinin, nitric oxide, angiotensin, aldosternone) [ Time Frame: 6 weeks ]
  2. change in sympathetic neuronal activity [ Time Frame: 6 weeks ]
    microneurographic measures of sympathetic function via peroneal nerve

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • continuous flow LVAD and able to provide informed consent and comply with follow-up

Exclusion Criteria:

  • < 18 years of age

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): NCT02044471

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United States, Texas
Baylor College of Medicine
Houston, Texas, United States, 77030
Sponsors and Collaborators
Baylor College of Medicine
Thoratec Corporation
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Principal Investigator: Gilberto Defreitas, RN Baylor College of Medicine

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Responsible Party: Gilberto Defreitas, RN, Baylor College of Medicine Identifier: NCT02044471    
Other Study ID Numbers: H-35006
First Posted: January 24, 2014    Key Record Dates
Last Update Posted: April 28, 2017
Last Verified: April 2017
Keywords provided by Gilberto Defreitas, Baylor College of Medicine:
left ventricular assist device
continuous flow
remote ischemic conditioning
sympathetic tone
endothelial dysfunction
Additional relevant MeSH terms:
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Heart Failure
Heart Diseases
Cardiovascular Diseases