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Microvascular Dysfunction in Aortic Stenosis (PRIMID-AS)

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: NCT01658345
Recruitment Status : Completed
First Posted : August 7, 2012
Last Update Posted : February 23, 2015
Information provided by (Responsible Party):
University Hospitals, Leicester

Brief Summary:

Aortic stenosis (AS), or narrowing of the aortic valve, is the commonest condition requiring valve surgery in the developed world. It is currently not known what determines who will go on to develop symptoms. Exercise testing may be able to identify these patients better than the severity of the narrowing itself, but with some limitations.

The purpose of this study is to compare whether MRI scanning or exercise testing can better identify patients with AS who are likely to benefit from surgery.

Design: The investigators will measure blood flow to the heart muscle with MRI scanning and perform exercise testing in 170 patients with AS and follow them for up to up to 2 years. Expected outcomes: MRI scanning will more accurately identify those patients with AS who will need surgery during this period. Anticipated Health Benefits: improved selection of patients with AS who are likely to benefit from early surgery. This is likely to reduce deaths in such patients.

Condition or disease
Aortic Stenosis

Detailed Description:

Surgical AVR remains the universally accepted management for symptomatic aortic stenosis (AS). However, the best management of severe aortic stenosis, in the absence of symptoms, remains one of the most controversial areas in modern Cardiology.

Exercise testing can identify asymptomatic patients with AS at increased risk, but with limited specificity. In a BHF funded project, the investigators have identified that cardiac MRI measured Myocardial Perfusion Reserve (MPR) may be a novel imaging biomarker in AS. MPR was the only independent predictor of aerobic exercise capacity (peak VO2) in patients with severe AS and was also inversely related to symptomatic status.

In this multi-centre, observational, cohort outcome study, the investigators will follow 175 patients with asymptomatic moderate to severe AS for a minimum of 12 months, and determine whether MPR is a better predictor of outcome than exercise testing, elucidate the mechanisms contributing to symptom development in AS and establish the determinants of MPR in AS. Patients will be recruited from tertiary Cardiac centres, as well as regional hospitals. Comprehensive CMR with adenosine stress to determine LV mass and function, focal and diffuse fibrosis and MPR; cardiopulmonary exercise testing (peak VO2 and exercise symptoms); rest and exercise echocardiography (AS severity, valve compliance) and NT-proBNP will be performed. The study will be run in conjunction with the Glasgow CTU. Investigations will be analysed blind to patient status and data will be entered in a validated database. Statistical analysis will be performed under the supervision of Prof. Ian Ford. The relationship between MPR and exercise testing with 1-year outcome will be analysed using logistic regression. Paired comparisons of the specificities of the two approaches on the same dataset will be carried out using McNemar's test.

The primary hypothesis is that MPR will be a better predictor of adverse outcome than exercise testing.

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Study Type : Observational
Actual Enrollment : 175 participants
Observational Model: Cohort
Time Perspective: Prospective
Official Title: Prognostic Importance of Microvascular Dysfunction in Asymptomatic Patients With Aortic Stenosis (PRIMID-AS)
Study Start Date : April 2012
Actual Primary Completion Date : November 2013
Actual Study Completion Date : October 2014

Resource links provided by the National Library of Medicine

Primary Outcome Measures :
  1. Typical AS Symptoms necessitating AVR. [ Time Frame: 12 months ]
  2. Cardiovascular death. [ Time Frame: 12 months ]
  3. Major adverse cardiovascular events (MACE) [ Time Frame: 12 months ]
    MACE: hospitalisation with heart failure, chest pain, syncope, arrhythmia or stroke

Secondary Outcome Measures :
  1. Individual components of primary composite outcome measures. [ Time Frame: Upto 2 years. ]
    Typical symptoms requiring referral for AVR, cardiovascular death, Major adverse cardiovascular events.

  2. Development of typical symptoms, AVR, death from any cause or MACE during the entire study period. [ Time Frame: 2 years ]

Biospecimen Retention:   Samples Without DNA

With consent, a blood sample (up to 50ml) will be drawn and banked for prospective research studies. All research projects will be related to cardiovascular disease and approved by the Trial Steering Committee (TSC) or a committee delegated this responsibility by the TSC.

All tissue will be collected, stored and disposed of in accordance with the Codes of Practice as laid out by the Human Tissue Authority.

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 85 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population
Cardiology outpatients department and echocardiography department.

Inclusion Criteria:

  1. Moderate-severe aortic stenosis (2 or more of: AVA < 1.5cm2, peak PG >36mmHg or mean PG > 25mmHg).
  2. Asymptomatic.
  3. Age > 18 years and < 85 years.
  4. Prepared to consider AVR if symptoms develop.
  5. Ability to perform bicycle exercise test

Exclusion Criteria:

  1. History of CABG or MI within previous 6 months.
  2. Severe valvular disease other than AS.
  3. Previous Valve surgery
  4. Persistent Atrial Fibrillation or Flutter
  5. History of Heart Failure
  6. Severe Asthma.
  7. Severe renal impairment eGFR < 30ml/min.
  8. Planned aortic valve replacement.
  9. Significant LV systolic dysfunction (EF < 40%)
  10. Any absolute contraindication to CMR
  11. Any absolute contraindication to Adenosine
  12. Participation in an Interventional Clinical Trial at Inclusion.
  13. Other medical condition that limits life expectancy or precludes AVR.
  14. Pregnancy

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): NCT01658345

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United Kingdom
Glenfield Hospital
Leicester, Leicestershire, United Kingdom, LE3 9QP
Leeds General Infirmary
Leeds, West Yorkshire, United Kingdom, LS1 3EX
University of Glasgow
Glasgow, United Kingdom, G12 8QQ
Sponsors and Collaborators
University Hospitals, Leicester
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Principal Investigator: Gerry P McCann, MBChB, MD University of Leicester
Publications automatically indexed to this study by Identifier (NCT Number):

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Responsible Party: University Hospitals, Leicester Identifier: NCT01658345    
Other Study ID Numbers: 87768
First Posted: August 7, 2012    Key Record Dates
Last Update Posted: February 23, 2015
Last Verified: February 2015
Keywords provided by University Hospitals, Leicester:
aortic stenosis
microvascular dysfunction
Cardiac MRI
Additional relevant MeSH terms:
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Aortic Valve Stenosis
Constriction, Pathologic
Pathological Conditions, Anatomical
Heart Valve Diseases
Heart Diseases
Cardiovascular Diseases
Ventricular Outflow Obstruction