Assessment of Natural Bypasses in the Lower Limb

June 17, 2013 updated by: Christian Seiler, University Hospital Inselspital, Berne

Quantitative Assessment of the Peripheral Artery Collateral Circulation in Patients With and Without Coronary Artery Disease (Pilot Study)

Concerning the promotion of peripheral collateral growth, clinical studies investigating new therapeutic strategies have used imprecise assessment methods and therefore determined only "weak" endpoints. In contrast to the coronary circulation, there is currently no gold standard available to document successful promotion of collateral growth in patients suffering from peripheral artery disease. Therefore, the purpose of this study is to evaluate a new invasive method to quantify arterial collateral flow in the lower extremity in patients undergoing elective coronary angiography.

Study Overview

Detailed Description

Background: Peripheral artery disease (PAD) of the lower extremities is due to arterial obstruction leading to reduced arterial flow during exercise and/or at rest. The disease is present in approximately 4 percent of persons >40 years of age, but in 15-20 percent of those >65 years. Claudication is the major symptom and can improve with pharmacotherapy or exercise rehabilitation. In patients with disabling claudication that persist despite exercise and pharmacotherapy or with critical limb ischemia (i.e. ischemic rest pain; ulcers or gangrene at risk of major amputation), revascularization therapies are indicated. However, in about 1/4 of these patients endovascular or surgical therapy fails or is not applicable, making alternative approaches necessary.1 Thus, promotion of angiogenesis, a process triggered by ischemia with sprouting of capillaries insufficient to provide adequate blood supply to jeopardized tissues, and arteriogenesis, which refers to positive remodeling of preformed collateral arterioles, i.e. collateral growth should be applied in these patients.2, 3 Despite the fact that numerous studies during the last decade pursued the important therapeutic strategy of improving collateral function in patients with PAD, there is currently no method available to quantify collateral arterial function of the lower limb and, thus, to determine therapeutic effects. Clinical studies investigating new therapeutic strategies for the promotion of peripheral collateral growth by application of growth factors and/or exercise rehabilitation have used imprecise and inadequate assessment methods and therefore determined only "weak" endpoints. In contrast to the coronary circulation, there is currently no gold standard available to document successful promotion of collateral growth in patients suffering from PAD.

Aim: The purpose of this study in patients undergoing elective coronary angiography with or without chronic stable coronary artery disease is to evaluate a new invasive method to quantify arterial collateral flow in the lower extremity.

Main hypothesis: Quantitative assessment of peripheral arterial collaterals by pressure-derived collateral flow index (CFIp) in the lower extremities is safe and feasible.

Methodology: Prospective exploratory trial. Primary study endpoint: Pressure-derived collateral flow index (CFIp) of the superficial femoral artery.

Potential significance: The results of this study will demonstrate that the concept of collateral flow index - which has been proven by our group in the coronary circulation - is a safe and feasible method for the quantitative assessment of peripheral limb collateral function. The results of this study may serve as preliminary data for larger clinical trials investigating therapeutic promotion of collaterals in patients with PAD and provide a reliable study endpoint.

Study Type

Observational

Enrollment (Actual)

30

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

      • Berne, Switzerland, 3010
        • University Hospital Inselspital

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 and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

Thirty patients with stable angina pectoris electively referred for coronary angiography to our department who give written informed consent.

Description

Inclusion Criteria:

  • Age > 18 years
  • Stable angina pectoris, electively referred for coronary angiography
  • Written informed consent to participate in the study

Exclusion Criteria:

  • Rest pain, ulceration or gangrene due to PAD (Rutherford 4-6)
  • Significant stenoses (>50%) or occlusion of superficial femoral or profunda femoral artery
  • Aortoiliac occlusion or significant stenoses (>50%)
  • Aneurysm of abdominal aorta or iliac arteries
  • Acute coronary syndrome
  • Congestive heart failure NYHA III-IV
  • Severe pulmonary arterial hypertension
  • Severe hepatic or renal failure (creatinine clearance < 15ml/min)

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

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Pressure-derived collateral flow index (CFIp) of the superficial femoral artery
Time Frame: Baseline
Baseline

Collaborators and Investigators

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

Investigators

  • Study Chair: Christian Seiler, MD, Prof., University Hospital Inselspital, Berne
  • Principal Investigator: Tobias Traupe, MD, University Hospital Inselspital, Berne

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.

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

February 1, 2010

Primary Completion (Actual)

January 1, 2013

Study Completion (Actual)

January 1, 2013

Study Registration Dates

First Submitted

November 27, 2012

First Submitted That Met QC Criteria

December 3, 2012

First Posted (Estimate)

December 5, 2012

Study Record Updates

Last Update Posted (Estimate)

June 18, 2013

Last Update Submitted That Met QC Criteria

June 17, 2013

Last Verified

June 1, 2013

More Information

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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