BRAVO: Biomarker Risk Assessment in Vulnerable Outpatients (BRAVO)

The investigators hypothesize that among people with lower extremity peripheral artery disease (PAD), biomarker levels are higher during time periods immediately preceding an acute coronary event compared to time periods not immediately preceding an acute coronary event. Biomarkers the investigators will study are CRP, SAA, and D-dimer. Biomarkers will be measured at baseline and every two months during follow-up.

The primary aims of this study are as follows. Specific Aim #1. Among participants with PAD who experience an acute coronary event during follow-up, the investigators will determine whether biomarker levels measured immediately prior to the coronary event are higher than levels that do not immediately precede coronary events. Specific Aim #2, Part 1. The investigators will determine whether participants who experience a coronary event (cases) have higher biomarker levels at the visit immediately prior to the event than participants who have not experienced a coronary event (controls) at the time of the case event. Specific Aim #2, Part 2. The investigators will determine whether participants who experience a coronary event (cases) have a greater increase in biomarkers during the time period leading up to the event compared to participants who have not experienced a coronary event (controls).

To achieve these aims, the investigators will enroll up to 650 participants with PAD and follow them prospectively, measuring blood samples every two months, and ascertaining the presence of acute coronary events every two months.

Study Overview

• Status: Completed
• Conditions: Peripheral Arterial Disease

• Study Type: Observational
• Enrollment (Actual): 595

Contacts and Locations

Study Locations

• United States
  • Illinois
    • Chicago, Illinois, United States, 60637
      • University of Chicago Medical Center
    • Chicago, Illinois, United States, 60611
      • Northwestern University Feinberg School of Medicine
    • Chicago, Illinois, United States, 60612
      • Rush Medical Center
    • Chicago, Illinois, United States, 60608
      • Mt. Sinai Medical Center
    • Chicago, Illinois, United States, 60612
      • Jesse Brown Veterans Administration Medical Center
    • Chicago, Illinois, United States, 60657
      • St. Joseph's Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

PAD participants from among consecutive patients with PAD identified from Chicago area non-invasive vascular laboratories and vascular surgery, cardiology, general internal medicine, geriatric, and endocrinology clinics.

Description

Inclusion Criteria:

• Peripheral arterial disease defined as an ABI less than or equal to 0.90 in either leg

We will also include PAD patients with an ABI > 0.90 who meet any of the following criteria:

• History of documented lower extremity revascularization. A written report from the medical record will be required as documentation
• An angiogram demonstrating >50% stenosis in one or more lower extremity arteries. Again, a written report will be required to document this. Participants with an angiogram noting moderate or greater stenosis will also be considered eligible, when a specific amount of stenosis is not denoted
• A report from the non-invasive vascular laboratory demonstrating a toe brachial pressure less than 0.60. Other criteria (i.e. PVR data) from the non-invasive vascular laboratory will not be considered sufficient for inclusion

Exclusion Criteria:

• Treatment for cancer other than non-melanoma skin cancer during the previous 2 years. (However, persons treated for non-invasive breast cancer or prostate cancer during the previous year will be potentially eligible if their physician indicates that their life expectancy is > 24 months, since non-invasive breast and prostate cancer often have an excellent prognosis)
• Unintentional weight loss of > 7.5 pounds in the last six months;
• Mini-Mental Status Exam (MMSE) score < 23 out of 30 or other history of cognitive impairment
• Communication difficulty due to language barriers
• Refusal to have regular blood draws or inability to obtain a blood sample at baseline
• Coronary or cerebrovascular event during the previous six months (these persons may become eligible at a later date)
• History of inflammatory arthritis (rheumatoid arthritis, lupus erythematosis, or polymyalgia rheumatic, gout), however participants with gouty arthritis will be eligible if the last episode was more than three months ago
• Residence more than 40 miles away from the medical center and unwillingness to travel to the medical center for every two month blood collection
• Unable to return for follow up testing for > a consecutive six month period in the next two years
• Heart transplant surgery
• Major surgery (one that required general anesthesia) within the past 3 months These persons may become eligible at a later date

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
PAD Participants; PAD participants from among consecutive patients with PAD identified from Chicago area non-invasive vascular laboratories

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
fatal and non-fatal coronary events	Our primary outcome is fatal and non-fatal coronary events. Non-fatal coronary events will be defined as acute myocardial infarction (MI), hospitalizations for unstable angina, and new ECG findings consistent with MI	Every two months for up to three and a half years

Collaborators and Investigators

• Sponsor: Northwestern University
• Collaborators: National Heart, Lung, and Blood Institute (NHLBI)

Study record dates

Study Major Dates

• Study Start: September 1, 2009
• Primary Completion (Actual): January 1, 2013
• Study Completion (Actual): January 1, 2013

Study Registration Dates

• First Submitted: October 24, 2014
• First Submitted That Met QC Criteria: October 27, 2014
• First Posted (Estimate): October 28, 2014

Study Record Updates

• Last Update Posted (Estimate): May 6, 2015
• Last Update Submitted That Met QC Criteria: May 4, 2015
• Last Verified: May 1, 2015

More Information

Terms related to this study

• Keywords: PAD; Biomarkers; Peripheral Arterial Disease
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Vascular Diseases; Arteriosclerosis; Arterial Occlusive Diseases; Atherosclerosis; Peripheral Arterial Disease; Peripheral Vascular Diseases
• Other Study ID Numbers: R01HL089619 (U.S. NIH Grant/Contract)