Brachial Artery t-PA Release in Heart Transplant Recipients (P1A3C)

Vanderbilt University

Status: Withdrawn

Conditions: Heart Transplantation

Treatments: Drug: Bradykinin

Study type: Interventional

Funder types: Other

Identifiers

NCT00780637

070517

Details and patient eligibility

About

Bradykinin stimulates t-PA release from intact vessels, but not from endothelial cells in culture. It has been proposed that the nerves of blood vessels are the source of bradykinin stimulated t-PA release. In order tho test this hypothesis, we intend to infuse bradykinin into the brachial (arm) artery and the coronary arteries of heart transplant recipients and control subjects. This is because heart transplant recipients do not have nerves to their coronary arteries.

This protocol studies the effects of bradykinin on t-PA release in the forearm of transplant recipients. The brachial artery has intact nerves.

Separate protocols address coronary artery infusions in healthy subjects and transplant recipients and forearm infusions in healthy subjects.

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

1. Adults 18 years and greater who have undergone heart transplantation
2. Healthy

Exclusion criteria

1. PVC < 30
2. Hypertensive subjects on ACE inhibitors
3. Pregnant or nursing mothers
4. Diabetic with HbA1C > 7.5 or stigmata of end organ damage (neuropathy, retinopathy, nephropathy, cardiomyopathy)
5. Cholesterol > 30 mg/dL above NCEP accepted level based on cardiac risk.
6. Triglycerides > 200
7. Previously diagnosed obstructive coronary artery disease
8. Renal insufficiency (Creatinine ≥ 1.5 mg/dl)
9. History of cerebrovascular disease
10. Any chronic inflammatory disease (rheumatologic, inflammatory bowel disease, etc)
11. Uncontrolled Stage 2 Hypertension (160/100 mmHg), or end organ damage due to hypertension (left ventricular hypertrophy, atrial fibrillation, hematuria, renal insufficiency, prior cerebrovascular disease).
12. Angiotensin converting enzyme inhibitor use
13. Coagulopathy (INR ≥ 1.5, PTT ≥ 150% of control)
14. Peripheral Vascular Disease
15. Other chronic medical illnesses at the discretion of the investigators

Trial design

Primary purpose: Basic Science

Allocation: Non-Randomized

Interventional model: Single Group Assignment

Masking: None (Open label)

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0 participants in 1 patient group

Bradykinin

Experimental group

Description:

Patients receive 0, 10, 20, and 40 ng/min/100cc forearm volume of intrabrachial bradykinin, for 5 minutes at each dose. Forearm blood flow will be measured by strain gauge plethysmography, blood samples will be obtained to measure t-PA, PAI-1 at each dose. FMD and Radial artery tonometry will also be performed under resting conditions.

Treatment:

Drug: Bradykinin