Bradykinin Receptor Antagonism During Cardiopulmonary Bypass

Summary

Each year over a million patients worldwide undergo cardiac surgery requiring cardiopulmonary bypass (CPB). CPB is associated with significant morbidity including the transfusion of allogenic blood products, inflammation and hemodynamic instability. In fact, approximately 20% of all blood products transfused are associated with coronary artery bypass grafting procedures. Transfusion of allogenic blood products is associated with well-documented morbidity and increased mortality after cardiac surgery. Enhanced fibrinolysis contributes to increased blood product transfusion in the perioperative period. The current proposal tests the central hypothesis that endogenous bradykinin contributes to the hemodynamic, fibrinolytic and inflammatory response to CPB and that bradykinin receptor antagonism will reduce hypotension, inflammation and transfusion requirements. In SPECIFIC AIM 1 we will test the hypothesis that the fibrinolytic and inflammatory response to CPB differ during ACE inhibition and angiotensin II type 1 receptor antagonism. In SPECIFIC AIM 2 we will test the hypothesis that bradykinin B2 receptor antagonism attenuates the hemodynamic, fibrinolytic, and inflammatory response to CPB. In SPECIFIC AIM 3 we will test the hypothesis that bradykinin B2 receptor antagonism reduces the risk of allogenic blood product transfusion in patients undergoing CPB. These studies promise to provide important information regarding the effects of drugs that interrupt the RAS and generate new strategies to reduce morbidity in patients undergoing CPB.

Conditions

• Cardiopulmonary Bypass
• Inflammation
• Fibrinolysis
• Surgery

Interventions

DRUG

HOE 140

HOE 140 (a bradykinin B2 receptor antagonist) was started in the operating room after induction of anesthesia and before heparinization, continued throughout the bypass period, and discontinued at the end of surgery. HOE 140 was given as an intravenous bolus of 22 µg/kg over one-half hour followed by an infusion of 18 µg/kg/hr.

DRUG

Aminocaproic Acid

Aminocaproic acid (an antifibrinolytic drug) was started in the operating room after induction of anesthesia and before heparinization, continued throughout the bypass period, and discontinued at the end of surgery. Aminocaproic acid was given as an intravenous bolus of 100 mg/kg over one-half hour followed by an infusion of 30 mg/kg/hr.

DRUG

Placebo

Normal saline (placebo) was started in the operating room after induction of anesthesia and before heparinization, continued throughout the bypass period, and discontinued at the end of surgery.

Sponsors & Collaborators

• Vanderbilt University

  lead OTHER

Principal Investigators

• Mias Pretorius, MBChB · Vanderbilt University

Study Design

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

QUADRUPLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

80 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2006-05-31

Primary Completion

2012-06-30

Completion

2012-06-30

Countries

• United States

Study Locations