Short-term Endothelin A Receptor Blockade in Patients With On-pump CABG

Short-term Endothelin A Receptor Blockade in Patients With On-pump Coronary Artery Bypass Grafting

Background: Although selected cardiac surgery can be performed off-pump, the vast majority of cardiac surgical procedures today are performed with the support of cardiopulmonary bypass (CPB). Blood cardioplegia is used to protect the heart during aortic cross-clamping. However, negative effects of myocardial hypoxia during surgery are often aggravated by ischemia/reperfusion injury. In addition, cardiopulmonary bypass leads to an inflammatory response including endothelial cell activation.

Comparable to the reperfusion injury following acute myocardial infarction resolved by percutaneous coronary intervention, the microcirculatory impairment observed after cardiac surgery may be caused by endothelin 1 (ET-1). ET-1 is a potent vasoconstrictor peptide upregulated in myocardial ischemia-reperfusion injury. Short-term administration of the selective ETA receptor blocker BQ-123 was found safe in a pilot study including patients with acute myocardial infarction.

Hypothesis: Acute local ETA receptor blockade by intracoronary administered BQ-123 reduces myocardial injury.

Methods: BQ-123 will be administered in patients undergoing on-pump aorto-coronary bypass grafting to the left anterior descending coronary artery with the use a left inner mammary artery graft and at least one vein graft. Subjects will be randomized to receive the endothelin-A receptor blocker BQ-123 or placebo administered intracoronarily in combination with cardioplegia in a double-blind manner. The primary endpoint will be enzymatic infarct size.

Clinical perspective: The implementation of BQ-123 as an add-on pharmacologic therapy in cardiac surgery performed with the use of cardiopulmonary bypass could lead to improved tissue reperfusion and reduced ischemia/reperfusion injury, potentially impacting clinical long-term outcome.

Study Overview

• Status: Unknown
• Conditions: Coronary Artery Disease; Aorto-coronary Bypass Grafting
• Intervention / Treatment: Drug: BQ-123; Drug: NaCl

Detailed Description

Background: Although selected cardiac surgery can be performed off-pump, the vast majority of cardiac surgical procedures today are performed with the support of cardiopulmonary bypass (CPB). Blood cardioplegia is used to protect the heart during aortic cross-clamping. However, negative effects of myocardial hypoxia during surgery are often aggravated by ischemia/reperfusion injury. In addition, cardiopulmonary bypass leads to an inflammatory response including endothelial cell activation.

Comparable to the reperfusion injury following acute myocardial infarction resolved by percutaneous coronary intervention, the microcirculatory impairment observed after cardiac surgery may be caused by endothelin 1 (ET-1). ET-1 is a potent vasoconstrictor peptide upregulated in myocardial ischemia-reperfusion injury. Short-term administration of the selective ETA receptor blocker BQ-123 was found safe in a pilot study including patients with acute myocardial infarction. Patients with posterior-wall STE-ACS (n=57) were randomly assigned to receive intravenous BQ-123 at 400nmol/minute or placebo over 60 minutes, starting immediately prior to primary percutaneous coronary intervention (PCI). No side branch occlusions, bleeding complications or severe systemic hypotensive episodes occurred and all patients were alive at 30 days.

Hypothesis: Acute local ETA receptor blockade by intracoronary administered BQ-123 reduces myocardial injury.

Methods: BQ-123 will be administered in patients undergoing on-pump aorto-coronary bypass grafting to the left anterior descending coronary artery with the use a left inner mammary artery graft and at least one vein graft. After a 1:1 randomized pilot safety-phase with 30 patients administering half the dose, 90 subjects will be randomized to receive 15µmol BQ-123 dissolved in NaCl 0.9% or placebo (NaCl 0.9% ) administered intracoronarily in combination with cardioplegia in a double-blind manner. The primary endpoint will be enzymatic infarct size assessed by the area under the curve of myocard specific creatine kinase-MB isoform (CK-MB). Left ventricular ejection fraction, diastolic dysfunction and, perioperative echocardiography, postoperative levels of myeloperoxidase and matrixmetalloproteinase-9 activity as well as MACE will serve as secondary endpoints.

Clinical perspective: The implementation of BQ-123 as an add-on pharmacologic therapy in cardiac surgery performed with the use of cardiopulmonary bypass could lead to improved tissue reperfusion and reduced ischemia/reperfusion injury, potentially impacting clinical long-term outcome.

• Study Type: Interventional
• Enrollment (Anticipated): 120
• Phase: Phase 2

Contacts and Locations

Study Locations

• Austria
  • Vienna, Austria, 1090
    • Medical University of Vienna

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

Patients undergoing on-pump coronary artery bypass grafting using the left mammary artery to the left anterior descendent artery and at least one vein graft due to coronary artery disease, aged 18 years and above.

Exclusion Criteria:

• Significant liver disease (Transaminases and/or gamma-GT > 3 fold upper limit)
• Glomerular filtration rate <40mL/h
• History of severe congestive heart failure (Left ventricular ejection fraction <35%)
• Current atrial fibrillation
• Significant valvular heart disease requiring valve replacement Department of Cardiac Surgery
• Primary myocardial disease
• Acute coronary syndrome or cardiogenic shock (sRR <90mmHg or need for inotropic support)
• Women with child-bearing potential
• Subjects with contraindications for CMR (cardiac magnetic resonance)
• Inability to read, understand and sign the informed consent
• Life expectancy <1y
• Prior organ transplantation
• Participation in a clinical trial using an investigational medical product

Study Plan

How is the study designed?

Design Details

• Primary Purpose: TREATMENT
• Allocation: RANDOMIZED
• Interventional Model: PARALLEL
• Masking: TRIPLE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
PLACEBO_COMPARATOR: NaCl	Drug: NaCl; NaCl, Route: intracoronary
ACTIVE_COMPARATOR: BQ-123	Drug: BQ-123; BQ-123 (Clinalfa, Läufelfingen, Switzerland) Dosage: 15µmol in two equal amounts (7.5µmol); in the first and last cardioplegia Route: intracoronary; Other Names: Cyclo(-D-Trp-D-Asp-Pro-D-Val-Leu) sodium salt

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
enzymatic infarct size	72h

Secondary Outcome Measures

Outcome Measure	Time Frame
Catecholamines	5h
Liver function	72h
catecholamine requirement	72h

Collaborators and Investigators

• Sponsor: Medical University of Vienna
• Investigators: Principal Investigator: Alfred Kocher, MD, Medical University of Vienna

Study record dates

Study Major Dates

• Study Start: July 1, 2012
• Primary Completion (ANTICIPATED): December 1, 2015
• Study Completion (ANTICIPATED): December 1, 2016

Study Registration Dates

• First Submitted: July 26, 2012
• First Submitted That Met QC Criteria: August 2, 2012
• First Posted (ESTIMATE): August 7, 2012

Study Record Updates

• Last Update Posted (ESTIMATE): August 7, 2012
• Last Update Submitted That Met QC Criteria: August 2, 2012
• Last Verified: August 1, 2012

More Information

Terms related to this study

• Keywords: Coronary artery disease; bypass grafting
• Additional Relevant MeSH Terms: Heart Diseases; Cardiovascular Diseases; Vascular Diseases; Arteriosclerosis; Arterial Occlusive Diseases; Coronary Artery Disease; Myocardial Ischemia; Coronary Disease; Molecular Mechanisms of Pharmacological Action; Antihypertensive Agents; Endothelin Receptor Antagonists; cyclo(Trp-Asp-Pro-Val-Leu)
• Other Study ID Numbers: 2010-023552-90