Ischaemic Pre-Conditioning in Elective Percutaneous Coronary Intervention (PCI) Patients
Ischaemic Pre-Conditioning in Elective PCI Patients - Attenuation of Subsequent Ischaemia in a Validated Animal Model
Study Overview
Status
Status
Conditions
Conditions
Intervention / Treatment
Intervention / Treatment
Detailed Description
Ischaemic preconditioning (IPC) was first described in a canine model by Murray et al in 1986. By deliberately inducing brief periods of myocardial ischaemia and reperfusion by intermittent occlusion of a coronary artery, the ability of the heart to withstand a subsequent, more prolonged episode of myocardial ischaemia was enhanced, to the extent that infarct size was reduced. This ubiquitous endogenous form of cardioprotection has been observed in many different species and is capable of limiting ischaemia-reperfusion in non-cardiac organs such as the brain, liver, gut, bladder and skin. It has been demonstrated to improve long term clinical outcomes in patients undergoing elective percutaneous coronary intervention (PCI)and to improve distal myocardial perfusion and mitigate infarct size in patients undergoing primary PCI . Despite extensive investigations into the cellular and molecular basis of IP, the precise mechanism(s) whereby myocytes develop tolerance to potentially fatal ischemia is unclear. There are also unanswered questions regarding the necessary frequency and duration of transient ischaemia needed to invoke the protection. Less than 60 seconds has been shown to be too short in some studies, whereas there is clearly an upper limit (above 10 minutes in most tissues) whereupon the preconditioning stimulus itself may have detrimental effects. Nonetheless, previous studies of IP in the heart have shown that a factor is released during IP, which can be transferred to protect another heart . Furthermore, preliminary data by our group suggests that 3 or 4 cycles of 5 minutes of transient limb ischaemia and 5 minutes of reperfusion (remote ischemic preconditioning, rIPC) leads to the release of a circulating cardioprotective factor(s) into the blood stream, which reduces cardiac damage in experimental animals, and patients undergoing cardiac surgery.
The proposed study will test whether these humoral factors are released from the heart, into the bloodstream, by patients undergoing PCI. The Langendorff method, in which a perfused rat heart is isolated ex vivo, is a well validated technique which has been used widely in studies of IP. It allows us to measure directly several cardiac physiological parameters, as well as the myocardial infarct size after prolonged ischaemia. We have previously shown that serum from healthy adults undergoing rIPC can be dialysed to produce a crystalloid perfusate. When this is used in the Langendorff preparation myocardial infarction size is reduced. We will employ the same method to examine the possible release, and any dose response to a pre-conditioning stimulus (coronary angioplasty balloon inflation) of varying duration in adults undergoing elective PCI.
Study Type
Study Type
Enrollment (Anticipated)
Enrollment
Phase
Phase
- Phase 2
- Phase 1
Contacts and Locations
Study Contact
Study Contact
- Name: Vladimir Dzavik, MD
- Phone Number: 6265 416-340-4800
- Email: vlad.dzavik@uhn.on.ca
Participation Criteria
Eligibility Criteria
Eligibility Criteria
Ages Eligible for Study
Accepts Healthy Volunteers
Genders Eligible for Study
Description
Inclusion Criteria:
- Ability to give written informed consent.
- All patients who are listed for elective PCI of at least one major epicardial artery.
- Patients ≥ 18 years and ≤80 years of age.
Exclusion Criteria:
- Any patient who has experienced chest pain within the preceding 24 hrs
- Any patient who exhibits haemodynamic instability (systolic BP <90mmHg, pulmonary oedema);
- Any patient with electrophysiologic instability (arrythmias eg rapid AF) or an abnormal baseline electrocardiogram (ECG) (e.g., significant ST segment depression, left bundle-branch block) which precludes analysis of the ST segment shift during PCI
- Patients unable to give informed consent
- Previous inclusion in this or any other clinical trial within one month prior to inclusion.
- Diabetes
- Uncontrolled hypertension (BP>180/110).
- Anaemia (Hb <10g/l).
Study Plan
How is the study designed?
Design Details
- Primary Purpose: Basic Science
- Allocation: Randomized
- Interventional Model: Parallel Assignment
- Masking: Triple
Number of Arms
Arms and Interventions
Participant Group / ArmParticipant Group / Arm |
Intervention / TreatmentIntervention / Treatment |
|---|---|
|
Experimental: A
Patients undergoing elective PCI will be randomised to 90 second balloon inflations rather than the standard less than 30 second inflations in order to induce peri-ischaemic conditioning.
|
90 second balloon inflation x 2
30 seconds or less balloon inflations x 2
|
|
Active Comparator: B
Control group.
These patients will have a standard procedure with balloon inflations of 30 seconds or less as per standard.
|
90 second balloon inflation x 2
30 seconds or less balloon inflations x 2
|
What is the study measuring?
Primary Outcome Measures
Primary Outcome Measures
Outcome Measure |
Time Frame |
|---|---|
|
Attenuation of infarct size and improved post-ischemia haemodynamic recovery in rat hearts.
Time Frame: immediate
|
immediate
|
Secondary Outcome Measures
Secondary Outcome Measures
Outcome Measure |
Time Frame |
|---|---|
|
Clinical endpoints: (i) induction of IP, defined as a minimum 33% reduction in magnitude of ST segment deviation in the territory of the affected artery between the first and second balloon inflation. (ii) Reduction in CK rise post procedure.
Time Frame: immediate
|
immediate
|
Collaborators and Investigators
Sponsor
Sponsor
Collaborators
Collaborators
Investigators
Investigators
- Principal Investigator: Vladimir Dzavik, MD, University Health Network, Toronto
Study record dates
Study Major Dates
Study Start
Study Start
Primary Completion (Anticipated)
Primary Completion
Study Completion (Anticipated)
Study Completion
Study Registration Dates
First Submitted
First Submitted
First Submitted That Met QC Criteria
First Submitted That Met QC Criteria
First Posted (Estimate)
First Posted
Study Record Updates
Last Update Posted (Estimate)
Last Update Posted
Last Update Submitted That Met QC Criteria
Last Update Submitted That Met QC Criteria
Last Verified
Last Verified
More Information
Terms related to this study
Additional Relevant MeSH Terms
Other Study ID Numbers
Other Study ID Numbers
- UHN 2008-1
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