Post Conditioning in PCI for Acute ST Elevation Myocardial Infarction

Myocardial Infarction Clinical Trial

Official title:

Post Conditioning in PCI for Acute ST Elevation Myocardial Infarction

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00334373
• Other study ID #: Ethics ID E-20039
• Status: Completed
• Phase: Phase 4
• First received: June 6, 2006
• Last updated: May 26, 2015
• Start date: June 2006
• Est. completion date: October 2011

Study information

• Verified date: May 2015
• Source: University of Calgary
• Contact: n/a
• Is FDA regulated: No
• Health authority: Canada: Ethics Review Committee
• Study type: Interventional

Clinical Trial Summary

The purpose of this trial is to compare post-conditioning to standard angioplasty (50/50 chance) in patients who present with an acute heart attack and are taken directly for an angioplasty procedure. Post conditioning is a procedure that involves balloon inflation followed by deflation in a series of cycles that appears to show (based on early data) that it can decrease the amount of damage to the heart muscle as compared to standard angioplasty procedures.

Hypothesis: For Subjects undergoing direct PCI for STEMI, post conditioning with cycles of balloon inflation/deflation within the first minute following the re-establishment of coronary blood blow, will decrease the amount of irreversible myocardial damage assessed by delayed enhancement contrast CMR.

Description:

In patients who suffer a myocardial infarction, the blood flow usually ceases due to plaque rupture leading to thrombus formation and vessel occlusion. The resultant entity is known as ST Elevation segment myocardial infarction (STEMI) and is a significant health issue in industrialized countries. There are over 50,000 STEMI's every year in Canada and up to 10% of these patients die in hospital and another 10% die within the first year after their heart attack. The more common problem however is not death, but irreparable damage to the left ventricle leading to LV dysfunction and subsequent heart failure and arrythmias. Re-establishing blood flow promptly by administering plasminogen activators (lytics) or mechanically by performing angioplasty is possible and has lowered the mortality rate dramatically.

Although reperfusion is necessary, it gives rise to an entity known as ischemia-reperfusion where acutely re-establishing blood flow and oxygen levels of the heart has detrimental effects. Clinically this is manifested as no-reflow that causes subsequent damage to the left ventricle and decreases the beneficial affect of early reperfusion by PCI. The ischemia-reperfusion effect sets off a molecular cascade of events involving unfavorable interaction between neutrophils, platelets and endothelium, that is fairly well identified. Efforts to pharmacologically block this effect have not proven to be particularly effective.

Post conditioning follows from a concept of pre-conditioning in animals that showed a decrease in myocardial infarct size. Pre-conditioning is not useful as it requires to be performed prior to the development of ischemia/injury. Post conditioning in preliminary studies with animals and one small study in humans have shown promising results for decrease in infarct size. Post conditioning is a procedure of gradual conditioning in which the artery is opened and closed in cycles with inflation/deflation of the culprit artery followed immediately by standard PCI and placement of stent.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 102
• Est. completion date: October 2011
• Est. primary completion date: October 2011
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years to 80 Years

Eligibility

Inclusion Criteria:

• 18 years and over

• ST elevation of >/= 2mm in 3 consecutive anterior leads or >/= to 2 mm in leads II, III and AVF with total 8 mm ST shift (ST depression of 1 mm in ant or lat leads)

Exclusion Criteria:

• Cardiogenic shock or severe heart failure

• Inability to undergo CMR (metallic objects or claustrophobia)

• Previous MI

• TIMI 2-3 flow in target artery

• Collaterals to infarct related artery > Rentrop grade 1

• Inability to undertake successful PCI at time of angio

• Significant LM disease or requiring CABG during hospital stay

• Inability to proceed with post conditioning within 1 minute of establishing blood flow in culprit artery

Study Design

Allocation: Randomized, Intervention Model: Parallel Assignment, Masking: Single Blind (Outcomes Assessor), Primary Purpose: Treatment

Related Conditions & MeSH terms

• Infarction
• Myocardial Infarction

Intervention

Procedure:
• Post conditioning
4 cycles of balloon inflation /deflation (post-conditioning) within first minute of opening up artery in primary PCI for STEMI vs usual balloon inflation sequence

Locations

Country	Name	City	State
Canada	Foothills Medical Centre	Calgary	Alberta

Sponsors (2)

Lead Sponsor	Collaborator
University of Calgary	Foothills Interventional Cardiology Research Group

Country where clinical trial is conducted

Canada, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Infarct size as measured by: salvage index = total area at risk - infarct size/total area at risk		3-5 days post MI	No
Secondary	Corrected TIMI frame count (cTFC)		Immediately post PCI	No
Secondary	Myocardial blush score		Immediately post PCI	No
Secondary	CK release (under the curve)		1st 48 hours post MI	No
Secondary	ST segment resolution by 48 hrs compared with admission		1st 48 hours post MI	No
Secondary	MRI infarct size		3-5 days and 6 months	No
Secondary	MRI maximal transmural extent of irreversible injury		3-5 days and 6 months	No
Secondary	CMR regional end-systolic wall stress		3-5 days and 6 months	No
Secondary	CMR Myocardial perfusion		3-5 days and 6 months	No
Secondary	CMR Myocardial oxygenation		3-5 days and 6 months	No
Secondary	Peripheral endothelial function testing (brachial u/s and pulse arterial tonometry) in hospital		3-5 days post MI	No
Secondary	CMR quantification of volume of no-reflow		3-5 days and 6 months	No