Postconditioning in ST-elevation Myocardial Infarction

Study Overview
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Brief Summary
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Study objectives: To assess the effects of postconditioning on infarct size in patients with ST-elevation infarction referred to PCI. Study design: Prospective, randomized, open-label study with blinded endpoint evaluation. Included patients will be randomly allocated to postconditioning or control. Patients with symptoms of acute myocardial infarction of less than 6 hours duration fulfilling ECG criteria for primary PCI are eligible. PCI follow established routines. In postconditioning patients, additional, short (1 min), intermittent balloon occlusions will be applied after initial opening of infarct related artery. After this intervention, PCI proceeds routinely with stent implantation. In the control group, stent implantation after initial opening proceeds as usual. Primary endpoint is final infarct size, determined by MRI after 4 months. 260 patients will be included. Follow-up is 1 year. Inclusion period: 18 - 24 months. Clinical implications: Reperfusion therapy, administered as early as possible after start of symptoms, has improved the prognosis in acute ST-elevation myocardial infarction. Still, however, many patients suffer large infarctions, subsequently with an increased risk of heart failure, arrhythmias, and death. In pilot studies, mechanical postconditioning has been shown to reduce infarct size and thus potentially improve prognosis. However, the effect of postconditioning must be confirmed in larger clinical trials before implemented in routine treatment.

Official Title
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Postconditioning in ST-elevation Myocardial Infarction Treated With Primary PCI

Conditions
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Myocardial Infarction

Intervention / Treatment
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* Procedure: Postconditioning
* Procedure: Control intervention


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: acute symptoms consistent with an acute myocardial infarction of less than 6 hours duration an occluded infarct related artery must be demonstrated (TIMI-flow 0-1) Exclusion Criteria: Prior myocardial infarction Demonstration of collaterals to the infarcted area TIMI-flow >1 before intervention or TIMI-flow <2 after initial balloon inflation Demonstration of a distal occlusion Patients given thrombolytic treatment Patients in cardiogenic shock Any contraindication to MRI (magnetic resonance imaging) Unwillingness to participate

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Postconditioning<br>Active arm:Postconditioning protocol before routine PCI/stenting of an occluded coronary artery | Procedure: Postconditioning<br>* After opening of IRA and establishment of TIMI-flow grade 2 or 3, the control group continues the procedure with stenting. In the postconditioning group 4 additional balloon inflations separated by 1 minute reperfusion are given, starting after 1 minute of reperfusion.<br>|
| Other: Control<br>Control arm: Routine PCI/stenting of an occluded coronary artery without postconditioning | Procedure: Control intervention<br>* After opening of IRA and establishment of TIMI-flow grade 2 or 3, the control group continues the procedure with stenting.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Infarct size, assessed by MRI |  | 4 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Myocardial blushing grade |  | assessed at the end of PCI procedure | 
| ST-resolution in ECG |  | Assessed after 1 hour | 
| Troponin-T and CK-MB |  | peak release values | 
| Echocardiographic evaluation of left ventricular function including speckle-tracking measurement. | Assesment of LV function. Comparison with CMR in the whole study population and between treatment groups. | assessed at baseline, 4 months and1 year | 
| Incidence of treated arrhythmias and heart failure during initial hospitalization Incidence of death, non-fatal myocardial infarction, unstable angina, heart failure, and cerebrovascular disease |  | 1-year follow up. | 
| Myocardial salvage | Myocardial salvage defined as (area at risk-final infarct size)/area at risk. Area at risk measured by CMR at baseline and final infarct size by CMR at 4 months. | Baseline to 4 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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ST-elevation myocardial infarction