Risk Stratification After Acute Myocardial Infarction With Cardiac MRI

Study Overview
=================
Brief Summary
-----------------
Given the existing controversy regarding the appropriate determination time for placement of implantable cardioverter-defibrillator (ICD) in patients at risk for sudden cardiac death (SCD) following acute myocardial infarction (AMI), the modest ability of current criteria to determine which patients will experience SCD, and the high impact of SCD to society, we propose to conduct a prospective non-randomized observational study to determine: Whether quantification of left ventricular (LV) scar volume by cardiac magnetic resonance (CMRI) prior to hospital discharge helps to predict which patients will have a low ejection fraction (35%) at follow up and qualify for ICD implantation. Whether quantification of infarct scar volume by CMRI will help to identify which patients will experience malignant ventricular arrhythmias and/or SCD at follow-up, independent of the LV ejection fraction (LVEF). Primary hypothesis: Percentage of left ventricular scar volume as measured by CMRI post-MI strongly correlates with LVEF at 40 days and 3 months. Secondary hypothesis: A volume of >40% of left ventricular scar measured by CMRI post-MI is predictive of LVEF less than 35% at 40 days and at 3 months Volume scar as measured by Cardiac magnetic resonance imaging after AMI (at day 5) is predictive of clinical outcomes: SCD, total mortality, heart failure admission and life-threatening malignant ventricular arrhythmias regardless of ejection fraction at 40 days and at 3 months. Safety hypothesis: ICDs will be implanted if patients meet criteria at 40 days post MI as per the current American College of Cardiology (ACC) /American Heart Association (AHA) /Heart Rhythm Society (HRS) 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities

Official Title
-----------------
Risk Stratification for Sudden Cardiac Death After Acute Myocardial Infarction by Measuring Left Ventricular Volume Scar With Cardiac MRI

Conditions
-----------------
Acute Myocardial Infarction (AMI)

Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Evidence of AMI either ST segment elevation or Non-ST segment elevation MI by biomarkers of cardiac injury and symptoms. Cut-off for creatine phosphokinase (CPK) >2 times and troponin >3 times the upper limit for the lab. Only Patients who undergo coronary revascularization (PCI, CABG) will be enrolled. LVEF < 45%. (Based on 10 points SD in echo measurements for LVEF) NYHA functional class I-III Patients aged 18 or above, both genders. Exclusion Criteria: Patients with spontaneous or induced sustained ventricular tachycardia after 48-72 hours. (30 beats or more at 120 bpm or greater) Absolute contraindications to undergo CMRI (Renal failure with GFR<30% or ICD/PPM) Antiarrhythmic medications for ventricular arrhythmias (other than beta-blockers) Severe non-ischemic cardiac pathology. (e.g., ARVD, HCM, severe, restrictive cardiomyopathies (amiloydosis/sarcoidosis). We are aware that non-ischemic and ischemic cardiomyopathy may co-exist. However, these cardiomyopathies convey further arrhythmic risk and diffuse LV impairment. Unwilling or unable to provide informed consent Life expectancy less than 1 year. Current drug or alcohol abuse. Pregnancy Claustrophobia Patients who are enrolled in other trials with a treatment arm. (Patients enrolled in diagnostic trials can be included). Difficulty to attend the follow-up schedule due to a history of medical noncompliance, living a distance from the study center, or anticipated nonresidence in the area for the length of time required for follow-up.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Acute Myocardial Infarction<br>Patients (aged 18 and above) with either ST segment elevation or Non-ST segment elevation MI by biomarkers of cardiac injury and symptoms. Cut-off for CPK >2 times and troponin >3 times the upper limit for the lab. Only Patients who undergo coronary revascularization (PCI, CABG), New York Heart Association (NYHA) functional class I-III, and with LVEF < 45% will be enrolled. | |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in LVEF in post MI patients | The degree of LVEF recovery after a first MI provides important prognostic information. Patients with no recovery in LVEF after MI are at high risk of sudden cardiac arrest events and death. | 40 days post-MI and 3 months post-MI | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| LVEF less than 35% | The degree of LVEF recovery after a first MI provides important prognostic information. Patients with no recovery in LVEF after MI are at high risk of sudden cardiac arrest events and death. | At 40 days post-MI | 
| Cardiovascular Mortality | Cardiovascular mortality in patients was defined as death attributable to myocardial ischemia and infarction, heart failure, cardiac arrest because of other or unknown cause, or cerebrovascular accident. | At 40 days post-MI | 
| Cardiovascular Mortality | Cardiovascular mortality in patients was defined as death attributable to myocardial ischemia and infarction, heart failure, cardiac arrest because of other or unknown cause, or cerebrovascular accident. | at 3 months post-MI | 
| Sustained ventricular tachycardia (VT) | Sustained ventricular tachycardia (VT) is a ventricular rhythm faster than 100 bpm lasting at least 30 seconds or requiring termination earlier due to hemodynamic instability. VT is defined as a wide complex tachycardia (QRS 120 milliseconds or greater) that originates from one of the ventricles, and is not due to aberrant conduction (e.g., from bundle branch block), at a rate of 100 bpm or greater. | At 40 days post-MI | 
| Sustained ventricular fibrillation (VF) | Sustained ventricular fibrillation is malignant arrhythmia | At 40 days post-MI | 
| Sustained ventricular tachycardia (VT) | Sustained ventricular tachycardia (VT) is a ventricular rhythm faster than 100 bpm lasting at least 30 seconds or requiring termination earlier due to hemodynamic instability. VT is defined as a wide complex tachycardia (QRS 120 milliseconds or greater) that originates from one of the ventricles, and is not due to aberrant conduction (e.g., from bundle branch block), at a rate of 100 bpm or greater. | At 3 months post-MI | 
| Sustained ventricular fibrillation (VF) | Sustained ventricular fibrillation is malignant arrhythmia | At 3 months post-MI | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Sudden Cardiac Death, Acute Myocardial Infarction, Implantable Cardioverter Defibrillator, Cardiac Magnetic Resonance