This is a prospective, multi-center cohort study of patients with a history of coronary artery disease (CAD) and documentation of either a prior myocardial infarction (MI) or mild to moderate left ventricular dysfunction (LVEF 35-50%). The primary objective of this study is to determine whether biologic markers and ECGs can be utilized to advance SCD risk prediction in patients with CHD and LVEF>30-35%. The overarching goal of the study is to identify a series of markers that alone or in combination specifically predict risk of arrhythmic death as compared to other causes of mortality among this at risk population of coronary heart disease (CHD) patients with preserved left ventricular ejection fraction (LVEF> 30-35%). If biologic or ECG markers are identified that can specifically predict risk of ventricular arrhythmias, then these markers may serve as relatively inexpensive methods to identify those at risk. The public health impact of identifying markers could be quite substantial, leading to more efficient utilization of ICDs and advances in our understanding of mechanisms underlying SCD.

The PRE-DETERMINE Study is a prospective, multi-center study of patients with a history of coronary artery disease (CAD) and documentation of either a prior myocardial infarction (MI) or mild to moderate left ventricular dysfunction (LVEF 35-50%). Patients were enrolled at 135 sites where information on baseline demographics, clinical characteristics, pertinent past medical history, lifestyle habits, cardiac test results, and medications were collected via electronic data capture. Electrocardiograms along with a blood sample was also collected at baseline, sent to central laboratories, and stored for future analyses. Contrast-enhanced magnetic resonance imaging (CE-MRI) scans were collected on a subset of patients and analyzed. Enrollment closed in November 2013 and patients are now being followed centrally by the Clinical Coordinating Center via mail/phone to document interim non-fatal arrhythmic events and cause-specific mortality. Questionnaires that inquire about intervening ICD implantations, ICD therapies, cardiac arrest, and other pertinent cardiovascular endpoints are mailed to participants every six months, and follow-up telephone calls are made to non-responders. Study endpoints are being confirmed through review of medical records, interviews with next-of-kin, and autopsy reports, if available.

Inclusion Criteria:

1. Evidence of Coronary Artery Disease (CAD) a or documented prior Myocardial Infarction.

2. LVEF >35% by any current standard evaluation technique (e.g.,) echocardiogram, MUGA, angiography). 2.1. Patients who have an LVEF between 30-35% and NYHA Class I heart failure who do not have history of ventricular tachyarrhythmias,or inducible ventricular tachycardia during electrophysiological (EP) testing can be enrolled.

3. If documented prior MI is not present, evidence of mild-moderate systolic Left Ventricular Dysfunction with an EF >35- ≤50% as measured by any current standard screening technique (e.g.,echocardiogram, MUGA, angiography) must be present.

4. Patients aged 18 years or above

   1. CAD will be defined as evidence of one of the following two (2) criteria:

      • Significant stenosis of a major epicardial vessel (>50% proximal or 70% distal) by coronary angiography
      • Prior revascularization (percutaneous coronary intervention or coronary artery bypass surgery)

   2. MI can be documented in the following ways:

      • From the MI hospitalization: Detection of a rise and fall of cardiac biomarkers > 99th percentile of lab (e.g., CPK elevation or Troponin at least > two times the upper limit of normal) together with myocardial ischemia with at least one of the following:

        • Symptoms of Ischemia
        • ECG changes indicative of new ischemia (new ST-T changes or new LBBB)
        • Development of pathological Q waves
        • Imaging evidence of new loss of viable myocardium or new regional wall motion abnormality

      • If no report from the MI hospitalization is available, prior MI can be met by either of the following:

        • Development of pathological Q waves
        • Imaging evidence of a region of loss of viable myocardium that is thinned and fails to contract, in the absence of a non-ischaemic cause

Exclusion Criteria:

1. History of cardiac arrest or spontaneous or inducible sustained VT (15 beats or more at a rate of 120 BPM or greater - the occurrence of cardiac arrest or spontaneous VT in the setting of an acute MI is not considered an exclusion).
2. Unexplained syncope
3. Current or planned implantable cardiac defibrillator (ICD)
4. Any condition other than cardiac disease that, in the investigator's judgment, would seriously limit life expectancy (poor survival)
5. Metastatic cancer
6. Marked valvular heart disease requiring surgical intervention
7. Current or planned cardiac, renal or liver transplant
8. Current alcohol or drug abuse
9. Unwilling or unable to provide informed consent
10. LVEF <35% with Class II-IV CHF or LVEF <30%
11. Participation in a clinical trial where the active treatment arm is testing an agent and/or intervention with known antiarrhythmic properties

Participants have been recruited throughout multicenter sites participating in the PRE-DETERMINE Cohort Study. Patients with a history of coronary artery disease and documentation of either a prior myocardial infarction (MI) or mild to moderate left ventricular dysfunction (LVEF 35-50%) have been enrolled. The clinical study staff at each site, which was either a research nurse, fellow, or physician approached eligible patients to discuss their potential participation.