Improving risk stratification for infarction related sudden cardiac death by combining cardiac magnetic resonance imaging, electrocardiographic imaging and epicardial mapping.

Patients with a history of myocardial infarction (MI) are at increased risk of
sudden cardiac death (SCD). An implantable cardiac defibrillator (ICD) is a
device designed for acute treatment of life threatening ventricular
tachyarrhythmias causing SCD.
Current guideline recommendations focused on ICD implantation for the
prevention of infarction related SCD are primarily based on a reduced left
ventricular ejection fraction. However, the majority of SCD cases occur in
patients with preserved or moderately reduced LVEF. In addition, relatively few
patients with a reduced LVEF ever experience a life-threatening arrhythmic
event. Consequently, current approaches for risk stratification for myocardial
infarction related SCD remain insufficient. In addition, inappropriate ICD
therapy (ICD therapy for atrial tachyarrhythmias instead of ventricular
tachyarrhythmias) occurs on a regular basis and is a large burden for patients
with an ICD. It is therefore of importance to improve risk stratification and
consequently patient selection for ICD therapy.

The aim of this study is to discover a new set of parameters to define the
electropathological substrate by integrating cardiac magnetic resonance imaging
(CMR) and non-invasive electrocardiographic imaging (ECGI) characteristics. In
the future, these new characteristics may contribute to improve risk
stratification for the occurrence of infarction related SCD and consequently
improve patient selection for ICD implantation.

This study will consist of a multi-center prognostic, follow-up study which
will be performed at Haga Teaching Hospital and Erasmus Medical Center. A total
of 330 CABG patients will undergo cardiac MRI and ECGI prior to surgery.
Epicardial mapping will be performed during surgery, immediately prior to
commencement to extracorporeal circulation. 3-6 Months after CABG, patients
will undergo a second CMR and ECGI to assess changes in the electrical and
tissue characteristics as a consequence of the CABG. In addition, a total of
300 patients with prior myocardial infarction scheduled for ICD implantation
will undergo cardiac MRI and ECGI prior to implantation. Total study duration
is maximal three years with a minimum follow-up of one year and a maximum
follow-up of three years.

An MRI scan is a prerequisite for the BSPM and to asses ICD indications.
Although non-invasive, this diagnostic modality can cause nausea, headache or
general discomfort, especially in subjects suffering from claustrophobia. ECGI
uses 256 or 512-channel ECG recordings. ECG electrodes can cause skin
irritation and allergic reactions. Epicardial mapping will prolong the surgical
procedure by 10 minutes on average. There are no additional risks associated
with the mapping procedures.