CMR predicts increased risk of sudden cardiac death in patients with myocardial infarction

Universitätsmedizin Berlin and Universität Leiden developed a method to identify a subgroup of patients with myocardial infarction that is at increased risk for sudden cardiac death. In cardiac magnetic resonance tomography (CMR) the scientists are able to detect the extent of infarction-related damage to the heart muscle and assess the risk for life-threatening arrhythmias. The results were now published in the Journal of the American College of Cardiology.

Myocardial infarction often leads to permanent complications such as arrhythmias, heart insufficiency or heart failure. Physicians refer to this as chronic myocardial infarction. A chronically ill heart muscle often works with a severely decreased function and is at higher risk to develop dangerous arrhythmias that can lead to sudden cardiac death. To prevent this, patients usually receive an implantable cardioverter-defibrillator (ICD). This device which is implanted like a pacemaker detects dangerous arrhythmias and delivers an electric shock to the heart muscle. In consequence normal sinus rhythm is reestablished. As it is difficult to predict who is really going to develop life-threatening arrhythmias after a myocardial infarction, physicians implant more preventive ICDs than needed. This results in a higher quantity of complications for patients and an enormous burden on national health systems. Therefore, the goal of the present study was to identify a method to improve the assessment of individual risk for developing dangerous arrhythmias. Prof. Jeannette Schulz-Menger and her team from the Experimental and Clinical Research Center (ECRC) of Charité and HELIOS-Krankenhaus Berlin Buch examined 52 patients with chronic myocardial infarction in CMR. With the use of contrast agents they were able to assess how much of the heart muscle was affected by the infarction. After ICD-implantation it proved that there was a significant association between relative infarct mass and development of arrhythmias. The depth of the scarred tissue in the heart muscle, the transmurality, previded the best prediction.

"We found a parameter that offers the chance to predict the individual risk for sudden cardiac death", explains Prof. Schulz-Menger. "We hope to be able to supply every patient with the adequate therapy and avoid unnecessary costs and complications", says Dr. Philipp Boyé, first author of the study.