Abstract 12481: Myocardial Scar Tissue in Patients with Coronary Artery Disease and Preserved Left Ventricular Function - Lessons Learned from Delayed Enhancement-MRI

Abstract

Background: In patients with coronary artery disease (CAD), the restricted blood supply to the myocardium can lead into myocardial injury. Delayed enhancement MRI (DE-MRI) allows the accurate detection and visualization of myocardial scar tissue.

Objective: The aim of this study was the determination of myocardial scar tissue in patients with CAD with preserved left ventricular (LV) function without regional wall motion abnormalities (RWMA) in transthoracic echocardiography (TTE) using DE-MRI.

Methods and Results: 582 patients (458 males, Age: 65.2±12.0 years) were examined for viability determination using DE-MRI. All patients had a history of CAD. 83 of these patients (14,3%; 61 male; Age: 66.3±12.4 years) were found with normal LV function without RWMA in TTE. Out of these eighty-three patients 45 patients (54.2%) suffered from an acute coronary syndrome (elevated Troponin, NSTEMI, STEMI) shortly before the MRI examination while 8 patients were found with a history of ACS further in the past. Myocardial scar tissue was found in 57 patients (68.7%), whereas 26 patients (31.3%, Figure 1) showed no myocardial enhancement using DE-MRI. The number of patients with transmural scar was significantly higher than patients with subendcardial scar (36 (63.2%) vs. 21 (36.8%); p=0.005; Figure 2). Incidence of myocardial scar tissue was independent of the number of diseased coronary vessels (Figure 3).

Conclusion: From our preliminary results, a significant numbers of patients with CAD, preserved LV function and without regional wall motion abnormalities can suffer from myocardial scar tissue. Transthoracic echocardiography may underestimate myocardial injury in these patients. Thus, MRI examinations of the heart for determination of myocardial viability should be considered in these patients to assess the extent of myocardial injury.