Abstract 13092: Association of Inhomogeneity of Myocardial Perfusion with Ventricular Arrhythmic Events in Patients with Hypertrophic Cardiomyopathy by Cardiac Magnetic Resonance

Abstract

Background: Ventricular arrhythmic events are the most common cause of sudden cardiac death in patients with hypertrophic cardiomyopathy (HCM). Recent papers revealed that myocardial perfusion abnormality exists in patients with HCM. However, little has been reported on the relationship between myocardial perfusion and ventricular arrhythmia based on CMR in patients with HCM.

Objective: The aim of this study was to assess myocardial perfusion by CMR for the prediction of ventricular arrhythmic events in patients with HCM.

Method: We studied 101 consecutive HCM patients who underwent CMR. First-pass myocardial perfusion studies were performed and four short-axis slices (basal, mediobasal, medioapical and apical) were analyzed quantitatively using the Qmass software package (MEDIS, Leiden, The Netherlands). Each slice image was divided into 20 segments, and time-intensity curve of each segment derived from perfusion image was assessed. The time to 50% of peak intensity (time 50% max) was calculated automatically, and standard deviation (SD) / mean of this time in each slice was used as an index for inhomogeneity of myocardial perfusion. Patients were followed for ventricular arrhythmias, appropriate ICD therapy and cardiac death.

Results: Of 101 patients, 46 patients had documented ventricular arrhythmic events. Maximum signal intensity was the highest at the basal slice in obstructive HCM and at the apical slice in apical HCM. SD / mean of time 50% max was significantly higher in patients with ventricular arrhythmic events than in those without (P < 0.01). In a multivariate analysis, SD / mean of time 50% max was identified as an independent factor associated with ventricular arrhythmic events (p < 0.05).

Conclusion: Abnormal myocardial perfusion in patients with HCM is associated with ventricular arrhythmic events. Assessment of first-pass myocardial perfusion imaging by CMR has the potential to provide important information for adverse outcome in patients with HCM.