Abstract 17166: Regional Peak Longitudinal Strain by Two Dimensional Speckle Tracking Echocardiography Provides Useful Information to Distinguish Fibrotic from Non-Fibrotic Lesions in Left Ventricular Myocardium on Cardiac Magnetic Resonance in Hypertrophic Cardiomyopathy Subjects

Abstract

Purpose: To differentiate focal fibrotic and non fibrotic lesions in left ventricular myocardium (LVM) in hypertrophic cardiomyopathy (HCM) subjects, by comparing myocardial regional peak strain values using 2 dimensional speckle tracking transthoracic echocardiography (TTE) in cardiac magnetic resonance (CMR).

Material and Methods: A total of 29 consecutive HCM subjects (18 males, mean age 62±12 years) underwent CMR (1.5T Intera Achieva, Philips) and speckle tracking TTE (iE-33, Philips). CMR was acquired 15 min after injection of Gadopentetate dimeglumine to detect fibrotic lesions in LVM. On TTE, regional peak longitudinal strain (LS) and transverse strain (TS) were analyzed in each of 17 LVM segments (American Heart Association classification). Regional peak LS and TS were measured in fibrotic and non-fibrotic LVM lesions detected by CMR.

Results: On TTE, 466 LS lesions (94.5%) had good tracking, of which 81 LS lesions showed fibrotic changes in 24 subjects (16 males, mean age 60±13 years) on CMR. Further, 398 TS lesions (81%) yielded good tracking, of which 66 TS lesions showed fibrotic changes in 24 subjects (16 males, mean age 60±13 years) on CMR. Regional peak LS absolute values were significantly lower in fibrotic-lesions than in non-fibrotic lesions (-8.9±5.6%, and -11.3±5.9%, respectively, P<0.001). However, differences in regional peak TS among fibrotic and non-fibrotic lesions were not significant (12.0±10.1%, and 12.2±8.7%, respectively). Receiver operating characteristic curves of regional peak LS and TS at a cutoff of -11.0% and 10.1%, respectively, showed sensitivity and specificity for detection of fibrotic lesion on CMR of 76.5% and 49.4% for LS and 52% and 51% for TS, respectively, with areas under curve of 0.636 (P<0.001) and 0.474 (P=not significant), respectively.

Conclusion: Regional peak LS by speckle tracking provides useful information noninvasively to distinguish fibrotic from non-fibrotic lesions in LVM in HCM subjects using CMR.