Abstract 2295: Abnormal Myocardial Strains in Hypertrophic Cardiomyopathy Patients Despite Preserved Ejection Fraction and Absence of Myocardial Fibrosis
Background: Hypertrophic cardiomyopathy (HCM) patients have a high prevalence of abnormal segmental strains and myocardial fibrosis (scar), despite preserved left ventricular (LV) ejection fraction (EF). Delayed hyperenhancement magnetic resonance imaging (DHE-MRI) accurately detects LV scar. In HCM patients, the strain pattern, in absence of scar, is unknown.
Methods: We assessed 20 consecutive HCM patients (age 45 ± 16 years, 11 men), without myocardial scar on DHE-MRI (Siemens 1.5 T scanner, Germany) or evidence of coronary disease, and 23 healthy controls (age 38 ± 10 years, 10 men). Segmental strains were derived from transthoracic echocardiography (TTE) by speckle tracking (EchoPac, GE Medical, USA). We used 16-segment model to measure longitudinal strains (LS) at 3 LV levels (base, mid, and apex), and circumferential strains (CS) at base and mid LV.
Results: LVEF was similar in both groups (64 ± 7 % vs. 66± 7%, p = ns). HCM patients had lower average LS (−13.7 ± 3.9 % vs. −20.0 ± 1.7%, p < 0.001). Difference in LS between HCM and controls was present at all LV levels (p<0.001 for all), but decreased from base to apex (p<0.001) (Figure⇓). Similarly, average CS was lower in HCM patients (−13.0 ± 6.1%, vs. −18.7 ± 5.5%, p< 0.001), with significant difference at both LV base and mid level (p < 0.001 for both).
Conclusion: Despite preserved LVEF and absence of scar, HCM patients have depressed LS (global and regional) and CS, compared to healthy subjects. Also, in HCM patients, abnormal LS is more evident at the base and mid LV. Comprehensive multi-modality imaging, using advanced TTE and MRI techniques, can play an important role in understanding LV mechanics and aid in management of HCM patients.