Abstract 17133: Cardiac Steatosis Detected in Hypertrophic Cardiomyopathy, Dilated Cardiomyopathy and Aortic Stenosis
BACKGROUND The failing heart is characterised by impaired myocardial energetics and a compensatory shift from fatty acid to glucose metabolism. Cardiac steatosis has been implicated in ventricular contractile dysfunction, hypertrophy, inflammation and arrhythmias.Therefore we assessed cardiac steatosis using 1H magnetic resonance spectroscopy in hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM, EF35 mmHg, LVEF>45%).
METHODS 75 prospectively enrolled subjects (15 DCM, LVEF34±15%; 17 HCM, LV mass 165±42g; 14 AS, gradient 44±2 mmHg and 29 normal volunteers) were scanned at 3T.1H magnetic resonance spectroscopy (MRS) was used to quantify myocardial lipid/water content(%) and 31P MRS to measure the phosphocreatine/adenosine triphosphate (PCr/ATP) ratio in the same region of the mid-ventricular septum. LVEF was assessed using cine imaging and tagging was used to assess global circumferential strain (% deformation normal -19±2; reduced contraction between -16 and 0%).
RESULTS All subjects were well matched between cohorts for BMI, fasting glucose and total cholesterol (26±4 kg/m2, 5.0±0.6mmol/l, 5.1±1.2 mmol/l, p<0.05). Cardiac lipid content was elevated in all patientcohorts compared with normal volunteers (HCM 0.7±0.4; DCM 0.7±0.3; AS 0.7±0.6 vs normals 0.33±0.2% lipid/water, p<0.01 for all). PCr/ATP ratios were also impaired in all patientgroups (HCM 1.6±0.2; DCM 1.7±0.2; AS 1.7±0.2 vs normals 2.1±0.2, p<0.01 for all).Peak systolic circumferential strain was impaired in HCM (-16±2%, p<0.01) and DCM (-14±3%, p<0.01) compared to normals (-19±2%) but unchanged in AS (-18±2%).
CONCLUSION Cardiac steatosis occurs in HCM and DCM in the presence of impaired energetics and abnormal contractile function andin patients with AS in the presence of preserved global contractile function. This suggests a potential role for cardiac steatosis as a novel biomarker and mechanism inboth early and advanced non-ischemic cardiac disease.
- Cardiovascular imaging
- Magnetic resonance imaging
- Magnetic resonance spectroscopy
- Aortic stenosis
- © 2011 by American Heart Association, Inc.