Circulation. Cardiovascular imaging
-
Circ Cardiovasc Imaging · May 2013
T1 measurements identify extracellular volume expansion in hypertrophic cardiomyopathy sarcomere mutation carriers with and without left ventricular hypertrophy.
Myocardial fibrosis is a hallmark of hypertrophic cardiomyopathy (HCM) and a potential substrate for arrhythmias and heart failure. Sarcomere mutations seem to induce profibrotic changes before left ventricular hypertrophy (LVH) develops. To further evaluate these processes, we used cardiac magnetic resonance with T1 measurements on a genotyped HCM population to quantify myocardial extracellular volume (ECV). ⋯ Myocardial ECV is increased in HCM sarcomere mutation carriers even in the absence of LVH. These data provide additional support that fibrotic remodeling is triggered early in disease pathogenesis. Quantifying ECV may help characterize the development of myocardial fibrosis in HCM and ultimately assist in developing novel disease-modifying therapy, targeting interstitial fibrosis.
-
Circ Cardiovasc Imaging · May 2013
Comparative StudyFree-breathing, motion-corrected late gadolinium enhancement is robust and extends risk stratification to vulnerable patients.
Routine clinical use of novel free-breathing, motion-corrected, averaged late-gadolinium-enhancement (moco-LGE) cardiovascular MR may have advantages over conventional breath-held LGE (bh-LGE), especially in vulnerable patients. ⋯ Myocardial infarction detection and quantification are similar between moco-LGE and bh-LGE when bh-LGE can be acquired well, but bh-LGE quality deteriorates with patient vulnerability. Acquisition time, image quality, diagnostic confidence, and the number of successfully scanned patients are superior with moco-LGE, which extends LGE-based risk stratification to include patients with vulnerability confirmed by outcomes. Moco-LGE may be suitable for routine clinical use.
-
Circ Cardiovasc Imaging · May 2013
Comparative StudyIdentification of therapeutic benefit from revascularization in patients with left ventricular systolic dysfunction: inducible ischemia versus hibernating myocardium.
Although the recent surgical treatment of ischemic heart failure substudy reported that revascularization of viable myocardium did not improve survival, these results were limited by the viability imaging technique used and the lack of inducible ischemia information. We examined the relative impact of stress-rest rubidium-82/F-18 fluorodeoxyglucose positron emission tomography identified ischemia, scar, and hibernating myocardium on the survival benefit associated with revascularization in patients with systolic dysfunction. ⋯ Among patients with ischemic cardiomyopathy, hibernating, but not ischemic, myocardium identifies which patients may accrue a survival benefit with revascularization versus medical therapy.
-
Circ Cardiovasc Imaging · May 2013
Cardiac-selective expression of extracellular superoxide dismutase after systemic injection of adeno-associated virus 9 protects the heart against post-myocardial infarction left ventricular remodeling.
Cardiac magnetic resonance imaging has not been used previously to document the attenuation of left ventricular (LV) remodeling after systemic gene delivery. We hypothesized that targeted expression of extracellular superoxide dismutase (EcSOD) via the cardiac troponin-T promoter would protect the mouse heart against both myocardial infarction (MI) and subsequent LV remodeling. ⋯ Cardiac-selective expression of EcSOD from the cardiac troponin-T promoter after systemic administration of AAV9 provides significant protection against both acute MI and LV remodeling.