Elimination of Transcoarctation Pressure Gradients Has No Impact on Left Ventricular Function or Aortic Shear Stress After Intervention in Patients With Mild Coarctation

Objectives: This study sought to investigate the impact of transcatheter intervention on left ventricular function and aortic hemodynamics in patients with mild coarctation of the aorta (COA). Background: The optimal method and timing of transcatheter intervention for COA remains unclear, especially when the severity of COA is mild (peak-to-peak transcoarctation pressure gradient  < 20 mm Hg). Debate rages regarding the risk/benefit ratio of intervention versus long-term effects of persistent minimal gradient in this heterogeneous population with differing blood pressures, ventricular function, and peripheral perfusion. Methods: We developed a unique computational fluid dynamics and lumped parameter modeling framework based on patient-specific hemodynamic input parameters and validated it against patient-specific clinical outcomes (before and after intervention). We used clinically measured hemodynamic metrics and imaging of the aorta and the left ventricle in 34 patients with mild COA to make these correlations. Results: Despite dramatic reduction in the transcoarctation pressure gradient (catheter and Doppler echocardiography pressure gradients reduced by 75% and 47.3%, respectively), there was only modest effect on aortic flow and no significant impact on aortic shear stress (the maximum time-averaged wall shear stress in descending aorta was reduced 5.1%). In no patient did transcatheter intervention improve left ventricular function (e.g., stroke work and normalized stroke work were reduced by only 4.48% and 3.9%, respectively). Conclusions: Transcatheter intervention that successfully relieves mild COA pressure gradients does not translate to decreased myocardial strain. The effects of the intervention were determined to the greatest degree by ventricular–vascular coupling hemodynamics and provide a novel valuable mechanism to evaluate patients with COA that may influence clinical practice. Key Words: aortic hemodynamics, left ventricle function, mild coarctation, peak-to-peak pressure gradient, transcatheter interventionNational Institute of Mental Health (U.S.) (R01 GM 49039)American Heart Association (Postdoctoral Fellowship 16POST26420039

Cross-sectional imaging of sinus of Valsalva aneurysms: lessons learned

Sinus of Valsalva aneurysm, dilatation of one or more of the aortic sinuses, is a rare but important aortic root defect, which can be a cause of some serious cardiac sequels. The purpose of this article is to review the etiopathogenesis, relevant anatomy, clinical manifestations, potential complications, multimodality imaging features, and management of this rare but important entity of sinus of Valsalva

Clinical experiences of delayed contrast enhancement with cardiac computed tomography: case series

Background: Myocardial delayed enhancement (MDE) by gadolinium-enhanced cardiac MRI is well established for myocardial scar assessment in ischemic and non-ischemic heart disease. The role of MDE by cardiac CT (CT-MDE) is not yet defined. Findings: We reviewed all clinical cases of CT-MDE at a tertiary referral center to present the cases as a case series. All clinical cardiac CT exams which utilized CT-MDE imaging between January 1, 2005 and October 1, 2010 were collected as a series and their findings were also compared with available myocardial imaging to assess for myocardial abnormalities, including echocardiography (wall motion, morphology), cardiac MRI (delayed enhancement, morphology), SPECT MPI (perfusion defects). 5,860 clinical cardiac CT exams were performed during the study period. CT-MDE was obtained in 18 patients and was reported to be present in 9 patients. The indications for CT-MDE included ischemic and non-ischemic heart diseases. In segments positive for CT-MDE, there was excellent agreement of CT with other modalities: echocardiography (n=8) demonstrated abnormal morphology and wall motion (k=1.0 and k=0.82 respectively); prior MRI (n=2) demonstrated abnormal delayed enhancement (MR-MDE) (k=1.0); SPECT MPI (n=1) demonstrated fixed perfusion defects (k=1.0). In the subset of patients without CT-MDE, no abnormal segments were identified by echocardiography (n=8), MRI (n=1) and nuclear MPI (n=0). Conclusions: CT-MDE was performed in rare clinical situations. The indications included both ischemic and non-ischemic heart disease and there was an excellent agreement between CT-MDE and abnormal myocardium by echocardiography, cardiac MRI, and nuclear MPI