Predicted Coronary Occlusion and Impella Salvage During Valve-in-Valve Transcatheter Aortic Valve Replacement.

We describe an interesting case of a 71 years old fragile female, with progressive shortness of breath on exertion and ankle swelling, cardiac failure NYHA class III. She also had chest irradiation due to Hodgkin's disease many years before, previous surgical aortic valve replacement using bioprosthetic stent-less Freestyle #25 mm valve (Medtronic, Inc) in 2000 for severe aortic stenosis, history of cardiac arrest in 2012 and angioplasty to ostial RCA, PCI to ostial RCA in 2014, CABG (RA graft to RCA) in 2014 (RCA intra-stent restenosis with refractory ischemia), anemia requiring regular transfusions, bronchiectasis and chronic kidney disease. Because of the great comorbidities, STS 4.9% and worsening of the symptoms due to severe aortic valve regurgitation, heart team decided to perform "valve-in-valve" Transcatheter Aortic Valve Replacement (VIV-TAVR), but we already predicted coronary occlusion while performing this procedure because of the low left main coronary ostium and short aortic valve sinus. So regarding the probable left main coronary occlusion during the valve implantation, we decided to perform the placement of a not deployed stent inside the left main prior to the valve procedure, and to deploy it in case the predicted left main occlusion occurred. So just after the VIV-TAVR procedure, we observed left main coronary occlusion and the patient got ischemic cardiogenic shock and cardiac arrest, so we performed immediate PCI and deployed the bailout stent. After some minutes of chest compressions, an Impella mechanical circulatory support system (Abiomed, Danvers, MA) had to be installed. Patient recovered spontaneous circulation, and after hemodynamic stabilization, she was sent to the Intensive Coronary Unit, without further complications. She was discharged successfully without neurological or cardiac sequelae after 1 week.

Deep learning segmentation of coronary calcified plaque from intravascular optical coherence tomography (IVOCT) images with application to finite element modeling of stent deployment.

Because coronary artery calcified plaques can hinder or eliminate stent deployment, interventional cardiologists need a better way to plan interventions, which might include one of the many methods for calcification modification (e.g., atherectomy). We are imaging calcifications with intravascular optical coherence tomography (IVOCT), which is the lone intravascular imaging technique with the ability to image the extent of a calcification, and using results to build vessel-specific finite element models for stent deployment. We applied methods to a large set of image data (>45 lesions and > 2,600 image frames) of calcified plaques, manually segmented by experts into calcified, lumen and "other" tissue classes. In optimization experiments, we evaluated anatomical (x, y) versus acquisition (r,θ) views, augmentation methods, and classification noise cleaning. Noisy semantic segmentations are cleaned by applying a conditional random field (CRF). We achieve an accuracy of 0.85 ± 0.04, 0.99 ± 0.01, and 0.97 ± 0.01, and F-score of 0.88 ± 0.07, 0.97 ± 0.01, and 0.91 ± 0.04 for calcified, lumen, and other tissues classes respectively across all folds following CRF noise cleaning. As a proof of concept, we applied our methods to cadaver heart experiments on highly calcified plaques. Following limited manual correction, we used our calcification segmentations to create a lesion-specific finite element model (FEM) and used it to predict direct stenting deployment at multiple pressure steps. FEM modeling of stent deployment captured many features found in the actual stent deployment (e.g., lumen shape, lumen area, and location and number of apposed stent struts).