8 research outputs found
Transcatheter Valve Implantation in Failed Surgically Inserted Bioprosthesis Review and Practical Guide to Echocardiographic Imaging in Valve-in-Valve Procedures
AbstractAn increased use of bioprosthetic heart valves has stimulated an interest in possible transcatheter options for bioprosthetic valve failure given the high operative risk. The encouraging results of transcatheter aortic valve implantation in high-risk surgical candidates with native disease have led to the development of the transcatheter valve-in-valve (VIV) procedures for failed bioprostheses. VIV procedures are unique in many ways, and there is an increased need for multimodality imaging in a team-based approach. The echocardiographic approach to VIV procedures has not previously been described. In this review, we summarize key echocardiographic requirements for optimal patient selection, procedural guidance, and immediate post-procedural assessment for VIV procedures
A neural system dynamics modeling platform and its applications in randomized controlled trial data analysis
Background: Conventional statistical methods used in clinical trials lack the ability to predict patient specific risk and very often do not consider the effects of time varying interventions. The aim of this study is to test a novel artificial neural network based model for clinical trial analysis to represent the continuous time evolution of risk. Methods: The novel methodology tested utilizes system dynamics and artificial neural networks. This methodology was applied to analyze data from 2,221 patients with acute myocardial infarction enrolled in a well characterized randomized study, the HORIZONS-AMI trial. Outcomes analyzed included: (1) target lesion revascularization (TLR) and (2) stent thrombosis. The proposed neural system dynamics (NSD) model was compared against traditional Cox Proportional Hazards (Cox PH) and Cox neural network (NN) models. Model performance was evaluated using C-statistic at 1, 2 -and 3- years follow-up and model-based simulation studies were performed to examine the effect of different variables on the predicted risk of TLR and stent thrombosis. Results: The NSD model achieved comparable performance to Cox models for TLR. For stent thrombosis, the NSD model outperformed Cox models (1-year C-statistic: Stent thrombosis – Cox PH: 0.60, Cox NN: 0.66, neural SD model: 0.69). The neural SD model identified clinically relevant variables such as stent count, stent type and multiple lesions treated as significant predictors for TLR; and stent count and peak platelet count for stent thrombosis. Simulations illustrated change in predicted TLR risk maximal for the neural SD model, compared to other models. For stent thrombosis, simulation scenario illustrated predicted event rate doubling when clopidogrel is discontinued at 6 months compared to extended use. Conclusions: We have demonstrated an alternative analytical methodology that combines system dynamics and artificial neural networks to analyze results from a randomized trial. This novel approach can incorporate patient-specific longitudinal data and provide personalized risk prediction
E/e' in relation to outcomes in ST-elevation myocardial infarction
10.1111/echo.14652ECHOCARDIOGRAPHY-A JOURNAL OF CARDIOVASCULAR ULTRASOUND AND ALLIED TECHNIQUES374554-56
Practical determination of aortic valve calcium volume score on contrast-enhanced computed tomography prior to transcatheter aortic valve replacement and impact on paravalvular regurgitation: Elucidating optimal threshold cutoffs
© 2017 Society of Cardiovascular Computed Tomography Background The threshold for the optimal computed tomography (CT) number in Hounsfield Units (HU) to quantify aortic valvular calcium on contrast-enhanced scans has not been standardized. Our aim was to find the most accurate threshold to predict paravalvular regurgitation (PVR) after transcatheter aortic valve replacement (TAVR). Methods 104 patients who underwent TAVR with the CoreValve prosthesis were studied retrospectively. Luminal attenuation (LA) in HU was measured at the level of the aortic annulus. Calcium volume score for the aortic valvular complex was measured using 6 threshold cutoffs (650 HU, 850 HU, LA × 1.25, LA × 1.5, LA+50, LA+100). Receiver-operating characteristic (ROC) analysis was performed to assess the predictive value for \u3e mild PVR (n = 16). Multivariable analysis was performed to determine the accuracy to predict \u3e mild PVR after adjustment for depth and perimeter oversizing. Results ROC analysis showed lower area under the curve (AUC) values for fixed threshold cutoffs (650 or 850 HU) compared to thresholds relative to LA. The LA+100 threshold had the highest AUC (0.81), and AUC was higher than all studied protocols, other than the LA x 1.25 and LA + 50 protocols, where the difference approached statistical significance (p = 0.05, and 0.068, respectively). Multivariable analysis showed calcium volume determined by the LAx1.25, LAx1.5, LA+50, and LA+ 100 HU protocols to independently predict PVR. Conclusions Calcium volume scoring thresholds which are relative to LA are more predictive of PVR post-TAVR than those which use fixed cutoffs. A threshold of LA+100 HU had the highest predictive value
Transcatheter Left Ventricular Restoration in Patients With Heart Failure
Background: Left ventricular (LV) volume reshaping reduces myocardial wall stress and may induce reverse remodeling in patients with heart failure with reduced ejection fraction. The AccuCinch Transcatheter Left Ventricular Restoration system consists of a series of anchors connected by a cable implanted along the LV base that is cinched to the basal free wall radius. We evaluated the echocardiographic and clinical outcomes following transcatheter left ventricular restoration. Methods and Results: We analyzed 51 heart failure patients with a left ventricular ejection fraction between 20% and 40%, with no more than 2+ mitral regurgitation treated with optimal medical therapy, who subsequently underwent transcatheter left ventricular restoration. Serial echocardiograms, Kansas City Cardiomyopathy Questionnaire scores, and 6-minute walk test distances were measured at baseline through 12 months. Primary analysis end point was change in end-diastolic volume at 12 months compared with baseline. Patients (n = 51) were predominantly male (86%) with a mean age of 56.3 ± 13.1 years. Fluoroscopy showed LV free wall radius decreased by a median of 9.2 mm amounting to a 29.6% decrease in the free wall arc length. At 12 months, the LV end-diastolic volume decreased by 33.6 ± 34.8 mL (P < .01), with comparable decreases in the LV end-systolic volume. These decreases were associated with significant improvements in the overall Kansas City Cardiomyopathy Questionnaire score (16.4 ± 18.7 points; P < .01) and 6-minute hall walk test distance (45.9 ± 83.9 m; P < .01). There were no periprocedural deaths; through the 1-year follow-up, 1 patient died (day 280) and 1 patient received a left ventricular assist device (day 13). Conclusions: In patients with heart failure with reduced ejection fraction without significant mitral regurgitation receiving optimal medical therapy, the AccuCinch System resulted in decreases of LV volume, as well as improved quality of life and exercise endurance. A randomized trial is ongoing (NCT04331769)