3-Dimensional printing to predict paravalvular regurgitation after transcatheter aortic valve replacement.

BACKGROUND: There is no effective method to predict paravalvular regurgitation prior to transcatheter aortic valve replacement (TAVR). METHODS: We retrospectively analyzed pre-TAVR computed tomography (CT) scans of 20 patients who underwent TAVR for severe, calcific aortic stenosis and subsequently printed 3-dimensional (3D) aortic root models of each patient. Models were printed using Ninjaflex thermoplastic polyurethane (TPU) (Ninjatek Manheim, PA) and TPU 95A (Ultimaker, Netherlands) on Ultimaker 3 Extended 3D printer (Ultimaker, Netherlands). The models were implanted at nominal pressure with same sized Sapien balloon-expandable frames (Edwards Lifesciences, CA) as received in-vivo. Ex-vivo implanted TAVR models (eTAVR) were scanned using Siemens SOMATOM flash dual source CT (Siemens, Malvern, PA) and then analyzed with Mimics software (Materialize NV, Leuven, Belgium) to evaluate relative stent appositions. eTAVR were then compared to post-TAVR echocardiograms for each patient to assess for correlations of identified and predicted paravalvular leak (PVL) locations. RESULTS: A total of 20 patients (70% male) were included in this study. The median age was 77.5 (74-83.5) years. Ten patients were characterized to elicit mild (9/10) or moderate (1/10) PVL, and 10 patients presented no PVL. In patients with echocardiographic PVL, eTAVR 3D model analyses correctly identified the site of PVL in 8/10 cases. In patients without echocardiographic PVL, eTAVR 3D model analyses correctly predicted the lack of PVL in 9/10 cases. CONCLUSION: 3D printing may help predict the potential locations of associated PVL post-TAVR, which may have implications for optimizing valve selection and sizing.

Validation of STS/ACC TVT-TAVR Score in Veterans Undergoing Transcatheter Aortic Valve Replacement.

BACKGROUND: The Society of Thoracic Surgeons (STS)/American College of Cardiology (ACC) transcatheter valve therapy (TVT) transcatheter aortic valve replacement (TAVR) score was developed to predict in-hospital mortality in patients undergoing commercial TAVR in the United States. Veterans Affairs (VA) hospitals are not included in the TVT registry. METHODS: The STS/ACC TVT-TAVR score was estimated in 195 veterans undergoing TAVR from 2015-2017. Discrimination was estimated by calculating the area under the receiver operating characteristics curve (AUC) for two outcomes of interest: in-hospital and 30-day mortality. The cohort was then divided into quartiles of TAVR and STS predicted risk of mortality (PROM) scores and long-term mortality was assessed with Kaplan-Meier curves. RESULTS: The mean age of the cohort was 77 ± 8 years and the population was 99% males. The median TAVR and STS-PROM risk scores were 3.1 (interquartile range [IQR], 2.1-5.1) and 4.5 (IQR, 2.6-7.4), respectively. Observed in-hospital and 30-day mortality rates were 2.6% and 4.6%, respectively. The AUCs for the TAVR risk score were 0.68 and 0.64 for in-hospital and 30-day mortality, respectively. During a mean follow-up period of 1.9 years, a total of 37 patients (20%) died. Long-term survival was similar in different quartiles of STS-PROM scores (P=.52). In contrast, patients in the highest quartile of TAVR risk score (8.4; IQR, 5.8-9.9) had significantly worse survival (P<.01). This group included 20 out of the 37 deaths (>50%). CONCLUSIONS: Developed and validated in commercial United States cases, the TAVR risk score has a similar performance in the veteran population for predicting short-term outcomes. In addition, the TAVR score predicts long-term mortality. Our results have implications for optimal patient selection.

Difference in caloric expenditure in sitting versus standing desks.

BACKGROUND: Traditional desks require students to sit; however, recently schools have provided students with nontraditional standing desks. The purpose of this study was to investigate differences in caloric expenditure of young adults while sitting at a standard classroom desk and standing at a nontraditional standing classroom desk. METHODS: Twenty (10 male/10 female) young (22.8 ± 1.9 y), healthy participants reported to the laboratory between the hours of 7:00 AM and 2:00 PM following a 12-h fast and 48-h break in exercise. Participants were randomly assigned to perform a series of mathematical problems either sitting at a normal classroom desk or standing at a nontraditional standing desk. Inspired and expired gases were collected for 45-min for the determination of oxygen consumption (VO2), carbon dioxide production (VCO2), and minute ventilation (VE) using a metabolic gas system. RESULTS: There were significant increases from sitting to standing in VO2 (0.22 ± 0.05 vs. 0.28 ± 0.05 L·min-1, P ≤ .0001), VCO2 (0.18 ± 0.05 vs. 0.24 ± 0.050 L·min-1, P ≤ .0001), VE (7.72 ± 0.67 vs. 9.41 ± 1.20 L·min-1, P ≤ .0001), and kilocalories expended per minute (1.36 ± 0.20 kcal/min, P ≤ .0001 vs. 1.02 ± 0.22 kcal/min, P ≤ .0001). CONCLUSIONS: Results indicate a significant increase in caloric expenditure in subjects that were standing at a standing classroom desk compared with sitting at a standard classroom desk.