Design Strategies for Global Clinical Trials of Endovascular Devices for Critical Limb Ischemia (CLI) - A Joint USA-Japanese Perspective

Practice Patterns and Outcomes of Transcatheter Aortic Valve Replacement in the United States and Japan: A Report From Joint Data Harmonization Initiative of STS/ACC TVT and J-TVT

Background

The practice pattern and outcome of medical devices following their regulatory approval may differ by country. The aim of this study is to compare postapproval national clinical registry data on transcatheter aortic valve replacement between the United States and Japan on patient characteristics, periprocedural outcomes, and the variability of outcomes as a part of a partnership program (Harmonization‐by‐Doing) between the 2 countries.

Methods and Results

The patient‐level data were extracted from the US Society of Thoracic Surgeons /American College of Cardiology Transcatheter Valve Therapy (STS/ACC TVT) and the J‐TVT (Japanese Transcatheter Valvular Therapy) registry, respectively, to analyze transcatheter aortic valve replacement outcomes between 2013 and 2019. Data entry for these registries was mandated by the federal regulators, and the majority of variable definitions were harmonized to allow direct data comparison. A total of 244 722 transcatheter aortic valve replacements from 646 institutions in the United States and 26 673 transcatheter aortic valve replacements from 171 institutions in Japan were analyzed. Median volume per site was 65 (interquartile range, 45–97) in the United States and 28 (interquartile range, 19–41) in Japan. Overall, patients in J‐TVT were older (United States: mean‐age, 80.1±8.7 versus Japan: 84.4±5.2; P<0.001), were more frequently women (45.9% versus 68.1%; P<0.001), and had higher median Society of Thoracic Surgeons Predicted Risk of Mortality (5.27% versus 6.20%; P<0.001) than patients in the United States. Japan had lower unadjusted 30‐day mortality (1.3% versus 3.2%; P<0.001) and composite outcomes of death, stroke, and bleeding (17.5 versus 22.5%; P<0.001) but had higher conversion to open surgery (0.94% versus 0.56%; P<0.001).

Conclusions

This collaborative analysis between the United States and Japan demonstrated the feasibility of international comparison using the national registries coded under mutual variable definitions. Both countries obtained excellent outcomes, although the Japanese had lower 30‐day mortality and major morbidity. Harmonization‐by‐Doing is one of the key steps needed to build global‐level learning to improve patient outcomes.

Japan-USA orbital atherectomy for calcific coronary lesions: COAST study, Hharmonization by Doing proof-of-concept

Effective treatment strategies and medical devices continue to be needed in Japan and the United States of America (US) to mitigate the growing burden of cardiovascular disease and coronary heart disease. Unfortunately, there can be a delay in gaining cardiovascular device approval in Japan after a device has already been approved and is in use in the US. The Harmonization by Doing (HBD) program; however, can eliminate this delay and reduce the cost of completing a clinical trial in Japan. The HBD proof-of-concept study, COAST, resulted in approval of the Diamondback 360® Coronary Orbital Atherectomy System Micro Crown simultaneously in Japan and the US on the same day. Subsequently, the Diamondback 360® Coronary OAS Classic Crown also received approval in Japan. The COAST study provides further evidence that global clinical trials via HBD for medical devices are practical and advantageous.

Overview of the Virtual 2021 FDA's Circulatory System Devices Advisory Panel on Lutonix 014 Drug-Coated Percutaneous Transluminal Angioplasty Catheter for Below-the-Knee Lesions in Critical Limb Ischemia

Peripheral artery disease, along with subsequent critical limb ischemia (CLI), is highly prevalent, increases with age, and carries high morbidity and mortality. Specific devices for treatment of below-the-knee (BTK) lesions are limited. On February 17, 2021, the United States Food and Drug Administration convened a virtual meeting of the Circulatory System Devices Panel of the Medical Devices Advisory Committee to consider a premarket approval application for the Lutonix 014 Drug-Coated Balloon Percutaneous Transluminal Angioplasty Catheter (Becton, Dickinson and Company, Franklin Lakes, New Jersey) for the treatment of obstructive de novo or non-stented restenotic lesions in BTK vessels (popliteal, tibial, and peroneal arteries) in patients with CLI. We summarize the presentations and the panel deliberations, including voting outcome and recommendations for risk versus benefit.

Pediatric Medical Devices - Survey of Pediatric Cardiologists and Cardiovascular Surgeons in Japan

Background: In Japan, the choice of pediatric medical devices is limited because of 2 "device lag" problems: Japan lags behind the USA and Europe in device development, and development of pediatric devices lags behind that of adult devices. We aimed to identify the problems with and impediments to pediatric medical device development as recognized by pediatric physicians in Japan. Methods and Results: A voluntary survey of pediatric medical devices for all council members of the Japanese Society of Pediatric Cardiology and Cardiac Surgery was conducted in 2019. The response rate was 47.1% (154/327). The respondents were 115 pediatric cardiologists (74.7%) and 39 cardiovascular surgeons (25.3%). Approximately 90% believed that difficulties in development existed. Approximately 70% were dissatisfied with the pediatric medical devices currently available in Japan, which was a result of the unavailability of medical devices approved overseas, few types and sizes, and off-label use. Factors that hindered the development of pediatric medical devices included anatomical issues specific to children with congenital heart disease, as well as system issues such as lack of corporate profitability, development cost, and amount of time for development. Conclusions: Pediatric cardiologists and cardiovascular surgeons regard "device lag" and "off-label use" in Japan as important hindrances to the delivery of better medical care for pediatric patients with congenital heart disease.

Convolutional neural networks for wound detection: the role of artificial intelligence in wound care

OBJECTIVE

Telemedicine is an essential support system for clinical settings outside the hospital. Recently, the importance of the model for assessment of telemedicine (MAST) has been emphasised. The development of an eHealth-supported wound assessment system using artificial intelligence is awaited. This study explored whether or not wound segmentation of a diabetic foot ulcer (DFU) and a venous leg ulcer (VLU) by a convolutional neural network (CNN) was possible after being educated using sacral pressure ulcer (PU) data sets, and which CNN architecture was superior at segmentation.

METHODS

CNNs with different algorithms and architectures were prepared. The four architectures were SegNet, LinkNet, U-Net and U-Net with the VGG16 Encoder Pre-Trained on ImageNet (Unet_VGG16). Each CNN learned the supervised data of sacral pressure ulcers (PUs).

RESULTS

Among the four architectures, the best results were obtained with U-Net. U-Net demonstrated the second-highest accuracy in terms of the area under the curve (0.997) and a high specificity (0.943) and sensitivity (0.993), with the highest values obtained with Unet_VGG16. U-Net was also considered to be the most practical architecture and superior to the others in that the segmentation speed was faster than that of Unet_VGG16.

CONCLUSION

The U-Net CNN constructed using appropriately supervised data was capable of segmentation with high accuracy. These findings suggest that eHealth wound assessment using CNNs will be of practical use in the future.