Data extraction
Chest X-ray images with adult implanted cardiac devices (pacemakers, ICD cardioresynchronizers, and event monitors) were collected between January 2010 and December 2021 at a single institution. Radiographs with AP and PA projection were included; those with lateral projection (except in the presence of a subcutaneous ICD) or those with suboptimal quality were excluded. Complementary data (age, sex, manufacturer, model, and indication for device implantation) were obtained by reviewing electronic medical records.
The images were downloaded from the Kanteron Viewer® system in JPG format (Joint Photographic Experts Group); each image was cropped at the region of interest and resized to 224 by 224 pixels. The REDCap® data collection tool was used (8). This study was approved by the research and ethics committee of the institute (FM-CIE-0243-21).
For the PIDa® application, an iPhone with a 12-megapixel camera was used. For CaRDIA-X ® visual algorithm, the images were reviewed by 4 independent evaluators with different levels of medical training blinded to the manufacturer (medical student, internal medicine resident, cardiology resident, and electrophysiology resident) using the CaRDIA-X® (3). They had to identify the type of device and the manufacturer.
Manufacturer options were: Biotronik® (Oregon), Boston Scientific® (including Guidant® and Cameron Health®, Massachusetts), Medtronic®, Sorin® (including Liva Nova®, Colorado), or St. Jude Medical® (owned by Abbott Medical®)