PROJECT SUMMARY/ABSTRACT Atrial fibrillation is a major cause of ischemic stroke and stroke-associated mortality worldwide. Though risk of ischemic stroke in patients with atrial fibrillation is reduced with oral anticoagulation (OAC), many are not suitable candidates for long-term OAC due to high bleeding risk. To help treat such patients, transcatheter left atrial appendage occlusion (LAAO) with the Watchman device was developed and approved as an alternative to OAC. However, efficient methods for evaluating clinical outcomes associated the Watchman device and other novel cardiovascular technologies are needed for long-term surveillance after regulatory approval. In this mentored patient-oriented career development award, Dr. Kamil Faridi will use a national registry of LAAO procedures linked to Medicare claims data to evaluate how different data sources and innovative statistical approaches can be utilized for evaluating the long-term safety and effectiveness of the Watchman device in real-world practice. In Aim 1, he will use traditional and advanced statistical methods to compare ischemic stroke and bleeding events identified with administrative claims data to site-reported events in a national registry of patients who undergo transcatheter LAAO. In Aim 2, he will use linked pharmacy claims data to evaluate registry-reported OAC use and compare outcomes between LAAO patients and medically managed patients with atrial fibrillation in real-world practice. To supplement quantitative strategies for post-marketing surveillance, in Aim 3 he will use qualitative methods to explore patient-reported perspectives and quality of life among patients referred for transcatheter LAAO. Accomplishing these research aims will lay the groundwork for future studies examining real-world surveillance of other cardiovascular therapies and other clinically important outcomes. This project will be led by Dr. Kamil Faridi, an early career investigator, cardiologist, and faculty member at the Yale School of Medicine with a track record of success in the field of cardiovascular outcomes research. During this 5-year program, Dr. Faridi will pursue additional training in machine learning, pharmacoepidemiology, comparative effectiveness and qualitative methods applied to patient-oriented research. This will be accomplished with a comprehensive career development program designed to provide Dr. Faridi with the skills needed to become a successful clinical researcher in cardiovascular medicine. His long-term career goal is to become an independent investigator with specific expertise in the areas of post- marketing surveillance and real-world data utilization for novel cardiovascular therapies, with the ultimate aim of improving patient care. Over the course of the research and training program, Dr. Faridi will be guided by an exceptional mentorship team and advisory committee consisting of established clinical investigators with expertise in cardiovascular medicine, outcom...