PROJECT SUMMARY
One in every 3 persons develops atrial fibrillation (AF) in their lifetime, and AF affects at least 10% of adults aged
≥65 years. Stroke prophylaxis with oral anticoagulants (OAC) is recommended, but half of older adults who are
eligible for OAC are not treated because of concerns for major bleeding. Treatment with OAC is even less
frequent in adults with frailty, who have excess risk for major bleeding but also for ischemic stroke. To reduce
AF risks in vulnerable populations, left atrial appendage occlusion (LAAO) was approved by Centers for Medicare
& Medicaid Services (CMS) and is recommended by practice guidelines to provide AF stroke prevention for
individuals deemed unsafe for long-term OAC. However, given its short-term procedural complications and life-
long requirement for antiplatelet therapy, the overall benefit of LAAO among adults with frailty is unknown. In
fact, because LAAO’s efficacy and safety were established against OAC in randomized controlled trials (RCT)
of OAC-eligible patients, LAAO’s effectiveness and safety remain uncertain for the population most likely to
benefit—patients with frailty or OAC ineligibility—resulting in a critical evidence-practice gap. The long-term goal
of our AF Outcomes Research program is to improve evidence-based, patient-centered care for older adults with
AF. To this end, our current objective is to evaluate utilization and outcomes of LAAO compared to therapeutic
alternatives in older adults with frailty. We will utilize multiple real-world data sources and apply advanced causal
inference methods to enhance generalizability and the validity of inference. In Aim 1 we will determine
characteristics of older adults who received LAAO and characterize concordance of LAAO use with CMS
approved and guideline recommended indication. In Aims 2 and 3 we will determine effectiveness, safety, and
net benefit (home time) of LAAO compared to OAC and no OAC, respectively. In absence of RCTs, the proposed
research will be the main source of evidence for guiding rational use of LAAO in vulnerable populations.
