# Safety and Effectiveness of Left Atrial Appendage Closure in Atrial Fibrillation (SAFELY-AF)

> **NIH NIH R01** · YALE UNIVERSITY · 2020 · $713,307

## Abstract

PROJECT SUMMARY. Atrial fibrillation (AF) is the most common cardiac arrhythmia and markedly increases
the risk for stroke and systemic embolism. Oral anticoagulation has been the mainstay of therapies to reduce
the risk of stroke and systemic embolism in AF, but studies have consistently shown that between 30-50% of
patients for whom oral anticoagulation is indicated are not treated with anticoagulants. Left atrial appendage
occlusion (LAAO) represents a new and increasingly important device-based approach for preventing stroke
and thromboembolism in AF patients. Randomized trials have evaluated LAAO for the prevention of stroke and
thromboembolism in atrial fibrillation, but the trial results were inconsistent, leaving important gaps in
knowledge regarding the safety and effectiveness of this procedure. The goal of this proposal, “Safety and
Effectiveness of Left Atrial Appendage Occlusion in Atrial Fibrillation (SAFELY-AF)”, is to leverage data from a
large national registry of LAAO procedures to enhance our understanding of the use and effectiveness of
LAAO in real-world practice. The National Cardiovascular Data Registry’s LAAO Registry represents the
largest prospective registry of LAAO procedures worldwide. Through a novel collaboration with Boston
Scientific and the American College of Cardiology (ACC), we propose a series of studies that will enhance our
understanding of the use and effectiveness of LAAO in real-world practice. First, we will use patient-level data
from the pivotal randomized trials of LAAO devices and data from the NCDR LAAO Registry to examine
differences in patient characteristics and outcomes following device implantation. We will further identify
patient, physician, and hospital predictors of adverse outcomes following device implantation and use this
information to develop a risk score to determine major adverse events. This information will be incorporated
into the ACC’s shared decision making (SDM) tool, developed to promote shared decision-making for patients
and physicians regarding LAAO procedures. Finally, we will conduct comparative-effectiveness research, using
cutting-edge computational approaches to characterize the association between different approaches to
periprocedural antithrombotic and anticoagulant therapies and patient outcomes following device implantation.

## Key facts

- **NIH application ID:** 9955314
- **Project number:** 5R01HL142765-02
- **Recipient organization:** YALE UNIVERSITY
- **Principal Investigator:** James Freeman
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $713,307
- **Award type:** 5
- **Project period:** 2019-09-01 → 2023-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9955314

## Citation

> US National Institutes of Health, RePORTER application 9955314, Safety and Effectiveness of Left Atrial Appendage Closure in Atrial Fibrillation (SAFELY-AF) (5R01HL142765-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9955314. Licensed CC0.

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