Related Experiment Video
Updated: May 5, 2026
The WATCHMAN Left Atrial Appendage Closure Device for Atrial Fibrillation
Published on: February 28, 2012
Predicting Major Adverse Events in Patients Undergoing Transcatheter Left Atrial Appendage Occlusion
Kamil F Faridi1,2, Emily L Ong1, Sarah Zimmerman2
1Section of Cardiovascular Medicine, Department of Medicine, Yale School of Medicine (K.F.F., E.L.O., J.P.C., J.V.F.).
Insights
A new risk model predicts major adverse events in patients undergoing Watchman FLX left atrial appendage occlusion (LAAO). A simplified bedside score aids shared decision-making for this transcatheter procedure.
Area of Science:
- Cardiovascular Medicine
- Interventional Cardiology
- Health Informatics
Background:
- The National Cardiovascular Data Registry Left Atrial Appendage Occlusion Registry (LAAO) captures most US transcatheter LAAO procedures.
- Watchman FLX is a common device for LAAO.
Purpose of the Study:
- To develop and validate a predictive model for in-hospital major adverse events (MAEs) in patients undergoing LAAO with Watchman FLX.
- To create a simplified bedside risk score based on the predictive model.
Main Methods:
- Utilized data from 41,001 Watchman FLX LAAO procedures (July 2020-September 2021).
- Developed a model using a 70% development cohort and validated it on a 30% validation cohort.
- Employed forward stepwise logistic regression and 1000 bootstrapped samples.
Main Results:
- Key predictors of MAEs included increased age, female sex, low hemoglobin, no prior AF termination attempt, and increased fall risk.
- The median in-hospital MAE rate was 1.50%.
- The model showed moderate discrimination (C-indices 0.67 and 0.66) and good calibration; the simplified score ranged from 0.26% to 3.90% risk.
Conclusions:
- A transcatheter LAAO risk model using registry data can predict in-hospital MAEs.
- The model demonstrates consistency and utility for quality improvement.
- A simple bedside risk score is predictive and can support shared decision-making.
Background:
The National Cardiovascular Data Registry Left Atrial Appendage Occlusion Registry (LAAO) includes the vast majority of transcatheter LAAO procedures performed in the United States. The objective of this study was to develop a model predicting adverse events among patients undergoing LAAO with Watchman FLX.
Methods:
Data from 41 001 LAAO procedures with Watchman FLX from July 2020 to September 2021 were used to develop and validate a model predicting in-hospital major adverse events. Randomly selected development (70%, n=28 530) and validation (30%, n=12 471) cohorts were analyzed with 1000 bootstrapped samples, using forward stepwise logistic regression to create the final model. A simplified bedside risk score was also developed using this model.
Results:
Increased age, female sex, low preprocedure hemoglobin, no prior attempt at atrial fibrillation termination, and increased fall risk most strongly predicted in-hospital major adverse events and were included in the final model along with other clinically relevant variables. The median in-hospital risk-standardized adverse event rate was 1.50% (range, 1.03%-2.84%; interquartile range, 1.42%-1.64%). The model demonstrated moderate discrimination (development C-index, 0.67 [95% CI, 0.65-0.70] and validation C-index, 0.66 [95% CI, 0.62-0.70]) with good calibration. The simplified risk score was well calibrated with risk of in-hospital major adverse events ranging from 0.26% to 3.90% for a score of 0 to 8, respectively.
Conclusions:
A transcatheter LAAO risk model using National Cardiovascular Data Registry and LAAO Registry data can predict in-hospital major adverse events, demonstrated consistency across hospitals and can be used for quality improvement efforts. A simple bedside risk score was similarly predictive and may inform shared decision-making.
