A New WATCHMAN Sizing Algorithm Utilizing Cardiac CTA

Background: The WATCHMAN left atrial appendage (LAA) occlusion device has emerged as an alternative for anticoagulation in patients with non-valvular atrial fibrillation who cannot tolerate oral anticoagulation therapy. Cardiac computed tomography (CTA) is increasingly being utilized to guide WATCHMAN device sizing, however no consensus algorithm exists. We present our experience with a new cardiac CTA LAA ostium area based sizing algorithm. Methods: This is a single center, prospective study analyzing consecutive patients who underwent cardiac CTA and WATCHMAN device implantation between March 2017 and October 2019 at University Hospitals Cleveland Medical Center. Patients baseline characteristics, procedural data, and clinical outcomes were collected and analyzed. Results: 115 patients were included in our study. The mean age of our population was 76.5 years ±8.3 years. 70.4% of our patients had preserved ejection fraction. The predominant indication for device implantation was gastrointestinal bleeding in 57.4% of patients. The mean CHADSVASC score was 4.68 ± 1.4. The procedure success rate was 99.1% and the mean number of device used per case of 1.15 ± 0.4 devices. Our CTA LAA ostium area based sizing algorithm accurately predicted the final deployed WATCHMAN device size in 95.6% of cases. Conclusion: Our study demonstrates that cardiac CTA LAA ostium area based sizing algorithm is highly accurate at predicting WATCHMAN device size and demonstrates excellent clinical outcomes with lower device utilization per case than what is reported in literature.