Impact of left atrial appendage (LAA) morphology on Outcomes of WATCHMAN device implantation (LMOW study)

Purpose: Left atrial appendage occlusion (LAAO) with a WATCHMAN device is approved to be used in atrial fibrillation (AF) patients who are not good candidates for long term oral anticoagulation therapy (OAT) as an alternative stroke prevention strategy. Over the years, a number of different trials have addressed the various aspects of LAAO procedure, but there is still not enough literature on the impact of LAA anatomy on procedural outcomes of WATCHMAN device implantation. Besides shape, the location and orientation of LAA is a significant determinant of the complexity and success of the procedure. Chicken wing morphology has well been described as a particularly challenging anatomy from an interventional standpoint. We would like to assess the impact of the LAA morphology, as per a prior accepted classification (Chicken Wing, Cauliflower, Wind Sock or others), on the intraprocedural outcomes including procedure success, duration, compression ratio, number of devices used and major complications in the periprocedural period. 2. Methods: A single center observational study from individual institutional registries attempting to assess the impact of LAA anatomy on outcomes after WATCHMAN device implantation. Procedural outcomes, as mentioned above, will be compared between patients with and without chicken wing LAA anatomy. 3. Results: A number of 77 patients were found in our registry between September 2015 and April 2018, out of which 31(40%) had Windsock, 31(40%) had Cauliflower and 15(19%) had Chicken wing morphology. All of them had 100% successful implantation. The mean duration was noted to be 74.8 minutes with 1.065 number of attempts (NOA) for the patients with Cauliflower, 72.3 min with 1.294 NOA for the Chicken Wing and 70.3 minutes with 1.182 NOA for the Windsock. 4. Conclusion: After a thorough analysis of 77 patients it was noted that the patients with Cauliflower morphology had the longest duration of the procedures but had the least number of attempts. The patients with Chicken wing morphology had the highest number of attempts and the patients with Windsock had the lowest duration of implantation. Although the patients with the Cauliflower morphology took the longest time to be implanted having the lowest number of attempts might decrease the risk of complications. We recommend a more extensive analysis with a larger sample of patients to be able to find a significant correlation.