br Results br Discussion The

Results
Discussion The results of this retrospective study demonstrate the feasibility and safety of combined left atrial catheter ablation and Watchman® implant procedures with satisfactory LAA occlusion maintained at follow-up. The rates of successful device implantation and complete LAA occlusion at follow-up in the current study compare favorably with results from the larger randomized controlled trials evaluating Watchman® implantation versus warfarin therapy [1]. The rates of successful device implantation were 91% in PROTECT-AF [7] and 95% in PREVAIL [10] as compared with 100% in our series. The 12 month rates of complete LAA occlusion on TOE studies in PROTECT-AF was 68% [11] as compared with 86% in this study. The development of ‘new,’ small peri-device leaks at the initial follow-up TOE has also been observed in 12–13% of patients in other Watchman® series [12,13], although, the rate was significantly higher in our study. The phenomenon is possibly related to a mismatch between the circular device and typical elliptical orifice of the LAA, that might be partially masked by an edema response at the time of implant. In the current series, the most common location for new leaks was at the posterior margin of the LAA ostium (best viewed in TOE angle 135°), which is commonly the largest dimension of the ostium (Fig. 1). Reassuringly, the majority of these new leaks were observed to resolve at follow-up, and the 12-month complete occlusion rate of 86% in our study was comparable to that in the other small series (93% and 66%). In our series, late persistent leaks were more frequently associated with device angulation or shoulder protrusion, suggesting that suboptimal device seating or apposition with the LAA walls is implicated. A statistically significantly lower amount of device cdc42 pathway was also noted for persistent late leaks as compared with complete occlusion (12±3% vs. 15±5%), suggesting that, where feasible, oversizing of the device by ≥15% may be preferred. Concern has been raised that residual peri-device leaks have the potential to further enlarge with time in patients with untreated AF [13]. Progressive atrial dilatation as a consequence of AF is widely recognized [14] – progressive dilatation of the LAA ostium may also occur [6]. Reversal of left atrial dilatation in patients maintaining sinus rhythm following successful catheter ablation is also well documented [15]. This may be beneficial for patients undergoing the combined procedure with Watchman® device implantation, with the potential for reverse remodeling to shrink the LAA ostium around the implanted device. Further study is required to evaluate the effects of longer term atrial remodeling in different AF populations undergoing LAA device occlusion procedures. Fortunately, the evidence to date suggests that small residual peri-device leaks are unlikely to compromise the efficacy of LAA occlusion devices [16,17]. A significant number of the procedures were performed on patients on uninterrupted warfarin with a therapeutic INR. The safety of femur approach has been documented for patients undergoing catheter ablation procedures for AF [18]. This series suggests this is also a safe approach for patients undergoing percutaneous LAA device occlusion. A small number of procedures were also performed on uninterrupted, novel oral anticoagulants. Further experience with performing catheterization procedures on the novel oral anticoagulants is required before drawing conclusions about the safety of this approach. Asymptomatic, early device-associated thrombus was also noted in 2 patients (2%) in this study – both on novel anticoagulants (1 on dabigatran and 1 on rivaroxaban). However, the incidence was not significantly different from that reported in the PROTECT AF trial (3%) using warfarin [16]. Overall, the current experience supports the use of the novel anticoagulants with the Watchman® prosthesis as safe. The results from catheter ablation in this cohort were comparable to previously reported outcomes [2,3]. The majority of patients with persistent or longstanding persistent AF, however, did not discontinue antiarrhythmic drug therapy post-procedure as an adjunctive measure to improve long-term maintenance of sinus rhythm. This strategy is aimed at reducing the significantly elevated long-term late recurrence rates associated with persistent AF [3]. The strategy is informed by demonstration of the relative safety of antiarrhythmic drug use in a patient populations receiving appropriate stroke prevention [19]. The presence of the Watchman® implant did not appear to impact the subsequent left atrial ablation procedure in patients requiring a redo, although, the repeat procedure was deferred at least 6 months to allow for implant healing [20].