We appreciate the interest in our report, “Overview of the Food and Drug Administration Circulatory System Devices Panel Meetings on WATCHMAN Left Atrial Appendage Closure Therapy” and that it stimulated provocative discussion in a letter to the editor. First, the WATCHMAN device was approved with the indication to reduce the risk of thromboembolism from the left atrial appendage (LAA) in patients with nonvalvular atrial fibrillation, who are at an increased risk for stroke and systemic embolism based on CHADS2 or CHA2DS2-VASc scores; are deemed by their physicians to be suitable for warfarin; and have an appropriate rationale to seek a nonpharmacologic alternative to warfarin, taking into account the safety and effectiveness of the device compared to warfarin. Although there is an unmet need for the population with nonvalvular atrial fibrillation who cannot take warfarin, the device is not approved in the United States for this indication, and patients who meet these criteria should be subject to rigorous study to demonstrate safety and effectiveness in this population. With respect to the risk of bleed, we recommend following the WATCHMAN trials’ regimens because they were proved to reduce the overall bleeding rate compared with the control group.
Transesophageal echocardiography at 1 year after implantation to detect a leak is an interesting proposal that should be subject to independent investigation to detect the incidence and the clinical consequences for acquired leaks over time. It should not, however, be a part of the commercialization of the device.
To the best of our knowledge, there is not sufficient autopsy or pathologic data to answer the causality of the unexplained death from the WATCHMAN studies.
Finally, to date there are no data to support the hypothesis raised by the letter’s authors that LAA elimination may impede physiologic regulations of heart failure and thirst perception. This phenomenon was not demonstrated after LAA resection with surgery or LAA occlusion by occluder devices. Therefore, there must be other compensatory mechanistic alternatives to take care of the response of the natriuretic peptides to certain physiological conditions. The use of the WATCHMAN device should not be a concern in this regard.