• FDA-Accepted Levels of Watchman Peridevice Leak Linked With Greater Long-Term Thromboembolism Risk

    A post-implantation peridevice leak (PDL) of 5 mm or less after percutaneous left atrial appendage (LAA) closure with the Watchman device is linked with greater risk of thromboembolism over 5 years, a new follow-up study has found.

    PDL of 5 mm or less is accepted by the U.S Food and Drug Administration (FDA) as “sufficient” closure in the device’s approval.

    Still, despite this increased risk of thromboembolism – with these patients at twice the risk of ischemic stroke or systemic embolism – the researchers found no rise in cardiovascular or all-cause mortality.

    The findings were published Monday online ahead of the Aug. 2 issue of the Journal of the American College of Cardiology, with authors led by Srinivas R. Dukkipati, MD, from the Icahn School of Medicine at Mount Sinai, New York. The researchers list various financial ties with the device’s manufacturer, Boston Scientific.

    They follow clinical trials of LAA closure in which a PDL ≤5 mm (PDL≤5) was considered by the FDA to be acceptable both at the time of implantation and at the 45-day transesophageal echocardiography (TEE) and allowed discontinuation of warfarin in favor of dual antiplatelet therapy per study protocols.

    The PROTECT-AF trial also found that these “small PDLs” were not associated with ischemic stroke or systemic embolism in follow-up; “however, the numbers of analyzed patients and overall event rates were small, decreasing the confidence of this finding,” the researchers noted.

    The current study was conducted after evidence in contrasting surgical literature that incomplete surgical ligation of the LAA is associated with stroke and systemic embolism, “even with PDL≤5.”

    5-year follow-up

    The researchers, therefore, combined data from Watchman trials, including PROTECT AF, PREVAIL (evaluating Watchman vs. long-term warfarin), and CAP2 (continued access to PREVAIL) to assess the significance of PDL≤5 on clinical outcomes followed to 5 years.

    The cohort included 1,054 patients with a mean age of 74 years, a mean CHA2DS2-VASc score for atrial fibrillation stroke risk of 4.1 ± 1.4, and the majority (65%) were men.

    TEE imaging at 45 days revealed 634 patients (60.2%) without and 404 (38.3%) with PDL≤5, and for the 904 patients who also had 1-year TEE, 704 patients (71.6%) did not have PDL≤5 and while 272 (27.7%) did.

    The majority of PDLs disappeared or decreased in severity over time, the researchers added. “In patients with PDL≤3 at 45 days, 47% (101/216) disappeared by 1 year. Similarly, in patients with PDL>3 to PDL≤5, 41% (51/124) disappeared and another 24% (30/124) decreased in severity.

    “Even for patients with PDL>5, most either disappeared or decreased in severity.”

    Nevertheless, the presence of PDL≤5 at 1 year – not at 45 days – was associated with a greater 5-year of ischemic stroke or systemic embolism (adjusted hazard ratio [HR]: 1.94; 95% confidence interval [CI]: 1.15-3.29; P = 0.014).

    The finding at 1 year but not 45 days “may be due in part to the temporal change in many leaks from 45 days to 1 year and changing antithrombotic regimens during this time frame,” the researchers speculated.

    The greater 5-year risk of ischemic stroke or embolism found for 1-year TEE patients with PDL≤5 was largely driven by an increase in nondisabling stroke (HR: 1.97; 95% CI: 1.03-3.78; P = 0.04), the researchers noted.

    Disabling or fatal stroke rates were similar between the groups (HR: 0.69; 95% CI: 0.19-2.46; P = 0.56).

    The researchers added that PDL≤5 was not associated with increased cardiovascular or unexplained death risk (HR: 1.20; P = 0.45) or with all-cause death (HR: 0.87; P = 0.42).

    Change in patient management needed

    While the mortality risk did not increase, increased ischemic stroke and systemic embolism hazard at 5 years shows that “operators should optimize device position to minimize PDL at the time of implantation,” the researchers concluded.

    They added that future studies should address whether closure of persistent PDL≤5 could reduce the risk of subsequent stroke.

    In an accompanying editorial, Boris Schmidt, MD, and K.R. Julian Chun, MD, from the Academic Teaching Hospital of Goethe University, Frankfurt, Germany, added that the study results should lead to a change in patient management following interventional LAA closure.

    The editorialists cited another recent analysis, which demonstrated that smaller PDLs (<3 mm) tend to regress over time but larger ones do not.

    “Depending on the indication for the LAA closure, the continued presence of a PDL 1 year after the implantation may affect the decision on antithrombotic management,” they said.

    “Future studies will have to show if continued anticoagulation is required. Moreover, interventional techniques to close PDLs need to be further evaluated. The optimal cut-off in PDL size as well as the optimal time point for interventional PDL closure needs to be determined in future studies.”

    Sources:

    Dukkipati SR, Holmes DR Jr., Doshi SK, et al. Impact of Peridevice Leak on 5-Year Outcomes After Left Atrial Appendage Closure. J Am Coll Cardiol 2022;80:469-483.

    Schmidt B, Chun KRJ. Peridevice Leaks: The Plot Hole of Left Atrial Appendage Closure for Stroke Prophylaxis. J Am Coll Cardiol 2022;80:484-485.

    Image Credit: Damian – stock.adobe.com

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