Key result
Post-WATCHMAN FLX Pro DAPT is linked to ~7.4-fold higher risk of high-grade device thickening than DOAC.
Why the study?
The association of discharge antithrombotic regimen with CT-detected high-grade hypoattenuated thickening and early clinical outcomes after WATCHMAN FLX Pro implantation was uncertain.
Does low-dose DOAC monotherapy reduce CT-detected high-grade hypoattenuated thickening compared to DAPT in patients undergoing WATCHMAN FLX Pro implantation?
Cohort (n=400)
No
Does low-dose DOAC monotherapy reduce CT-detected high-grade hypoattenuated thickening compared to DAPT in patients undergoing WATCHMAN FLX Pro implantation?
Following WATCHMAN FLX Pro implantation, discharge on low-dose DOAC monotherapy is associated with a markedly lower risk of device-related thrombus imaging correlates on CT compared to DAPT, without an observed increase in bleeding or stroke.
May favor DOAC monotherapy over DAPT to reduce high-grade HAT post-WATCHMAN FLX Pro; hypothesis-generating, should not yet change practice.
OBJECTIVES: The authors sought to determine whether discharge antithrombotic regimen (dual antiplatelet therapy [DAPT] vs low-dose direct oral anticoagulant [DOAC] monotherapy) is independently associated with computed tomography (CT)-detected high-grade hypoattenuated thickening (HAT), an imaging correlate of device-related thrombus, and with early clinical outcomes following WATCHMAN FLX Pro (Boston Scientific) implantation. METHODS: A single-center retrospective analysis of 427 consecutive patients undergoing attempted WATCHMAN FLX Pro implantation (July 2024-October 2025) was conducted. After excluding 10 patients with screen failure and 17 on alternative antithrombotic regimens, 400 patients (263 DAPT, 137 low-dose DOAC) were included. The primary endpoint was high-grade HAT on 4-month surveillance cardiac CT. Secondary endpoints were appendage patency, peridevice leak (PDL), incomplete neoendocardial coverage, and 180-day clinical outcomes. RESULTS: Surveillance CT was performed in 322 of 400 patients (80.5%). High-grade HAT occurred in 12/213 patients on DAPT (5.6%) vs 1/109 patients on DOAC (0.9%; P = .046); 92.3% of high-grade HAT cases were in the DAPT group. DAPT remained independently associated with high-grade HAT on multivariable analysis (adjusted odds ratio, 7.43; 95% CI, 1.01-54.44; P = .048). Appendage patency, PDL, and incomplete neoendocardial coverage were similar between groups. Through 180 days, stroke, bleeding, and mortality did not differ significantly by regimen. CONCLUSIONS: In this real-world WATCHMAN FLX Pro cohort, low-dose DOAC monotherapy was associated with a markedly lower risk of CT-detected high-grade HAT than DAPT, without an observed increase in bleeding or stroke. Anticoagulation during the early post-implant healing period may mitigate thrombus formation more effectively than antiplatelet therapy. Randomized trials are needed to confirm these findings.
No takes yet. Share an insight, caveat, or question.
Nikoo et al. (2026) conducted a cohort in Left atrial appendage occlusion (n=400). Dual antiplatelet therapy (DAPT) vs. Low-dose DOAC monotherapy was evaluated on High-grade hypoattenuated thickening (HAT) on 4-month surveillance cardiac CT (adjusted OR 7.43, 95% CI 1.01-54.44, p=0.048). Following WATCHMAN FLX Pro implantation, DAPT was independently associated with a higher risk of high-grade hypoattenuated thickening on CT than low-dose DOAC (OR 7.43; 95% CI 1.01-54.44; P=0.048).
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: