AnchorMan vs. Watchman: A Challenger Device Clears Its First Head-to-Head Test in Left Atrial Appendage Closure
Twelve-month data from a randomized China-based trial suggest a new occluder can match the market leader on safety and efficacy, and may seal better.
A novel left atrial appendage closure device out of China has posted one-year outcomes that look essentially indistinguishable from the market-leading occluder.
The device, called AnchorMan, comes from MicroPort CardioFlow, a Shanghai-based structural heart company.
Its comparator was the first-generation Watchman 2.5 device, the implant that opened the LAAC category in the United States back in 2015.
For a physician audience managing stroke-risk conversations in nonvalvular atrial fibrillation every week, this trial is a useful checkpoint on where device competition in this space is heading.
Why This Trial Matters
Roughly nine in ten strokes tied to nonvalvular AFib originate from thrombus forming in the left atrial appendage, which is the rationale behind mechanically excluding it from circulation.
The original Watchman device was approved to reduce thromboembolic risk in patients with an appropriate reason to avoid chronic anticoagulation, and it has since become the dominant device worldwide.
Because anatomic variability in the appendage remains a real procedural challenge, newer occluders keep entering development to improve sealing and ease of deployment.
The trial behind this analysis, called SAFE-PROTECT, randomized patients head-to-head between AnchorMan and Watchman 2.5 rather than comparing either device to a historical benchmark.
How the Devices Differ
AnchorMan's distal end is rounded, a design choice intended to increase surface contact with appendage tissue while reducing the chance of intraoperative or delayed perforation.
Twelve so-called "3D folding" units form what the manufacturer describes as a semiclosed cage, a structural approach meant to combine features of both open and closed occluder designs.
This cage construction is also designed to let operators implant the device at a shallower depth within the appendage than some competing occluders require.
What the Trial Found
A total of 216 patients with nonvalvular AFib and elevated stroke risk were randomized between the two occluders.
The primary endpoint, 12-month clinical success (freedom from stroke, systemic embolism, and cardiovascular or unexplained death), landed at 98.1% in both arms, meeting the prespecified noninferiority margin.
Echocardiography-confirmed appendage occlusion at 12 months was essentially identical between groups as well.
Rates of all-cause death, major bleeding, and device-related complications did not differ meaningfully between the two occluders.
The one signal that separated the devices was peridevice leak greater than 3mm, which occurred less often with AnchorMan, a finding the investigators attributed to its distinct sealing geometry.
A follow-up randomized study comparing AnchorMan against the newer Watchman FLX and FLX Pro platforms is already being planned.
| Parameter | Detail |
|---|---|
| Design | Multicenter, randomized, head-to-head |
| Population | Nonvalvular AFib, elevated ischemic stroke risk, poor candidates for long-term anticoagulation |
| Comparator device | Watchman 2.5 (Boston Scientific) |
| Investigational device | AnchorMan (MicroPort CardioFlow) |
| Primary endpoint | 12-month clinical success, 98.1% vs. 98.1% |
| Funding | MicroPort CardioFlow-sponsored; sponsor reported no role in data analysis or the decision to publish |
| Device | Milestone | Regulator / Year |
|---|---|---|
| Watchman (original) | First LAAC device cleared for stroke risk reduction | FDA, 2015 |
| Watchman FLX | Fully rounded, recapturable design | FDA, July 2020 |
| Watchman FLX Pro | Thromboresistant coating, larger size option | FDA, September 2023 |
| AnchorMan | Market approval, China only; not yet FDA-reviewed | NMPA, January 2024 |
The Investor Overlay
For a physician-investor readership, this trial is as much a competitive-landscape story as a clinical one.
| Company | Ticker | Analyst Consensus | 12-Month Price Target |
|---|---|---|---|
| Boston Scientific | NYSE: BSX | Strong Buy (31 analysts) | $77.10, roughly 69% above the recent price |
| MicroPort CardioFlow | HKG: 2160 | Strong Buy (2 analysts, limited coverage) | HK$7.06, a wide-range estimate given thin analyst following |
Boston Scientific's Watchman franchise remains the dominant revenue driver in the LAAC category, and the company has already layered two newer-generation devices, FLX and FLX Pro, on top of the original 2.5 platform used in this trial.
MicroPort CardioFlow is a much smaller, thinly covered name whose Hong Kong-listed shares carry considerably more volatility and analyst uncertainty than BSX.
AnchorMan's commercial footprint today is limited to China and a handful of early international cases in Latin America and Europe, and it has not yet been reviewed by the FDA.
Any US market entry would likely require AnchorMan to be tested against the newer Watchman FLX and FLX Pro devices rather than the older 2.5 platform used in SAFE-PROTECT, which is exactly the next study the investigators say is planned.
The Medical Alternative: Anticoagulation
Long-term anticoagulation remains the non-device comparator physicians weigh against LAAC in most stroke-prevention conversations.
| Option | Brand / Generic | Approx. Monthly Cost | Company |
|---|---|---|---|
| LAAC device | Watchman 2.5 / FLX / FLX Pro | One-time procedural cost, not a recurring drug expense | Boston Scientific (NYSE: BSX) |
| LAAC device | AnchorMan | One-time procedural cost; not commercially available in the US | MicroPort CardioFlow (HKG: 2160) |
| Oral anticoagulant | Brand Eliquis (apixaban) | Roughly $350–$600, before manufacturer copay assistance | Bristol Myers Squibb (NYSE: BMY) / Pfizer (NYSE: PFE) |
| Oral anticoagulant | Generic apixaban | Roughly $30–$80 with a discount card | Multiple generic manufacturers |
Drug prices shown are point-in-time GoodRx figures and vary by pharmacy, region, and insurance coverage.
Case Vignette
A 74-year-old woman with paroxysmal nonvalvular AFib, a CHA₂DS₂-VASc score of 5, and a gastrointestinal bleed six months ago on apixaban is referred for stroke-prevention options.
She has already failed a trial of dose-reduced anticoagulation with recurrent minor bleeding, and her HAS-BLED score is 4.
Transesophageal echocardiography shows a chicken-wing morphology appendage without thrombus, making her anatomically suitable for closure.
She undergoes Watchman FLX implantation uneventfully and is transitioned to a short antiplatelet regimen per current protocols.
This is exactly the patient population in which a competitor device with a lower peridevice-leak signal, like AnchorMan, could eventually matter clinically once (and if) it reaches FDA review.
Bottom Line
AnchorMan met noninferiority against Watchman 2.5 on the primary safety and efficacy endpoint at 12 months, with a possible sealing advantage that will need confirmation.
The device is not yet available in the United States, and its next comparative trial will need to clear the higher bar set by Watchman FLX and FLX Pro rather than the first-generation platform.
For US-based physicians, this is a name worth tracking rather than a near-term change to practice.
Watch
References
- SAFE-PROTECT 12-month randomized trial results, EuroIntervention, July 2026.
- TCTMD coverage of the initial SAFE-PROTECT presentation, EuroPCR 2023.
- MicroPort primary endpoint announcement, May 2023.
- ACC update on Watchman FLX Pro approval, September 2023.
- TCTMD coverage of original Watchman FLX approval, July 2020.
- MicroPort update on AnchorMan's NMPA approval and China rollout, September 2024.
Want this reformatted as a short YouTube script, a one-paragraph social summary, or a patient-facing handout on LAAC options? Just ask.
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