J&J Paid $400M for This Heart Device in 2023. Now It's Quietly Handed It Back to Its Original Owners

Johnson & Johnson paid $400 million in cash to buy Laminar, a tiny heart-device startup, in November 2023. Less than three years later, that same program quietly left the building — handed to a brand-new company called Jaguar LAA that was formed by the very venture firm and management team who owned Laminar before J&J showed up. The price J&J got for it: not disclosed. That silence is the story.

First, what this is actually about. Laminar makes a left atrial appendage (LAA) closure device, a catheter implant that seals off a small pouch in the upper-left chamber of the heart to cut stroke risk in people with non-valvular atrial fibrillation — a condition affecting tens of millions globally, many of whom can't tolerate blood thinners. Its differentiation is real: instead of plugging the appendage like the market-leading devices, it "eliminates" it with rotational motion, leaving minimal hardware inside the atrium.

Now the part the headline buries. Jaguar LAA is not an up-and-coming company that spotted a bargain. It was created for this transaction, in partnership with Santé Ventures — the same firm that was Laminar's sole venture backer before J&J bought it — along with members of the Laminar management team. In other words, the largest health-care company on earth bought this technology for $400 million, folded it into its Biosense Webster cardiac business, and then returned it, largely intact and at undisclosed terms, to the people it bought it from.

Think about what a divestiture like that says. J&J did not need the cash. It handed the program back because carrying it through FDA approval and into a commercial launch, against entrenched competition, no longer fit. When an owner with J&J's resources and Biosense Webster's cardiac expertise declines to fund a pivotal readout it had already started, that is a revealed preference, not a press release. Bringing the asset home to its originators — the people most convinced it can work — is still a markdown from $400 million.

The stakes explain the choice. This program was always aimed at a two-player market. Boston Scientific's Watchman has owned LAA closure for more than two decades — the company holds roughly 62% of the market — and Abbott's Amulet is the challenger. It is a roughly $1.8 billion business growing around 14% a year, a real but hard market to enter. The pivotal trial J&J had begun in early 2024 was built as a randomized head-to-head against the commercially available devices — effectively against Watchman — and a newcomer with a novel mechanism would need favorable data, reimbursement, and years of industry trust to take share from either.

To be fair to the technology, this does not prove the device fails. A giant's portfolio can be a bad home for a single novel product, and a focused company with management skin in the game and a healthcare investor behind it can be a better one. Santé has conviction — it was in alone the first time and now it's effectively in again.

But the durable takeaway is where the moat sits. A well-capitalized third entrant with a differentiated device, one a $640 billion company had already funded, just declined to fight Watchman and Amulet for that market. That is a data point, not a colorful headline. It changes nothing in Boston Scientific's or Abbott's financials, and it does not add Jaguar to your screen — it's private. What it does is tell you why LAA closure keeps belonging to two companies, and how to read a release that says "acquires assets" when what really happened is a giant handing a $400 million bet back to its original owners on terms it chose not to disclose.

The next thing worth watching isn't the announcement. It's whether Jaguar, now on its own, can raise the money and generate the head-to-head data to finish what a company with far deeper pockets decided not to. That is the real test the press release leaves unanswered.