A Tool Built to Save Lives, Then Quietly Broken

🫀 Atrial fibrillation is the kind of medical problem that hides. It flickers in and out, sometimes lasting less than a minute. It rarely announces itself during a doctor’s appointment. And if left undetected, it can cause stroke or sudden death.

AliveCor, a California medical technology company, built something to catch it. In 2017, two years after Apple released the Apple Watch, AliveCor released KardiaBand: a replacement watch strap with FDA clearance to take electrocardiograms. Paired with AliveCor’s Kardia app, it let Apple Watch users take ECGs at any time and share them with their doctors.

But KardiaBand’s most powerful feature was SmartRhythm. SmartRhythm ran continuously in the background, using heart rate data from the Apple Watch’s Workout Mode to monitor for the irregular rhythms that signal an Afib episode. When it detected one, it prompted the user to take an ECG. SmartRhythm’s effectiveness was documented in a peer-reviewed medical journal. It worked. ✅

Then Apple broke it.

Inside the Allegations: What Apple Actually Did

SmartRhythm relied on a specific Apple algorithm called the Heart Rate Path Optimizer, or HRPO. This algorithm ran inside the Apple Watch’s Workout Mode and calculated the user’s heart rate approximately every five seconds. Apple shared that data with third-party app developers through a programming interface. AliveCor used it. Another company, Cardiogram, was building a similar tool.

In September 2018, Apple introduced a new algorithm called the Heart Rate Neural Network, or HRNN. HRNN was more accurate than HRPO during exercise and could calculate heart rate even when the user had not selected a specific workout activity. Apple replaced HRPO with HRNN in Workout Mode and stopped sharing HRPO data with third-party developers.

The problem: SmartRhythm was built around HRPO’s specific data characteristics. When Apple switched to HRNN, SmartRhythm could no longer accurately recognize Afib episodes. AliveCor tried to fix it and failed. In 2019, AliveCor discontinued SmartRhythm and KardiaBand entirely.

At the same time Apple introduced HRNN, it also released its own heart rhythm feature: Irregular Rhythm Notification, or IRN. IRN used a completely different algorithm and a different data feed. Apple cleared IRN through the FDA for detecting irregular rhythms suggestive of Afib, specifically in adults without a prior Afib diagnosis. Apple shared IRN’s data feed with third-party developers. But no competitor had managed to build a working alternative using it. ⚠️

AliveCor obtained internal Apple documents during discovery. Those documents showed Apple engineers knew that changes to HRPO could harm competitors’ features. They also showed Apple saw a financial opportunity in controlling both the hardware and the health-monitoring software on that hardware, with an eye toward healthcare industry partnerships.

AliveCor filed suit in 2021, arguing Apple had violated Section 2 of the Sherman Antitrust Act by deliberately denying third-party developers access to HRPO data in order to break competing apps and capture the market for heart rhythm analysis on the Apple Watch. AliveCor alleged Apple ended up with 100 percent of that market.

Profit-Maximization at All Costs

The internal Apple documents at the heart of AliveCor’s case tell a straightforward story about corporate priorities. Apple’s own engineers identified a financial upside in controlling the full stack: the watch, the algorithms, and the health software running on top of them. The path to healthcare industry partnerships ran through owning the entire product, not sharing its pieces with rivals who might build something better.

This is not unusual corporate thinking. But it becomes troubling when the “pieces” being withheld are data that a medical company used to build a clinically validated, FDA-cleared tool for detecting a dangerous heart condition. 💰

Apple’s IRN feature, the one that replaced SmartRhythm in the market, came with a significant limitation built in. The FDA cleared IRN only for adults without a prior diagnosis of Afib. Apple’s own product warnings state explicitly that IRN is not intended for people who already have Afib. SmartRhythm, by contrast, was designed specifically to help people with a history of Afib monitor for recurrent episodes. Those are two different patient populations, and Apple’s product serves only one of them.

The Replacement Was Not a Substitute

The court record makes clear that AliveCor’s Kardia app continues to function on Apple devices. Users can still record ECGs and share them with doctors. But without SmartRhythm, Kardia no longer continuously monitors heart rhythms in the background. The passive, always-on detection that could catch a brief Afib episode during an ordinary day is gone.

AliveCor argued, and the case record supports, that no competitor has managed to build a working alternative to IRN using the Tachogram API data Apple now provides. The passive continuous monitoring that SmartRhythm offered has simply disappeared from the Apple Watch ecosystem.

Corporate Accountability Fails the Public

AliveCor lost this case on a narrow legal point, not on the facts. The Ninth Circuit did not find that Apple’s conduct was benign. It found that AliveCor could not satisfy the specific legal requirements needed to force a monopolist to share its data with competitors.

The court applied a doctrine called the “general rule that there is no antitrust duty to deal.” Under this principle, a company, even a monopolist, generally has the right to decide who it shares its resources with. Exceptions exist, but they are narrow and demanding. AliveCor could not fit its claims inside those exceptions.

The court considered two possible exceptions. The first, from a 1985 Supreme Court case called Aspen Skiing, applies when a company abandons a previously profitable cooperative arrangement in order to harm a competitor. AliveCor did not argue this applied. The second, the “essential facilities doctrine,” applies when a competitor needs access to something the monopolist controls and that cannot reasonably be duplicated. The court rejected this argument because Apple’s own IRN feature does not use HRPO data. If HRPO data were truly essential to compete in the market, the court reasoned, then Apple itself would need it to run its own competing product. Since Apple does not use it, it cannot be essential. 🏛️

The Law Protected the Monopolist, Not the Patient

The court’s logic is legally coherent. It is also, from a public health standpoint, deeply uncomfortable. The outcome of this case is that Apple holds 100 percent of the market for passive, background heart rhythm monitoring on the Apple Watch, a product used by tens of millions of people. The one competitor that built a clinically validated alternative is out of that market. And the legal system found no viable mechanism to challenge it.

No fine was levied. No remedy was ordered. No conduct changed. The legal process ran for nearly five years, from the 2021 filing to the January 2026 appellate ruling, and the result is a formal declaration that everything Apple did was within its rights. 📋

The Economic Fallout

AliveCor discontinued not just SmartRhythm but the entire KardiaBand product line in 2019. The company’s Kardia app survived, but a significant product category was eliminated. AliveCor had built an FDA-cleared, peer-reviewed medical device and a continuous monitoring software feature, and both were rendered nonviable within two years of Apple’s algorithm change.

Cardiogram, the other company developing a similar Afib-detection feature for the Apple Watch, was also affected. The case record notes that Cardiogram was working on a feature analogous to SmartRhythm when Apple made its changes. The result was the elimination of a nascent competitive ecosystem for third-party cardiac monitoring on the Apple Watch.

The broader economic signal is familiar: building on a platform controlled by a monopolist is a structurally precarious business. The platform owner can change the rules at any time, and the legal system, at least under current antitrust doctrine, offers limited protection. This dynamic discourages investment in third-party health applications for closed platforms. 📉

How Capitalism Exploits Delay

AliveCor filed its lawsuit in 2021. The Ninth Circuit issued its final ruling in January 2026. That is nearly five years of litigation during which Apple’s 100 percent market share remained intact, unchallenged by any competing continuous monitoring tool, and during which patients with Afib histories continued to use an Apple Watch ecosystem that offered them no passive background detection.

This is a structural feature of antitrust litigation, not a bug. Litigation is expensive, slow, and uncertain. For a smaller company challenging a trillion-dollar corporation, the cost and duration of the legal process itself functions as a barrier. Even in losing, Apple was never required to restore the data access or compensate affected users. The cost of the fight fell entirely on AliveCor and its investors.

Meanwhile, the healthcare partnership opportunity Apple’s internal documents described remained open. Apple continued to develop its health monitoring capabilities. The window of competitive threat from SmartRhythm closed permanently in 2019. The lawsuit arrived years later and resolved years after that. By the time the court ruled, the market outcome Apple was alleged to have engineered was a settled fact. ⚖️

Legal Minimalism: Complying With the Form, Not the Intent

Apple’s legal defense in this case is a model of technical compliance. Apple did not block AliveCor from the App Store. It did not refuse to sell Apple Watches to AliveCor’s customers. It did not publicly threaten competitors. It updated its own product, an entirely normal corporate activity, and as part of that update, it stopped sharing a specific data feed.

The change was real, documented, and, according to Apple’s own engineers, foreseeable in its impact on competitors. But it was packaged as a product improvement. The Ninth Circuit ultimately accepted Apple’s framing: the new algorithm was better, and Apple had no legal obligation to keep running the old one for competitors’ benefit.

This is legal minimalism in its most refined form. The conduct achieves a competitive outcome, and the mechanism is technically defensible at every step. The law, as written, offers no grip. 🧩

This Is the System Working as Intended

Nothing in this case represents an aberration. Apple is a company with a legal obligation to its shareholders. It identified a market opportunity in health monitoring, controlled the hardware platform that made monitoring possible, and used that control to enter the software market on favorable terms. When a competitor built something better, Apple changed the platform in ways that eliminated the competitor’s advantage. When sued, Apple hired excellent lawyers and won.

The antitrust laws, as interpreted by the courts, are not designed to produce a different outcome here. They protect competition as an abstract process, not specific competitors or specific patients. The law does not ask whether people with Afib histories are worse off. It asks whether Apple violated a specific legal standard. It did not.

Wealth disparity and corporate power in the digital health space operate exactly this way: the entity that controls the infrastructure controls the market, and the legal system provides limited tools to challenge that control. AliveCor’s experience is not an unusual story. It is the predictable outcome of how platform economics work under current law. 🏢

Global Parallels: Platform Power and Health Data

The AliveCor case is a specific instance of a broader global pattern. Technology platforms that control both hardware and software ecosystems have repeatedly used that control to disadvantage third-party developers in adjacent markets. The European Union’s Digital Markets Act, enacted specifically to address this pattern, imposes interoperability requirements on designated “gatekeepers” that go beyond what U.S. antitrust law currently demands. Under EU rules, a platform like the Apple Watch might be required to provide data access to third-party health app developers on non-discriminatory terms.

In the health data sector specifically, the stakes are elevated. When the platform at issue is a wearable medical device used by millions of people with cardiac conditions, the question of who controls health monitoring software is not purely a market competition question. It is a public health question. Current U.S. antitrust doctrine is not equipped to ask it. 🌍

Pathways for Reform

The AliveCor case illustrates a gap in U.S. antitrust enforcement that reformers have identified for years. The current framework was designed for an industrial economy and struggles with digital platform markets where data access, API control, and interoperability are the mechanisms of competition and exclusion.

What Structural Change Would Look Like

Stronger regulatory tools could include mandatory interoperability requirements for health data platforms above a certain market size, similar to the EU’s Digital Markets Act approach. These requirements would compel platform owners to provide third-party developers with access to health data on terms that do not disadvantage them relative to the platform owner’s own competing products.

Sector-specific regulation through the FDA could address this directly. If the Apple Watch is regulated as a medical device in health monitoring contexts, the FDA could impose conditions on data access as part of device clearance. A platform that benefits from FDA clearance for its own health features could be required to share the underlying data with cleared competitors on equal terms.

Whistleblower protection for technology company employees who document anticompetitive conduct in internal communications could also strengthen future cases. The internal Apple documents AliveCor obtained in discovery were central to the factual record. Stronger protections for employees who report this kind of conduct would improve the public record and reduce the information asymmetry that disadvantages smaller companies in antitrust litigation. 📢

Conclusion: The Legal Win and What It Cost

Apple won this case completely. The Ninth Circuit affirmed summary judgment in Apple’s favor and declined to find any antitrust violation. From a legal standpoint, the matter is resolved.

From a public health standpoint, the picture is different. A peer-reviewed, FDA-cleared tool for continuously monitoring Afib in people with a history of the condition was removed from the market in 2019. Seven years later, no replacement exists in the Apple Watch ecosystem. Apple’s IRN feature serves a different patient population. The people SmartRhythm was built for are not served by it.

The internal Apple documents that surfaced in this litigation show a company that understood the competitive consequences of its decisions and made them anyway, with an eye toward healthcare industry partnerships and vertical control of the wearable health platform. The law as currently written could not reach that conduct.

That is not a story about Apple breaking the law. It is a story about what the law permits, and about who pays the price when the answer is: almost anything, as long as you call it a product improvement. 🩺

Frivolous or Serious Lawsuit?

This lawsuit was serious. AliveCor had a documented, peer-reviewed product that worked using Apple’s data. It obtained internal Apple communications showing Apple knew its changes would harm competitors and saw financial benefit in controlling both the platform and the health software on it. The timing of Apple’s algorithm change and the simultaneous launch of its own competing feature was not coincidental in the way AliveCor described it.

The case failed not because AliveCor’s factual allegations were implausible, but because U.S. antitrust doctrine sets an exceptionally high bar for compelling a company to share its proprietary data with competitors. The court itself did not characterize Apple’s conduct as innocent. It characterized it as not meeting the specific legal standard required to impose a duty to deal. Those are meaningfully different conclusions. AliveCor raised a legitimate challenge to a real pattern of conduct. The law, as written, was insufficient to address it.