Delayed diagnosis isn't a statistical inconvenience — it means preventable death.
About one in every 500 Americans carries a heart condition they may not know they have. Hypertrophic cardiomyopathy — HCM — is the most commonly inherited heart disease in the country, a chronic thickening of the heart muscle that can quietly progress for years before it announces itself through symptoms serious enough to send someone to a hospital. By then, the window for early intervention has often closed. That gap between the disease's prevalence and the care people actually receive is what a new three-year initiative, backed by the American Heart Association and now supported by biopharmaceutical company Cytokinetics, is trying to close.
Cytokinetics, a South San Francisco company that has spent more than two decades focused on cardiovascular medicine, announced on November 17, 2025 that it would join the AHA's multi-stakeholder effort as a supporting partner. The initiative is built around a straightforward but difficult premise: hundreds of thousands of Americans are living with HCM, many of them undiagnosed, and the systems meant to catch and treat them are inconsistent, fragmented, and inequitable.
The numbers tell a stark story. Estimates suggest roughly one in 500 people in the United States has HCM, which translates to hundreds of thousands of individuals. Yet a significant portion of them remain undiagnosed or untreated until the disease forces the issue — through chest pain, fainting, dangerous arrhythmias, or worse. Delayed diagnosis isn't just a statistical inconvenience; it means delayed treatment, higher risk of complications, and, in some cases, deaths that might have been prevented.
The AHA initiative is designed to attack that problem from several directions at once. It will work to expand the number of medical sites participating in a national HCM registry that runs through the Association's Get With The Guidelines program — a data infrastructure that helps standardize care and track outcomes. It will also broaden certification pathways for referring centers and the clinicians who work in them, with the goal of reaching patients in communities that currently have limited access to HCM specialists. Patient support services will be introduced at key diagnosis and treatment centers. And perhaps most consequentially, the initiative will pilot a prospective test of an AHA-developed algorithm designed specifically to detect HCM earlier, before symptoms escalate.
Anjali Owens, a cardiologist who co-chairs the AHA's HCM initiative, described the condition as one that is often inconsistently managed across the healthcare system — a pattern that compounds risk at every stage of a patient's journey. Her framing was direct: inconsistent management leads to delayed treatment, which leads to complications, which leads to preventable death. The goal of the initiative, she said, is to drive change that empowers patients, better equips clinicians, and strengthens the overall care continuum.
Robert Blum, Cytokinetics' president and chief executive, pointed to what he called a persistent lack of awareness among patients about their own condition — a problem that sits upstream of everything else. If patients don't know they have HCM, they can't seek care. If referring physicians aren't trained to recognize it, they can't route patients to the right specialists. The initiative is trying to address both ends of that chain simultaneously.
Cytokinetics has a direct stake in the HCM space beyond its philanthropic posture. The company is preparing for potential regulatory approval of aficamten, a cardiac myosin inhibitor that showed positive results in a pivotal Phase 3 clinical trial called SEQUOIA-HCM, which enrolled patients with obstructive HCM. Aficamten is also being studied in additional trials covering both obstructive and non-obstructive forms of the disease. The company's pipeline includes other cardiovascular candidates at various stages of development, but HCM is clearly a central focus.
The three-year timeline gives the initiative room to build infrastructure, run the detection algorithm pilot, and begin measuring whether any of it is actually moving the needle on diagnosis rates. The registry expansion will be the most visible early indicator — more participating sites means more data, and more data means a clearer picture of where the gaps are worst. Whether the algorithm pilot can demonstrate a measurable reduction in underdiagnosis will be the harder, more important test. That result, when it comes, will say a great deal about whether a coordinated, multi-sector push can do what fragmented clinical practice has not.
Notable Quotes
HCM is often inconsistently managed, leading to delayed treatment, increased risk of complications and preventable death.— Dr. Anjali Owens, co-chair of the AHA's HCM initiative
Too many patients living with HCM face a lack of awareness about their condition, delayed diagnoses, and limited access to specialty care.— Robert I. Blum, President and CEO of Cytokinetics
The Hearth Conversation Another angle on the story
Why does a disease this common stay so underdiagnosed for so long?
Because it's quiet. HCM doesn't announce itself the way a heart attack does. People live with it for years, sometimes decades, before anything dramatic happens — and by then the diagnosis feels like a crisis rather than a discovery.
So the detection algorithm is trying to catch it before the crisis?
That's the idea. If you can build a tool that flags likely HCM cases earlier in the clinical workflow — before symptoms escalate — you change the whole trajectory of care for that patient.
What's the registry actually doing that isn't already happening?
It's creating a shared data infrastructure. Right now, care is fragmented — one hospital does things one way, another does it differently. The registry pulls outcomes into a common framework so you can actually see what's working and where the gaps are worst.
Is this mostly about geography? Rural patients not having access to specialists?
That's part of it. But it's also about which clinicians are trained to recognize HCM in the first place. A patient can live near a major hospital and still get missed if the referring physician doesn't know what to look for.
Cytokinetics has a drug in late-stage trials for HCM. Does that complicate the picture here?
It's worth noting, but the infrastructure being built — the registry, the certification programs, the detection algorithm — those benefit any treatment, not just Cytokinetics' pipeline. More diagnosed patients means a larger population that can access care, whatever form that care takes.
What's the most important thing to watch over the next three years?
The algorithm pilot. Expanding a registry is valuable but incremental. If the detection algorithm can demonstrably reduce underdiagnosis rates in a prospective test, that's the kind of result that changes clinical practice at scale.