FDA authorizes 'Queen of Hearts' AI to flag heart attacks on ECGs
Powerful Medical's AI model can now be used in the US to catch STEMI heart attacks and lookalike patterns that doctors sometimes miss on an ECG.
What happened: The FDA has granted a first-of-its-kind De Novo authorization to Queen of Hearts, an AI model built by New York medtech company Powerful Medical to spot ST-elevation heart attacks (STEMI) and look-alike patterns on standard ECGs. The tool already carries Europe's CE mark and won the FDA's breakthrough device designation in March 2025. About seven months later, new results were presented at the TCT 2025 conference in San Francisco and published in JACC: Cardiovascular Interventions, linking the model to notably better heart attack detection and fewer false alarms. With authorization now in hand, Powerful Medical is expanding rollout of PMcardio, the platform that runs Queen of Hearts alongside other diagnostic algorithms inside hospital and ambulance workflows.
Why it matters: STEMI is the most dangerous kind of heart attack: a coronary artery is fully blocked, and every extra minute without treatment costs heart muscle. Doctors have long relied on human eyes to catch STEMI signs on an ECG printout, but subtle STEMI-equivalent patterns are easy to miss, and diagnosis delays are common, especially in busy emergency rooms or in the field before a patient reaches a hospital. Powerful Medical's leadership argues many US heart attack patients still miss their treatment window because of exactly these bottlenecks. An AI reading that flags danger signs at first medical contact, in an ambulance or an ER doorway, could shorten the time to the cath lab, the biggest lever for survival and long-term heart function.
How it works, plainly: Queen of Hearts was trained by Stephen W. Smith, an emergency physician at Hennepin County Medical Center who has spent years studying ECG patterns that predict STEMI, including ones that don't show the classic textbook ST-elevation. The FDA's De Novo pathway, used because there was no directly comparable approved device to measure it against, creates a brand-new device category rather than simply matching Queen of Hearts to an existing approval. In practice, the algorithm runs inside Powerful Medical's PMcardio software, reading a patient's ECG and returning a STEMI risk flag that clinicians see alongside the raw tracing, meant to support rather than replace a doctor's own read of the heart rhythm.
What we don't know yet: Powerful Medical says it is now ramping up US deployment of PMcardio following authorization, building on its existing CE-marked presence in Europe. Co-founders Robert Herman and Felix Bauer both framed the approval as a way to close gaps in diagnosis speed and triage accuracy at first contact. What the source doesn't specify: the exact sensitivity and false-positive numbers from the JACC study, how many US hospitals or ambulance services have committed to buying in, what it costs, or how insurers will handle reimbursement, all questions that will decide whether this becomes routine care or stays a niche add-on.