Kardi Ai Raises $5.9M Series A to Expand AI Heart Monitoring

Kardi Ai, a Czech medtech startup, has raised €5.3 million (about $5.9 million) in a Series A round led by German healthtech fund Callisto Health, according to The Recursive. The round values the company at €23 million (about $26 million).

Česká spořitelna and Slovenská sporiteľňa joined through their Seed Starter corporate venture programs, and existing backers BrightCap Ventures, Purple Ventures, DEPO Ventures and Garage Angels also invested. The company says it is the largest round a Czech medtech startup has raised to date.

Long-Term Heart Monitoring at Home

Founded in 2022, Kardi Ai offers a certified system for long-term heart rhythm monitoring and early arrhythmia detection. It pairs a fitness-style chest strap with an ECG sensor, a mobile app and AI analysis of the ECG data, so patients can be monitored during everyday activity rather than for a day or two on a traditional Holter device.

Physicians receive real-time data and reports directly. The product carries Class IIa certification under the EU Medical Device Regulation.

The case for longer monitoring is in the numbers. CEO Vlastimil Hrabal has said the company's internal data shows only about 10% of arrhythmias appear on the first day of monitoring, while detection climbs to 57% by month three, according to MedTech World.

Traction So Far

Kardi Ai serves more than 6,000 users and partners with more than 70 hospitals in Czechia, along with medical networks in Slovakia, per FinSMEs. Česká spořitelna has offered the service to its own employees as a benefit since 2024, giving the bank a view of the product before investing.

Where the Money Goes

The funding will support expansion across Europe, led by Germany, alongside its current presence in Czechia, Poland, Slovakia, Romania and Bulgaria. In Asia, the company is targeting India, the UAE and Singapore.

Kardi Ai also plans to develop predictive models that estimate a patient's risk of cardiac arrhythmia, moving the product from detecting problems to anticipating them.

The investor mix reflects that strategy. Callisto Health, the lead, is a German healthtech fund that can help with introductions in the DACH market, while the participation of two of Central Europe's largest retail banks gives Kardi Ai a distribution channel through employee benefits. Returning seed investors BrightCap, Purple Ventures, DEPO Ventures and Garage Angels putting in more money also suggests early backers are satisfied with the company's progress since its last raise in 2025.

Why It Matters

Atrial fibrillation and other arrhythmias often go undiagnosed because they come and go, and short-term monitoring misses them. Affordable, wearable monitoring that doctors can trust could catch more cases earlier, when treatment is most effective.

Germany is the key test. It is Europe's largest healthcare market, and winning hospital and insurer adoption there would give Kardi Ai a reference market for its wider expansion and its next fundraise.

Source

The Recursive — Czech Kardi AI Raises €5.3M Series A Led by Callisto Health