IRhythm ECG patch study shows fewer atrial fibrillation hospitalizations, more outpatient visits

IRhythm Technologies has found that its continuous ECG monitoring chest patch was not only able to improve the diagnosis of atrial fibrillation but also helped lower the numbers of emergency room visits and hospitalizations by shifting patients to outpatient cardiology settings.

That latter data point is important, the former Fierce 15 winner said, because routine ECG screening for atrial fibrillation is currently not recommended due to its unknown impacts on the healthcare system and utilization.

The study, known as mHealth Screening to Prevent Strokes, or mSToPS, was conducted by researchers at the Scripps Translational Science Institute, Aetna and Janssen Pharmaceuticals. The results were unveiled at the annual meeting of the American College of Cardiology in New Orleans—and presented contemporaneously with preliminary data from the Apple Heart Study, which evaluated the ability of the Apple Watch to correctly identify atrial fibrillation in more than 400,000 users, by tracking their pulse and heart rate.

While just 0.5% of participants were alerted to an irregular heartbeat by their Apple Watch, they still needed to be confirmed through an additional week of monitoring with an ECG chest patch, such as iRhythm’s. Only about a third of those 2,000 people were found to have atrial fibrillation, though 57% ended up seeking medical attention—raising concerns over whether more consumer-focused wearables have come far enough yet to be relied upon as a widespread diagnostic tool.

RELATED: iRhythm upsizes IPO launch by raising $107M to support its Zio heart monitor

Meanwhile, the mSToPS study enrolled 1,738 participants with no history of atrial fibrillation, who wore iRhythm’s Zio XT patch for an average of nearly 25 days. Atrial fibrillation was diagnosed in 6.3% of actively monitored participants compared to 2.3% in observational controls, the company said.

Among newly diagnosed patients, the average number of emergency department visits among 100 people per month dropped from 6.7 to 2.3 with active monitoring, while inpatient hospitalizations dropped 14.4 to 3.8. Across the study’s full population, outpatient visits increased from 4.7 to 6.7.

RELATED: Kerrisdale targets iRhythm in short attack, claiming tenuous reimbursements

Recently, iRhythm was targeted by short-seller Kerrisdale Capital, which published a report describing the reimbursement structure for its flagship Zio patch as outdated and tenuous and potentially posing a financial crisis for the company.

The firm said the rapid growth in use of the patch over the past few years has attracted competition from other device companies and could lead to cutbacks in Medicare and commercial reimbursements. In addition, the Zio patch is currently reimbursed via a temporary CPT code, with a permanent code expected to be established for 2021.

In response, iRhythm issued a statement saying: "iRhythm welcomes all investor feedback. We are proud of our progress in making Zio XT accessible for patients and currently have contracts in place with all major commercial payers and Medicare, putting Zio XT in-network for 93 percent of covered lives in the U.S."

"We maintain strong relationships with medical societies and are committed to proven and documented clinical performance, as evidenced by 26 peer reviewed published studies. We are focused on strong execution and providing meaningful value for all our stakeholders: investors, healthcare providers, patients and payers."

Editor's note: This story has been updated with the statement from iRhythm, as well as additional details about the study.