The wearable ECG patch didn't replace the Holter monitor — the U.S. ambulatory-ECG market ended up about 1.4 times its 2015 size
Nationally the new way is now 72% of the pair, and it leads in 47 of the 51 state markets — the rest still lean to classic Holter monitor.
The two devices did not trade places: the patch's gains outran the Holter's losses, and the subtraction does not come out even. Whether the surplus is real volume or an artifact of how the two devices bill is what the rest of the page settles.
Both devices are still here, which is the first surprise. The classic Holter monitor — a recorder worn on wires for a day or two — carried an estimated 1.0 million Medicare monitoring studies in 2015 and an estimated 0.4 million in 2024. The multi-day wearable patch ended the decade at an estimated 1.1 million. The patch gained more than the Holter lost, so the two do not net out.
Before trusting that arithmetic, check what a study is. It is not a bill. Recording, scanning and interpretation can each be billed separately, and the two devices split those pieces differently — so counting bills would credit one device with volume that is really one patient's session billed in more parts. Here a session counts once, through its all-in claim or its interpretation claim, never both.
One more thing could have bent the picture. Before 2021 the patch billed under temporary codes Medicare has since retired, so a plain count would have it appearing out of nowhere at the changeover. Those early years are pooled into its line here. The seam itself is small: on the fee-for-service record the pooled patch line carries 314,000 studies in 2020 and 322,000 in 2021 — a step of about 2.5%.
With both corrections made, the subtraction still does not work. Had the patch taken the Holter's place, the market would have ended the decade near where it started. Instead it went from an estimated 1.1 million studies to an estimated 1.5 million — about 1.4 times its 2015 size. Longer wear windows, the convenience of a patch worn home, and broader reasons to order monitoring at all could each plausibly matter. The record measures the volume, not the reason.
A volume record, not a verdict on which monitor is better for a patient. The two devices suit different monitoring needs, and nothing here compares how patients did.
Medicare monitoring studies for two ambulatory-ECG device families — the classic Holter monitor and the multi-day wearable patch — each episode counted once, 2015 to 2024.
Not billed claim lines (the families split component billing differently), not device unit sales, not all-payer, and not a clinical-outcomes comparison.