Dive Brief:

• The volume of transcatheter aortic valve replacements (TAVR) performed in the U.S. may have fallen in the third quarter, according to a survey of interventional cardiologists.

• Seasonal changes in demand likely contributed to the reversal but analysts at Leerink think it may also reflect slower-than-expected adoption of the devices in intermediate-risk patients.

• If the Leerink analysts are right, the explosive growth TAVR experienced in high-risk patients will not be replicated in other populations, suggesting devices from Edwards Lifesciences, Boston Scientific and Medtronic will perform steadily rather than spectacularly.

Dive Insight:

TAVR has emerged as a fast-growing, multibillion dollar device market in recent years, making it a key battleground for Edwards and the challengers to its first-mover dominance, namely Boston Scientific and Medtronic.

The early growth of the procedure, a minimally-invasive alternative to open-heart valve replacement, was underpinned by outcomes data in high-risk and inoperable patients with severe aortic stenosis. If the market is to continue growing rapidly, Edwards and its rivals will need to persuade physicians that TAVR is a good option for intermediate and lower-risk patients.

The survey of 30 interventional cardiologists at centers that account for around 5% of all U.S. TAVR volumes shows the persuasion push may take time. According to the poll, which has underestimated TAVR use in the past, volume growth fell by 2% sequentially in the third quarter. Leerink forecast 2% growth.

While seasonal changes in demand may have played a role in the dip, the respondents reported 4% growth in the third quarter of last year, suggesting other factors are involved. One explanation is that it is taking companies longer to penetrate the intermediate-risk market.

Analysts at Leerink think this is the case. In making that argument, the analysts point out that, unlike in the high-risk niche, there is unlikely to be a backlog of intermediate-risk patients awaiting TAVR. The survey also detected “more aggressive surgeon pushback” as TAVR moves beyond the high-risk, over-85-years-old patients who were treated in the initial surge of procedures.

In younger patients, the durability of the implants is more of a concern. The survey suggests device companies have yet to alleviate this worry. Uncertainty about durability emerged as one of the top factors affecting volume growth and use of TAVR in people aged under 75 is forecast to increase by just four percentage points from 2016 to 2019.

Even with these challenges, the TAVR market remains a fast-growing niche. Leerink’s survey predicts volumes will increase by 15% this year and 13% in 2019. More broadly, analysts expect it to grow by around 17% this year and up to 20% in 2019.

Whether the survey or analysts prove to be more accurate will rest, in part, on the effect upcoming clinical trial readouts have on uptake. Edwards is due to present data on its TAVR device, Sapien 3, in low-risk patients in March and secure an expanded label in the U.S. later in 2019. That could trigger a surge in use in a new patient population. Equally, durability doubts may stymie growth.

Edwards must contend with these factors while holding off competition from Medtronic and Boston Scientific. The survey suggests Medtronic made “modest” market share gains for the third quarter on the bounce. Next year, Medtronic is forecast to hold steady while Boston Scientific’s Lotus Edge Valve System starts to chip away at Edwards’ market share.