Coverage and Use of Impella and Watchman: A Tale of Four Countries

Use of two high-risk cardiovascular devices—the Watchman (Boston Scientific) left atrial appendage occluder and the Impella (Abiomed) left ventricular assist device—is highest in the United States compared with several other high-income countries with different regulatory and reimbursement environments, a new review shows.

Public funding of the devices varies in Canada, United Kingdom, and the Netherlands, researchers found, but Watchman and Impella are both covered by Medicare in the US, and this appears to have had an impact.

“Medical devices really have two barriers to use,” said Nathan Smith, MD (Baylor College of Medicine, Houston, TX), one of the study’s investigators. “They need regulatory approval by whatever government agency approves the device for use in patients. In the United States, that’s the FDA and in Europe they need to get CE Mark before they can be marketed to patients. You need all your supporting evidence to show that the device is safe and also effective in treating the disease. That’s step one. Step two is that to get these devices used, somebody has to pay for them.”

Led by Marta Williams (Harvard Medical School, Boston, MA), the study was published last week in Circulation: Cardiovascular Quality and Outcomes and highlights the dual impact of regulatory clearance and reimbursement.

“We often get focused on one or the other, but not both together, and yet they’re really married together in how doctors use the devices,” Smith told TCTMD.

Sanket S. Dhruva, MD (San Francisco VA Medical Center/University of California, San Francisco), who has previously documented the increase in Impella use in the US, said the review makes one thing clear: “There are definitely financial incentives that inform the use of these different devices.” 

Under the current diagnosis-related group, for example, Medicare pays significantly more for a PCI with Impella than for a PCI with stenting alone.

“I don't think that there are any doctors out there who are putting in an Impella just for the reimbursement,” Dhruva told TCTMD. “That’s not happening. We’re not evil as physicians, but there are multiple factors that go into the decision. Should this PCI be done with Impella? Do we need to have the mechanical support? This could be a factor if my hospital gets reimbursed for it. We’re human—we know that financial incentives can play a role.”

To get these devices used, somebody has to pay for them. Nathan Smith

In the past, Impella usage has spurred contentious debates around safety and effectiveness stemming from the lack of randomized, controlled data as well as conflicting results from observational studies.

Recently, however, the DanGer Shock trial delivered a decisively positive result for Impella in highly selected patients with STEMI complicated by cardiogenic shock. On the strength of that trial, the recent American College of Cardiology/American Heart Association ACS guidelines gave a class 2a recommendation for using a microaxial intravascular flow pump like Impella to reduce the risk of death in selected patients with STEMI and cardiogenic shock.

The Watchman LAAO was approved on the basis of the PROTECT AF and PREVAIL studies, but here, too, the path to clinical use hasn’t always been smooth. Both trials faced criticism over methodological issues and inclusion criteria, such as the decision to enroll patients without a contraindication to warfarin. PROTECT-AF was first published in 2009, but the US Food and Drug Administration struggled to interpret the data and requested the creation of a registry to track outcomes.

Over the years, newer studies have raised concerns about the limited efficacy data, risks of device-related thrombus and leakage, and signals that the procedure might be riskier in women than men. It is currently approved for patients with nonvalvular atrial fibrillation at moderate-to-high risk of stroke with and without a contraindication to oral anticoagulation (2a and 2b recommendation, respectively).

Public Funding of Two Devices

Regulatory processes differ among the US, Canada, UK, and the Netherlands; approvals for both devices occurred earlier in Europe than in North America.

In the US, Watchman is covered by Medicare based on a national coverage determination (NCD). In Ontario, which stood in as a provincial proxy for Canada, the ministry of health recommended funding the device, but this happens infrequently given strict eligibility requirements, say investigators, leaving hospitals to dip into global budgets or philanthropic funds. Payment for Watchman is also limited in the UK, with only select patients meeting criteria for reimbursement, while in the Netherlands, funding for Watchman is not endorsed by the national body. In fact, Dutch regulators had allocated funding for the COMPARE-LAAO study assessing the safety and efficacy of Watchman, but that study was recently shuttered partly due to low enrollment, said Smith.

A similarly mixed situation is seen with Impella, with Medicare creating an NCD in 2016. In Ontario, the ministry of health currently does not reimburse hospitals using the device nor does the UK healthcare system. In the Netherlands, however, the device has been reimbursed by health insurers since 2012.   

Prior to DanGer Shock and the US guideline change, researchers say that utilization of Impella differed substantially across the four countries, with uptake highest in the US. Of note, Impella use increased over time even without randomized data, with one study estimating that approximately 3.5% of all PCI procedures in the US included mechanical circulatory support in 2016. The researchers say this would translate into approximately seven to eight Impella implantations per 100,000 people in the US.  

In the UK, however, the British Cardiovascular Intervention Society estimated that just 0.1% of all PCIs used an Impella and there are no data available for Ontario, given that it’s not reimbursed. Between 2017 and 2021, 133 Impella devices were implanted in the Netherlands, or 5.7% of all patients with acute MI complicated by cardiogenic shock undergoing PCI.

With Watchman, the researchers cite 2017 data showing that roughly 3.4 Watchman devices were implanted per 100,000 adults with atrial fibrillation in the US. In Ontario, however, there were just 0.98 devices implanted per 100,000 adults in 2022/2023. There is no publicly available data on the use of Watchman in the UK, although the National Health Service has recently established a registry of implantations to evaluate post-approval effectiveness.

Once Medicare agreed to reimbursement, use of Impella and Watchman “kind of took off,” said Smith. “In Europe and Canada, there is less funding for the devices so their usage was limited, even though they were approved much earlier [in Europe].”

We’re human—we know that financial incentives can play a role. Sanket S. Dhruva

To TCTMD, Smith said that healthcare systems always have a difficult time balancing appropriate usage of medical devices. Once approved, US payers are quick to provide reimbursement, whereas other countries are slower despite devices being cleared. He suggested there might be a middle ground of making sure that the rapid adoption doesn’t occur before the evidence comes out, but not so slowly that advances in technology aren’t used, poor outcomes as a result.  

Dhruva said that he would also like to see greater alignment between resource allocation and therapies/technologies where there is proven benefit.

“I think in some cases that's not happening in some of the health systems that were studied in this paper,” he said. “And in some instances, we might be overpaying for procedures. Just stepping back, you know, there might be benefits to other interventions like medical therapy that perhaps might be more cost-effective, so I would like to see a better alignment of those [financial] incentives and the evidence of clinical outcome benefits to patients.”