Bad BVS News: Analysis Points to Fast Reaction by Interventionalists to Absorb Safety Issues

ORLANDO, FL—Interventional cardiologists have a reputation for being early adopters of device technology, their enthusiasm occasionally outstripping the evidence. But a new analysis addressing usage of the Absorb bioresorbable vascular scaffold (BVS, Abbott Vascular) suggests operators were cautious in taking up the novel technology and quick to abandon it when studies revealed the device’s flaws and limitations.

In an analysis of US centers with access to Absorb BVS after its approval in July 2016, the dissolving scaffold was used in a mere 1.42% of procedures. Moreover, use of Absorb peaked just prior to the presentation of negative 3-year data from the ABSORB II trial and dropped off almost immediately after those results were aired.

Ajay Kirtane, MD (NewYork-Presbyterian/Columbia University Irving Medical Center, New York, NY), who presented the analysis at the American College of Cardiology 2018 Scientific Session, said it suggests physicians and hospitals were “highly selective” in their use of the new technology, and that they responded swiftly to Absorb’s safety concerns.

“What’s most instructive, at least for me, are the immediate, month-to-month changes after the data were presented,” Kirtane told TCTMD. “Many people argue that it takes years for guidelines to get into clinical practice, but with the modern way news gets disseminated, whether it’s through Twitter or news coverage like TCTMD and beyond, we saw changes in the next month. It doesn’t drop a whole lot, but it drops.”

Bad News From the Get-go 

Bad news surrounding the Absorb BVS technology started before the scaffold was approved by the US Food and Drug Administration (FDA) on July 5, 2016. Several meta-analyses published earlier that year suggested use of Absorb was associated with an increased risk of scaffold thrombosis. Still, Absorb BVS was approved on the basis of 1-year data from the ABSORB III study, a large-scale trial comparing the scaffold against the Xience everolimus-eluting stent (Abbott Vascular).    

From there, however, a series of studies highlighted a significantly increased risk of clinical events with Absorb BVS. For example, the 3-year data from ABSORB II, which were presented at TCT in October 2016, showed that treatment with the disappearing scaffold was associated with a twofold increased risk of device-oriented clinical events, specifically an increased risk of target-vessel MI, as well as an increased risk of late scaffold thrombosis.

Using the National Cardiovascular Data Registry (NCDR) CathPCI Registry, the researchers analyzed data from 1,033,843 PCI procedures performed between January 2016 and July 2017. During this entire 18-month period, Absorb BVS was used in 0.4% of procedures. After July 2016, when the FDA approved Absorb for the treatment of coronary artery disease, usage rose slightly—of 682,951 PCI procedures performed, Absorb BVS was implanted in 0.6%.

Monthly use of Absorb BVS peaked at 1.25% of stent procedures in the fall of 2016. Following the presentation of ABSORB II, however, use of the bioresorbable scaffold declined to 0.95%, 0.76%, and 0.63% of clinical procedures in November 2016, December 2016, and January 2017.

Overall, only one in five centers participating in the CathPCI Registry used the device.

Utilization rates were cut yet again following the presentation and publication of negative 2-year results from ABSORB III and AIDA, both of which were reported in March 2017. Additionally, the FDA issued a safety alert in March warning physicians about the risks of target lesion failure with Absorb BVS when compared with patients treated with Xience. By April 2017, just 0.19% of procedures performed per month used Absorb BVS. By June 2017, the monthly utilization rate was 0.12% of stent procedures.

Abbott Vascular stopped selling Absorb in September 2017 because of low commercial sales.   

There are other possible reasons for the low usage, Kirtane noted. “The device was more expensive, it wasn’t rolled out to every site, and it’s harder to implant than conventional DES. . . . Many interventionalists were discerning and didn’t necessarily believe that the upfront price was worth it until they saw the late data, which we still haven’t seen.”

David Cohen, MD (Saint Luke’s Mid America Heart Institute, Kansas City, MO), who moderated the ACC session, pointed out that some centers were enthusiastic adopters of the technology, noting that some hospitals implanted Absorb BVS in as many as 40% patients in a given month. Kirtane agreed there was variability in terms of the maximal monthly usage, adding that some physicians truly bought-in to the device’s promise. Such usage was not the norm, though. The median maximal per month usage was just 6.8% of stent procedures.

For Kirtane, the analysis shows that interventional cardiologists will react to data. “It’s one of the most data-driven fields as a whole, in terms of the amount of studies we do, sometimes to our own detriment, but it’s reassuring to see that it occurs,” he said.

The researchers also credit the FDA for getting the message out to physicians about the device’s potential risks, which had an impact on physicians discarding the product. Kirtane said Abbott Vascular deserves credit, too, for the slow rollout of product to operators trained to use the device. As a result, utilization rates of the first-generation device were kept low from the beginning.