Absorb Comparable to Xience in Economic Analysis, but BVS Safety Concerns Could Alter Balance

An economic analysis of the ABSORB III trial suggests the bioresorbable vascular scaffold (BVS) is associated with marginally higher procedural and index hospitalization costs when compared with patients who received a DES, but results in similar total healthcare costs at 1 year.

The total cost of using the Absorb GT1 BVS (Abbott Vascular) was approximately $350 more compared with the everolimus-eluting Xience (Abbott Vascular), with total 1-year costs for Absorb and Xience estimated to be $17,848 and $17,498, respectively.

The researchers, led by Suzanne Baron, MD (Saint Luke’s Mid America Heart Institute, Kansas City, MO), say there “does not seem to be a major economic downside to the use of the Absorb scaffold at present, although the true economic value of the device will depend on whether [a difference in] late clinical outcomes (and associated effects on cost) emerges between the two groups.”

The Absorb scaffold is presently under scrutiny, and the device will no longer be widely available in Europe as of May 31, 2017, given concerns raised from the recently published ABSORB II study. As reported by TCTMD, those 3-year outcomes showed the Absorb BVS was associated with an increased risk of target-vessel MI and late scaffold thrombosis compared with Xience.

The 2-year results from the recently published AIDA trial also showed the rate of definite/probable scaffold thrombosis was nearly fourfold higher with Absorb compared with the Xience stent.  

Although the CE Mark approval remains in place, Abbott is restricting use of Absorb to European centers participating in clinical registries in order to better collect real-world data, specifically whether improved implantation techniques can mitigate the higher event rates with the device. In March, the US Food and Drug Administration sent a letter to doctors warning them of the increased risk of MACE with Absorb and reminding them not to implant the device in small vessels, as per the indication.   

For one cardiologist, the troublesome data from ABSORB II, AIDA, and other registries suggest it might not be the best time to examine the cost of Absorb BVS.  

“The main thing is that clinical effectiveness has to override cost-effectiveness,” Hitinder Gurm, MD (University of Michigan, Ann Arbor), told TCTMD. “The challenge we’re seeing right now is that these are promising devices but they’re not able to beat the current standard of care, which is our second-generation drug-eluting stents. The outcomes are so good with second-generation devices, we’d have to see significant improvements in safety and efficacy [with bioresorbable scaffolds] before we’d consider replacing the current standard. Until then, cost-effectiveness needs to take a back seat.”

To TCTMD, Baron agreed, saying that longer-term follow-up of ongoing trials, such as ABSORB III and ABSORB IV, will be needed to “fully characterize any late clinical and economic advantages or disadvantages associated with a bioresorbable scaffold.”

“Really, the true economic value of a bioresorbable scaffold will ultimately lie in its ability to reduce late cardiovascular events by improving physiological vascular responses with scaffold resorption,” she said. “If rates of late repeat revascularization are reduced with the Absorb scaffold, then an economic advantage for the device may emerge. That said, it is unknown at this time whether the Absorb scaffold will be associated with improved late clinical outcomes and the recent data regarding late stent thrombosis events associated with the scaffold is certainly concerning in this regard.”     

The results of the study are published in April 24, 2017, issue of JACC: Cardiovascular Interventions.

Estimating the 1-Year Economic Impact of Absorb

In the analysis, the researchers estimated the cost of the Absorb device to be $100 more than the Xience stent ($1,350 vs $1,250), which translated into higher upfront procedural costs. In addition, use of the Absorb scaffold was associated with greater use of balloon catheters, which was likely related to the need for appropriate lesion preparation and postdilatation with the device, said Baron. Overall, the index procedural costs were higher with Absorb: $6,316 versus $6,103 for the Xience stent (P = 0.02).

The researchers did not observe an increased use of imaging with IVUS or optical coherence tomography (OCT) in the Absorb arm, a finding that may be attributable to the straightforward lesions treated in ABSORB III or variable use of the PSP protocol (prepare, size, and postdilate). “Certainly, if increased use of intravascular imaging and aggressive pre- and postdilation of lesions with Absorb scaffold implantation is required to obtain good clinical outcomes, this would likely contribute to a further increase in the index procedure cost,” said Baron.

At 1 year, there was no significant difference in clinical outcomes between the devices—Absorb was noninferior to Xience for the primary endpoint of TLF—but the researchers noted a trend toward increased rates of repeat PCI with Absorb. This translated into slightly higher follow-up costs compared with Xience ($2,813 vs $2,596; P = 0.43), although the cumulative 1-year cost difference between the devices was not statistically significant.

Quibbling With Costs

For Gurm, further follow-up is required to truly assess the economics of the bioresorbable technology, particularly given the risk of late and very late scaffold thrombosis. “You have to do much longer-term follow-up where you could argue one device was as good as the contemporary device, and if it is as safe,” he said. If the ABSORB studies had not shown such safety concerns, then a 1-year economic analysis would have been justified,” he said. “With all the data we’re seeing, looking at cost is a premature analysis,” he said.

In an editorial accompanying the study, Michael Kutcher, MD (Wake Forest School of Medicine, Winston-Salem, NC), agrees that the 3-year results from ABSORB II are worrisome, saying the data “darken the horizon” in terms of the device’s long-term cost-effectiveness. He notes that there is a push to extend dual antiplatelet therapy with the BVS, which could also increase costs and morbidity.  

Overall, the editorialist says one could “quibble” with the estimated cost of Absorb in the economic analysis, noting that the $100 price difference between devices seems “extremely optimistic and rather low.” However, he points out that the price could vary significantly from one center to another depending on “preferred vendor status and global contracts.”

To TCTMD, Baron said for the purposes of the study, the cost of the device was derived from an informal survey of five US hospitals and from generalized pricing data provided by the manufacturer. The investigators also performed a sensitivity analysis and confirmed that the higher the cost of the BVS, the greater the 1-year difference in total costs between it and Xience.

In his editorial, Kutcher argues that the theoretical concept of a dissolving stent remains sound. Gurm, too, is a believer in the technology, and both caution that Absorb is a first-generation device still evolving and hopefully improving.