Bioresorbable Scaffolds Not to Be Chosen Over DES, Says European Task Force

A task force from the European Society of Cardiology (ESC) and European Association of Percutaneous Cardiovascular Interventions (EAPCI) is now providing physicians with updated guidance on the use of bioresorbable scaffolds (BRS) in clinical practice, ultimately stating the devices have no role over drug-eluting stents.

In a new ESC/EAPCI report, which was published recently in EuroIntervention, experts led by Robert Byrne, MBBCh, PhD (Deutsches Herzzentrum München, Germany), state that as long as concerns about the long-term clinical safety of bioresorbable scaffolds remain—namely, an increased risk of MI and scaffold thrombosis—physicians should not use the devices in place of current-generation metallic DES.

The task force focused on the five bioresorbable scaffolds that had CE Mark approval in Europe when the report was being written. In the lag between the report being finalized and it being published, however, Abbott Vascular halted sales of its beleaguered Absorb device as a result of low commercial demand. The remaining bioresorbable devices include DESolve (Elixir Medical), Arterial Remodeling Technologies bioresorbable scaffold (ART), Fantom (Reva Medical), and Magmaris (Biotronik).

“It is time for a pause and reflection, waiting for the next wave of better devices,” Davide Capodanno, MD, PhD (University of Catania, Italy), one of the ESC/EAPCI authors, told TCTMD.

“Surely, I would like to see some rigorous testing for the other scaffolds, as it was the case of Absorb,” he said. “The fact that we cannot use Absorb anymore does not imply an automatic shift to the other ‘non-Absorb BRS’ before convincing data will dissipate the ongoing concerns. With the other BRS we are still at the stage of nonrandomized small series—it is their time now to play a role and prove their value.”

The ESC/EAPCI report provides an overview of clinical and angiographic outcomes with the CE Mark-approved bioresorbable scaffolds, but as Capodanno noted, Absorb is the only one with clinical trial data. Those studies clearly highlighted an increased risk of target-vessel MI and definite/probable scaffold thrombosis when compared with a current-generation everolimus-eluting stent (Xience; Abbott Vascular). Additionally, longer-term outcomes out to 2 or 3 years also showed an excess of very late scaffold thrombosis, target-vessel MI, and target lesion failure with Absorb.

Capodanno said he’s interested in seeing the results from future landmark analyses of the ABSORB clinical trials, specifically the head-to-head comparison of Absorb versus Xience at a time point when Absorb is fully dissolved. Such data, however, will not be available for some time.   

To date, there are limited data available regarding DESolve and Magmaris, with just a single-arm study for each. There are no published clinical outcomes studies for the ART and Fantom devices.

How to Manage Treated Patients? 

The ESC/EAPCI’s new document, which is an extension of a consensus statement requested by the European Commission on the evaluation of coronary stents, also provides recommendations for dual antiplatelet therapy (DAPT) in patients who have been treated with one of the scaffolds.

In their review, the task force states that DAPT with aspirin and a P2Y12 inhibitor after implantation is mandatory to reduce the risk of scaffold thrombosis, but that the “optimal duration of such DAPT treatment is unknown.” The ESC currently recommends a minimum of 6 months for drug-eluting stents, but provides no guidance on bioresorbable scaffolds.

For the ESC/EAPCI task force, patients currently on DAPT following scaffold implantation should continue with treatment for at least 3 years with Absorb (or the full bioresorption period with other scaffolds). In a patient who has stopped DAPT prior to the bioresorption of the scaffold, a decision to restart DAPT should be made on a case-by-case basis after an evaluation of the thrombotic and bleeding risks, they say.

“I think it would be unrealistic and probably inappropriate to ask our BRS patients to come back to the cath lab at 3 or 4 years and have an [optical coherence tomography exam] to evaluate how the healing process is going on, especially if they are asymptomatic and they are doing well,” said Capodanno. “Therefore, to keep patients on DAPT until the device is absorbed is probably the only reasonable thing we can do to decrease the risk of thrombosis, if the bleeding risk is acceptable and DAPT is tolerated.”

Finally, the task force provides procedural recommendations if any of the approved devices are used. They recommend lesion assessment with pre- and postprocedural intravascular imaging, the avoidance of small vessels (< 2.5 mm), and pre- and postdilatation with noncompliant balloons, among other things.

Importantly, they also provide directions for the nonclinical and clinical evaluation of bioresorbable scaffolds. For clinical studies, they state that a noninferiority study design with a 1-year endpoint would be acceptable, but sequential follow-up should also include a superiority assessment during longer-term follow-up (3 to 5 years).

To TCTMD, Capodanno said physicians should avoid straying too far into pessimism, noting that while first-generation bioresorbable scaffolds had difficulties and inferior results, the next-generation devices may be better. He noted that first- and second-generation drug-eluting stents did not perform as well as the devices currently used by physicians.

“At the same time, I would avoid overenthusiasm for the promise of other BRS that are still in their infancy of clinical development,” he said.

In August, Boston Scientific announced they would no longer pursue development of Renuvia, which was their thinner-strut bioresorbable scaffold. The market for bioresorbable technology, the company said, simply wasn’t developing as quickly as they anticipated.