Expert highlights evolution, current applications of BMS for PCI

Once a game changer in the progression of PCI, bare-metal stents may soon be edged out by improved, newer-generation drug-eluting stents, according to a speaker at TCT 2017.

“Balloon angioplasty, which despite being quite successful in the early days of PCI, was limited by abrupt vessel closure and restenosis,” Raffaele Piccolo, MD, PhD, from Bern University Hospital in Switzerland, said during his presentation. “In this context, it was clear that the advent of BMS was instrumental in reducing the rates of restenosis and repeat PCI.”

Nevertheless, the technology was imperfect, as the absolute rates of these adverse events remained high, Piccolo noted. Therefore, it was not until the introduction of early-generation DES that clinicians found a more effective way to inhibit neointimal hyperplasia by combining antiproliferative agents with metallic platforms.

Early-generation DES, however, were not free from problems, he said, noting that they were associated with an increased risk for late thrombotic events. Eventually, new-generation DES resolved this issue and improved safety and efficacy outcomes, all of which was achieved through improvements in antiproliferative drugs, polymer and platform materials, and strut thickness, according to Piccolo.

He also highlighted data linking new-generation DES to the lowest rates of target vessel revascularization and definite stent thrombosis compared with BMS and early-generation DES.

“There is no discussion that in routine clinical practice, new-generation DES should be preferred over BMS,” Piccolo said.

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BMS in certain subgroups

Piccolo said even randomized, head-to-head comparisons of new-generation DES with BMS demonstrate a significant reduction in cardiac death, MI and stent thrombosis favoring the use of new-generation DES over BMS. Similar results have also been seen in low-risk patients, such as those included in the NORSTENT trial.

Despite these data, the use of BMS has been recommended in certain patient and lesion subsets, although more recent studies suggest that new-generation DES may actually perform better than BMS in these subgroups.

For instance, BMS has been recommended over DES for patients with acute MI, Piccolo said. Results from the EXAMINATION and COMFORTABLE trials, however, not only showed improvement in outcomes with new-generation DES vs. BMS in patients with acute MI at 1-year follow-up but at 5-year follow-up as well. These improvements included a reduction in the risk for death, MI or any revascularization in EXAMINATION and a reduction in the risk for cardiac death, target-vessel MI and target lesion revascularization in COMFORTABLE.

Large vessel disease also once represented an indication for BMS, mainly due to a subgroup analysis of the BASKET trial that indicated a higher risk for cardiac death or MI in patients with large vessel disease who were randomly assigned to DES. Additionally, the data showed no benefit in terms of TVR, according to Piccolo. Nevertheless, these data have not been subsequently confirmed by the BASKET-PROVE II trial, which showed that use of new-generation DES reduced the primary endpoint of cardiac death, MI and TVR in patients with large vessel disease, he said.

For some clinicians, patients requiring short-term dual antiplatelet therapy were also viewed as being better suited for BMS vs. DES implantation, Piccolo said. However, in the LEADERS FREE trial, which compared polymer-free DES with BMS in patients at high risk for bleeding who were managed with 1 month of DAPT, use of the polymer-free DES was associated with a significant reduction in the composite endpoint of cardiac death, MI or stent thrombosis as well as lower rates of TLR at 2 years. These data were also confirmed by a subgroup analysis of the ZEUS trial, according to Piccolo.

“In this context, what really matters are the circumstances and clinical indications that are associated with the DAPT cessation,” he said.

Piccolo also cited data from the PARIS registry indicating that disruption, rather than brief interruption or physician-guided discontinuation of DAPT, is associated with an increased risk for stent thrombosis during follow-up at 2 years.

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Current state of BMS vs. DES

To learn more about outcomes with new-generation DES vs. BMS, Piccolo and colleagues are conducting an individual patient data meta-analysis for 17 randomized clinical trials that will include more than 20,000 patients. The primary outcome is a composite of cardiac death or MI.

But with existing and emerging evidence, the question is whether BMS still has a place in PCI, according to Piccolo.

“I believe the answer is no because the use of new-generation DES is associated with lower rates of any revascularization, lower rates of stent thrombosis, reduced risk for MI and a similar or even lower risk for death compared with BMS,” he said. “Moreover, new-generation DES have addressed the issues of acute MI and large vessel disease, and patients requiring short-term DAPT can be safely and very well managed with polymer-free DES at the moment. We also have several trials evaluating the use of new-generation DES with short-term DAPT in patients at high risk for bleeding that will be presented in the next few years.” – by Melissa Foster

Reference:

Mehilli J, et al. Session I. Bare Metal Stents and Specialty DES: Evolution and Current Applications. Presented at: TCT Scientific Symposium; Oct. 29-Nov. 2, 2017; Denver.

Disclosure: Piccolo reports no relevant financial disclosures.