Biolimus-Eluting Stents Perform Well in STEMI, Unselected Populations

PARIS, France—Two different biolimus-A9-eluting stents, each with biodegradable abluminal coatings, showed positive results in separate randomized trials presented Tuesday, May 15 at EuroPCR 2012.

One trial showed that the BioMatrix stent (Biosensors, Singapore) is superior to an equivalent BMS in STEMI patients, while the other trial showed comparable results between the Nobori stent (Terumo, Tokyo, Japan) and the Xience-V/Promus everolimus-eluting stent (Boston Scientific, Natick, MA; Abbott Vascular, Abbott Park, IL) in a “real-world” cohort.

Benefit Seen in STEMI Setting

For the COMFORTABLE-AMI trial, Lorenz Räber, MD, of Bern University Hospital (Bern, Switzerland), and colleagues randomized 1,157 STEMI patients (1,282 lesions) to treatment with BioMatrix or BMS from September 2009 to January 2011.

At 1 year, BioMatrix showed improved results for the primary endpoint of MACE (composite of cardiac death, target-vessel reinfarction and ischemia-driven TLR) as well as several of the component endpoints (table 1).

Table 1. One-Year Results  

The number needed to treat to prevent a single MACE event at 1 year with a BioMatrix stent was 24. In addition, target-vessel MIs due to restenosis or stent thrombosis were reduced in the BioMatrix group (3 events vs. 14 events; P = 0.01).

Other safety endpoints such as death, stroke, and MI were similar between the 2 groups at 1 year, while there was a trend for fewer overall reinfarctions with BioMatrix (2.0% vs. 3.7%; P = 0.08).

“The use of stents eluting biolimus from a biodegradable polymer is more effective and safer than bare-metal stents in patients presenting with STEMI undergoing primary PCI at 1 year,” Dr. Räber concluded.

A New Day Dawns

Commenting on the trial, Upendra Kaul, MD, of Batra Hospital and Medical Research Centre (New Delhi, India), observed that, “the new generation of DES are very effective in reducing MACE, including stent thrombosis, yet maintaining a very low TLR and TVR.”

He added that with the latest DES models, “the superior safety concept of bare-metal stents in AMI is seriously questioned.”

COMFORTABLE AMI may be practice changing, but not just yet, Dr. Kaul noted. “The days of first generation DES are over,” he said. “The use of BMS for superior safety cannot be justified. But we need longer follow-up data up to 2 to 3 years without dual antiplatelet therapy and larger trials like HORIZONS II to address this subject further.” At 1 year, dual antiplatelet therapy use in COMFORTABLE AMI was similar between the BioMatrix and BMS arms at 90.0% and 88.1%, respectively (P = 0.30).

Ron Waksman, MD, of Washington Hospital Center (Washington, DC), noted that a key question is whether permanent-polymer DES can be replaced by biodegradable-polymer devices.

Also, “if you’re mainly a DES user, should you switch to [biolimus-eluting stent] technology? Unfortunately, COMFORTABLE AMI didn’t address this question,” he said.

“The bottom line is, should you change your practice after COMFORTABLE AMI?” Dr. Waksman said. “I’m comfortable switching from BMS to DES; I’m not comfortable switching from DES to [biolimus-eluting stents] for all patients with AMI yet. I’m eager to see the results of the next study that will test biodegradable- vs. durable-polymer DES for AMI patients, a LEADERS-like study for STEMI populations.”

Nobori COMPAREs Well with EES

For the real-world COMPARE II trial, Pieter C. Smits, MD, PhD, of Maasstad Ziekenhuis (Rotterdam, the Netherlands), and colleagues randomized 2,707 PCI-eligible patients to the Nobori stent (n = 1,795) or the Xience/Promus EES (n = 912) at 12 European sites with minimal inclusion and exclusion criteria.

Baseline characteristics were similar between the patient groups, with more than half (58%) presenting with ACS and more than one-third (63-64%) having type B2/C lesions.

The primary endpoint of cardiac death, MI, and clinically indicated TVR was equivalent between groups, meeting the criteria for noninferiority with Nobori compared to Xience. Multiple secondary endpoints were also similar between the 2 groups (table 2).

Table 2. Clinical Outcomes at 1 Year

^aP value for noninferiority.

After presenting the results, Dr. Smits observed that, “we now have more options for treating our patients and more options for what’s on our shelves.”

He theorized that the Nobori stent’s biggest potential advantage is that “with the biodegradable polymer, you have the possibility perhaps of stopping dual antiplatelet therapy earlier. That was not the purpose of this study, but that can be explored.”

Most likely a combination of the stent’s features—biolimus elution, biodegradable polymer—contribute to the device’s safety and effectiveness, Dr. Smits suggested.

Ultimately, Not Practice Changing

Junbo Ge, MD, of Zhongshan Hospital, Fudan University (Shanghai, China), questioned which factor provides the main mechanism of action: the polymer or the drug. “Where does the key benefit come from over long-term follow-up?” he asked.

Meanwhile, Kari Niemelä, MD, PhD, of Tampere University Hospital (Tampere, Finland), noted the study’s relatively short length of follow-up. “The real story, as we know, starts after 12 months, and therefore, what happens in the coming years is very important,” he said.

“For sure, we have now a wider range of modern drug-eluting stents available, but perhaps the question for industry is [whether] this biodegradable coating is worth investing in with new devices,” Dr. Niemelä said. “For me, at this point, this will not change my practice because we need more data.”

:
1. Räber L. Biolimus-eluting stents with biodegradable polymer versus bare metal stents in acute myocardial infarction: The COMFORTABLE AMI trial. Presented at: EuroPCR; May 15, 2012; Paris, France. 

2. Smits P. COMPARE II trial: A large scale, multicenter, prospective randomised comparison between the durable polymer everolimus-eluting stent and the abluminal biodegradable polymer biolimus-eluting stent in a real life setting. Presented at: EuroPCR; May 15, 2012; Paris, France. 

Disclosures:

• The COMPARE II trial received an unrestricted grant from Terumo.
• Dr. Räber reports no relevant conflicts of interest.

Related Stories:

• Meta-analysis: Biodegradable Polymer DES Reduce Stent Thrombosis, TLR at 3 Years
• Positive Signs for Biolimus A9-Eluting Stents

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