Article taken from TCTMD.com - Looks like Dr. Renu Virmani does not think much of bioabsorbable stents.

By Caitlin E. Cox
Friday, December 03, 2010

 

The second generation of a new everolimus-eluting bioabsorbable stent shows improved results on optical coherence tomographic (OCT) imaging compared with its previous incarnation, with less late shrinkage and neointimal growth at 6 months, according to an analysis of the ABSORB trial published online December 1, 2010, ahead of print in the European Heart Journal.

 

For ABSORB, Patrick W. Serruys, MD, PhD, of the Erasmus Medical Center (Rotterdam, The Netherlands), and colleagues followed 2 cohorts of patients with single de novo coronary artery lesions who underwent PCI with the BVS (Bioabsorbable eVerolimus-eluting Stent; Abbott Vascular, Santa Clara, CA). The stent has a backbone of poly-L-lactic acid that provides support and a coating of poly-DL-lactic acid that contains and controls the release of everolimus. All components of the BVS, except for 2 radio-opaque markers, are expected to fully absorb into the human body within 2 years.

 

Cohort A included 30 patients treated with BVS 1.0, while Cohort B tested the newer BVS 1.1 in 101 patients. The current analysis compares 12 lesions from each cohort that were imaged at baseline and 6-month follow-up with OCT.

 

Baseline clinical, angiographic, and OCT characteristics largely were similar between the 2 groups, with the exception of smoking, which was significantly higher in the 1.0-treated patients (33% vs. 0%; P = 0.03). By 6 months, late shrinkage—which occurs due to the scaffold’s loss of structural integrity in conjunction with fatigue and constrictive remodeling of the vessel following injury—was less severe in BVS 1.1-treated lesions than in those treated with the previous design. Neointimal area and thickness also were reduced with the newer model.

 

These changes translated into significantly smaller reductions in mean and minimal lumen areas from baseline to 6 months for the newer stent (table 1).

 

Table 1. Outcomes on OCT at 6 Months

 

^a In-scaffold area obstruction.

 

 By 6 months, the strut appearance of BVS 1.0 on OCT had substantially changed from baseline, whereas 100% of BVS 1.1 struts maintained a black box appearance.

In addition, patients treated with the BVS 1.0 had significant angiographic late loss, with a decrease in minimum lumen diameter of 0.43 mm from baseline (P = 0.01). Those receiving BVS 1.1, meanwhile showed a non-significant 0.08-mm decrease. The difference in late loss between the 2 designs did not reach statistical significance by 6 months (P = 0.07).

Optimizing Design

According to Dr. Serruys and colleagues, the manufacturing process was modified between BVS 1.0 and 1.1 “to enhance the mechanical strength and mechanical durability of the struts. Moreover, the new design has in-phase zigzag hoops linked by bridges that allow for a more uniform strut distribution, reduce maximum circular unsupported surface area, and provide more uniform vessel wall support and drug transfer. The polymer mass, coating content, amount of drug, and the strut thickness remain the same.”

“The slower bioresorption process of the BVS 1.1, compared with the BVS 1.0, is the most plausible explanation for the near elimination of the late shrinkage and for the higher inhibition of the neointimal response,” they conclude, adding that further research will assess whether these differences are preserved.

But Does It Matter?

In a telephone interview with TCTMD, Renu Virmani, MD, of CVPath Institute (Gaithersburg, MD), expressed skepticism about the paper. “These measurements, are they leading to something? Do they tell us something? I don’t believe so,” she said. “I think that the improvement they’ve made [in design] is real, but I doubt very much whether we can glean anything from [this small number of patients] because they are too few.”

“You need a large study, you cannot do cherry picking,” Dr. Virmani stressed, adding that the degree of difference between the stents appears implausible and that the mechanism also needs better explanation. “If you had done a preclinical study and shown me that the flow rate and sheer forces are much better in one than the other, I would understand that more,” she said.

David E. Kandzari, MD, of Piedmont Heart Institute (Atlanta, GA), however, was more optimistic that the paper held useful information.

“Bare-metal stents came into existence in interventional cardiology because, while they don’t necessarily prevent neointimal hyperplasia more than just balloon angioplasty, [they] provide architectural scaffolding that would prevent elastic recoil. No matter how appealing a bioresorbable stent may be, if it cannot fulfill those initial requirements that we demanded back in the mid-90s, it still may not be effective,” he explained. Although it is unclear whether BVS 1.0 [stent’s] limitations arose from the design of the stent itself or properties of absorption, “the newer design of the stent seems to provide the essential requirement of preventing recoil but at the same time provides the opportunity for drug elution and eventual bioresorption.”

Moving Forward Amid Uncertainty

In terms of the future for bioabsorbable stents, Dr. Virmani said the main question is whether they are worth the expense. “If you can afford it, yes, [but] we will have to pay an enormous price. It’s not going to be cheap when it comes to market,” she commented. “Unless you show me longevity for the patient, I don’t see the point. [Is it worth it] just because the vessel looks less jailed? I’m not convinced by that.” She also questioned whether the observed reduction in neointimal growth would persist and expressed doubt that BVS, with a strut thickness of 150 μm, could be widely used.

Moreover, Dr. Virmani pointed out that just because the scaffold is absorbed does not mean the vessel returns to its original state.

Dr. Kandzari agreed that for bioabsorbable stents the “late impact on vessel remodeling and health are complete unknowns today.”

These factors may affect whether clinicians are willing to adopt the technology, he noted. “My impression is that if this stent were to be available on the worldwide market today, it would still have a definite appeal and have fairly large market share,” said Dr. Kandzari. “But in speaking with physicians about it, I’m struck by the variability of responses and enthusiasm. And I think it’s in part because of the advances that we’ve had in everolimus-eluting stents,” with their apparent durability and favorable outcomes.

Existing second-generation DES set a very high standard, Dr. Kandzari commented. Designing trials that can demonstrate superiority is challenging, he said, so “do you just market them on physician intuition alone and hope adoption will be driven by perception rather than on actual clinical proof?”

Like Dr. Virmani, Dr. Kandzari said that cost might be an obstacle. He also pointed out that the BVS does not solve all of the challenges inherent to a permanent platform, in that most TLR occurs during the first year, when the scaffold would not yet be fully absorbed.

Even so, he said, “If you asked clinicians in 2006—with the whole drug-eluting stent dilemma and concerns about stent safety—do we need a bioresorbable stent? I think the answer would have been a unanimous yes. I think if you ask clinicians today, given the intuitive appeal, the answer would still be yes.”

Survey Reveals Cardiologist Preference for Bioabsorbable Stents Will Fuel Interventional Cardiology Market by 2013

DJ MARKET TALK:C&O Pharma May Rise On Sumitomo Stake Buy News (2010/12/01 08:55AM)

More on Lenovo and Hony Capital, BIG`s largest shareholder and our future hope is very bright with them on board. 

Hu Zhongbin Hony Capital Nov. 18 officially announced that the second phase of its RMB 10 at the end of 2010 Fund was established. The holding of funds by the association as a sponsor, the National Social Security Fund has once again become a key investor.

After June 2008 the first phase of the Hony 20 billion yuan RMB fund investment, the National Social Security Fund as a key investor once again invest in Hony two yuan fund, the investment amount to 30 billion yuan. As a result, Hony Capital to become the first consecutive two-time National Social Security Fund Investment Fund Management team.

Hony investment, said fund raising goal of 8 billion yuan original, but given the amount raised the first delivery is more than 7 billion yuan, now plans to raise the total size of funds has been adjusted to no more than 100 billion yuan, is expected before the end of May 2011 complete a full delivery.

Chairman of the National Social Security Fund Council, said Dai, "A Phase II National Social Security Fund the first private equity investment fund management company is yi, yi we have great confidence in, worked out really well."

Hony Capital Fund, the first phase of a total of 5.026 billion yuan RMB, investment has been completed, the investment involved in financial services, cultural media, consumer, construction and other industries related to several leading companies, is expected to create huge returns for investors. Yi yuan fund the second phase will continue to focus on M & A investment and growth investments, focusing on upgrading and urban China's consumption growth in the process of two major investment themes.

Hony Capital CEO John H. Zhao said, "is both over-subscribed investment fund to obtain people's trust and support of Hony Capital, also shows that PE in China have bright prospects. Hony as a major force in the industry, not only for their own investors to earn good return on investment, but hopes to play in promoting economic development in China should have a positive role. "

After the completion of fund raising, the total capital investment management Hony more than 30 billion yuan, total assets of over RMB one billion, China PE fund management industry's largest fund management companies.

Hony Capital was established in 2003, Lenovo Holdings Limited's equity investment and management business in a professional company.

Hony Capital manages two funds dollar and the yuan, by 2010, the total size of over 30 billion yuan of funds.

Hony Capital is solid and has a lot of connection. good for BIG

24 Nov 2010

Hony Capital to Receive RMB 3 billion Investment from China's Social Security Fund