FDA Approves Zilver PTX Drug-Eluting Stent For Peripheral Arterial Disease Reply

The FDA today approved Cook Medical’s Zilver PTX stent. It is the first drug-eluting stent (DES) approved for the treatment of peripheral arterial disease (PAD) in the superficial femoral and proximal (i.e., above the knee) popliteal artery. The new stent will provide a new treatment option for treating patients with PAD. Current treatments include exercise, drug therapy, balloon angioplasty, bare-metal stents, and surgical bypass.

“The clinical study demonstrated that the Zilver is more effective than balloon angioplasty for the treatment of symptomatic peripheral artery disease in above-the-knee femoropopliteal artery,” said Christy Foreman, of the FDA’s Center for Devices and Radiological Health, in an FDA press release. “This approval expands the treatment options for patients suffering from symptomatic peripheral artery disease to include the Cook Zilver PTX drug eluting stent.”

The FDA said the Zilver PTX stent is contraindicated in people with “stenoses that cannot be dilated to permit passage of the catheter or proper placement of the stent, patients who cannot receive recommended drug therapy due to bleeding disorders, or women who are pregnant, breastfeeding, or plan to become pregnant in the next five years.” In clinical studies the most common major adverse event associated with the stent was restenosis requiring treatment to restore patency.

The FDA is requiring Cook Medical to perform a five-year post-approval study of 900 patients.

“This approval marks the start of Cook’s program to bring the benefits of drug elution to U.S. physicians treating the peripheral arteries,” said a Cook Medical executive, Rob Lyles. He said that Cook Medical intends by the end of 2013 to offer a “full suite of drug-eluting peripheral stents in the most commonly used lengths and diameters.” The Zilver PTX will be initially available in an 80 mm length in 6 mm and 7 mm diameters. The company has also received approval to market 40 and 60 mm length stents, though these will not be available until early 2013. Cook said that it expects to receive FDA approval for a 120 mm length stent next year.
Click here to read the FDA and Cook Medical press releases…

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Studies Examine Less Burdensome Dual Antiplatelet Regimens Reply

Two new studies published in the Journal of the American College of Cardiology offer hope but not, yet, compelling evidence to support less burdensome requirements for dual antiplatelet therapy (DAPT) after drug-eluting stent (DES) implantation.

In the first study, Spanish investigators followed 1,622 consecutive patients who received a drug-eluting stent (DES) for one year. They found that 10.6% of the DES patients interrupted at least one antiplatelet drug during the first year. Two-thirds (64.5%) of the  interruptions were temporary, lasting a median of 7 days. After discontinuation of therapy 4.1% of patients had an acute coronary syndrome (ACS), but this was not significantly different from the 5.5% rate of major cardiac events in patients who remained on DAPT.

The authors concluded that early discontinuation of DAPT “is not exceptional and is usually temporary. Although further knowledge about individual risk is desirable, our results suggest that discontinuation for a few days (median: 7 days) of DAT after the first month of DES implantation may be reasonably safe in terms of major cardiac events.”

In an accompanying editorial, Bernhard Witzenbichler points out several limitations of the study, and concludes that “the data can only suggest that a brief interruption of DAPT does not have a large impact on ischemic risk.”

In the second study, Korean investigators randomized 2,117 patients to receive either the Endeavor zotarolimus-eluting (ZES) stent plus 3 months of DAPT therapy or standard therapy, consisting of another DES with a full year of DAPT. There was no difference between the two groups in the primary endpoint (the composite of CV death, MI, stent thrombosis, TVR, or bleeding), which occurred in 4.7% of patients in each group, and there were no significant differences in any of the components of the endpoint. The authors concluded that the Endeavor ZES plus 3 month DAPT “could be safe and beneficial for the selected patients with coronary artery disease who may need to stop DAPT early after DES implantation.”
Click to continue reading…

Drug-Eluting Stents Often Used In Patients At Low Risk Of Restenosis 2

The chief advantage of drug-eluting stents (DES) over bare-metal stents is that they significantly reduce the risk of restenosis. The chief disadvantages of DES are their greater cost and the requirement for prolonged dual antiplatelet therapy after DES implantation.

In a study published in Archives of Internal Medicine,  Amit Amin and colleagues analyzed data from 1.5 million PCI procedures included in the National Cardiovascular Data Registry (NCDR) CathPCI registry to assess whether a higher risk for target vessel revascularization (TVR) is associated with greater DES use and to estimate the economic impact of lower DES use in patients who are at low risk for TVR.

The authors calculated that 43.0% of patients were at low risk for TVR, 43.8% were at moderate risk, and 13.2% were at high risk. DES was used 73.9% of the time in the low risk group (TVR risk <10%), 78.0% in the moderate risk group (TVR risk 10-20%), and 83.2% in the high risk group (TVR risk >20%). According to the investigators, cutting DES use by half in low-risk patients would lower US health care costs by $205 million each year, at the cost of an increase in the overall TVR rate of 0.5%.

The authors concluded that “a strategy of lower DES use among patients at low risk of TVR could present an important opportunity to reduce health care expenditures while preserving the vast majority of their clinical benefit.”

In an invited commentary, Peter W. Groeneveld writes that “the use pattern of DES during the past 9 years illustrates how far away the system is from consistently embracing value-based medical decision making, and it also enumerates the many barriers and inertial practices in US health care that must be surmounted to reach economic sustainability.”

Click here to read the Archives press release…

Xience Stents Gain European Nod For Three-Month Dual Antiplatelet Therapy Reply

The biggest drawback to drug-eluting stents has been the requirement for prolonged dual antiplatelet (DAPT) therapy following stent implantation to prevent stent thrombosis and other potential complications. The precise length of DAPT has been the subject of considerable discussion and research.

Now the Xience Prime and Xience V everolimus-eluting stents have received the CE Mark in Europe for a DAPT length of only three months, according to an Abbott press release. The manufacturer of the stents, Abbott, said this was the “shortest duration  for any major drug eluting stent (DES) in Europe.”

Abbott said that data presented this week at the EuroPCR congress found no cases of stent thrombosis in more than 10,000 patients who received a Xience stent and who discontinued DAPT after three months.

An Abbott spokesperson told CardioBrief that the company is “currently exploring our filing strategies with the FDA for a three-month DAPT indication.”
Click here to read the press release from Abbott…

Meta-Analysis Compares Drug-Eluting and Bare-Metal Stents for Primary Angioplasty Reply

A new meta-analysis comparing drug-eluting stents (DES) and bare-metal stents (BMS) in patients with myocardial infarction has provoked opposing take-away messages from an author of the study and an editorialist. The authors emphasize the reduction in target-vessel revascularization (TVR) associated with DES, but the editorialist focuses on several potential DES weaknesses suggested by the study.

In the paper, published in Archives of Internal Medicine, members of the Drug-Eluting Stent in Primary Angioplasty (DESERT) Cooperation pooled patient data from more than 11 clinical trials in which more than 8,600 patients were randomized to either sirolimus-eluting or paclitaxel-eluting stents or BMS.  After a mean follow-up of 1201 days, DES was associated with a significant reduction in TVR but there were no significant differences in death, reinfarction, or stent thrombosis (ST):

  • TVR: 12.7% for DES vs 20.1% for BMS, HR 0.57, CI 0.50-0.66, p<.001
  • Mortality: 8.5% vs 10.2%, HR 0.85, CI 0.70- 1.04, p = .11
  • Reinfarction: 9.4% vs 5.9%, HR 1.12, CI 0.88-1.41, p = .36
  • Stent thrombosis: 5.8% vs 4.3%, HR 1.13, CI 0.86-1.47, p = .38

However, after two years there was a significant increase in the risk of stent thrombosis associated with the DES group (HR 2.81, CI 1.28-6.19, p=0.04).

The findings, write the authors,

provide strong evidence of the beneficial effects of SES and PES during primary PCI in STEMI. With follow- up as late as 6 years, a robust and sustained decrease in TVR was noted with use of these DES. Although the rates of late reinfarction and ST progressively increased, with the difference becoming statistically significant after 2 years in patients receiving SES and PES, the HR for mortality, while not significantly different between DES and BMS, favored DES.

Click to continue reading, including a comment from Gregg Stone…