Transcatheter aortic heart valve data, and Edwards Lifesciences' Sapien valve in particular, are set to take the spotlight at yet another major cardiology conference this weekend.

This time the product will get top billing at the American College of Cardiology's 2011 annual meeting in New Orleans, where Sapien will be featured in its own "scientific showcase and late-breaking clinical trials" session kicking off the meeting's data presentations on April 3.

ACC will wait until the following day to start releasing other late-breaking clinical trial data on stents, drugs and other cardiology topics. The meeting is set to conclude on April 5.

Sapien Expected To Match Surgery

The first data out of the gate will be a report by investigators from the second of two cohorts in Edwards' pivotal PARTNER trial for Sapien.

Last year at the Transcatheter Cardiovascular Therapeutics conference, investigators presented highly superior results for Sapien against medical therapy for patients (cohort B) deemed too unstable to undergo conventional open heart valve replacement surgery. That data is before FDA right now as part of a PMA submission for use of the valve in non-candidates for surgery, which Edwards predicts will be approved by year-end. (See " Also see "Edwards' Sapien Valve: Big Survival Boost In Those Too Sick For Surgery" - Medtech Insight, 27 September, 2010. " – "The Gray Sheet" Sept. 27, 2010.)

The ACC data will address a randomized comparison of the Sapien procedure against open surgery in slightly more stable patients. The expectation is extremely high among clinicians and investors that the catheter-delivered valve will meet its "cohort A" primary endpoint of non-inferiority to surgery on all-cause mortality.

"I do not think it is a wild guess to say that non-inferiority in this study, the primary endpoint, will be met," said Ron Waksman, associate director of cardiology at Washington Hospital Center, Washington, D.C. Waksman spoke during a March 24 conference call organized by Morgan Stanley device analysts to preview ACC.

Based on the cohort B data, results from various European registries and historical surgical outcomes, it is possible the Sapien cohort A survival numbers will trend better than surgery, he said, although the study is not powered to show a clinical advantage.

Edwards Lifesciences’ Sapien heart valve being delivered via the femoral artery. (Photo: Edwards Lifesciences)

Edwards Lifesciences’ Sapien heart valve being delivered via the femoral artery. (Photo: Edwards Lifesciences)

About 700 patients were enrolled in cohort A. It is the first randomized study with outcomes comparing transcatheter aortic valve placement to surgery, as well as the first to include a transcatheter valve delivered via the transapical route through the rib cage in addition to transfemoral delivery through the femoral artery.

Patients enrolled in the cohort whose femoral artery was accessible were randomized to transfemoral Sapien delivery, or to surgery; those whose femoral artery was not sufficiently accessible were randomized to transapical delivery, or surgery.

The transapical route may be particularly important for long-term adoption of the transcatheter valve since the procedure may often be performed by cardiac surgeons. Heart surgeons are known to sometimes push back against adoption of new catheter-based procedures. (See " Also see "Edwards Hits Snags With Trial Of Catheter-Delivered Heart Valve" - Medtech Insight, 29 October, 2007. " – "The Gray Sheet" Oct. 9, 2007.)

Focus On Stroke, Cost-Effectiveness Data

Based on the cohort A data, Edwards has said it plans to submit a PMA for Sapien in the high-risk surgical population later this year for anticipated 2012 approval.

Non-Sapien Studies To Watch At ACC

PLATINUM: Non-inferiorty head-to-head comparison of Boston Scientific's Promus Element and Xience V/Promus (Abbott/Boston Scientific)
RESOLUTE US: Non-randomized pivotal U.S. trial of Medtronic's Endeavor Resolute stent
RIVAL: Transradial versus femoral access for coronary angiography or intervention
PRECOMBAT: Randomized study of bypass surgery versus angioplasty with Johnson & Johnson's Cypher stent in patients with left-main artery disease
ISAR-CABG: Long-term outcomes comparison of several drug-eluting stents and bare-metal stents for saphenous vein graft lesions
EVEREST II: Two-year outcomes data for Abbott's MitraClip transcatheter mitral valve repair device
Rheos pivotal trial: Assessment of CVRx's baroreflex activitation therapy for lowering blood pressure in patients with resistant hypertension
PROTECT II: Abiomed will try to make the case for use of its Impella cardiac assist device in high-risk PCI cases based on subgroup analyses despite halting the trial in December because the primary endpoint could not be reached

If there is any potential for a misstep in the Sapien data, it could come from the stroke rate, some analysts suggest.

In the cohort B results unveiled at TCT last year, the 5% stroke rate in Sapien-treated patients was significantly higher than the medical group’s 1.1% rate. The importance of this event rate in that group was somewhat diluted by the substantial survival benefit from the valve. But if there were a statistically significant stroke rate increase in patients for whom surgery remains a viable option, it could have more of an impact.

Waksman suggests that while it is likely that Sapien will be linked to a stroke rate in cohort A that is similar to that of cohort B, it is possible that the stroke rate for cohort A’s surgery group will be high enough to make the comparison a statistical wash. If not, it could raise some questions from FDA, though it would be unlikely to prevent PMA approval, Waksman suggested.

"It is something everybody is worried about," he acknowledged.

The only other data that will be presented in the same session as the PARTNER cohort A results is from a cost-effectiveness analysis of the cohort B portion of the trial. This could have a significant near-term impact as Edwards prepares for its anticipated launch of Sapien in non-surgical patients later this year.

The company has already secured a recommendation from CMS for a unique insurance code for transcatheter valve replacement, which likely puts it on a path to get reimbursed in the near-term at payment levels equal to surgery.

Edwards also may request a new-technology add-on payment from Medicare for the procedure; favorable cost-effectiveness data could be important to winning that premium payment, in addition to helping drive overall adoption.

Going PLATINUM In Stent Sector

The ACC meeting also will feature another 20 late-breaking clinical trial presentations over the subsequent two days.

Stent or percutaneous coronary intervention data will be addressed in at least five of the reports. The trial that could have one of the more significant impacts on product adoption is Boston Scientific's PLATINUM study, which will be presented April 4.

Boston Scientific hopes to take back stent market share with its platinum-chromium Element platform, above. (Photo: Boston Scientific.)

Boston Scientific hopes to take back stent market share with its platinum-chromium Element platform, above. (Photo: Boston Scientific.)

The study compares Boston Scientific’s Promus Element everolimus-eluting stent with the everolimus-eluting stents currently available in the U.S. (marketed by Abbott as Xience V and by Boston Scientific as Promus ).

Abbott's Xience stent has come to dominate the market in recent years in response to favorable data comparisons. While Boston Scientific has also been able to benefit from that trend with its private-label version of the same product (Promus), the firm’s bottom-line gain has been limited by the terms of the Abbott supply agreement, which expires next year.

Promus Element is a Boston Scientific-developed product with the same drug and polymer as Xience/Promus, but with a new platinum-chromium stent design with improved radiopacity, the company explains, making the implant easier to spot on an angiogram.

Waksman said he would be "stunned" if Promus Element did not meet the study's composite non-inferiority endpoint because of the equivalent drugs and polymers.

With that result, combined with the radiopacity advantage, Boston Scientific's new stent –which the company expects to gain U.S. approval for in the middle of 2012 – could start taking back market share from Abbott, the interventional cardiologist predicted.

Separately, stent data from Medtronic's pivotal 1,400-patient, non-randomized RESOLUTE US trial will be reported April 4; the data is intended to support the firm's PMA for its Endeavor Resolute zotarolimus-eluting stent. (See " Also see "Medtronic's Resolute Efficacy On Par With Abbott's Xience In One-Year Study" - Medtech Insight, 31 May, 2010. " – "The Gray Sheet" May 31, 2010.)

Another April 4 presentation that could have a broader impact on percutaneous coronary interventions and stenting is the 7,000-plus-patient RIVAL trial, which compares interventional procedures performed via the standard transfemoral groin-insertion route versus those performed via the transradial wrist/arm-insertion approach.

Transradial procedures account for only about 3% to 5% of percutaneous interventions in the U.S., although preliminary data has suggested the technique is associated with a much lower bleeding risk compared to transfemoral procedures. (See " Also see "Interest In Transradial PCI Grows In U.S. But Barriers Remain" - Medtech Insight, 12 October, 2009. " – "The Gray Sheet" Oct. 12, 2009.)

Terumo Interventional Systems, which was not involved in the trial, launched a coronary guiding catheter last year specifically designed for transradial procedures, and the firm has signaled its interest in becoming the "premier global transradial access products provider."

Other device-relevant data to be unveiled at the ACC meeting include two-year results from Abbott's EVEREST II trial assessing the firm's MitraClip mitral valve repair device on April 4. One-year data from the trial headlined last year's ACC meeting.

Also on deck is data from CVRx's U.S. pivotal study of its Rheos baroreflex activation device to treat resistant hypertension on April 5. CVRx previously had signaled that the device did not meet one of its endpoints.

Another company seeking to make the best of imperfect data at the meeting will be Abiomed. In December, the firm disclosed that its PROTECT II study assessing its Impella percutaneous cardiac assist device to support high-risk percutaneous coronary interventions had been halted because the primary endpoint could not be reached. At the time, the company promised more detailed subgroup analyses at ACC that would make a case for using the product for this indication. (See " Also see "Abiomed: Cardiologists Will Respond To Positive Trends In Unfinished Impella Trial" - Medtech Insight, 13 December, 2010. " – "The Gray Sheet" Dec. 13, 2010.)

The analysis will be presented at ACC on April 3, but not as part of the late-breaking trial program.

By David Filmore

Big Data In The Big Easy: Sapien Versus Surgery Results Get Top ACC Billing

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