June 26th, 2012

Unlikely PARTNERs Support TAVR

I had the privilege of serving on both Circulatory Device Advisory Panels that recommended FDA approval of the Sapien Transcatheter Heart Valve (Edwards LifeSciences) in patients with severe, symptomatic, aortic stenosis — in June 2011 for those who are inoperable and in June 2012 for those at high risk for complications of surgical aortic valve replacement (AVR) — on the basis of the PARTNER B and PARTNER A trials, respectively.

Here’s an insider’s perspective on the process:

1) The collaborative support for TAVR by cardiac surgeons and interventional cardiologists is unprecedented. I never imagined I’d see the president of the Society of Thoracic Surgery (STS) championing a percutaneous cardiac procedure . . . much less doing so twice.

2) Sponsor collaboration with the FDA, the Center for Medicare Services (CMS), STS, and the American College of Cardiology (ACC) resulted in a groundbreaking collaborative national registry for TAVR. This sets the standard for future post-marketing studies . . . a long overdue development.

3) Edwards LifeSciences demonstrated a disciplined commercial rollout of this technology in the United States, a sincere commitment to training, and ongoing tracking of procedure success. Hats off to Edwards. Take a bow.

Any concerns about TAVR?  Naturally!

1) Patient sex may influence effectiveness.  A post hoc analysis of PARTNER A data showed noninferiority of TAVR to surgical AVR in women but not in men (in fact, treatment effects were in the opposite direction for men and women).

2) Strokes are more common with TAVR than with surgical AVR (at 1 year, 5.5% vs. 2.9%) and more common with the transapical then with the transfemoral approach (at 1 year, 9.6% vs .4.6%). Interestingly, the stroke rate in the Continued Access Protocol (nonrandomized) cohort appears to have decreased (at 1 year, 3.7%). Studies are needed to determine the role of procedural technique, patient selection, antithrombotic agents or other factors that may be responsible for this difference.

3) Approximately 15% of TAVR-treated patients develop moderate or severe paravalvular aortic regurgitation, which is associated with increased mortality.

4) Valve durability is unknown. It just hasn’t been around long enough.

The FDA and sponsor agree that post-approval studies are essential. In addition to extending follow-up for the patients enrolled in the PARTNER trial, a prospective registry of consecutively enrolled patients undergoing TAVR is needed.

Based on what we know, would you generally prefer TAVR over surgical AVR in patients considered to be high-risk (surgical mortality >15%)?


One Response to “Unlikely PARTNERs Support TAVR”

  1. Judith Andersen, AB, MD says:

    Yes — with careful consideration of all the caveats discussed above — and continuing follow-up of study participants such that issues such as valve durability, minimization of procedural embolic risk, gender-related outcomes and impact of antithrombotic therapy can be appropriately assessed. Assessing an individual patient’s ability to undergo surgical AVR is, perhaps, the most difficult portion of the calculus: all of us have seen seemingly inoperable patients survive surgery and thrive thereafter (and seen simple “temporizing” valvuloplasty without TAVR render “inoperable” patients operable). Nevertheless, particularly given the frequent reluctance of older patients to undergo surgical replacement, TAVR is a welcome option.