Shelley Wood

November 11, 2011

November 10, 2011 (San Francisco) — Quality-of-life (QoL) data from the PARTNER A trial should prompt a "rethink" of how many transcatheter aortic-valve implantations (TAVI) are performed via the transapical route, investigators say.

New QoL data released today at TCT 2011 show that while high-risk, surgery-eligible patients treated via a transfemoral route in PARTNER A reported substantial QoL benefits compared with surgery in the early weeks postprocedure, this was not the case for patients treated via a transapical route.

In fact, said Dr David Cohen (Saint Luke's Mid America Heart Institute, Kansas City, MO), who presented the results, "for patients eligible only for the transapical approach, there was no benefit of transcatheter aortic-valve replacement over surgical aortic-valve replacement at any time point, and in fact, QoL tended to be better with surgical replacement both at one and six months."

Life After TAVI

Dr David Cohen

As previously reported by heartwire , PARTNER A tested the Edwards Sapien valve against surgery in high-risk patients, with all suitable patients randomized to TAVI undergoing a transfemoral procedure if appropriate and a transapical procedure if the patient was deemed unsuitable for a transfemoral approach. At one year, the transcatheter procedures were found to be noninferior to surgical replacement for the primary end point of one-year mortality.

For a number of secondary end points, TAVI and surgery were associated with differences in procedure-related complications and valve performance at 12 months, but the impact of these differences on patient QoL was previously unknown, Cohen said.

For the current analysis, Cohen et al measured QoL in PARTNER A using the Kansas City Cardiomyopathy Questionnaire (KCCQ), the SF-12, and the EQ-5D, with questionnaires administered at one, six, and 12 months.

For the overall comparison, researchers saw differences between TAVI and surgery at three months, but these had disappeared by six and 12 months. What was clear, however, was that there was significant interaction between the treatment effect and the type of TAVI procedure.

Cohen and colleagues therefore conducted further analyses of QoL according to whether patients had undergone a transfemoral or transapical procedure.

QoL Improvements

"For the transfemoral group, the message is one that clinicians won't find surprising," Cohen said--these largely reflect the QoL findings from PARTNER B. The less invasive nature of the transfemoral [TAVI] procedure results in pretty important differences in QoL at one month, although by six and 12 months the patients have really come together."

At one month, however, the improvement in QoL was meaningful--in line with about a one to 1.5 level improvement in NYHA class, Cohen said.

"But on the flip side, the transapical group was really somewhat of a surprise and showed certainly no benefit in terms of QoL of transapical over surgery at any time point, not a hint of a benefit. And for several different measures, [transapical TAVI] was actually doing worse. The trends were all toward worse QoL at one month with the transapical approach."

At one month, scores were numerically lower for transapical TAVI compared with surgery across the various QoL scales used. At six months, this difference was actually "of borderline statistical significance" at p=0.04 for the primary end point (KCCQ overall summary). By 12 months, all differences disappeared.

The Hardest Cuts

His hypothesis, although it's yet to be proven in this setting, is that healing from the medial sternotomy is actually easier and less painful than healing from the smaller, cosmetically "better" lateral thoracotomy used for transapical TAVI.

"A lot of what really hurts and impairs breathing and other sorts of things in these patients after cardiac surgery is motion of the wound. So if the wound is fixed, if the sternum is wired back together so it really can't move, patients heal quite well, and it doesn't cause a tremendous amount of pain once the first couple days are past. Whereas the smaller incision, the lateral thoracotomy, is always moving every time you take a breath. There is no way to wire that back together. I think it's a more painful incision for patients to recover from."

Cohen expects his presentation to meet with much debate, since it's the first real suggestion that TAVI is not better than surgery, at least via the transapical route.

Dr Joseph Bavaria

Indeed, in a morning press conference, surgeons Dr Michael Mack (Baylor Health Care System, TX) and Dr Joseph Bavaria (University of Pennsylvania, Philadelphia) both made the point that many of the US PARTNER centers actually performed very few procedures over the course of the trial, such that the transapical results truly represent a very early experience with this procedure. To heartwire, Bavaria noted that some of these transapical patients actually had complications that kept them in the hospital longer than expected. "I'd like to see the data from the continued-access registry, to see if those patients did better," Bavaria said.

And Cohen agreed that centers in Europe, which have a longer history with these devices and procedures, may have found ways of improving patient recovery, involving better technique or using local anesthesia or nerve blocks, after transapical TAVI.

Already, however, while some registry data in Europe have pointed to much better results with a TA approach than those reported today, other European data have hinted that alternatives to the transfemoral route, such as the subclavian approach, may yield outcomes closer to those of the transfemoral route. So far, the Medtronic CoreValve is the only established TAVI device (approved in Europe) that can be implanted via a subclavian route. The CoreValve is still in the early stage of its pivotal clinical trial in the US.

Cohen acknowledged that done well, the transapical procedure is "slick, smooth, and quick," but "we can't assume just because the incision is small that the procedure is going to be easier to recover from."

Dr Michael Mack

Asked what he thought the future of the transapical approach might be, Cohen replied: "I think it's going to have a role, but I'm hopeful that this analysis leads us to reconsider the extent of that role. And for places that have access to multiple technologies for doing nontransfemoral procedures, this should be taken into account. And we may want to really rethink how much transapical we do."

Mack, however, was less concerned, pointing out that the surgery group in PARTNER A did better than expected. "I think we cannot ignore [these results] and say there are not some concerns here . . . but I'm not as concerned about it as the data may [suggest]."

Still, the results should raise some eyebrows, experts speaking to the media seemed to agree. Dr Samir Kapadia (Cleveland Clinic, OH), speaking at the press conference, said, "This is a little bit shocking. This is a learning [moment]--it's clear we have to improve the transapical procedure."

Cohen disclosed receiving grant support/research contracts from Abbott Vascular, Boston Scientific, Medtronic, AstraZeneca, and Edwards Lifesciences and consulting/honoraria/speaker's bureau fees from Daiichi-Sankyo/Eli Lilly, and Medtronic.