The American College of Cardiology (ACC) and Society of Thoracic Surgeons (STS) recently published a consensus statement warning that transcatheter valve therapy (TVT) must be adopted carefully and selectively until these emergent technologies are tested more thoroughly. Also, according to the authors of the document, the procedures should only be performed at specialty centers with multidisciplinary teams of cardiologists and surgeons. To clarify for our readers the implications of the position statement, we asked cardiologist Robert Kipperman, M.D., the principal investigator for the Everest II MitraClip Trial and the CoreValve trial at the Advanced Therapy Unit at Gagnon Cardiovascular Institute at Morristown Medical Center in New Jersey, to answer the following questions:
Medgadget: What kind of training or credentialing will be required before physicians or surgeons can perform this procedure?
Robert Kipperman: First, I think it’s best to adhere to the joint guidelines from the American College of Cardiology and Society of Thoracic Surgeons, but, in general, those who are participating in clinical trials with these devices will be best prepared.
I think, in this regard, physicians will fall into three categories of readiness: those where clinical trials are underway, and training is already in place; those who are fellowship-trained who will now need additional formal training; and lastly, those who are currently in practice who will need additional training with the devices, as well as in structural heart diseases.
This last group will likely be the most problematic, as the training won’t be readily available in many places. Therefore, for people who are already in practice, it’s going to be a little bit of a challenge. These procedures will probably be limited to centers of excellence, starting with hospitals that are already doing the clinical trials. It will probably not be done in every hospital the way open heart is done in many hospitals.
Medgadget: It has been recommended that this be performed only at specialty centers with multidisciplinary teams of cardiologists and surgeons. Will there be some kind of “center of excellence” designation for these centers. If not, how will these centers be decided upon?
Robert Kipperman: I think much of this is already being done by the process of selecting sites for the clinical trials, and I think that’s how it will continue to be done. I’m sure there are probably more qualifying centers – centers identified with high volume, as well as the equipment and hybrid rooms where these procedures are done and there is a good collaboration between surgeons and cardiologists.
Medgadget: The preliminary data seems to offer a benefit from the transcatheter valve therapy in terms of bleeding and avoidance of atrial fibrillation, but at the cost of a higher stroke rate. Can you comment on the risk/benefit ratio for this new technology?
Robert Kipperman: In terms of mitral valve repair, the rate of safety is far better for percutaneous repair, while at the expense of not having quite as good efficacy. In terms of aortic valve repair, it does appear that there is a much lower rate of some of the typical surgical complications but a higher rate of stroke. However, keep in mind that many of these procedures are still in trial, such as CoreValve, so this might not. Many of these are first-generation devices, which will get smaller and better in future iterations, and with that, the rate of safety will only get better.
Medgadget: The Partner trial consisted of a cohort of patients with very high risk factors for perioperative mortality. Do you think this data can be extrapolated to a less-sick overall population? Do you see a future role for TAVI in low risk Severe Aortic Stenosis patients?
Robert Kipperman: Yes. The big questions will be durability. In the short term, it can be extrapolated. The questions will be the long term.
Medgadget: Can you comment on the cost benefit of this new therapy, taking into account device cost and possible shorter hospitalization times?
Robert Kipperman: I think the economic analysis shows it is cost effective and probably a little cheaper than traditional surgical treatment.
Medgadget: What advice would you have for a physician who encounters a patient with aortic stenosis today who has seen the news stories about this new less invasive procedure? How should we counsel our patients about this?
Robert Kipperman: I think if the patient is high-risk, he or she should be referred to a center doing a clinical trial. With ongoing trials like the one at Morristown Medical Center, it will help to answer many of the questions they have and move the therapy along.
Medgadget: As TVT procedures improve, where do you see the future role of open heart surgery for aortic stenosis or mitral regurgitation?
Robert Kipperman: I think there will certainly be less reliance on open heart surgery over time. I think there will always be a role for it, but it will certainly decrease. For very complex diseases, it will still have a role.
EXPERT CONSENSUS DOCUMENT: Transcatheter Valve Therapy: A Professional Society Overview from the American College of Cardiology Foundation and the Society of Thoracic Surgeons J Am Coll Cardiol, 2011; 58:445-455
Flashbacks: Transcatheter Valve archives…
Image: Medtronic‘s CoreValve transcatheter aortic valve replacement system