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Transcatheter aortic valves: Cost-effective compared to standard surgery?

NEW YORK (Reuters Health) – Transcatheter aortic valve replacement (TAVR) via the transfemoral approach is more cost-effective than conventional surgical aortic valve replacement (AVR) in patients with severe aortic stenosis, a new report says.

That’s not the case when the transcatheter valve is delivered transapically, however.

And Dr. David J Cohen of Saint Luke’s Mid America Heart Institute in Kansas City, Missouri, the paper’s corresponding author, told Reuters Health in an email, “Although I expect that TAVR utilization will continue to increase steadily over the next several decades, particularly as we gain experience and understanding of long-term valve durability, it probably will never completely replace surgical AVR.”

His group’s paper, published online today in the Journal of the American College of Cardiology, notes that compared to medical management, TAVR has been found effective for severe aortic stenosis in patients who are too sick to undergo surgical AVR. In November 2011, the U.S. Food and Drug Administration approved the Edwards’ Sapien transcatheter valve for patients deemed too sick to undergo open-heart surgery.

Last month, the FDA widened its approval to include patients with aortic stenosis who are eligible for surgery but at high risk of serious surgical complications or death.

Last month the FDA also approved transapical delivery of the device. Transfemoral TAVR can be done in a cardiac catheterization lab, but transapical TAVR requires a thoracotomy and access to the aortic valve via the apex of the left ventricle.

For their cost-effectiveness analysis, the authors analyzed data from the randomized PARTNER trial of TAVR vs surgical AVR that was reported last year in the New England Journal of Medicine. In that trial, 647 patients received either transfemoral or transapical TAVRs, or surgical AVRs. Patients in the three groups had similar baseline characteristics.

For the transfemoral TAVR group, ICU and hospital lengths of stay were significantly shorter, but total costs were not different because the higher cost of the transcatheter valve offset the longer lengths of stay and operating room times of surgical AVR.

The transapical TAVR was nearly more expensive than surgical AVR (p=0.06) because there was no difference in hospital or ICU length of stay.

Resource costs at one-year were not significantly different for either transfemoral or transapical TAVR compared to surgical AVR.

The research team used a comparison method called the incremental cost-effectiveness ratio (ICER).

“The ICER is the ratio of the net cost of a therapy to its net clinical benefit and represents a measure of value for money,” Dr. Cohen explained. He added that a lower ICER indicates a better economic outcome. In the U.S. healthcare system, treatments with ICERs less than $50,000/QALY (quality-adjusted life-year) tend to be viewed as reasonable value for money. The bootstrap data are analogous to confidence intervals in standard research studies, and they show how confident one can be in the results of the study, given the uncertainty in both the clinical and economic outcomes.

The result of the cost-effectiveness analysis showed no clear advantage for the combined TAVR cohort compared to those who had surgical AVR. But when the subset of transfemoral TAVR patients was compared to surgical AVR using bootstrap simulations, transfemoral TAVR “was economically dominant compared with surgical AVR in 55.7% of replicates and economically attractive at an ICER of $50,000 per QALY gained in 70.9%.”

Surgical AVR dominated economically when compared to transapical AVR.

Dr. Cohen said, “After all the complex methods, the central message of the paper is actually pretty straightforward. For these high risk surgical candidates, transfemoral TAVR is a “win-win” proposition.” He pointed out that it is less costly in the long run than standard surgical AVR and it leads to better quality of life in the short run.

But for patients who can only be treated via a transapical approach, there was no clinical or economic advantage to TAVR. Dr. Cohen points out, however, that these results represent some of the earliest experiences with TAVR on the part of the sites in the trial, and it is likely that clinical and economic outcomes will improve with increasing experience.

Dr. Ron Goeree from the Department of Clinical Epidemiology and Biostatistics at McMaster University, who was not involved in the new analysis, told Reuters Health, “Although TAVR may appear cost-effective in the transfemoral population in this particular study based on assumptions used by the authors, the longer term uncertainty of TAVR in transfemoral or transapical and operable or inoperable patients remains very high.”

Dr. Goeree directs the Programs for Assessment of Technology in Health (PATH) Research Institute at St. Joseph’s Healthcare in Hamilton, Ontario, and he also co-authored a recent paper for the Ontario Health Technology Assessment Series analyzing the literature on TAVR, including the PARTNER A trial.

His paper concluded that TAVR was cost-effective for patients who were not candidates for surgical AVR but not so for those who can undergo standard surgical AVR. (The paper is available online at http://1.usa.gov/TYJfPa.)

Using Markov models, Dr. Goeree’s PATH group found that given the high cost of TAVR and patients’ relatively short life expectancy, the cost-effectiveness of TAVR in either group critically depends on assumptions needed for longer term cost and outcome predictions, most of which are not yet available and have a qualitatively important impact on any cost-effectiveness result.

Dr. Cohen’s study was funded by Edwards Lifesciences. Nearly half of the 17 authors disclosed conflicts of interest.

SOURCE: http://bit.ly/X6Mmes

J Am Coll Cardiol 2012