Readers write in: TAVI


Thanks again to ‘Lapeyre’, who as it turns out is Dr. Didier Lapeyre, a renowned, French cardiothoracic surgeon credited with the development of the first mechanical valves.

Dr. Didier Lapeyre was gracious enough to send some additional literature to add to our ongoing discussions regarding severe aortic stenosis and TAVI/ TAVR therapies.  He also commented that the best way to avoid these ‘high risk situations’ is by earlier intervention with conventional surgery – something we discussed before in the article entitled, “More patients need surgery.”

He also points out that ‘elderly’ patients actually do quite well with aortic valve replacement and offers a recently published meta-analysis of 48 studies on patients aged 80 or older.

As readers know, on June 13, 2012 – the FDA ruled in favor of expanding the eligibility criteria for this therapy.  Previously, this treatment modality, due to its experimental nature and high rate of complications including stroke and serious bleeding, has been limited in the United States to patients deemed ineligible for aortic valve replacement surgery.

Now on the heels of the Partner A trial, in which researchers reported favorable results for patients receiving the Sapien device, the FDA has voted to approve expanding criteria to include patients deemed to be high risk candidates for surgery.  As we have discussed on previous occasions, this opens the door to the potential for widespread abuse, misapplication of this therapy and potential patient harm.

In the accompanying 114 page article, “Transcatheter aortic valve implantation (TAVI): a health technology assessment update,” Belgian researchers (Mattias, Van Brabandt, Van de Sande & Deviese, 2011) looking at transcatheter valve procedures have found exactly that in their examination of the use of TAVI worldwide.

Most notably, is the evidence of widespread abuse in Germany (page 49 of report), which has become well-known for their early adoption of this technology, and now uses TAVI for an estimated 25 – 40% of valve procedures*.  Closer examination of the practices in this country show poor data reporting with incomplete information in the national registry as well as a reported mortality rate of 7.7%, which is more than double that of conventional surgery.  Unsurprisingly, in Germany, TAVI is reimbursed at double the amount compared to conventional surgery**, providing sufficient incentive for hospitals and cardiologists to use TAVI even in low risk patients. (and yes, german cardiologists are often citing “patient refused surgery” as their reason, particularly when using TAVI on younger, healthy, low risk patients.)

In their examination of the data itself, Mattias et al. (2011) found significant researcher bias within the study design and interpretation of results.  More alarmingly, Mattias found that one of the principle researchers in the Partner A study, Dr. Martin Leon had major financial incentives for reporting successful results.  He had recently received a 6.9 million dollar payment from Edward Lifesciences, the creators of the Sapien valve for purchase of his own transcatheter valve company.   He also received 1.5 million dollar bonus if the Partner A trial reached specific milestones.  This fact alone, in my mind, calls into question the integrity of the entire study.

[Please note that this is just a tiny summary of the exhaustive report.]

Thank you, Dr. Lapeyre for offering your expertise for the benefit of our readers!

* Estimates on the implantation of TAVI in Germany vary widely due to a lack of consistent reporting.

** At the time of the report, TAVI was reimbursed at 36,000 euros (45,500 dollars) versus 17,500 euros (22,000 dollars) for aortic valve replacement.

For more posts on TAVI and aortic stenosis, see our TAVI archive.

References

Mattias, N., Van Brabandt, H., Van de Sande, S. & Deviese, S. (2011).  Transcatheter aortic valve implantation (TAVI): a health technology assessment .  Belgian Health Care Knowledge Centre.

Vasques, F., Messori, A., Lucenteforte, E. & Biancari, F. (2012).  Immediate and late outcome of patients aged 80 years and older undergoing isolated aortic valve replacement: a systematic review and meta-analysis of 48 studies.  Am Heart J 2012; 163: 477-85.

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