Analysis raises concerns on appropriateness of transcatheter aortic valve implantation
An analysis published in BMJ has suggested that transcatheter aortic valve implantation may only be appropriate in a minority of patients currently considered for the treatment and that the widespread use does not stand up to scrutiny.
Researchers from Belgium conducted the study using available data on transcatheter aortic valve implantation (TAVI), including papers published in peer-reviewed journals and proceedings from congresses. They subsequently found what they called “serious unanswered questions” about the clinical outcomes and the cost-effectiveness of the procedure, as well as the regulatory process, particularly in Europe. According to the analysis, a health technology assessment commissioned by the Belgian government concluded that the Belgian health authorities should pay for TAVI in only 10% of patients currently considered for treatment — specifically in patients deemed inoperable for technical reasons.
Existing evidence
In the analysis, the researchers highlighted the United Kingdom’s National Institute for Health and Clinical Excellence (NICE) guidance issued in March, which stated that “for patients for whom surgery is suitable, albeit risky, the evidence for using TAVI was inadequate.” Despite this, two different transcatheter valves gained CE marks in 2007, leading to TAVI gaining a large market in Europe quickly, they said.
In addition, although the results of the PARTNER trial showed a significantly lower mortality rate among inoperable patients with TAVR compared with medical therapy (30.7% vs. 50.7%; P<.001), the researchers cited an unpublished follow-up study authorized by the FDA, which indicated that inoperable patients treated with TAVR fared worse than those given standard therapy (1-year mortality, 34.3% vs. 21.6%). According to the FDA, any further data analysis of a premarket application is proprietary information and it was the choice of the sponsor (Edwards Lifesciences) whether or not to release it. Requests to the trial sponsor for further details on this trial, the researchers said, went unanswered.
Practical concerns
One of the major concerns prompted by the study results was the fact that, in Europe, use of transapical TAVI “far exceeds what is justified by clinical evidence,” the researchers said.
Currently, the transapical approach is widely used in Europe, despite this lack of evidence. In the UK TAVI registry, for example, 25% of patients were treated transapically, which was similar to the 20% rate of transapical procedures observed in the FRANCE-2 registry.
The researchers also drew attention to the halted Danish STACCATO trial. The trial tested the transapical TAVI procedure and found that five of 34 patients treated with transcatheter valves died compared with only one of 36 patients treated with surgery. Although this study has received criticism for its design, additional concern regarding the average cost of transapical TAVI was raised, since it was found to be substantially higher than the transfemoral approach (€49,000 vs. €40,900).
A call for change
Moving forward, the researchers concluded that European licensing laws, which currently allow for medical devices to fall outside the scope of the European Medicines Agency and qualify for CE mark approval in a similar fashion as domestic appliances, should “require high-quality randomized trials to show clinical efficacy and safety before granting marketing approval to innovative, high-risk medical devices. And a major improvement in transparency of information is also needed to allow clinicians to practice evidence-based medicine, patients to make informed decisions and health technology assessment agencies to make the right judgments.”
For more information:
Brabandt HV. BMJ. 2012;doi:10.1136/bmj.e4710.
Disclosure: The researchers report no relevant financial disclosures.