ACC – Transcatheter aortic valves march on
It is not quite like Oprah Winfrey announcing that everyone in the audience gets a car, but new data on Edwards Lifesciences’ Sapien transcatheter valves could mean that soon everyone with aortic valve disease will get a catheter-delivered device, rather than a surgically implanted one.
Transcatheter valves are already standard therapy for patients who cannot undergo surgery, but the data from the Partner II trial presented at ACC on Saturday position the devices to be used in intermediate-risk patients, too. Unlike Oprah and the Pontiacs, of course, Edwards is not giving the valves away. Its shares were up 18% in early trading as investors consider the prospect of use in intermediate-risk patients but also in those at low risk – in other words, just about everyone.
The first Partner trial conclusively proved an earlier iteration of Sapien a better bet than surgery in two groups of valve disease patients: those at high risk of experiencing complications from an open procedure, and those who were so sick as to be inoperable.
This first tranche of data from the Partner II study concerns intermediate-risk patients with symptomatic aortic valve stenosis. Two years after treatment the primary composite endpoint of all-cause death or disabling stroke occurred in 19.3% of the 1,011 Sapien XT-treated patients and 21.1% of the 1,021 patients treated with surgically implanted prosthetic valves. With a p value of 0.25, there was no significant difference between the therapies.
There is a trade-off when it comes to adverse events. Short-term safety favoured surgical intervention: major vascular complications were significantly more frequent with Sapien XT. But the opposite was true over the longer term, with bleeding, acute kidney failure and atrial fibrillation being significantly more common with surgery.
Since surgical valves are more expensive after operation costs and hospital time are factored in, Edwards’ valve will now be the preferred choice in this group. The valve used in practice will probably not be the XT but Sapien 3, a more advanced product approved in the US last year for high-risk patients. Following the Partner II results, interventional cardiologists will have no hesitation in using it off-label in intermediate-risk patients.
And if they will use Sapien 3 in intermediate-risk patients, it becomes increasingly likely that they will use it in low-risk patients too. But there are caveats. The risk categories used in the Partner trials are slightly misleading: though the patients in this study are considered intermediate-risk for the purpose of clinical evaluation they are actually in the highest-risk quintile of patients with aortic stenosis who are candidates for surgery.
Still, transcatheter valves have been proven consistently safe and effective and there is no reason that this would not hold true among lower-risk patients. At this point the argument for their widespread use begins to become economic.
Among low-risk patients the costs of surgery are markedly lower than for higher-risk patients. It is not guaranteed that the cost-effectiveness argument will hold for low-risk patients, meaning that Edwards might be forced to sell Sapien 3 more cheaply if it wants to increase its reach.
Edwards plans an approval submission to the FDA for intermediate-risk patients this year, though with many doctors using Sapien 3 for these patients anyway obtaining Medicare reimbursement in this population is the more important goal.
Medtronic's rival product CoreValve is so far only approved in extreme and high-risk patients in the US.
Catheter-mounted aortic valves continue their journey to replace surgically implanted devices as standard therapy for all patients with valve disease. This quarter Edwards is scheduled to begin the Partner III trial of Sapien 3 in around 1,200 low-risk patients; with a one-year endpoint data could be available in late 2018.
If that is as successful as earlier studies, transcatheter valves will become the preferred technology for the majority of patients with aortic valve disease – if the price is right.
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