Doctor says media exaggerated findings from recent TAVR study, and more quick hits from TCT
The Cardioband for minimally invasive mitral valve repair--Courtesy of Valtech Cardio

The ongoing Transcatheter Cardiovascular Therapeutics conference in San Francisco couldn't be any more timely, with bigwigs Abbott ($ABT), Edwards ($EW), and Medtronic ($MDT) dropping more than $1 billion on the burgeoning transcatheter mitral valve repair/replacement market in recent months. HeartWare ($HTWR) is attempting to enter the TMVR market too, transforming itself from an LVAD specialist to a cardiology generalist (though its deal to acquire Valtech is not popular on Wall Street). And Boston Scientific ($BSX) just announced its option to acquire MValve Technologies for $200 million.

Due to all the wheeling and dealing, several aspirants in the transcatheter and (and related minimally invasive surgical) mitral valve space are exiting stealth mode and will present data at TCT.

But don't forget about transcatheter aortic valve replacement (TAVR), whose clinical and economic success is responsible for the strong interest in TMVR. A recent study in the New England Journal of Medicine has raised a potentially troublesome safety issue with TAVRs, just in case the field was already being relegated as yesterday's big thing in light of the TMVR mania.

Here are some quick hits from the weekend session of the conference. Note that the conference isn't limited strictly to transcatheter devices, in spite of its (highly marketable) name.

  • Dr. Raj Makkar was critical of the mainstream media (namely the Wall Street Journal and Associated Press) for exaggerating the results of his NEJM study, which was in fact inconclusive about the risk posed by reduced leaflet mobility, a phenomenon that has been found to occur in at least two TAVRs and even traditional surgically implanted heart valves. The paper did find a tentative link between stroke and reduced leaflet mobility, but the sample size was too small to make an empirical conclusion. Moreover, the study says that the correlation between the adverse event and mechanical issue of leaflet mobility is probably not the result of causation.

  • Valtech's Cardioband transcatheter mitral valve repair device passed its feasibility study. Successful implantation of the device was achieved in 37 of 40 high-risk mitral valve regurgitation. Quality of life improved following implantation, as evidenced by patient questionnaire and 6-minute walk test, said Dr. Alec Vahanian of Bichat Hospital in Paris. One limitation is that the device is not supposed to be used as a stand-alone treatment; it can be used adjunctive with other transcatheter devices like Abbott's MitraClip. The device just receiving a CE mark for commercialization in Europe, bolstering HeartWare's case for its disputed acquisition of Valtech.

  • Catheterization labs lose $7,500 per TAVR patient. Expect fewer overnight stays at the hospital following a TAVR procedure, as part of a bid to improve the treatment paradigm's economics. "Same-day discharge appears to be as safe as overnight observation," said Dr. Sunil Rao of Duke University Medical, pointing to new observational data. "In selected patients, a 6-hour period of observation post-PCI is reasonable before sending the patient home," he told TCTMD.

  • More data was released in supporting of the use of fractional flow reserve (FFR) technology during percutaneous coronary interventions, such as stent implantation procedures. Results show the technique can cut down on unnecessary procedures. "A large proportion of [nonculprit lesions that appear severe on angiography] are not flow limiting and potentially do not need treatment or further investigation when FFR is done in the acute phase," Dr. Pieter Smits of Maasstad Hospital in Rotterdam, Netherlands, said, according to TCTMD.

Industry bigwigs have several announcements planned for session's main days. Medtronic plans to release lots of new information about its CoreValve TAVR and In.Pact drug-eluting balloon for peripheral artery disease (PAD). And the company just announced the preliminary results of the trial of its investigational Drug-Filled Stent.

Meanwhile Boston Scientific plans to provide update on its CE-marked (but not FDA-approved) Lotus TAVR and stroke fighting Watchman left atrial appendage device, while Abbott will present the latest data from its clinical trial to secure FDA approval for its CE-marked Absorb BVS bioresorbable stent.

- read Medtronic's conference preview | here's more on its Drug-filled Stent
- read Boston Scientific's conference preview