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SAN FRANCISCO -- The release of data last week showing reduced leaflet mobility in as many as 40% of bioprosthetic aortic valves, apparently due to subclinical thrombosis, doesn't mean a return to the woes around drug-eluting stents in the mid-2000s.
That was the message from a panel of interventional and surgical cardiologists at a hastily-convened for the press here at the Transcatheter Cardiovascular Therapeutics meeting, emphasizing that the need for further research instead of anticoagulation.
"This is not late stent thrombosis," said panelist , director of interventional cardiology at Beth Israel Deaconess Medical Center in Boston. "Late stent thrombosis was a clinical presentation, blood clot on the stent that was associated with myocardial infarction. This is not. This is an imaging observation of uncertain clinical significance at this point."
, director of the Cardiovascular Interventional Center at Cedars-Sinai Medical Center in Los Angeles and lead author on the imaging findings and their correlation with subtherapeutic or no warfarin (Coumadin) use, had the same message at a session earlier in the meeting and doubled down on it at the press conference.
"We should not make a leap from this imaging finding and make the conclusion that everyone getting transcatheter aortic valves should be on blood-thinning medications, which have a risk in themselves," he told reporters.
"Neither are we recommending systematic CT scanning on all patients," Makkar added in an interview with ľֱ. "We should not react; we need to study this phenomenon further."
However, he and several panelists did suggest implications for valve improvements, hearkening back to the design revisions sparked by the finding of with DES.
Makkar noted that while the study was really too small for confidence in comparing surgical and transcatheter aortic valves, there did appear to be associations with low ejection fraction and low gradients, as well as lower implantation of the device in the valve.
"There may be technical reasons also in addition to how the valves are deployed," he said.
Seeing reduced leaflet mobility could be an early window onto degeneration and an opportunity to "improve on what are already excellent clinical outcomes," said panelist , chair of radiology at Providence Health Care in Vancouver.
Meanwhile, the imaging findings were associated with very few events, of which most were transient ischemic events and thus hard to adjudicate, noted , director of the Heart Valve Program at New York-Presbyterian/Columbia University Medical Center in New York City.
Reduced leaflet mobility was also seen with surgically-implanted valves, which have been used for 30 years, Makkar noted. "That allows us to somewhat extrapolate that I think we're okay."
Nor has there been any signal of late stroke risk in the TAVR trials, whereas bleeding events nearly triples mortality risk, Kodali added.
Guidelines do not recommend anticoagulation after TAVR but do recommend antiplatelet drugs, which did not appear protective against leaflet issues on CT imaging in the study.
As to why this is showing up now, Leipsic said that "we never looked routinely" and "the cameras have simply gotten better for lack of a better term. We are able to investigate things we couldn't see before ... It was previously occult and now Pandora's box is open."