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SAN FRANCISCO -- News reports claiming an increased stroke risk for patients with bioprosthetic aortic valves overstated the risk and triggered a near panic among patients implanted with the valves, according to lead author of the study, which was published in The New England Journal of Medicine.

Makkar, who spoke as part of a transcatheter aortic valve replacement (TAVR) panel at the Transcatheter Cardiovascular Therapeutics (TCT) meeting here, was especially critical of national news reports in the Wall Street Journal and by the Associated Press, which ignored the paper's cautious language describing "possible subclinical leaflet thrombosis" and trumpeted stroke risk. He said those news reports prompted a flurry of calls to physicians from worried patients.

Identifying himself as "a TAVR believer," Makkar, director of interventional cardiology and the cardiac catheterization laboratory at Cedars-Sinai Medical Center in Los Angeles, repeatedly said that the risk observed on imaging was seen with both TAVR and surgical aortic valve replacement (SAVR), a point that he said was also overlooked.

He summarized the key points of the NEJM study as:

• Although he and others thought the valve leaflet thickening observed on imaging might be an artifact, "we have confirmed that it is real and across all platforms." He said he thinks the cause may be related to leaflet thrombosis.
• That said, he added that there is "no conclusive evidence regarding the clinical significance of this finding. This requires longer and larger adequately powered studies."
• There is no reason for routine imaging in patients with bioprosthetic valves. But in patients with "elevated gradients, worsening heart failure, stroke/transient ischemic attack, myocardial infarction and other clinical situations concerning for embolic phenomenon, CT imaging should be performed to rule out leaflet thrombus."
• Warfarin eliminates the risk, but antiplatelet therapy does not. Nonetheless, since patients have an increased bleeding risk following TAVR and SAVR, routine anticoagulation "would not be recommended."

If the audience was concerned about leaflet thrombosis as potential roadblock for the expansion of TAVR, of Northwestern University Feinberg School of Medicine, who offered a non-interventional cardiologist's take on TAVR, put those worries to rest by proclaiming that "all of my patients are asking for this new less invasive procedure."

Bonow, a former American Heart Association president, said "guidelines will need to adapt to the rapidly-evolving TAVR evidence base." He noted that TAVR is already gaining acceptance as an alternative to SAVR in intermediate- and low-risk patients.

Other possible TAVR indications cited by Bonow included:

• Moderate aortic stenosis in primary cardiomyopathy
• Asymptomatic severe aortic stenosis and asymptomatic moderate aortic stenosis.

The evolution of TAVR technology, Bonow said, suggests the need for biomarkers to identify those asymptomatic patients.

Additional affirmation of the ascendancy of TAVR came from , of Columbia University Medical Center and a lead investigator for the pivotal PARTNER studies, which lead to FDA marketing approval of the Sapien valve.

Leon said roughly 71,000 TAVR procedures will be performed in 2015, and by 2025 the global market for TAVR will reach $5 billion, which would exceed the stent market.

As annoyed as Makkar was by the news coverage of the NEJM study, he was additionally frustrated when his presentation to a room of close to 200 attendees was cut off before he could present "what I really think."

TCT prides itself on bringing techno-wizardry to its gatherings, and this year that wizardry included settings on slide presentations that automatically cut off all presenters at the 5 minute mark -- and there was no changing that, even though Makkar insisted he had "received an email earlier today that said I had 10 minutes."

Perhaps signaling a cultural difference between interventional and medical cardiologists, Bonow used just five slides presented in just over 4 minutes to deliver his guideline message.

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