麻豆传媒

Transcatheter aortic valve implantation (TAVI) has been incorporated into the updated valvular heart disease guidelines from the American Heart Association and American College of Cardiology.

Surgical valve replacement remains the recommended treatment option for patients with severe aortic stenosis and a low or intermediate surgical risk, but TAVI is recommended for patients who are not candidates for surgery and would be expected to survive longer than a year after an intervention.

For patients who have an indication for aortic valve replacement and a high surgical risk, TAVI is tagged as a reasonable alternative to surgery in the guidance, which was written by a group co-chaired by , of the Mayo Clinic in Rochester, Minn., and , of the University of Washington in Seattle.

TAVI is not recommended, however, in patients with a comorbidity burden that would cancel out any expected benefit from correcting the stenosis.

The recommendations -- the first on the management on aortic stenosis, mitral regurgitation, and other adult valvular heart diseases from the AHA/ACC since a focused update released in 2008 -- will be published in and the .

One of the new additions is a four-category disease classification system that goes from "at risk" to "progressive" to "asymptomatic severe" to "symptomatic severe." It takes into account the severity of the valve disease, symptoms, ventricular responses to the volume or pressure overload caused by the disease, effects on the pulmonary or systemic circulation, and changes in heart rhythm.

The new guidelines also include a risk assessment tool that should be used for all patients being considered for intervention, according to the authors. Included in the assessment are procedure-specific impediments, major organ system dysfunction, frailty, and the Society of Thoracic Surgeons predicted risk of mortality model.

In addition, the updated recommendations lower the bar for when some patients should undergo an intervention -- in some cases, even before symptoms develop.

Aortic valve replacement, for example, is recommended for asymptomatic patients with severe aortic stenosis and a left ventricular ejection fraction below 50% and is considered reasonable in asymptomatic patients with very severe aortic stenosis and a low surgical risk.

"As the risks of surgical and percutaneous intervention have gone down we've been able to shift the timing of intervention a little bit earlier," one of the members of the writing group, , of the Cleveland Clinic, told 麻豆传媒.

A multidisciplinary approach to treating patients came into focus in the new guidance with recommendations surrounding the use of a Heart Valve Team for those with severe disease who are being considered for intervention and the use of Heart Valve Centers of Excellence -- either through consultation or referral -- when discussing treatment options.

Thomas pointed out that the new document was somewhat experimental in design in that it took on the form of various modules designed to ease future updates and incorporation into computer software.

"While it was quite a process to go through this the first time, now as new information comes on the scene we should be able to update these guidelines going forward without having to rewrite all the guidelines, but just update ones that have new evidence to be brought to bear," he said.

The guideline was developed in collaboration with five other groups: the American Association for Thoracic Surgery, the American Society of Echocardiography, the Society for Cardiovascular Angiography and Interventions, the Society of Cardiovascular Anesthesiologists, and the Society of Thoracic Surgeons.

From the American Heart Association:

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