WASHINGTON, D.C.—Large disparities are found between the prevalence of aortic stenosis and the treatment of the disease, which needs to become more aggressive. Aortic valve replacement procedures may serve this purpose best, said Raj R. Makkar, MD, of Cedars-Sinai Medical Center, Los Angeles, during a presentation Sept. 22 at the Transcatheter Cardiovascular Therapeutics (TCT) annual meeting.
Currently, in the U.S. an estimated 3.5 million patients are diagnosed with aortic stenosis, but only about 60,000 undergo aortic valve replacement (AVR).
Heart failure patients with an onset of aortic stenosis symptoms survive three years, while those with angina and aortic stenosis symptoms survive five. “Are we undertreating aortic stenosis and should we be more aggressive?” Makkar asked.
In a previous clinical trial conducted at Loma Linda Medical Center in Southern California, researchers evaluated the contemporary management of aortic stenosis in 740 patients. Makkar noted that two out of three of the patients evaluated did not undergo AVR. Additionally, the one-, five- and 10-year survival rates were 62, 32 and 18 percent, respectively, which Makkar called “dismal."
“If you look at patients who underwent no AVR compared to those who underwent AVR, there was clearly a big difference in terms of survival,” he said. “AVR helps, even in asymptomatic aortic stenosis.”
Multiple trials have found that patients who undergo AVR compared to no AVR see better outcomes. “If you look at a number of previously published studies, you will see that anywhere from one-half to one-third of patients do not get treated with AVR, so there is opportunity here,” he said.
One reason patients don't have surgery is because of the invasive nature of the procedure. Makkar noted that only 25 percent of patients who could benefit from AVR actually receive it.
Additionally, he said that physicians do not use aortic valvuloplasty because the procedure does not exhibit good long-term outcomes. Balloons are not very effective against aortic calcium. Studies have shown high recurrence rates, with survival rates comparable to controls.
“It is only AVR that makes a difference in survival,” he said.
Transcatheter aortic valve technologies such as the Edwards Lifesciences Sapian valve and the Medtronic CoreValve, which are approved in Europe but not the U.S,, have made headway in the treatment of aortic stenosis.
In fact, at the TCT meeting, researchers reported successful results from the PARTNER trial and called for transcatheter aortic valve implantation (TAVI) to be standard of care for older patients who cannot undergo surgery.
The PARTNER II trial will enroll lower-risk patients and evaluate a smaller version of the Sapien valve. y. Additionally, an investigational device exemption from the FDA for the CoreValve device is on the horizon, Makker said.