ARRS: MDCT trumps echo in picking TAVI valve size

Multidetector CT (MDCT) is superior to 2D echocardiography in measuring annular size in patients with aortic stenosis who are candidates for transcatheter aortic valve implantation (TAVI), according to a study abstract in the electronic exhibit program at the American Roentgen Ray Society Annual (ARRS) annual meeting in Washington, D.C.

“Measurement of the aortic annulus is crucial for implant size selection and procedure success,” Vineeta Sethi, MD, of the University of Ottawa, said in a release. “If the implanted valve is too small, blood will leak outside of the valve apparatus back into the heart.”

Sethi and colleagues studied 69 patients who underwent an MDCT and transthoracic and transesophageal echocardiography before having a TAVI, which is used to treat severe aortic stenosis in patients not eligible for surgery.

Results showed MDCT measurements were significantly different from echocardiography, with valve size decisions altered in about 55 percent of patients if MDCT had been used instead of echocardiography, according to Sethi. “This includes patients who were wrongly sized as well as those who would have been disqualified from having TAVI due to the large size of their aortic annulus,” said Sethi.

Echocardiography-derived measurements are the current standard, though Sethi noted that increasing awareness is pushing more people to use MDCT to pick appropriate valve size.