ACC: With TAVI, how low risk can you go?

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Sapien transcatheter aortic valve
Image source: Edwards Lifesciences

NEW ORLEANS— Outcomes of transcatheter aortic valve implantation (TAVI) when compared with the gold standard of aortic valve replacement are similar, and TAVI is now being called the new standard of care for high-risk patients who are ineligible for surgery, even though these percutaneous devices are not yet FDA-approved, according to data from the PARTNER trial presented today during the late-breaking clinical trials at the American College of Cardiology (ACC) annual meeting.

While aortic stenosis affects almost 9 percent of the population over the age of 65, without valve replacement, half of these patients die within two years. However, what if the patient cannot tolerate surgery?

Craig R. Smith, MD, co-principal investigator of the study and chief of the division of cardiothoracic surgery at New York-Presbyterian Hospital/Columbia University Medical Center in New York City, and colleagues have shown that in high-risk patients who are inoperable, TAVI improves one-year survival compared with the gold standard of treatment, 50 percent vs. 70 percent, respectively (in cohort B).

During the trial, these high risk patients were randomized to receive either TAVI (349 patients) or aortic valve replacement (350 patients). Patients had a median age of 84.1.

In addition to being linked to a 20 percent survival benefit at one-year, TAVI patients also saw significant improvements in symptoms and quality of life. Patients who underwent TAVI procedures also saw reduction in hospitalizations for aortic stenosis at one-year, 22 percent vs. 44 percent.

“Comparing TAVI to the gold standard surgical procedure AVR [aortic valve replacement], TAVI in its current state of evolution, is statistically noninferior to the gold standard in a high-risk population,” Smith said.

However, despite these promising results, TAVI devices are not yet approved in the FDA and only are available in Europe.

“No one wants surgery and no one should want surgery,” Smith said. These data show that TAVI is now the standard of care for these inoperable patients. “This opens up a new set of patients who will benefit as much by TAVI.”

Smith reported that 30-day all-cause death rates were 3.4 percent vs. 6.5 percent for TAVI and the standard care approach and these rates were similar at one year.

However, the researchers did find that TAVI was associated with complications including stroke and major vascular complications. Stroke and TIA were significantly more frequent in TAVI than the surgical control group.” These rates at one year were 5.1 percent in TAVI patients and 2.4 percent for those who underwent surgery.

Major vascular injuries were also more frequent in TAVI and were 11 percent in the TAVI group compared with 3.2 percent in the surgical arm at 30 days. Smith offered that these higher rates will likely improve as smaller devices develop and the procedure gains traction and clinicians gain experience.

Incidence of major bleeding was significantly lower in the in the TAVI arm compared with the standard of care arm at 30 days, 9.3 percent vs. 19.5 percent.

“You are all witnessing history in the making,” said panelist David J. Moliterno, MD, a professor of Medicine at the University of Kentucky. “We have seen a change already from PARTNER [Cohort] B to PARTNER [Cohort] A in terms of stroke and mortality.” In fact, he estimated that rates of stroke have decreased by almost 35 percent and mortality by almost 21 percent. “This was with the same generation of device,” said Moliterno. “What more can we expect or hope for with the second generation of device?”

While Moliterno advised that para-valvular leaks, major vascular events and embolization still need to be considered for evaluation, PARTNER II, approved by the FDA in February, will compare the next-generation smaller device with the current device and also study TAVI in a lower risk population.

Whether TAVI will become the preferred method of treatment for aortic stenosis patients and whether the procedure can be expanded to lower risk patient populations remain unanswered, however, further cost and clinical data will help answer these important questions.