Fears that physicians may be treating patients who are suitable candidates for standard care with less invasive transcatheter aortic valve replacement (TAVR) may be allayed, based on results presented April 28 at the American Association of Thoracic Surgery meeting in Toronto.

The FDA has approved two TAVR devices as a therapy in the U.S. for inoperable or extremely high risk patients with severe aortic stenosis. It also gave the green light to Edwards Lifesciences for the use of its Sapien valve in high-risk patients.

Researchers evaluating Medtronic's CoreValve TAVR system presented positive results on March 29 for its use in high-risk patients at the American College of Cardiology’s scientific session in Washington D.C. In the U.S., CoreValve is approved for extremely high-risk patients but is investigational only in high-risk patients.

There are concerns that the lines between risk groups may become blurred as TAVR use increases, with physicians treating moderate-risk patients who qualify for surgical aortic valve replacement (SAVR) with TAVR instead. To assess whether risk creep may be occurring, Donald D. Glower, MD, a heart surgeon at Duke University Health System in Durham, N.C., and colleagues analyzed data at their institution from its initiation of a TAVR program.

They looked at patient characteristics, annual volume, operative details and mortality in patients undergoing TAVR and SAVR or SAVR plus CABG from 2006 to 2013. The time frame included three study periods: pre-TAVR (January 2006 through June 2009); transition (July 2009 through March 2011) and TAVR (April 2011 through June 2013).  

They identified 1,308 SAVR patients for the analysis. Median age increased between the pre-TAVR and TAVR periods, from 69 years to 74 years, and redo sternotomy increased from 14.7 percent to 21.1 percent. Comorbidities such as chronic obstructive pulmonary disease, unstable angina and New York Heart Association class IV heart failure decreased. SAVR case volume increased from 131 cases to 256 cases between periods.

Preoperative mortality risk for SAVR patients based on euroSCORE increased from 9.8 percent to 12.1 percent and the Society of Thoracic Surgeons predicted risk score and 30-day mortality remained stable from the pre-TAVR to the TAVR periods.

The findings suggested that introducing TAVR did not precipitate risk creep, they concluded, but they recommended research be continued as TAVR availability expands in the U.S.