Mechanical and bioprosthetic aortic valve replacements were found to be equally safe and effective for patients aged 50 to 59 years, according to a study published Oct. 1 in JAMA. No difference was seen in stroke or long-term survival rates between the two replacement options.

According to Yuting P. Chiang, BA, of the Mount Sinai Medical Center in New York, and colleagues the current guidelines did not include the most recent research in the field. Some of the data backing the guidelines, they wrote, was nearly 40 years old, and innovations have changed aortic valve replacement surgery.

The research team retrospectively analyzed aortic valve implants performed from January 1997 to December 2004, with follow up as late as December of 2012.

In that time, the proportions of surgeries have changed. The number of bioprostheses implanted have dramatically increased over the last 15 years, going from around 15 percent of surgeries in 1997 to 74 percent by 2012.

Chiang et al found that the bioprosthesis group and the mechanical prosthesis group had a 15-year survival rate of 60.6 percent and 62.1 percent, respectively. Stroke rates over the 15 year span was similarly close: 7.7 percent with bioprosthetics vs. 8.6 percent for mechanical valves.

More patients in the bioprosthesis group experienced reoperation at 15 years, as 12.1 percent of bioprosthesis required aortic valve reoperation vs. 6.9 of mechanical implants.

On the other hand, more major bleeding occurred in mechanical prosthesis at 15 years with incident rates of 13 percent for mechanical valves and 6.6 percent for bioprosthesis.

In light of these findings, Chiang et al suggested that the recommendations could be extended beyond patients aged 60 to 69 years to include those in the 50 to 59 year range.

“The absence of a significant survival benefit associated with one prosthesis type over another focuses decision making on lifestyle considerations, including the burden of anticoagulation medication and monitoring, and the relative risks of major morbidity—primarily stroke, reoperation, and major bleeding events,” Chiang et al wrote.