By Nancy Lapid
(Reuters) – Middle-aged adults who need an aortic valve replacement fare better with mechanical devices than with the valves made from animal tissues that they currently most often receive, U.S. researchers reported at the Society for Thoracic Surgery annual meeting in Los Angeles.
The researchers reviewed data on nearly 110,000 patients who underwent surgical replacement of aortic valves between the ages of 40 and 79. They found that in those aged 60 or younger, mechanical valves were independently associated with a lower risk of death from any cause over the next 12 years, compared with bioprosthetic devices from animals such as pigs or cows.
“The decision between a bioprosthetic and mechanical valve is one of the most consequential for patients requiring aortic valve replacement,” study leader Dr. Michael Bowdish of Cedars-Sinai Medical Center in Los Angeles said in a statement.
“Our research underscores that for patients with an age threshold of 60 years, mechanical valves confer a significant survival advantage. This data will help patients and providers make more informed choices about their care.”
Despite superior outcomes in younger populations, mechanical valve use decreased from 20% to 10% in the age group over the study’s 12-year period, the researchers also found.
Overall, only about 14% of the patients in the current study received mechanical valves. Implantation of mechanical valves also requires lifelong use of drugs to prevent blood clots.
“The favorable survival data demonstrated in the current study may provide a basis for a clinical reconsideration of these valves” in patients aged 60 or younger, the researchers wrote in a report published in the Journal of the American College of Cardiology.
Cannabis may slow young adults’ brain function
Cannabis use can adversely impact brain function in young adults, according to a new study that used imaging technology to track brain activity during cognitive tasks.
The study involved 1,003 volunteers ages 22 to 37, including 88 who reported more than 1,000 uses of the drug and were categorized as heavy users, 179 moderate users, and 736 nonusers.
During tasks testing working memory, 63% of heavy lifetime cannabis users exhibited reduced brain activity and cognitive performance, compared to what was observed in nonusers, according to a report published on Tuesday in JAMA Network Open.
Reduced working memory performance was also seen in recent cannabis users, the researchers said.
Working memory involves using recently-acquired information to follow instructions or to mentally visualize and manipulate information, like solving a math problem.
Heavy cannabis use also appeared to reduce activity in regions of the brain that are involved in decision-making, memory, attention and emotional processing.
Abstaining from using cannabis before doing a cognitive task could help to improve performance, the researchers suggested, although heavy users may need to be more cautious because stopping cold turkey could disrupt their cognition as well.
“There are a lot of questions we still need answers to regarding how cannabis impacts the brain,” study leader Joshua Gowin of University of Colorado Anschutz Medical Campus said in a statement.
“Large, long-term studies are needed next to understand whether cannabis use directly changes brain function, how long these effects last and the impact on different age groups.”
(This is an excerpt of the Health Rounds newsletter, where we present latest medical studies on Tuesdays and Thursdays.)
(Reporting by Nancy Lapid; editing by Bill Berkrot)