‘Silent’ strokes common after non-cardiac surgery

“Silent” strokes are more common than overt strokes in older patients undergoing elective non-cardiac surgery, investigators with the NeuroVISION study have found.

Co-principal investigator and professor Marko Mrkobrada, MD, and colleagues followed 1,114 patients aged 65 years or older for one year after they received surgery for a non-cardiac indication. NeuroVISION participants, who were enrolled from 12 centers across North and South America, Asia, New Zealand and Europe, all underwent an MRI within nine days of their surgery to look for imaging evidence of silent stroke, and Mrkobrada’s team tracked them for 12 months to assess their cognitive capabilities.

“Over the last century, surgery has greatly improved the health and the quality of life of patients around the world,” Mrkobrada said in a release. “Surgeons are now able to operate on older and sicker patients thanks to improvements in surgical and anesthetic techniques. Despite the benefits of surgery, we also need to understand the risks.”

Covert strokes are only really obvious on brain scans, like MRIs, the authors said in The Lancet, where their findings were published August 15. They found one in 14 people in their study had a silent stroke after surgery, representing as many as three million cases per year in over-65s.

The team also reported patients who had a silent stroke post-op were more likely to experience cognitive decline, perioperative delirium, overt stroke or transient ischemic attack within a year compared to their counterparts who didn’t show evidence of a stroke. 

“Vascular brain injuries, both overt and covert, are more frequently being detected, recognized and prevented through research funded by our Institute and CIHR,” Brian Rowe, scientific director of the Institute of Circulatory and Respiratory Health at the Canadian Institutes of Health Research (CIHR), said in the release. “The NeuroVISION study provides important insights into the development of vascular brain injury after surgery and adds to the mounting evidence of the importance of vascular health on cognitive decline.”