Global study led by UCalgary researchers establishes long-term risk of stroke

University of Calgary researchers say if you’ve had a minor stroke or transient ischemic attack (TIA), you remain at high risk of having another, more severe stroke for several years thereafter.

A lot of focus has been put on preventing stroke in the first 90-days post-TIA or minor stroke, which is when a person is at the highest risk of a second stroke. However, what we’re seeing in this study is that the risk continues and remains high for at least the next decade,” says Dr. Faizan Khan, PhD, postdoctoral fellow at the Cumming School of Medicine (CSM) and lead author of the study. What’s really important from these findings is that people need to stay vigilant. Attention to and treatment of stroke risk factors, such as high blood pressure, is essential not just when people are released from hospital, but for their lifetime.”

The study was a global collaboration led by researchers at the Hotchkiss Brain Institute at the CSM. Anonymized data on 171,068 patients who experienced a minor stroke or TIA were analyzed from hospital- or community-based studies conducted across four continents spanning 20 countries. Khan says the findings are relevant to everyone no matter where they live in the world.

The findings published in JAMA show that risks of a subsequent stroke are 5.9 percent in the first year, 12.8 percent within five years, and 19.8 percent within 10 years.

I know that adherence to medical recommendations can wane over time. People start to feel better, and the more time that passes after the first stroke, they might reconsider whether the medication and lifestyle changes are necessary,” says Dr. Michael Hill, MD, neurologist, professor at the CSM and principal investigator on the study. I hope this study serves as a bit of a wake-up call. If you know your risk is one in five of having another stroke over 10 years, and 10 percent of those cases are fatal you may be more likely to continue the medications and lifestyle changes.”

Along with awareness for people who have a stroke, there is also a take-away for healthcare providers,” says Khan. “Many people who experience a minor stroke or TIA see a neurologist in the hospital, and maybe once again in the first few months, but then care transfers to the community and their family doctor. Our findings should prompt healthcare providers to be mindful of the persistently high risk of a future stroke, and to consider ongoing monitoring and risk reduction strategies beyond the initial high-risk period.”

The researchers hope the findings provide a benchmark to improve efforts on long term prevention care, and additional research on long term prevention strategies.