There is both good and news on transient ischaemic attacks (TIAs) from a more than six-decade long study: TIAs are indeed harbingers of strokes, but also the incidence of post-TIA strokes has been falling over the decades.
A TIA is defined as a passing episode of neurologic dysfunction due to the focal brain, spinal cord, or retinal ischaemia, without acute infarction or tissue injury. The results were derived from the Framingham Heart Study had 14 059 participants and ran for over six decades, allowing for a more-complete picture of strokes that happen after a TIA. Of the participants, 435 had a TIA; these were compared against a second group of 2175 participants who did not have a TIA.
Even after accounting for other risk factors such as hypertension or diabetes, people who had experienced a TIA had a 4.5 to five times greater chance of a stroke. Study lead author Vasileios-Arsenios Lioutas, MD, said that the results show a need for intensive follow-up of TIA : “According to our findings, people continue to have a high risk of stroke for a sustained time after they’ve had a TIA. Therefore, one shouldn’t think that the high-risk period is just in the first 90 days after the attack and then one can relax. It seems these patients should be followed closely over time, keeping in mind that they are at risk for stroke and paying close attention to controlling their cardiovascular risk factors.”
The 66 years of study data was broken into three epochs. One- and five-year risks of post-TIA stroke in the 2000-2017 epoch were 7.6% and 16.1%, compared to 23.9% and 35.5% during the earliest epoch, from 1948 to 1985.
Sudha Seshadri, MD, professor of neurology at The University of Texas Health Science Center at San Antonio, said: “We examined 66 years of follow-up from Framingham participants, which allowed us to study trends over time. We can see that starting in the very early years of the Framingham study, the 1950s, moving on to the most recent times, the risk of subsequent stroke went down a lot.”
Source: News-Medical.Net
Journal information: Lioutas, V-A., et al. (2021) Incidence of Transient Ischemic Attack and Association With Long-term Risk of Stroke. JAMA.doi.org/10.1001/jama.2020.25071.
