First-time TIA patients and ischemic stroke patients face similar long-term MI rate, reveals study

A new study found that first-time transient ischemic attack (TIA) individuals had 5-year myocardial infarction rates as same as the ischemic stroke patients and the general population. The findings were published in the recent issue of Stroke journal.

In individuals who have experienced a transient ischemic attack or an ischemic stroke, recurrent cerebral and cardiovascular events can have serious repercussions and are often identified as the primary cause of mortality and persistent disability. The long-term risk of MI after TIA is largely unclear, despite the increasing focus on the cardiovascular consequence of acute myocardial infarction.

Estimates of the yearly risk of MI after TIA and stroke varied significantly in previous publications, ranging from 1.0% to 6.5%. Over the past 20 years, the long-term risk of all-cause death has varied between 10% and 42%. This research compared the long-term risk of MI and all-cause mortality in patients who have experienced a first-time TIA to the general population and patients who have experienced a first-time ischemic stroke.

First-time TIA patients were found in the Danish Stroke Registry (2013-2020) and matched 1:1 with patients who had their first ischemic stroke and 1:1 with the general population based on age, sex, and calendar year. The Aalen-Johansen and Kaplan-Meier estimators were used to calculate the 5-year risks of MI and all-cause death. Cox regression was used to compare the groups while accounting for cardiovascular comorbidities.

The study found 21,743 ischemic stroke patients, 86,972 matched members of the general community, and 21,743 matched control patients. 52% of the population were male, and the median age was 70 (25th to 75th percentile, 60-78). The comorbidity load was highest in ischemic stroke patients, moderate in TIA patients, and lowest in general population controls.

The 5-year risk of MI was 2.2% in the population with ischemic stroke, 1.5% in the general population, and 2.0% in patients with TIA. The patients with TIA had a 17.0% 5-year risk of death, whereas the general population had a 14.0% risk and the patients who had an ischemic stroke had a 27.0% risk. Overall, individuals who had first-time TIA had a low 5-year incidence of MI, which was no different from the general population or patients with first-time ischemic stroke.

Reference:

Safi, H., Kristensen, S. L., Sørensen, R., Kruuse, C., Johnsen, S. P., Gislason, G., Torp-Pedersen, C., Køber, L., Fosbøl, E. L., & Vinding, N. E. (2024). Long-Term Risk of Acute Myocardial Infarction in Patients With a Transient Ischemic Attack: A Danish Nationwide Cohort Study. In Stroke. Ovid Technologies (Wolters Kluwer Health). https://doi.org/10.1161/strokeaha.123.045605