Transient ischemic attack doubled risk for MI

**Burns J. Stroke. 2011;doi:10.1161/STROKEAHA.110.593723.**

Issue: May 2011

Those who experience a transient ischemic attack have twice the annual incidence of MI compared with the general population. This risk proved to be especially high in those who were younger than 60 years of age, new data suggest.

“CAD is the leading cause of death after TIA,” the researchers wrote. “Despite the key role played by CAD … reliable estimates of the risk of MI after TIA and the excess risk of MI in those who have had a TIA compared with the general population are lacking.”

This led the group of researchers from the Mayo Clinic in Rochester, Minn., to cross-reference pre-existing incidence cohorts from the Rochester Epidemiology Project for TIA and MI. The final study population included 388 patients who were at risk for incident MI after TIA. These data were then compared with MI incidences in the general population.

During a median follow-up of 10.2 years, the mean annual occurrence of MI after TIA was 0.95%, with an RR compared with the general population of 2.09 (95% CI, 1.52-2.81). This risk proved to be highest among patients aged younger than 60 years (RR=15.1; 95% CI, 4.11-38.6). For those who had an MI after TIA, the risk for death was more than three times higher than those who did not have an MI after TIA (HR=3.19; 95% CI, 2.19-4.66).

Additionally, researchers reported the following independent risk factors for MI after TIA: use of lipid-lowering therapy at the time of TIA (HR=3.1; 95% CI, 1.2-8); male sex (HR=2.19; 95% CI, 1.18-4.06); and increasing age (per 10 years, HR=1.51; 95% CI, 1.14 -2.01).

“Given that CAD plays an important role in the mortality of patients after TIA, these data support the existing concept that careful attention to the primary prevention of CAD is warranted in all patients who have had TIA and that screening for asymptomatic CAD may be useful in select TIA patients,” the researchers concluded.

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