A comprehensive meta-analysis found that patients who experienced a transient ischemic attack or minor stroke faced a persistently elevated long-term risk of subsequent stroke that continued well beyond the first year following the index event.

In the systematic review and meta-analysis, published in JAMA, the PERSIST (Prognosis After Transient Ischemic Attack or Minor Stroke) collaborators analyzed data from 38 studies involving 171,068 patients (median age = 69 years). The analysis revealed a 10-year cumulative incidence of stroke of 19.8%, with half of subsequent strokes occurring following the first year.

“Patients who have had a transient ischemic attack (TIA) or minor stroke are at a persistently high risk of subsequent stroke. Findings from this study underscore the need for improving long-term stroke prevention measures in this patient group,” the study authors wrote.

The pooled analysis showed an annual stroke rate of 5.94 events per 100 person-years in the first year, decreasing to 1.80 events in years 2 to 5, and remaining relatively stable at 1.72 events in years 6 to 10. The 5-year cumulative incidence of stroke was 12.5%.

In the first year, 61.7% of recurrent strokes occurred within the initial 90 days. The pooled stroke rate during this early high-risk period was 16.09 events per 100 person-years, declining to 3.04 events between days 91 to 365.

Stroke type analyses showed 10-year cumulative incidences of 17.8% for ischemic stroke, 2.8% for hemorrhagic stroke, and 3.2% for fatal stroke. The case-fatality rate for subsequent stroke was 10.4%.

Several secondary outcomes were also assessed. Among patients without recurrent stroke, the 10-year cumulative incidence of disability—defined as a modified Rankin Scale score greater than 1—was 42.6%. The cumulative 10-year incidence of myocardial infarction was 5.9%, and all-cause mortality was 35.1%.

Subgroup analyses revealed higher stroke rates in North American and Asian studies compared with in European studies. Higher rates were also observed in cohorts recruited in or after 2007—which accounted for 27 of the 38 included studies—suggesting improved diagnostic precision and more active surveillance in recent years.

The investigators noted that their meta-analysis differed from traditional approaches by using unpublished aggregate-level data from study investigators. This method enabled the standardization of follow-up durations and accurate calculation of person-time at risk across discrete intervals, allowing for more precise estimation of changes in stroke risk over time.

While modern secondary prevention strategies have been effective in reducing short-term stroke risk, the study findings indicated that stroke risk may continue beyond the initial high-risk period. As noted by the investigators, many secondary prevention clinics monitor patients only during the first 90 days, with long-term care often transitioning to primary care physicians. The continued incidence of stroke beyond the first year supported the need for risk reduction efforts over a longer time frame.

Disclosures can be found in the study.