Presentation (CTI)

OBJECTIVES: To assess the incidence of recurrent ischemic stroke (IS) and associated mortality rates among Medicare beneficiaries with non-cardioembolic ischemic stroke (NCIS) or transient ischemic attack (TIA).
METHODS: Adults ≥65 years of age with a primary diagnosis of NCIS or TIA during an inpatient stay or emergency room visit, and without prior history of stroke, were identified from Medicare fee-for-service data (January 2007-September 2024). Incidence rates of the index NCIS/TIA and each recurrent IS following the previous stroke were estimated within the population at risk, as were all-cause mortality rates following the index and each recurrent stroke. Kaplan-Meier analysis was used to estimate incidence and mortality at landmark time points.
RESULTS: A total of 1,291,897 patients with NCIS/TIA were included (mean ± standard deviation [SD] age 77.8 ± 8.0 years; 56.3% females), with 62.0% having NCIS and 38.0% having TIA at index. Incidence rates of index NCIS/TIA and second, third, fourth, and fifth IS were 0.3, 3.0, 6.7, 10.0, and 13.6 per 100 person-years (PYs), respectively. Rates of second stroke at 30 days, 90 days, 1 year, and 5 years were 2.6%, 3.8%, 6.1%, and 13.9%; third: 4.2%, 6.7%, 12.0%, and 25.6%; fourth: 5.0%, 8.5%, 16.6%, and 33.8%; fifth: 5.8%, 10.4%, 20.4%, and 40.0%. The 1-year all-cause mortality rate was 15.0% following the index NCIS/TIA, 27.4% following the second stroke, 32.8% following the third, 36.8% following the fourth, and 36.5% following the fifth. Compared with patients with TIA, those with NCIS had higher rates of second stroke (NCIS: 3.9 per 100 PYs; TIA: 2.0 per 100 PYs) and higher 1-year mortality following the index event (19.8% vs 7.2%); however, rates were similar for subsequent recurrent strokes.
CONCLUSIONS: The risk of recurrent IS and associated mortality increases progressively with each subsequent event, highlighting the need for effective secondary stroke prevention strategies.