Twenty-Year Time Trends in Long-Term Case-Fatality and Recurrence Rates After Ischemic Stroke Stratified by Etiology

Background and purpose: Data on long-term survival and recurrence after stroke are lacking. We investigated time trends in ischemic stroke case-fatality and recurrence rates over 20-years stratified by etiological subtype according to the Trial of ORG 10172 in Acute Stroke Treatment classification within a population-based stroke register in Germany.

Methods: Data was collected within the Erlangen Stroke Project, a prospective, population-based stroke register covering a source population of 105 164 inhabitants (2010). Case fatality and recurrence rates for 3 months, 1 year, and 5 years were estimated with Kaplan-Meier estimates. Sex-specific time trends for case-fatality and recurrence rates were estimated with Cox regression. We adjusted for age, sex, and year of event and stratified for etiological subtypes. A sensitivity analysis with competing risk analysis for time trends in recurrence were performed.

Results: Between 1996 and 2015, 3346 patients with first ischemic stroke were included; age-standardized incidence per 100 000 was 75.8 in women and 131.6 in men (2015). Overall, 5-year survival probabilities were 50.4% (95% CI, 47.9-53.1) in women and 59.2% (95% CI, 56.4-62.0) in men; 5-year survival was highest in patients with first stroke due to small-artery occlusion (women, 71.8% [95% CI, 67.1-76.9]; men, 75.9% [95% CI, 71.3-80.9]) and lowest in cardioembolic stroke (women, 35.7% [95% CI, 31.0-41.1]; men, 47.8% [95% CI, 42.2-54.3]). Five-year recurrence rates were 20.1% (95% CI, 17.5-22.6) in women and 20.1% (95% CI, 17.5-22.7) in men; 5-year recurrence rate was lowest in women in stroke due to small artery occlusion 16.0% (95% CI, 11.7-20.1) and in men in large-artery atherosclerosis 16.6% (95% CI, 8.7-23.9); highest risk of recurrence was observed in undefined strokes (women, 22.3% [95% CI, 17.8-26.6]; men, 21.4% [95% CI, 16.7-25.9]). Cox regression revealed improvements in case-fatality rates over time with differences in stroke causes. No time trends in recurrence rates were observed.

Conclusions: Long-term survival and recurrence varied substantially by first stroke cause. Survival probabilities improved over the past 2 decades; no major trends in stroke recurrence rates were observed.