Long-term survival in older critically ill patients with acute ischemic stroke

Abstract

Objectives: To compare survival in older patients with acute ischemic stroke admitted to intensive care units (ICUs) with those not requiring ICU care and to assess the impact of mechanical ventilation (MV) and percutaneous gastrostomy tubes (PEG) on long-term mortality.

Design: Multicentered retrospective cohort study.

Setting: Administrative data from the Centers for Medicare and Medicaid Services covering 93 metropolitan counties primarily in the eastern half of the United States.

Patients: 31,301 patients discharged with acute ischemic stroke in 2000.

Interventions: None.

Measurements and main results: Mortality from the time of index hospitalization up to the end of the follow-up period of 12 months. Information was also gathered on use of mechanical ventilation, percutaneous gastrostomy, sociodemographic variables and a host of comorbid conditions. Of all patients with acute ischemic stroke, 26% required ICU admission. The crude death rate for ICU stroke patients was 21% at 30 days and 40% at 1-yr follow-up. At 30 days, after adjustment of sociodemographic variables and comorbidities, ICU patients had a 29% higher mortality hazard compared with non-ICU patients. MV was associated with a five-fold higher mortality hazard (hazard ratio 5.59, confidence interval [CI] 4.93-6.34). The use of PEG was not associated with mortality at 30 days. By contrast, at 1-yr follow up in 30-day survivors, ICU admission was not associated with mortality hazard (hazard ratio 1.01, 95% CI 0.93-1.09). MV still had a higher risk of death (hazard ratio 1.88, 95% CI 1.57-2.25), and PEG patients had a 2.59-fold greater mortality hazard (95% CI 2.38-2.82).

Conclusions: Both short-term and long-term mortality in older patients with acute ischemic stroke admitted to ICUs is lower than previously reported. The need for MV and PEG are markers for poor long-term outcome. Future research should focus on the identification of clinical factors that lead to increased mortality in long-term survivors and efforts to reduce those risks.

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