Five-year readmission and mortality differ by ischemic stroke subtype.

Background: Ischemic stroke subtype may influence the risk of readmission and mortality after ischemic stroke (IS) and transient ischemic attack (TIA) due to differences in comorbidity, risk factors, and stroke severity. We aimed to study the five-year incidence and risk of all-cause readmission, cause-specific readmission and mortality after IS or TIA by stroke subtype.

Methods: The medical records of 1453 patients admitted with IS or TIA to the stroke unit at Haukeland University Hospital, Norway, between 2007 and 2012 were reviewed for identification of unplanned readmissions within five years after discharge. Stroke etiology was classified as large-artery atherosclerosis (LAA), cardioembolism (CE), small vessel occlusion (SVO), stroke of other determined etiology (SOE), multiple etiologies (ME), or cryptogenic stroke (CS). Kaplan-Meier estimates and Cox regression analyses were used to determine incidences and risk of readmission and death.

Results: The five-year incidence of all-cause readmission was 72.6% (74% LAA, 81% CE, 65% SVO, 55% SOE, 71% ME, and 67% CS), with infections, cardiac disease, stroke-related events and fractures as the most frequent causes. Compared to patients with other subtypes, SVO subtype had a 21% lower risk of all-cause readmission and a 48% lower risk of death, whereas CE had a 25% higher risk of all cause readmission and a 34% higher risk of death. CE subtype also had a 75% higher risk of readmission due to cardiac disease, whereas CS subtype had a 44% lower risk of readmission with cardiac disease.

Conclusions: The five-year incidence of readmission and mortality varied among the stroke subtypes. The risk of readmission and death are especially high in patients with CE subtype, and lowest for patients with SVO subtype.