Hospital Outcomes of Acute Ischemic Stroke in Lymphoma Patients During 2015-2022

Background and Objectives Lymphoma may predispose individuals to stroke through mechanisms including hypercoagulability, direct vascular invasion, endothelial dysfunction, and treatment‐related myelosuppression (Ong et al., 2021; Mishra et al., 2021). Despite the growing recognition of cancer‐related stroke, patients with hematologic malignancies are often excluded from large AIS clinical trials (PMID: 30337902). Our retrospective cohort study analyzes a large, nationally representative sample of AIS hospitalizations to compare outcomes in patients with and without lymphoma. Methods A retrospective cross‐sectional study was conducted using data from the National Inpatient Sample database between October 1st, 2015 and December 31st, 2022. This nationally representative sample included patients ≥ 18 years‐old in the United States, hospitalized primarily with AIS and an existing diagnosis of lymphoma. Outcomes included odds of inpatient mortality, routine discharge, complications, comorbidities, treatment modalities, and the safety/efficacy of reperfusion therapy. Propensity score‐based inverse probability of treatment weighting (IPTW) adjusted for confounding factors. Multivariable logistic regression was used to estimate adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for all outcomes. Results A total of 3,831,909 primary AIS hospitalizations were identified between 2015 and 2022. Overall, lymphoma was recorded in 12,160 (0.3%) hospitalizations. Patients with lymphoma and AIS were significantly older on average (74.02 ± 11.90 years vs. 69.98 ± 13.85 years, p<0.001), had longer LOS (5.80 ± 6.59 days vs. 5.18 ± 7.08 days, p<0.001), higher Elixhauser Comorbidity Index (5.57 ± 2.09 vs. 4.20 ± 2.02, p<0.001), and equivalent NIHSS scores (6.89 ± 7.44 vs. 6.61 ± 7.25, p=0.225). Patients with lymphoma treated with EVT exhibited nearly five‐fold increased risk of hemorrhagic transformation (4.84 [3.76‐6.23], p<0.001), but equivalent odds of routine discharge (0.814 [0.637‐1.04], p=0.099) and inpatient mortality (1.03 [0.705‐1.51], p=0.872). Patients with lymphoma and stroke who received IVT displayed more than three‐fold increased risk of hemorrhagic transformation (3.52 [2.89‐4.29], p<0.001), equivalent odds of inpatient mortality (1.08 [0.828‐1.40], p=0.579), and increased likelihood of routine discharge (1.39 [1.21‐1.60], p<0.001). Conclusion Using the NIS, 3,831,909 primary AIS hospitalizations were identified, and 12,160 of those had comorbid lymphoma. Patients with lymphoma were 39.8% and 30% less likely to be treated with EVT and IVT, respectively. Patients with lymphoma and AIS had nearly a five‐fold and greater than three‐fold increased risk of hemorrhagic transformation after EVT and IVT respectively. This elevated hemorrhagic risk after reperfusion therapy did not translate to any meaningful differences in inpatient mortality or rate of routine discharge. Future research can be done to optimize reperfusion practices and further mitigate risks, especially hemorrhagic, in this vulnerable population.