Occurrence and Outcomes of Acute Cerebrovascular Events in Patients with Non-Hodgkin Lymphoma
Authors: Ostos Catherine , Velez Quinones Virginia , Menchaca Kristina , Jones Can , Duchow Mariel , Isaac Shaun , Hardigan Patrick 
Published: December 2023

Background
Stroke or Cerebrovascular Accident (CVA) is one of the leading causes of mortality in the world whether it be ischemic or hemorrhagic 1,2. There has been an association of increased incidence of stroke in patients with cancer due to multiple factors 3. Regarding hematologic malignancies, there have been studies to assess the risk of developing stroke in patients with Hodgkin lymphoma (HL), however the information on non-Hodgkin lymphoma (NHL) is limited and not well understood4. We conducted a retrospective case-control study to assess the incidence, risks, and complications and length of stay of patients with current or prior history of NHL who developed an ischemic stroke.
Methods
This case-control study identified 29,632 patients older than 18 years, with or without CVA and with or without active or history of Non-Hodgkin Lymphoma (NHL) who were admitted to diverse private hospitals between 2018-2022. The patients were divided into two groups, one with current or prior NHL (n=10,699) and a control group of patients (n=18,933) with similar characteristics. Patients with active hemorrhagic stroke, pregnancy, malignancies other than NHL, prior hemorrhagic or ischemic stroke, infective endocarditis, atrial fibrillation, and acute coronary syndrome on admission were excluded. We compared patient's characteristics and the risk of developing a stroke based on the presence or absence of NHL as well as the factors that increased hospital mortality. Length of stay was evaluated as a secondary outcome. Bivariate statistical analysis was used to calculate the odds ratios using RStudio 4.2.2 and JMP Pro 16.0 for all data analysis.
Results
Of the group with NHL 46.39 % (n=4958) were female, and 53.61% (n=5729) were male, 42% were current or former smokers (n=4497), 27.49% (n=2941) had diabetes, 44.68% (n=4780) had hypertension; 3.34% (357) of them passed away. Of the control group 57.51 % (n=10876) were female, and 42.49% (n=8036) were male, 35% were current or former smokers (n=6763), 16.43% (n=3111) had diabetes, 28.89% (n=5469) had hypertension; 0.47% (n=88) of them passed away. The mean length of stay of patients with stroke was 7.99 days in the NHL group, and 5.99 days in the control group. Regarding the admissions due to stroke, there were 214 patients in the group with NHL, and in the control group where there were 113. Patients with NHL are more likely to have a CVA compared to the control group (OR 2.39 p&lt;0.0001 CI 1.47~3.85) Patients who have NHL are more likely to die (OR=6.08 p&lt;0.001) CI 4.77~7.74) compared to patients without NHL from all causes.
Conclusion
Patients with Non-Hodgkin lymphoma have an increased risk of developing a stroke compared to patients with similar characteristics but without NHL (or other malignancies). It was also noted that patients had an increased length of stay. Other variables and characteristics of patients that were identified to be more likely to have a CVA and statistically significant for this sample are already well-known risk factors for CVA including diabetes, hypertension, and cardiovascular disease. However, this study aimed to isolate those variables to identify the risk for stroke in this unique population. Our study limitation is the broad spectrum of NHL and possible confounders between the different variants of NHL. More studies are needed to investigate this.
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