Anemia Not Associated with Early Neurological Deficit After Ischemic Stroke

Angelique Ceulemans

Credit: LinkedIn

A new investigation identified an association between pre-endovascular treatment (EVT) anemia and clinical outcomes among patients with acute ischemic stroke with a large vessel occlusion of the anterior circulation.

The primary study results revealed both anemia and hemoglobin (Hb) levels were significantly associated with the modified Rankin Scale (mRS) and poor functional outcomes at 90 days but not with the National Institutes of Health Stroke Scale (NIHSS) scores at 24 to 48 hours or mortality at 90 days.

“Given the fact we did not observe an association with the NIHSS at 24–28 hours post-EVT, it seems more likely that anemia is a marker for frailty rather than an early neurological outcome marker after acute ischemic stroke,” wrote the investigative team, led by Angelique Ceulemans, department of neurology, Maastricht University Medical Center.

Now the standard of care, EVT has benefited patients with acute ischemic stroke with a large vessel occlusion of the anterior circulation.² However, various comorbidities, including anemia, can be a predictor of poor clinical outcomes post-acute ischemic stroke when treated with EVT, but the evidence is conflicting. Prior literature has used the mRS post-acute ischemic stroke as a primary outcome, but an association between anemia and early outcome measures has not been made clear.³

Ceulemans and colleagues suggested early outcome assessment using the NIHSS during hospitalization may be less influenced by other clinical factors and more useful for clinical practice.¹ The team noted up to 40% of patients with acute ischemic stroke exhibit anemia, making it clinically relevant to understand this relationship post-treatment.

This retrospective study evaluated the association between pre-EVT anemia and clinical outcomes across different time points, focusing on the NIHSS scores at 24 to 48 hours post-treatment. Using data from their institution, the investigative team screened patients who received EVT between 2010 and 2019. Collected from patient medical files, hemoglobin levels (g/dL) were used to categorize anemia status: Hb≤12.9/dL for males and Hb ≤11.9 g/dL for females.

Overall, the investigative team screened 651 EVT records for eligibility. Ultimately, 560 patients underwent statistical analysis, with anemia identified in 26% of patients. Upon multivariable regression analysis, anemia and Hb levels were not significantly associated with an increase in NIHSS at 24–48 hours post-EVT (adjusted β anemia, 1.44 [95% CI, –0.47 to 3.36]; adjusted β Hb, –0.37 [95% CI, –0.88 to 0.13).

Meanwhile, further multivariable regression models revealed significant associations between anemia and decreasing Hb levels with the mRS (adjusted common odds ratio [acOR] anemia, 1.66 [95% CI, 1.12 to 2.48; acOR Hb, 0.83 [95% CI, 0.75 to 0.93) and poorer functional outcome at 90 days (adjusted OR [aOR] anemia, 2.09 [95% CI, 1.21 to 3.63]; aOR Hb, 0.80 [95% CI, 0.69 to 0.92]).

In the discussion, Ceulemans and colleagues reiterated their hypothesis that anemia may be a suitable marker of frailty, rather than neurologic deficit, immediately post-stroke. They indicated the positive association between anemia and lower Hb levels with advanced age and comorbidities supported the hypothesis, but more research is needed to confirm.

“However, given the retrospective nature of the present study, we did not evaluate frailty in a specific way,” investigators wrote. “Therefore, this hypothesis has to be interpreted with caution.”

References

1. _{Ceulemans A, Pinckaers FME, Postma AA, van Zwam WH, van Oostenbrugge RJ. Association Between Anemia and Clinical Outcome in Acute Ischemic Stroke Patients Treated With Endovascular Treatment. J Stroke. Published online January 22, 2024. doi:10.5853/jos.2023.01669}
2. _{Compagne KCJ, Kappelhof M, Hinsenveld WH, Brouwer J, Goldhoorn RB, Uyttenboogaart M, et al. Improvements in endovascular treatment for acute ischemic stroke: a longitudinal study in the MR CLEAN registry. Stroke 2022;53:1863- 1872}
3. _{Barlas RS, Honney K, Loke YK, McCall SJ, Bettencourt-Silva JH, Clark AB, et al. Impact of hemoglobin levels and anemia on mortality in acute stroke: analysis of UK regional registry data, systematic review, and meta-analysis. J Am Heart Assoc 2016;5:e003019}