Detrimental effect of anemia after mechanical thrombectomy on functional outcome in patients with ischemic stroke

Ryoma Inui; Junpei Koge; Kanta Tanaka; Takeshi Yoshimoto; Masayuki Shiozawa; Soichiro Abe; Hiroyuki Ishiyama; Hirotoshi Imamura; Jin Nakahara; Hiroharu Kataoka; Masafumi Ihara; Kazunori Toyoda; Masatoshi Koga

doi:10.3389/fneur.2023.1299891

Detrimental effect of anemia after mechanical thrombectomy on functional outcome in patients with ischemic stroke

Front Neurol. 2023 Dec 19:14:1299891. doi: 10.3389/fneur.2023.1299891. eCollection 2023.

Authors

Ryoma Inui^{1

2}, Junpei Koge¹, Kanta Tanaka³, Takeshi Yoshimoto⁴, Masayuki Shiozawa¹, Soichiro Abe⁴, Hiroyuki Ishiyama⁴, Hirotoshi Imamura⁵, Jin Nakahara², Hiroharu Kataoka⁵, Masafumi Ihara⁴, Kazunori Toyoda^{1

2}, Masatoshi Koga¹

Affiliations

¹ Department of Cerebrovascular Medicine, National Cerebral and Cardiovascular Center, Osaka, Japan.
² Department of Neurology, Keio University School of Medicine, Tokyo, Japan.
³ Division of Stroke Care Unit, National Cerebral and Cardiovascular Center, Osaka, Japan.
⁴ Department of Neurology, National Cerebral and Cardiovascular Center, Osaka, Japan.
⁵ Department of Neurosurgery, National Cerebral and Cardiovascular Center, Osaka, Japan.

Abstract

Background: Anemia can occur due to an aspiration maneuver of blood with thrombi during mechanical thrombectomy (MT) for stroke. However, the association between postoperative anemia and stroke outcomes is unknown.

Methods: In a registry-based hospital cohort, consecutive patients with acute ischemic stroke who underwent MT were retrospectively recruited. Patients were divided into the following three groups according to their hemoglobin (Hb) concentrations within 24 h after MT; no anemia (Hb concentrations ≥13 g/dL for men and ≥ 12 g/dL for women), mild anemia (Hb concentrations of 11-13 g/dL and 10-12 g/dL, respectively), and moderate-to-severe anemia (Hb concentrations <11 g/dL and < 10 g/dL, respectively). A 3-month modified Rankin Scale score of 0-2 indicated a favorable outcome.

Results: Of 470 patients, 166 were classified into the no anemia group, 168 into the mild anemia group, and 136 into the moderate-to-severe anemia group. Patients in the moderate-to-severe anemia group were older and more commonly had congestive heart failure than those in the other groups. Patients in the moderate-to-severe anemia group also had more device passes than those in the other groups (p < 0.001). However, no difference was observed in the rate of final extended thrombolysis in cerebral infarction ≥2b reperfusion or intracranial hemorrhage among the groups. A favorable outcome was less frequently achieved in the moderate-to-severe anemia group than in the no anemia group (adjusted odds ratio, 0.46; 95% confidence interval, 0.26-0.81) independent of the baseline Hb concentration. A restricted cubic spline model with three knots showed that the adjusted odds ratio for a favorable outcome was lower in patients with lower Hb concentrations within 24 h after MT.

Conclusion: Moderate-to-severe anemia within 24 h after MT is independently associated with a reduced likelihood of a favorable outcome.

Clinical trial registration: https://www.clinicaltrials.gov, NCT02251665.

Keywords: anemia; endovascular therapy; ischemic stroke; large vessel occlusion; mechanical thrombectomy.

Associated data

ClinicalTrials.gov/NCT02251665

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This study was supported in part by a Grant-in-Aid for Scientific Research (20K16716 and 23H02831).