Association of Glycated Hemoglobin (HbA1c) with Functional Outcomes After Endovascular Thrombectomy for Acute Ischemic Stroke

Background: The impact of chronic glycemic control, measured by glycated hemoglobin (HbA1c), on functional outcomes after endovascular thrombectomy (EVT) for acute large vessel occlusion (LVO) stroke remains to be fully elucidated. Methods: We conducted a retrospective cohort study of 443 consecutive patients with anterior circulation LVO stroke who underwent EVT. Patients were categorized by HbA1c levels: low (< 6.0%), medium (6.0– 7.0%), and high (> 7.0%). The primary outcome was a poor functional outcome (modified Rankin Scale score 3– 6) at 3 months. The secondary outcome was symptomatic intracranial hemorrhage (sICH). Results: Among the 443 patients, 229 (51.7%) had a poor functional outcome. Higher HbA1c levels were significantly associated with an increased risk of poor outcome after adjustment for confounders ( P for trend = 0.013). When analyzed as a continuous variable, HbA1c showed a nonlinear relationship with poor outcome; risk increased with rising HbA1c until a threshold of 7.1%, after which the rate of increase attenuated. No significant association was found between HbA1c and sICH. Subgroup analysis revealed a significant interaction between HbA1c and thrombolysis (t-PA) administration ( P for interaction = 0.042), indicating that the association between high HbA1c and poor outcome was more pronounced in patients who received t-PA. Conclusion: Elevated HbA1c is independently associated with an increased risk of poor 3-month functional outcomes after EVT, with a risk threshold observed at 7.1%. These findings underscore the importance of long-term glycemic control in stroke management. Keywords: HbA1c, endovascular thrombectomy, functional outcome, ischemic stroke, glycemic control