Impact of Diabetes on Collateral Circulation and Thrombectomy Outcomes in Acute Ischemic Stroke: A Prospective Cohort Study.

BACKGROUND

In large-vessel occlusion (LVO) stroke, mechanical thrombectomy (MT) restores flow yet outcomes vary. Collateral robustness and the metabolic milieu especially diabetes may shape tissue rescue, but the diabetes-collateral link and its impact on recovery remain uncertain.

OBJECTIVE

To determine whether pre-existing diabetes is independently associated with (1) poorer angiographic collateral status at baseline and (2) higher 90-day functional dependence after mechanical thrombectomy, and to evaluate whether collateral grade modifies the diabetes-outcome relationship after accounting for baseline infarct core volume, stroke territory, and reperfusion success.

METHODS

Prospective cohort of 41 adults with acute ischemic stroke (AIS) undergoing MT. Collaterals were graded using the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) score for anterior circulation and the Basilar Artery on Computed Tomography Angiography (BATMAN) score for posterior circulation. The primary analysis prespecified anterior strokes (n=33). The primary endpoint was 90-day functional dependence (modified Rankin Scale (mRS) 3-6). Multivariable logistic regression adjusted for clinical, imaging, and procedural covariates; sensitivity analyses included all strokes with a posterior-circulation indicator.

RESULTS

Diabetes was present in 59%. In the anterior subgroup, patients with diabetes more often had poor collaterals (45.0% vs 7.7%) and higher functional dependence (60.0% vs 15.4%), with similar reperfusion rates. In adjusted models, baseline diffusion-weighted imaging (DWI) core independently predicted poor outcome (per 10 cc: odds ratio (OR) 2.85; p=0.012), while diabetes showed a large but imprecise association (OR 19.02; p=0.081). The modified Thrombolysis in Cerebral Infarction (mTICI) grade was not independently significant. In the full cohort, posterior location (OR 19.33; p=0.045) and DWI core (OR 3.02; p=0.004) remained associated; diabetes trended similarly (OR 12.25; p=0.064).

CONCLUSIONS

Diabetes clusters with weaker collaterals, larger cores, and greater disability despite high reperfusion. Tissue burden, not angiographic grade, chiefly drives outcomes. Metabolic phenotyping and pragmatic glycemic stewardship warrant testing.