The Cortical Vein Opacification Score (COVES) is independently associated with good and excellent functional outcomes at 90-days in minor stroke patients with anterior circulation large vessel occlusion: A Multicenter Study

BACKGROUND: There is currently no consensus on the most appropriate emergent treatment for patients with acute ischemic stroke secondary to large vessel occlusion (AIS-LVO) and minor stroke. These patients were excluded from prior randomized controlled trials assessing the efficacy of mechanical thrombectomy (MT) in LVO, making it challenging to determine the best treatment approach. Therefore, identifying markers that can predict functional outcomes would be invaluable for triaging these patients for MT. This study aimed to investigate pretreatment clinical and imaging markers and their association with functional outcomes at 90 days in minor AIS- LVO patients.

METHODS: We included patients with AIS-LVO and minor strokes from four sites across North America and Europe. Minor stroke was defined as a baseline National Institutes of Health Stroke Scale (NIHSS) score of ≤5. The primary outcome measure, good functional outcome, was defined as a modified Rankin Scale (mRS) score of 0–2 at 90 days. The secondary outcome, excellent functional outcome, was defined as an mRS score of 0–1 at 90 days. Univariable and multivariable logistic regression analyses, along with receiver operating characteristic (ROC) curve analysis, were performed.

RESULTS: Among 168 consecutive patients with minor strokes, 123 achieved a good functional outcome, and 103 patients had an excellent functional outcome at 90 days. The cortical vein opacification score (COVES) was independently associated with both excellent and good functional outcomes, whereas no other CT, CTA, or CTP markers showed a significant association with these outcomes. ROC analysis of COVES showed an area under the curve (AUC) of 0.638 (95% CI: 0.517–0.759, p = 0.026) for predicting a good functional outcome and 0.689 (95% CI: 0.537–0.741, p = 0.008) for predicting an excellent functional outcome. Similar results were observed in the subgroup of patients who underwent mechanical thrombectomy (MT). Interestingly, neither intravenous thrombolysis (IVT) nor mechanical thrombectomy (MT) was associated with functional outcomes.

CONCLUSIONS: Our analysis demonstrates that COVES is independently associated with good and excellent functional outcomes at 90 days in minor AIS-LVO cases. Further prospective studies are needed to better understand the role of COVES in determining optimal management strategies for these patients.

ABBREVIATIONS: CS: Collateral status; COVES: Cortical vein opacification score; MT: mechanical thrombectomy; IVT: intravenous thrombolysis; NIHSS: National Institutes of Health Stroke Scale