Acute ischemic stroke caused by large-vessel occlusion represents a critical medical emergency requiring rapid vascular recanalization. In recent years, endovascular thrombectomy has fundamentally transformed acute neurointerventional care. However, the precise clinical role of bridging intravenous thrombolysis prior to mechanical intervention remains an active area of investigation. Administering tenecteplase before thrombectomy provides rapid pharmacologic thrombus dissolution. Yet, clinical trials have shown variable treatment responses across distinct patient cohorts. Consequently, clinicians need reliable neuroimaging biomarkers to identify which individuals derive the greatest therapeutic benefit from bridging thrombolysis. The Alberta Stroke Program Early Computed Tomography Score serves as a standardized imaging metric for quantifying early ischemic injury. Recent evidence now demonstrates that initial ischemic extent strongly dictates patient response to combination therapy.

Baseline ASPECTS and Tenecteplase Before Thrombectomy

The randomized BRIDGE-TNK trial evaluated the comparative efficacy of bridging intravenous tenecteplase against direct mechanical thrombectomy alone in patients with acute large-vessel occlusion presenting within 4.5 hours of symptom onset. To assess treatment heterogeneity, researchers conducted a post hoc analysis stratifying 550 enrolled patients by their initial non-contrast computed tomography findings. Specifically, investigators divided patients into lower baseline ASPECTS (scores under 8) and higher baseline ASPECTS (scores between 8 and 10). Consequently, this stratification allowed researchers to evaluate how established ischemic core volume modifies clinical recovery. Notably, the trial utilized a standard intravenous tenecteplase bolus dose of 0.25 mg/kg administered immediately prior to groin puncture. The study protocol ensured rigorous neuroimaging assessment through centralized, core-laboratory evaluations. Therefore, the findings provide granular insights into tissue-level factors that determine thrombolytic responsiveness before mechanical recanalization begins.

Differential Clinical Outcomes Across ASPECTS Subgroups

The post hoc analysis demonstrated a remarkable interaction between baseline ischemic extent and treatment efficacy. Specifically, among patients presenting with an ASPECTS under 8, administering tenecteplase prior to mechanical thrombectomy yielded a substantial increase in 90-day functional independence. Functional independence was defined as a modified Rankin Scale score of 0 to 2. In this subgroup, bridging thrombolysis achieved an adjusted relative risk of 1.67 compared to thrombectomy alone. Conversely, patients presenting with an ASPECTS of 8 to 10 experienced no statistically significant difference in 90-day functional recovery between the two treatment arms. Furthermore, statistical testing confirmed a highly significant interaction between the baseline ASPECTS category and the therapeutic benefit of tenecteplase. Thus, these data indicate that patients with established early ischemic changes paradoxically experience the greatest clinical benefit from rapid systemic thrombolytic administration.

Safety Profiles, Reperfusion Rates, and Hemorrhagic Risks

Safety parameters represent a primary consideration when evaluating systemic fibrinolytic agents before mechanical intervention. In the BRIDGE-TNK post hoc cohort, the overall rates of symptomatic intracranial hemorrhage remained comparable across treatment arms. However, subtle safety variations emerged when examining specific ASPECTS strata. Patients with baseline scores between 8 and 10 exhibited numerically higher incidences of symptomatic intracranial hemorrhage and 90-day mortality when receiving bridging tenecteplase compared with direct thrombectomy alone. In contrast, patients with lower baseline scores did not demonstrate an increased hemorrhagic liability despite having larger initial ischemic tissue burdens. Furthermore, bridging therapy consistently facilitated higher rates of complete pre-procedural recanalization and microvascular reperfusion. Therefore, the overall benefit-risk profile strongly favors bridging thrombolysis in patients with moderate early tissue injury, while demanding greater clinical vigilance in those with minimal early baseline changes.

Mechanistic Insights into Microvascular Salvage

Several pathophysiological mechanisms explain why patients with lower ASPECTS derive superior therapeutic advantage from bridging therapy. When a proximal arterial occlusion occurs, microvascular thrombosis and platelet aggregation rapidly propagate throughout downstream capillary beds. In patients with lower baseline ASPECTS, extensive ischemic penumbral tissue depends heavily on microvascular patency. Systemic tenecteplase quickly dissolves distal microthrombi and microvascular plugs that mechanical thrombectomy catheters cannot physically reach. Consequently, this pharmacological clearance restores downstream tissue perfusion and mitigates the dangerous no-reflow phenomenon upon macrovascular recanalization. In addition, tenecteplase softens the proximal thrombus burden, facilitating faster and more complete mechanical retrieval with fewer device passes. Conversely, patients with high ASPECTS possess robust collateral circulation, meaning macrovascular retrieval alone often suffices to restore adequate tissue nutrition.

Clinical Implications for Emergency Stroke Systems in India

These findings hold profound practical implications for emergency stroke triage and referral networks across India. In many Indian healthcare settings, patients first arrive at community facilities or secondary hospitals that lack dedicated endovascular suites. Establishing streamlined 'drip-and-ship' protocols with tenecteplase enables rapid treatment initiation before transferring patients to comprehensive stroke centers. Because tenecteplase requires only a single, rapid intravenous bolus, clinicians can initiate thrombolysis without delaying ambulance transport. Furthermore, evaluating non-contrast CT scans with ASPECTS provides a cost-effective, universally accessible decision-making tool. Emergency physicians can rapidly quantify ischemic damage without waiting for advanced perfusion imaging. Implementing structured tenecteplase bridging pathways based on baseline imaging will optimize acute reperfusion therapy and significantly improve neurological survival rates across diverse clinical settings.

Frequently Asked Questions

How does baseline ASPECTS influence the benefit of tenecteplase before thrombectomy?

Baseline ASPECTS measures early ischemic tissue damage. Patients with lower scores (under 8) derive significant clinical benefit and improved 90-day functional recovery from bridging tenecteplase. Conversely, patients with higher scores (8 to 10) achieve excellent recovery with mechanical thrombectomy alone and show less incremental gain from pre-treatment thrombolysis.

What is the recommended dosage of tenecteplase in acute large-vessel occlusion stroke?

Clinical stroke protocols recommend a single intravenous bolus dose of tenecteplase at 0.25 mg per kilogram of body weight, up to a maximum dose of 25 mg. Clinicians administer this bolus rapidly over five to ten seconds, allowing immediate preparation for subsequent endovascular catheterization without infusion delays.

Why might patients with higher baseline ASPECTS show less incremental benefit from bridging thrombolysis?

Patients with higher baseline ASPECTS usually maintain robust collateral blood flow and minimal microvascular thrombosis. Consequently, rapid mechanical clot extraction alone successfully reperfuses the brain tissue. In these patients, adding systemic thrombolysis offers diminishing incremental efficacy while exposing intact microvasculature to potential reperfusion injury and minor hemorrhagic risks.

Disclaimer: This content is for informational and educational purposes only and does not constitute formal medical advice, diagnosis, or treatment recommendations. Healthcare professionals should evaluate individual patient circumstances and refer to the latest local and national guidelines for clinical practice.

References

Huang X et al. Effect of Baseline ASPECTS on Tenecteplase Efficacy Before Thrombectomy in Acute Large-Vessel Occlusion Stroke: A Post Hoc Analysis of the BRIDGE-TNK Randomized Trial. Neurology. 2026 Sep 22. doi: 10.1212/WNL.0000000000218467. PMID: 42623571.

BRIDGE-TNK Trial Investigators. Intravenous Tenecteplase before Thrombectomy in Stroke. New England Journal of Medicine. 2025 Jul 10;393(2):139-150. doi: 10.1056/NEJMoa2503867.

Campbell BCV et al. Tenecteplase versus Alteplase before Thrombectomy for Ischemic Stroke. New England Journal of Medicine. 2018 Apr 26;378(17):1573-1582. doi: 10.1056/NEJMoa1716405.