What is the best management approach for a patient presenting with right-sided weakness due to a proximal anterior circulation occlusion and a moderate-sized infarct core, 12 hours after symptom onset?

Management of Acute Ischemic Stroke at 12 Hours with Proximal Anterior Circulation Occlusion and Moderate Infarct Core

The optimal management is combined tPA and mechanical thrombectomy (Option D), provided the patient meets specific imaging criteria demonstrating salvageable tissue despite the moderate infarct core. 1

Why Combined Therapy is Superior at 12 Hours

Combined tPA and mechanical thrombectomy should be administered in parallel when salvageable tissue is confirmed by advanced perfusion imaging, as this approach maximizes functional outcomes and reduces mortality compared to either therapy alone or observation. 1, 2

Evidence Supporting Combined Therapy

• The American Heart Association recommends combined tPA and mechanical thrombectomy for patients with proximal anterior circulation occlusion and small to moderate ischemic cores, with treatment decisions based on tissue viability rather than time alone 1

• In the landmark ESCAPE trial, 91.5% of patients who benefited from mechanical thrombectomy also received IV tPA, demonstrating that combined therapy is the standard approach that produced the positive trial results 1, 2

• The adjusted odds ratio for improved functional outcomes with combined therapy versus medical management alone is 1.67 (95% CI 1.21-2.30), with functional independence rates of 53.0% versus 29.3% for control 3

• Mortality is significantly reduced with combined therapy (10.4% versus 19.0% with control, P=0.04) 3

Critical Imaging Requirements Before Proceeding

You must confirm salvageable tissue using advanced perfusion imaging before treating at 12 hours—this is non-negotiable. 1

Required Imaging Criteria (Must Meet One)

DAWN Criteria: 1

• Age <80 years with NIHSS ≥10 and infarct core <31 mL, OR
• NIHSS ≥20 and infarct core <51 mL

DEFUSE-3 Criteria: 1

• Ischemic core <70 mL, AND
• Mismatch ratio ≥1.8, AND
• Mismatch volume ≥15 mL

Absolute Contraindications to Treatment

Do not proceed if imaging shows: 1

• ASPECTS score of 0
• No perfusion mismatch
• Large established infarct core >70 mL by DEFUSE-3 criteria
• Failure to meet DAWN criteria

Implementation Algorithm

Step 1: Immediate Actions (Parallel, Not Sequential)

• Initiate IV tPA in the emergency department while simultaneously mobilizing the interventional team 2
• Critical pitfall to avoid: Never delay mechanical thrombectomy while waiting to assess clinical response to tPA—every 30-minute delay reduces favorable outcome probability by 10.6% 2

Step 2: Technical Execution

• Target door-to-groin puncture time <110 minutes from arrival 1, 2
• Use stent retrievers as the preferred device (achieves TICI 2b/3 recanalization in 59-87.8% of cases) 2
• Goal is TICI 2b/3 reperfusion to maximize functional outcomes 1

Step 3: Post-Procedure Management

• Maintain blood pressure ≤180/105 mmHg for 24 hours after thrombectomy to reduce hemorrhagic complications 1
• Monitor closely for compartment syndrome and hemorrhagic transformation 1

Why Not the Other Options?

Option A (tPA alone): IV alteplase achieves recanalization in less than 50% of large vessel occlusions, with particularly poor results in proximal occlusions like M1—inadequate for this patient 2

Option B (Mechanical thrombectomy alone): While thrombectomy is essential, withholding tPA contradicts the evidence base, as 83.7-91.5% of patients in positive thrombectomy trials received IV tPA alongside mechanical intervention 1, 2

Option C (Observation): Unacceptable—60-80% of patients with proximal vessel occlusion die or fail to regain functional independence without intervention, even with a moderate infarct core if salvageable tissue exists 3

Safety Profile

• Symptomatic intracerebral hemorrhage occurs in 3.6% with combined therapy versus 2.7% with control (P=0.75)—not significantly different 3
• Intravenous alteplase may actually be protective, associated with a 68% reduction in infarct in new territory (3.0% with tPA versus 9.1% without, OR 0.32) 4

Key Clinical Nuance

The presence of a "moderate" infarct core does not automatically exclude treatment at 12 hours—what matters is whether salvageable tissue exists based on perfusion imaging criteria. 1 The ESCAPE trial specifically excluded patients with large infarct cores or poor collateral circulation but included those with small infarct cores and moderate-to-good collateral circulation up to 12 hours 3