Which patient is a candidate for systemic thrombolysis (tissue plasminogen activator (tPA)) and most likely to benefit without additional interventions in a suspected ischemic stroke after a head computed tomography (CT) scan shows no hemorrhage?

Optimal Candidate for Systemic Thrombolysis in Acute Ischemic Stroke

The 78-year-old previously healthy man with isolated aphasia that started 4 hours ago is the best candidate for systemic thrombolysis and most likely to benefit without additional interventions.

Rationale for Selection

Time Window Considerations

The 78-year-old patient with isolated aphasia at 4 hours falls within the established treatment window for IV tPA. Strong evidence supports IV tPA administration within 4.5 hours of symptom onset 1. The American College of Chest Physicians recommends IV r-tPA for patients who can be treated within 4.5 hours but not within 3 hours of symptom onset (Grade 2C) 1.

Stroke Severity and Benefit Profile

• Aphasia indicates a clinically significant stroke with substantial salvageable tissue, making this patient likely to derive meaningful benefit from thrombolysis 1
• The isolated nature of the deficit suggests a focal, potentially reversible ischemic territory without evidence of completed large infarction 1
• Patients with moderate stroke severity demonstrate the greatest absolute benefit from thrombolytic therapy 1

Why Other Options Are Less Suitable

Option A (60-year-old with complete MCA infarct): A complete infarct of the left MCA territory represents extensive established ischemia. Large acute hypodensity on CT increases the risk for hemorrhagic transformation after thrombolytic therapy and is considered a relative contraindication 1. While not an absolute contraindication within 3 hours, evidence of ischemia affecting more than one-third of a cerebral hemisphere suggests poor risk-benefit ratio 1.

Option B (70-year-old with isolated left-hand numbness at 2 hours): This represents a very mild stroke. Patients with mild strokes (typically NIHSS <5) are frequently undertreated but also have lower absolute benefit from thrombolysis 2. Approximately 13-18% of patients within the treatment window are excluded due to mild symptoms 3, 2. While this patient is within the time window, the isolated sensory deficit suggests minimal tissue at risk and lower potential for meaningful functional improvement.

Option D (85-year-old with facial paresis at 4 hours): Isolated facial paresis represents a mild stroke with limited functional impact. Similar to Option B, mild stroke severity reduces the absolute benefit from thrombolysis 3, 2. Additionally, advanced age (>85 years) is associated with lower treatment rates in clinical practice, though not an absolute contraindication 2.

Clinical Decision Framework

Key Eligibility Criteria Met by the 78-Year-Old Patient

• Time window: 4 hours from symptom onset falls within the 0-4.5 hour treatment window 1
• Stroke severity: Aphasia indicates moderate-to-severe stroke with meaningful functional deficit 1
• No hemorrhage on CT: Head CT shows no hemorrhage, meeting the fundamental requirement for thrombolysis 1
• Previously healthy: No medications suggests absence of anticoagulation or other contraindications 1
• Focal deficit: Isolated aphasia without mention of large territory involvement suggests salvageable tissue 1

Treatment Approach

IV tPA should be administered immediately at 0.9 mg/kg (10% bolus over 1 minute, remainder over 59 minutes) without delay for additional vascular imaging 1. Emergency treatment should not be delayed to obtain multimodal imaging studies (Class III recommendation) 1. Vascular imaging should not delay treatment of patients whose symptoms started within the treatment window 1.

Common Pitfalls to Avoid

• Do not delay treatment for vascular imaging in patients within 4.5 hours who are otherwise eligible for IV tPA 1
• Do not withhold treatment based solely on age in otherwise eligible patients; the 78-year-old patient's age alone is not a contraindication 1
• Do not assume mild symptoms will remain mild; approximately 32% of patients excluded for mild or improving symptoms either remain dependent or die during hospitalization 3
• Do not wait to assess clinical response before considering additional interventions; evaluation of responses to IV thrombolysis should not delay catheter angiography if mechanical thrombectomy is being considered 4