Thrombolytic Therapy for Acute Ischemic Stroke

Primary Treatment Algorithm

• The American College of Chest Physicians recommends administering IV recombinant tissue plasminogen activator (r-tPA) at 0.9 mg/kg (maximum 90 mg) if treatment can be initiated within 3 hours of clearly defined symptom onset, with weaker support for treatment between 3-4.5 hours 1, 2

Time-Based Treatment Windows

• For acute ischemic stroke patients, strongly recommend IV r-tPA (Grade 1A evidence) within 0-3 hours from symptom onset, representing the highest quality evidence with 154 more favorable events per 1,000 patients treated 1, 3
• Suggest IV r-tPA (Grade 2C evidence) for patients within 3-4.5 hours from symptom onset, with a smaller benefit of 69 more favorable events per 1,000 patients 1, 3, 4

Dosing Protocol

• Administer IV r-tPA at a dose of 0.9 mg/kg (maximum dose 90 mg) 2

Clinical Scoring and Patient Selection

• Use the National Institutes of Health Stroke Scale (NIHSS) to assess stroke severity and predict outcomes, with lower baseline NIHSS scores predicting more favorable outcomes 3
• Use the Modified Rankin Scale (mRS) as the primary outcome measure at 3 months, with a score of 0-1 indicating a very favorable outcome and a score of 0-2 indicating functional independence 3

Adjunctive Therapy

• Administer 160-325 mg aspirin within 48 hours of stroke onset (Grade 1A), with aspirin preferred over therapeutic anticoagulation in acute stroke 1, 2, 4
• Use prophylactic-dose subcutaneous low-molecular-weight heparin (LMWH) as the preferred method for venous thromboembolism (VTE) prophylaxis in patients with restricted mobility (Grade 2B) 1, 2, 4

Common Pitfalls to Avoid

• Do not delay treatment for difficult IV access, and consider alternative access methods 5
• Establish IV access in the non-paretic arm when possible to preserve the affected limb for rehabilitation 5

Alternative Therapies Beyond Standard Window

• Consider intraarterial r-tPA for proximal cerebral artery occlusions in patients who don't meet IV r-tPA eligibility criteria (Grade 2C), initiated within 6 hours of symptom onset 1, 4
• Mechanical thrombectomy may be considered in carefully selected patients who value uncertain benefits over risks (Grade 2C) 1