Thrombolysis in Multifocal Acute and Hyperacute Infarcts

Introduction to Thrombolysis Guidelines

The American College of Chest Physicians recommends proceeding with tPA if the patient meets standard eligibility criteria within the appropriate time window and the combined infarct volume does not suggest extensive early ischemic changes that would increase hemorrhagic risk, in patients with multifocal infarcts 1, 2

The American Heart Association strongly recommends IV tPA (0.9 mg/kg, maximum 90 mg) with 10% as bolus over 1 minute, followed by 90% infused over 60 minutes, if the patient meets eligibility criteria, regardless of multifocal nature, with a Grade 1A recommendation for treatment within 3 hours 1, 2
The American Stroke Association conditionally recommends IV tPA using the same dosing protocol if eligibility criteria are met (Grade 2C) for patients presenting between 3-4.5 hours of symptom onset 1, 5
The American College of Cardiology recommends against the use of IV tPA (Grade 1B recommendation against use) beyond 4.5 hours of symptom onset 1, 5

The American College of Radiology recommends assessing total infarct burden across all lesions, as extensive early ischemic changes involving more than one-third of the MCA territory (or equivalent combined territory) substantially increases hemorrhagic transformation risk 3
The International Journal of Stroke recommends identifying any hemorrhagic transformation in existing infarcts using the Heidelberg Classification system, with HI1 (small petechiae) allowing for cautious proceeding with thrombolysis, and HI2, PH1, PH2 (confluent petechiae or parenchymal hemorrhage) requiring delay of thrombolysis for 7-10 days 7

The American Heart Association recommends against thrombolysis in patients with evidence of hemorrhagic transformation (HI2 or higher grade) in any of the existing infarcts, or combined infarct volume suggesting extensive early ischemic changes (>1/3 MCA territory equivalent across all lesions) 3, 7

The American College of Cardiology recommends initiating aspirin 160-325 mg within 24-48 hours for patients not receiving thrombolysis, and considering mechanical thrombectomy if proximal arterial occlusion is present and patient presents within 6 hours (or up to 12 hours with favorable imaging criteria) 1, 3, 4, 5
The American Stroke Association recommends considering intraarterial thrombolysis within 6 hours for patients with documented proximal cerebral artery occlusions who do not meet IV tPA eligibility criteria (Grade 2C) 6

The American Heart Association recommends monitoring closely for symptomatic ICH, which occurs in 4-6% of appropriately dosed patients, and delaying antiplatelet therapy for 24 hours after tPA administration 1, 2