Thrombolysis Contraindications and Considerations

Absolute Contraindications

• Previous hemorrhagic stroke at any time is listed as an absolute contraindication to thrombolytic therapy for acute myocardial infarction, according to the American College of Cardiology 1
• History of prior cerebrovascular accident or known intracerebral pathology represents a relative contraindication requiring careful consideration, as stated by the American College of Cardiology 1
• The risk of symptomatic intracranial hemorrhage (ICH) with tissue plasminogen activator (tPA) ranges from 3-9% in acute ischemic stroke patients, with 30-day mortality rates of 60% or more when ICH occurs post-thrombolysis, as reported by the American Heart Association and the American Stroke Association 2, 3, 4

Risk Factors and Emerging Evidence

• Advanced age (>65 years), low body weight (<70 kg), hypertension on presentation, and use of tPA all increase ICH likelihood, according to the American College of Cardiology 1
• Patients with multiple risk factors have substantially elevated risk, with likelihood ratios ranging from 0.34 (no risk factors) to 2.89 (three risk factors), as stated by the American College of Cardiology 1
• The presence of brain metastases is not an absolute contraindication to anticoagulation, with therapeutic anticoagulation not increasing ICH risk in this population compared to primary brain tumors, as reported by the American Society of Clinical Oncology 5

Clinical Decision Algorithm and Management Approach

• Hemorrhagic transformation of prior ischemic stroke carries different risk than primary ICH, and location matters, with lobar hemorrhages (suggesting amyloid angiopathy) having higher recurrence risk than deep hemorrhages, as reported by the American Heart Association and the American Stroke Association 2, 3, 4, 7
• Check for microbleeds on gradient-echo MRI; <5 microbleeds may not significantly increase symptomatic ICH risk with thrombolysis, while multiple microbleeds (>5) represent undetermined but likely elevated risk, as stated by the American Heart Association and the American Stroke Association 7
• High-risk conditions (mechanical heart valves, CHADS₂ score ≥4 points) may justify anticoagulation despite ICH history, while lower thromboembolic risk (atrial fibrillation without prior ischemic stroke) favors avoiding thrombolysis, as reported by the American College of Chest Physicians and the American Heart Association 2, 3, 4, 8