However, when tPA is given beyond 4.5 hours of stroke onset, deleterious effects of the drug ensue, especially, hemorrhagic transformation (HT), which causes the most significant morbidity and mortality in stroke patients.
Although beneficial within 4.5 hours of stroke onset, administering recombinant tissue plasminogen activator (tPA) beyond that window appears to increase the risk of dying, a pooled analysis of eight clinical trials showed.
Background and Purpose— tPA (tissue-type plasminogen activator) is the only recommended intravenous thrombolytic agent for ischemic stroke. However, its application is limited because of increased risk of hemorrhagic transformation beyond the time window.
When NOT to Administer tPA? For the 3 to 4.5 hours from the moment of the stroke, the benefits of tPA outweigh the risk. Studies show that after that window, the benefits of tPA drop significantly.
Alteplase (IV r-tPA) within 4.5 hours of stroke onset remains the standard of care for most ischemic stroke patients.
For patients treated within 3 hours of stroke, thrombolytic therapy appeared to be more effective (OR, 0.58; 95% CI, 0.46 to 0.74). Trials testing intravenous rtPA suggest that it may be associated with a lower mortality when given up to 6 hours after onset (OR, 1.24; 95% CI, 0.85 to 1.81).
When administered quickly after stroke onset (within three hours, as approved by the FDA), tPA helps to restore blood flow to brain regions affected by a stroke, thereby limiting the risk of damage and functional impairment.
A door-to-treatment time of 60 minutes or less is the goal. This 60-minute period is often referred to as the “golden hour” of acute ischemic stroke treatment during which a focused diagnostic workup must be completed to rule out conditions that may mimic stroke as well as contraindications to rt-PA administration.
In contrast to WAKE-UP and THAWS, wake-up stroke patients are treated with either tenectepplase or intravenous tPA. For patient selection in the wake-up stroke subgroup, DWI–FLAIR mismatch is used as in WAKE-UP.
The timing of treatment is important, because giving a strong blood thinner like tPA during a stroke can cause bleeding inside the brain.
Current guidelines recommend that intravenous (IV) alteplase should only be administered for patients with acute stroke who meet criteria and can be treated within 4.5 hours. However, some patients with salvageable brain tissue beyond the current time window might benefit from IV alteplase.
Thrombolytic therapy is contraindicated in patients with a systolic blood pressure greater than 185 mmHg or diastolic blood pressure greater than 110 mmHg. Elevated blood pressure can lead to a delay in thrombolytic therapy, which is associated with increased morbidity.
As with IV tPA, treatment with mechanical thrombectomy should be initiated as quickly as possible. Administration of aspirin is recommended in acute stroke patients within 24-48 hours after stroke onset. For patients treated with IV tPA, aspirin administration is generally delayed for 24 hours.
A stroke drug known as tPA, or tissue plasminogen activator, has been a lightning rod since it was first approved in the United States in 1996. Although studies have found that the drug can reduce the brain damage wrought by strokes, it can also cause potentially fatal bouts of cerebral bleeding.
HOUSTON -- Keeping the head elevated is the favored head position for acute stroke patients, but some studies have indicated that lying flat may improve recovery. A new, international study suggests it may not matter.
Because of the risk of hemorrhage is thought to outweigh any potential benefits, patients with any absolute contraindication should not be given tPA.
Transient ischemic attack (TIA) is not an indication for tPA administration; only confirmed strokes have received this indication. In fact, rapidly improving symptoms, as can occur with TIAs, are a contraindication to the administration of tPA.
Conclusions: The majority of patients are unable to receive TPA for acute ischemic stroke because they do no not reach the hospital soon enough.
The 3 Rs of Stroke Biology: Radial, Relayed, and Regenerative.
Posterior circulation stroke affects around 20% of all ischemic strokes and can potentially be identified by evaluating or assessing the “Five D's”: Dizziness, drowsiness, dysarthria, diplopia, and dysphagia.
You may be familiar with the acronym F.A.S.T. to help you recognize a stroke. The letters (Face, Arms, Speech, and Time) can help you see the symptoms of an acute stroke in someone else and find help as soon as possible.
Treating ischemic stroke
If you get to the hospital within 3 hours of the first symptoms of an ischemic stroke, you may get a type of medicine called a thrombolytic (a “clot-busting” drug) to break up blood clots.
Clinicians should avoid adjunctive therapies with anticoagulants and antiplatelets within 24 hours of thrombolytic treatment for acute ischemic stroke.
Most SICH hemorrhages will occur within the first 24 hours after receiving IV r-tPA, with the bulk of fatal hemorrhages occurring within the first 12 hours.