Stoke Guidelines
Joey Sweeney, PharmD, BCPS
Updates to the American Heart Association/American Stroke Association guidelines, published in Stroke late in 2019, detail early management of acute ischemic stroke in both prehospital and hospital care settings, including secondary prevention therapies initiated in the hospital, with a focus on hospital care interventions.
When the 2018 guidelines were published, certain randomized controlled trials (RCTs) were not available for consideration within certain recommendations. Once these RCTs were published between November 2018 and April 2019, a writing group convened to comment on relevant recommendations. A group of 14 peer reviewers was tasked with evaluating these comments and updating the 2018 recommendations where appropriate.
These revisions underwent an expedited peer review process by relevant experts, and as a result, three recommendations were updated.
Post-alteplase treatment
The first updated guideline removed the recommendation to target systolic blood pressure of less than 185 mm Hg and diastolic blood pressure of less than 110 mg Hg prior to fibrinolytic treatment.
Results from the ENCHANTED study showed that intensive blood pressure (BP) lowering prior to fibrinolytic therapy, although safe, did not improve outcomes. By removing this recommended BP target, a patient can more rapidly receive fibrinolytic therapy, and the time saved may result in better outcomes for that patient.
The recommendation to maintain BP at less than 180/105 mm Hg for at least the first 24 hours after I.V. alteplase treatment was unchanged in the 2019 update. Of note, the prefibrinolytic therapy BP target has been removed, but the postfibrinolytic therapy BP target remains.
I.V. fibrinolytics and sonothrombolysis
Two recently published studies (CLOTBUST-ER and NOR-SASS) evaluated the safety and outcomes of using ultrasound to attempt to break up a clot after receiving fibrinolytic therapy. Both studies were stopped early, CLOTBUST-ER because the second interim analysis showed no statistical benefit, and NOR-SASS because of a lack of funding. Nevertheless, sufficient data were collected to derive certain statistically significant conclusions.
Although both studies showed this therapy to most likely be safe, they also showed no statistical benefit compared with sham ultrasound. No published data support a clinical benefit to sonothrombolysis; it was safe, but it was also ineffective. Therefore, use of sonothrombolysis as adjuvant therapy to I.V. fibrinolytics is no longer recommended.
Mechanical thrombectomy 0 to 6 hours from symptom onset
Direct aspiration thrombectomy as first-pass mechanical thrombectomy is now recommended as noninferior to stent retriever for patients who have a prestroke modified Rankin Scale score of 0 to 1; have causative occlusion of the internal carotid artery or M1; are age 18 years or older; have a National Institutes of Health Stroke Scale score of 6 or greater and an Alberta Stroke Program Early CT Score of 6 or greater; and undergo treatment initiation within 6 hours of symptom onset. The 2018 guideline recommended only the stent retriever.
Material costs for the aspiration intervention were significantly lower than for the stent retrieval strategy. Given the similar safety and efficacy profiles of each intervention and the significantly less-expensive cost for the aspiration intervention, it is likely that this intervention will become increasingly common in the future.
In summary, no longer having to wait for a specific BP target will expedite care and prevent further injury for certain fibrinolytic-eligible patients; sonothrombolysis is ineffective; and mechanical thrombectomy is noninferior to stent retriever therapy (while also being less expensive). These three updates will have a significant impact on patient care.