The 2026 AHA/ASA Guideline Updates to
Management of Patients with Acute Ischemic
Stroke: A Guide for Radiologists
Pranjal Rai, John C. Benson, Sabha Ahmed, Ian T. Mark,
Radhika Rajeev, Dhairya A. Lakhani, Guiseppe Lanzino,
James P. Klaas and Girish Bathla
This information is current as
of June 18, 2026. AJNR Am J Neuroradiol published online 4 June 2026
http://www.ajnr.org/content/early/2026/06/04/ajnr.A9455
, Published June 4, 2026 as 10.3174/ajnr.A9455
REVIEW ARTICLE
The 2026 AHA/ASA Guideline Updates to Management
of Patients with Acute Ischemic Stroke: A Guide
for Radiologists
Pranjal Rai, John C. Benson, Sabha Ahmed, Ian T. Mark, Radhika Rajeev, Dhairya A. Lakhani, Guiseppe Lanzino,
James P. Klaas, and Girish Bathla
T
IP
ABSTRACT
R
The 2026 guideline for early management of acute ischemic stroke (AIS) retains many foundational recommendations while intro-
SC
ducing clinically meaningful updates spanning imaging, broader inpatient management, and reperfusion strategies including intrave-
nous thrombolysis (IVT) and endovascular therapy (EVT). Notably, it provides expanded guidance for medium vessel occlusions and
introduces pediatric recommendations that were largely absent from prior iterations. Given their impact on imaging workflows in
AIS, the authors present a focused review of the updated guidelines for the radiologist.
U
INTRODUCTION As imaging capabilities, artificial intelligence (AI) applica-
AN
S troke remains a major public health challenge in the United
States, with an estimated prevalence of 3.3% and ranking as
the fourth leading cause of death.1 The Global Burden of Disease
tions, and automated post-processing tools continue to expand,
neuroradiologists must remain updated with evolving stroke
guidelines and understand how imaging findings interface with
2019 study reported that acute ischemic stroke (AIS) accounts for clinical decision-making. Doing so supports precise, clinically
M
62.4% of all strokes, followed by intracranial hemorrhage (27.9%) actionable reporting and facilitates efficient coordination with the
and subarachnoid hemorrhage (9.7%).2 In both men and women, care teams.
stroke incidence rises with advancing age.3 Over the past decade, This review aims to emphasize the radiology-focused implica-
D
AIS incidence has increased, while its management has evolved tions of the recently published 2026 American Heart Association
rapidly, reflected in guideline updates issued every few years as (AHA)/American Stroke Association (ASA) guidelines for early
TE
evidence accrues from large national and international clinical management of patients with AIS, emphasizing imaging-driven
trials.4 triage and reporting priorities that influence acute stroke
Neuroradiology remains central to contemporary stroke workflows.3
care, enabling timely confirmation of diagnosis, delineation of
EP
infarcted and at-risk tissue, identification of complications UNDERSTANDING THE 2026 AHA/ASA
and underlying etiology, and informing treatment selection RECOMMENDATION FRAMEWORK
and prognosis. Ongoing clinical trials continue to use imaging The 2026 update incorporates recent advances and emerging evi-
as a surrogate to refine therapeutic time windows, optimize
C
dence in stroke evaluation and treatment, and replaces the 2018
patient triage, and anticipate downstream complications.5 guideline and its 2019 focused update.3 It reflects an evolution
Therapeutic options have also advanced over the past two dec-
AC
from primarily time-based reperfusion decision-making toward
ades, with a shift towards newer intravenous thrombolytics selection based on clinically and neuroradiologically defined
and continued innovation in mechanical thrombectomy devi-
treatment subsets. For the adult neuroradiologist, two practical
ces and techniques.6,7
principles are central. First, the dominant guideline-supported
treatment horizon for acute reperfusion therapy is now 24 hours
Received May 6, 2026; accepted after revision May 31. for appropriately selected patients, although a small subset of
From the Department of Radiology (P.R., J.C.B., I.T.M., G.B.), Neurologic Surgery patients beyond 24 hours may remain potentially treatable and
(G.L., J.P.K.), Mayo Clinic, 200 1st Street Southwest, Rochester, MN 55902;
Department of Neuroradiology (S.A.), National Institute Of Mental Health & Neuro represents an area of ongoing investigation. In late-window sce-
Sciences (NIMHANS), Hosur Main Road, Lakkasandra, Ayappa Garden, Adugodi, narios, treatment decisions are not based on time alone, but on
Bengaluru, Karnataka 560029, India; Department of Radiology (R.R.), Massachusetts
General Hospital, 55 Fruit St, Boston, MA 02114 and Department of Neuroradiology the patient’s clinical status, occlusion site, infarct burden, pre-
(D.A.L.), Rockefeller Neuroscience Institute, West Virginia,University, Morgantown, stroke functional status, comorbidities, and emergency imaging
WV, USA.
findings.
Corresponding Author:Pranjal Rai, MD, Address: 1804, 2nd St, SW, Apt. 2, Rochester
MN 55902; e-mail: ; Telephone no. (507)-250-9777 Second, rapid parenchymal and vascular imaging is the mini-
http://dx.doi.org/10.3174/ajnr.A9455 mum imaging framework for acute stroke triage, while advanced
AJNR Am J Neuroradiol : 2026 www.ajnr.org 1
Copyright 2026 by American Society of Neuroradiology.
, tissue imaging (CT and MR perfusion), remains diagnostically including a meta-analysis of 14 studies showing low rates of acute
useful, particularly for extended-window IVT, smaller or distal kidney injury (3%) and hemodialysis (0.07%) after
occlusions; however, it should be viewed as adjunctive rather CTA/CTP.10,11 A second example is advanced imaging for EVT
than universally essential for EVT selection. This distinction is selection in the 6- to 24-hour window. Previously recommended
discussed in greater detail in the subsequent IVT and EVT at COR: 1, LOE: A, this has been changed to COR: 2a, LOE: A in
sections. 2026.3 The guideline now states that adjunctive CTP or MR
In the subsequent sections, Class of Recommendation (COR) DWI-PWI with automated post-processing can be useful if im-
and Level of Evidence (LOE) are reported according to the mediately available, rather than uniformly recommended. This
AHA/ASA framework. COR: 1 indicates a strong recommenda- likely reflects broader trial evidence from large core trials
tion in which benefit greatly exceeds risk; 2a indicates a moderate (RESCUE-Japan LIMIT, SELECT2, ANGEL-ASPECT, and
recommendation in which the intervention is reasonable; 2b indi- LASTE) which showed that even patients with lower ASPECTS
cates a weaker recommendation in which the intervention may score and large core infarcts may still benefit from EVT and con-
be considered; 3—No Benefit, indicates that the intervention is tinued patient selection based on the more strict criteria outlined
T
not useful or effective; and 3—Harm indicates that the interven- in DAWN and DEFUSE 3 may exclude such patients.12–16
tion may be harmful and should not be performed. LOE: A ¼
IP
high-quality evidence; B-R ¼ moderate-quality randomized evi- Systems-Level, and Population-Specific Updates
dence; B-NR ¼ moderate-quality nonrandomized evidence; C- Given the accumulating evidence supporting direct triage to angi-
R
LD ¼ limited data; and C-EO ¼ consensus expert opinion. ography suite (DTAS) in AIS patients with LVO, the guideline
provides two DTAS-related recommendations. For suspected
SC
Imaging Workflow and Advanced Imaging Selection LVO identified by validated prehospital assessment, DTAS may
Some of the prior guidelines remain unchanged. For example,
be considered for flat-panel CT followed by catheter-based angi-
emergency brain imaging (NCCT) is still recommended on initial
ography (COR: 2b, LOE: B-R). In transferred patients with AIS
evaluation to assess ischemic burden and exclude intracranial
due to LVO, who remain EVT eligible, DTAS without repeating
U
hemorrhage before reperfusion interventions (COR: 1, LOE:
brain imaging may be considered (if there is no clinical change or
A).3,8,9 The recommendation for MRI for initial evaluation how-
transfer delay) (COR 2b, LOE: B-NR). This is based on several
AN
ever has been updated, and is now at par with NCCT (COR: 1,
studies supporting DTAS, including a multicenter study of 1140
LOE: A). The 2026 guideline preserves the same operational mes-
patients which showed shorter arrival to groin puncture (34 min
sage by stating that in suspected AIS with LVO within 24 hours,
versus 60 min) as well as better functional and safety outcomes.17
brain and vascular imaging with either NCCT or MRI should be
Notably, the 2026 guideline also introduces dedicated recom-
M
performed as rapidly as possible for EVT selection and treatment
mendations for pediatric stroke care, reflecting an expanding evi-
planning (COR 1, LOE A) while also reiterating that advanced
dence base and the need for more standardized guidance in this
imaging is not required in every early-window case.3 Similarly,
population.3 Finally, another important update in the 2026 guide-
D
the emphasis on rapid imaging and treatment persists, although
lines has been the incorporation of patient age, type of vessel
the 2026 guideline explicitly targets door-to-imaging within
occlusion, time since onset, underlying ASPECTS score and base-
TE
approximately 25 minutes (COR: 1, LOE: B-NR).3,8,9 Current
line mRS to provide level of evidence for EVT, which can be seen
guidelines also maintain some older core eligibility framework,
as steps toward a more personalized recommendation for AIS
especially with respect to intravenous alteplase administration
management. Figures 1-3 summarize the proposed EVT treat-
(now more broadly termed intravenous thrombolysis [IVT] fol-
EP
ment algorithms derived from the 2026 AHA/ASA guidelines for
lowing inclusion of tenecteplase). Whereas prior guidelines
adult anterior circulation stroke, adult posterior circulation
issued separate recommendations for IV alteplase (0.9 mg/kg) in
stroke, and pediatric stroke, respectively.
the 0-3 hour (COR: 1; LOE: A) and 3-4.5 hour (COR: 1; LOE: B-
C
R) windows, the 2026 update preserves this treatment paradigm
but streamlines it into a single Class 1 recommendation for eligi- INTRAVENOUS THROMBOLYSIS
AC
ble patients presenting within 4.5 hours of symptom onset (COR One of the most consequential IVT-related updates in the 2026
1; LOE B-NR), while also clarifying that treatment should not be guideline is the elevation of tenecteplase to a co–first-line throm-
delayed for additional imaging, including not only CT/MR perfu- bolytic alongside alteplase. In the prior guidance, tenecteplase
sion but also CTA or MRA. As in the previous update, patients was positioned more narrowly, described as a “reasonable” alter-
presenting ,24 hour of last known well should undergo emer- native at 0.25 mg/kg for patients otherwise eligible for thrombec-
gency brain and vascular imaging (CT/CTA or MRI/MRA) of the tomy and as an option that “might be considered” at 0.4 mg/kg in
cervical and intracranial circulation as rapidly as possible to guide patients with minor neurologic impairment and no major intra-
EVT selection and treatment planning (COR 1, LOE A). cranial occlusion. The current guideline more explicitly defines
Some recommendations retain the same core principle but tenecteplase’s role, stating that for eligible patients treated within
have been expanded or recalibrated in strength in the 2026 4.5 hours, either alteplase or tenecteplase may be administered,
update. For example, under the new guidelines, CTA and/or CTP with a dedicated dosing table and a recommended tenecteplase
imaging should not be delayed while awaiting serum creatinine, dose of 0.25 mg/kg (maximum 25 mg). Importantly, the guideline
regardless of any prior history of renal impairment (COR: 1, advises against the 0.4 mg/kg regimen, citing concern for
LOE: B-NR). This change is supported by accumulating evidence, increased symptomatic intracranial hemorrhage without
2 Rai 2026 www.ajnr.org
Management of Patients with Acute Ischemic
Stroke: A Guide for Radiologists
Pranjal Rai, John C. Benson, Sabha Ahmed, Ian T. Mark,
Radhika Rajeev, Dhairya A. Lakhani, Guiseppe Lanzino,
James P. Klaas and Girish Bathla
This information is current as
of June 18, 2026. AJNR Am J Neuroradiol published online 4 June 2026
http://www.ajnr.org/content/early/2026/06/04/ajnr.A9455
, Published June 4, 2026 as 10.3174/ajnr.A9455
REVIEW ARTICLE
The 2026 AHA/ASA Guideline Updates to Management
of Patients with Acute Ischemic Stroke: A Guide
for Radiologists
Pranjal Rai, John C. Benson, Sabha Ahmed, Ian T. Mark, Radhika Rajeev, Dhairya A. Lakhani, Guiseppe Lanzino,
James P. Klaas, and Girish Bathla
T
IP
ABSTRACT
R
The 2026 guideline for early management of acute ischemic stroke (AIS) retains many foundational recommendations while intro-
SC
ducing clinically meaningful updates spanning imaging, broader inpatient management, and reperfusion strategies including intrave-
nous thrombolysis (IVT) and endovascular therapy (EVT). Notably, it provides expanded guidance for medium vessel occlusions and
introduces pediatric recommendations that were largely absent from prior iterations. Given their impact on imaging workflows in
AIS, the authors present a focused review of the updated guidelines for the radiologist.
U
INTRODUCTION As imaging capabilities, artificial intelligence (AI) applica-
AN
S troke remains a major public health challenge in the United
States, with an estimated prevalence of 3.3% and ranking as
the fourth leading cause of death.1 The Global Burden of Disease
tions, and automated post-processing tools continue to expand,
neuroradiologists must remain updated with evolving stroke
guidelines and understand how imaging findings interface with
2019 study reported that acute ischemic stroke (AIS) accounts for clinical decision-making. Doing so supports precise, clinically
M
62.4% of all strokes, followed by intracranial hemorrhage (27.9%) actionable reporting and facilitates efficient coordination with the
and subarachnoid hemorrhage (9.7%).2 In both men and women, care teams.
stroke incidence rises with advancing age.3 Over the past decade, This review aims to emphasize the radiology-focused implica-
D
AIS incidence has increased, while its management has evolved tions of the recently published 2026 American Heart Association
rapidly, reflected in guideline updates issued every few years as (AHA)/American Stroke Association (ASA) guidelines for early
TE
evidence accrues from large national and international clinical management of patients with AIS, emphasizing imaging-driven
trials.4 triage and reporting priorities that influence acute stroke
Neuroradiology remains central to contemporary stroke workflows.3
care, enabling timely confirmation of diagnosis, delineation of
EP
infarcted and at-risk tissue, identification of complications UNDERSTANDING THE 2026 AHA/ASA
and underlying etiology, and informing treatment selection RECOMMENDATION FRAMEWORK
and prognosis. Ongoing clinical trials continue to use imaging The 2026 update incorporates recent advances and emerging evi-
as a surrogate to refine therapeutic time windows, optimize
C
dence in stroke evaluation and treatment, and replaces the 2018
patient triage, and anticipate downstream complications.5 guideline and its 2019 focused update.3 It reflects an evolution
Therapeutic options have also advanced over the past two dec-
AC
from primarily time-based reperfusion decision-making toward
ades, with a shift towards newer intravenous thrombolytics selection based on clinically and neuroradiologically defined
and continued innovation in mechanical thrombectomy devi-
treatment subsets. For the adult neuroradiologist, two practical
ces and techniques.6,7
principles are central. First, the dominant guideline-supported
treatment horizon for acute reperfusion therapy is now 24 hours
Received May 6, 2026; accepted after revision May 31. for appropriately selected patients, although a small subset of
From the Department of Radiology (P.R., J.C.B., I.T.M., G.B.), Neurologic Surgery patients beyond 24 hours may remain potentially treatable and
(G.L., J.P.K.), Mayo Clinic, 200 1st Street Southwest, Rochester, MN 55902;
Department of Neuroradiology (S.A.), National Institute Of Mental Health & Neuro represents an area of ongoing investigation. In late-window sce-
Sciences (NIMHANS), Hosur Main Road, Lakkasandra, Ayappa Garden, Adugodi, narios, treatment decisions are not based on time alone, but on
Bengaluru, Karnataka 560029, India; Department of Radiology (R.R.), Massachusetts
General Hospital, 55 Fruit St, Boston, MA 02114 and Department of Neuroradiology the patient’s clinical status, occlusion site, infarct burden, pre-
(D.A.L.), Rockefeller Neuroscience Institute, West Virginia,University, Morgantown, stroke functional status, comorbidities, and emergency imaging
WV, USA.
findings.
Corresponding Author:Pranjal Rai, MD, Address: 1804, 2nd St, SW, Apt. 2, Rochester
MN 55902; e-mail: ; Telephone no. (507)-250-9777 Second, rapid parenchymal and vascular imaging is the mini-
http://dx.doi.org/10.3174/ajnr.A9455 mum imaging framework for acute stroke triage, while advanced
AJNR Am J Neuroradiol : 2026 www.ajnr.org 1
Copyright 2026 by American Society of Neuroradiology.
, tissue imaging (CT and MR perfusion), remains diagnostically including a meta-analysis of 14 studies showing low rates of acute
useful, particularly for extended-window IVT, smaller or distal kidney injury (3%) and hemodialysis (0.07%) after
occlusions; however, it should be viewed as adjunctive rather CTA/CTP.10,11 A second example is advanced imaging for EVT
than universally essential for EVT selection. This distinction is selection in the 6- to 24-hour window. Previously recommended
discussed in greater detail in the subsequent IVT and EVT at COR: 1, LOE: A, this has been changed to COR: 2a, LOE: A in
sections. 2026.3 The guideline now states that adjunctive CTP or MR
In the subsequent sections, Class of Recommendation (COR) DWI-PWI with automated post-processing can be useful if im-
and Level of Evidence (LOE) are reported according to the mediately available, rather than uniformly recommended. This
AHA/ASA framework. COR: 1 indicates a strong recommenda- likely reflects broader trial evidence from large core trials
tion in which benefit greatly exceeds risk; 2a indicates a moderate (RESCUE-Japan LIMIT, SELECT2, ANGEL-ASPECT, and
recommendation in which the intervention is reasonable; 2b indi- LASTE) which showed that even patients with lower ASPECTS
cates a weaker recommendation in which the intervention may score and large core infarcts may still benefit from EVT and con-
be considered; 3—No Benefit, indicates that the intervention is tinued patient selection based on the more strict criteria outlined
T
not useful or effective; and 3—Harm indicates that the interven- in DAWN and DEFUSE 3 may exclude such patients.12–16
tion may be harmful and should not be performed. LOE: A ¼
IP
high-quality evidence; B-R ¼ moderate-quality randomized evi- Systems-Level, and Population-Specific Updates
dence; B-NR ¼ moderate-quality nonrandomized evidence; C- Given the accumulating evidence supporting direct triage to angi-
R
LD ¼ limited data; and C-EO ¼ consensus expert opinion. ography suite (DTAS) in AIS patients with LVO, the guideline
provides two DTAS-related recommendations. For suspected
SC
Imaging Workflow and Advanced Imaging Selection LVO identified by validated prehospital assessment, DTAS may
Some of the prior guidelines remain unchanged. For example,
be considered for flat-panel CT followed by catheter-based angi-
emergency brain imaging (NCCT) is still recommended on initial
ography (COR: 2b, LOE: B-R). In transferred patients with AIS
evaluation to assess ischemic burden and exclude intracranial
due to LVO, who remain EVT eligible, DTAS without repeating
U
hemorrhage before reperfusion interventions (COR: 1, LOE:
brain imaging may be considered (if there is no clinical change or
A).3,8,9 The recommendation for MRI for initial evaluation how-
transfer delay) (COR 2b, LOE: B-NR). This is based on several
AN
ever has been updated, and is now at par with NCCT (COR: 1,
studies supporting DTAS, including a multicenter study of 1140
LOE: A). The 2026 guideline preserves the same operational mes-
patients which showed shorter arrival to groin puncture (34 min
sage by stating that in suspected AIS with LVO within 24 hours,
versus 60 min) as well as better functional and safety outcomes.17
brain and vascular imaging with either NCCT or MRI should be
Notably, the 2026 guideline also introduces dedicated recom-
M
performed as rapidly as possible for EVT selection and treatment
mendations for pediatric stroke care, reflecting an expanding evi-
planning (COR 1, LOE A) while also reiterating that advanced
dence base and the need for more standardized guidance in this
imaging is not required in every early-window case.3 Similarly,
population.3 Finally, another important update in the 2026 guide-
D
the emphasis on rapid imaging and treatment persists, although
lines has been the incorporation of patient age, type of vessel
the 2026 guideline explicitly targets door-to-imaging within
occlusion, time since onset, underlying ASPECTS score and base-
TE
approximately 25 minutes (COR: 1, LOE: B-NR).3,8,9 Current
line mRS to provide level of evidence for EVT, which can be seen
guidelines also maintain some older core eligibility framework,
as steps toward a more personalized recommendation for AIS
especially with respect to intravenous alteplase administration
management. Figures 1-3 summarize the proposed EVT treat-
(now more broadly termed intravenous thrombolysis [IVT] fol-
EP
ment algorithms derived from the 2026 AHA/ASA guidelines for
lowing inclusion of tenecteplase). Whereas prior guidelines
adult anterior circulation stroke, adult posterior circulation
issued separate recommendations for IV alteplase (0.9 mg/kg) in
stroke, and pediatric stroke, respectively.
the 0-3 hour (COR: 1; LOE: A) and 3-4.5 hour (COR: 1; LOE: B-
C
R) windows, the 2026 update preserves this treatment paradigm
but streamlines it into a single Class 1 recommendation for eligi- INTRAVENOUS THROMBOLYSIS
AC
ble patients presenting within 4.5 hours of symptom onset (COR One of the most consequential IVT-related updates in the 2026
1; LOE B-NR), while also clarifying that treatment should not be guideline is the elevation of tenecteplase to a co–first-line throm-
delayed for additional imaging, including not only CT/MR perfu- bolytic alongside alteplase. In the prior guidance, tenecteplase
sion but also CTA or MRA. As in the previous update, patients was positioned more narrowly, described as a “reasonable” alter-
presenting ,24 hour of last known well should undergo emer- native at 0.25 mg/kg for patients otherwise eligible for thrombec-
gency brain and vascular imaging (CT/CTA or MRI/MRA) of the tomy and as an option that “might be considered” at 0.4 mg/kg in
cervical and intracranial circulation as rapidly as possible to guide patients with minor neurologic impairment and no major intra-
EVT selection and treatment planning (COR 1, LOE A). cranial occlusion. The current guideline more explicitly defines
Some recommendations retain the same core principle but tenecteplase’s role, stating that for eligible patients treated within
have been expanded or recalibrated in strength in the 2026 4.5 hours, either alteplase or tenecteplase may be administered,
update. For example, under the new guidelines, CTA and/or CTP with a dedicated dosing table and a recommended tenecteplase
imaging should not be delayed while awaiting serum creatinine, dose of 0.25 mg/kg (maximum 25 mg). Importantly, the guideline
regardless of any prior history of renal impairment (COR: 1, advises against the 0.4 mg/kg regimen, citing concern for
LOE: B-NR). This change is supported by accumulating evidence, increased symptomatic intracranial hemorrhage without
2 Rai 2026 www.ajnr.org
