Unpacking the 2023 American Heart Association Guidelines: The Ascendancy of Neuroendovascular and Neurocritical Care in Aneurysmal Subarachnoid Hemorrhage Management

 When the hell will we get EXACT PROTOCOLS that follow from an EXACT DAMAGE DIAGNOSIS? Until then you better hope your doctor guesses correctly.

Unpacking the 2023 American Heart Association Guidelines: The Ascendancy of Neuroendovascular and Neurocritical Care in Aneurysmal Subarachnoid Hemorrhage Management

Fawaz Al‐Mufti, MD https://orcid.org/0000-0003-4461-7005 fawaz.al-mufti@wmchealth.org, and Stephan Mayer, MDAuthor Info & Affiliations

Stroke: Vascular and Interventional Neurology

Volume 4, Number 4

https://doi.org/10.1161/SVIN.123.001264

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• Nonstandard Abbreviation and Acronym
• Guiding Precision Care and Tailoring Treatment: Neuroendovascular Techniques at the Forefront
• The Rise of Neurocritical Care
• References
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Nonstandard Abbreviation and Acronym

B‐NR evidence

moderate‐quality evidence

The publication of the 2023 American Heart Association (AHA) Guidelines for the Management of Aneurysmal Subarachnoid Hemorrhage represents a milestone in the evolving landscape of cerebrovascular medicine.¹ In this commentary, we aim to examine the fundamental shifts brought into focus by these updated guidelines, highlighting the pivotal roles of neuroendovascular management and the neurocritical intensive care unit (neuro‐ICU). While neurointerventionalists have traditionally played a pivotal role in the management of this condition, these guidelines now expand their responsibilities beyond the confines of the operating room.

Traditionally, aneurysmal subarachnoid hemorrhage (aSAH) management has been centered around the timely repair of ruptured cerebral aneurysms. Indeed, the urgency of preventing rebleeding and securing the aneurysm cannot be overstated, as it most significantly impacts patient outcomes. However, the 2023 AHA Guidelines introduce a paradigm shift by recognizing that the battle against aSAH is 2‐fold. While aneurysm repair remains a critical front, there is a more equitable consideration of securement modality. Furthermore, the neuro‐ICU emerges as an equally vital theater where the clinical outcome is determined.

Guiding Precision Care and Tailoring Treatment: Neuroendovascular Techniques at the Forefront

The updated guidelines for managing aSAH emphasize the importance of personalized treatment strategies that consider the unique characteristics of each aneurysm.¹ Extensive research, exemplified by landmark studies such as the ISAT (International Subarachnoid Aneurysm Trial) and the BRAT (Barrow Ruptured Aneurysm Trial), has provided compelling evidence in favor of coiling as the preferred method, particularly for improving patient outcomes in the critical first year following treatment. However, the landscape of aneurysm management is far from 1‐size‐fits‐all, and these guidelines acknowledge the need for a tailored approach(So guessing).

Timing of Treatment

These guidelines stress the significance of prompt intervention for aSAH.¹ Whether through open surgery or endovascular procedures, treating the ruptured aneurysm as early as possible after presentation, preferably within 24 hours, is strongly recommended. This emphasis on timely care reflects the evolving landscape of aneurysm treatment, where precision and expeditiousness are central to achieving the best results for patients. This recommendation is classified as class I, supported by level B‐NR (nonrandomized) evidence. Delaying treatment, particularly beyond a 3‐day window, is discouraged.

Treatment Goal

The primary objective in treating patients with aSAH is the complete obliteration of the ruptured aneurysm whenever feasible(Why not 100% recovery? That's what all survivors want?).¹ This strategy is advocated to reduce the risk of rebleeding and the need for retreatment. In cases for which immediate complete obliteration is not achievable, partial obliteration to secure the rupture site is an acceptable strategy(So failure is acceptable? Good to know!), with retreatment considered for those displaying functional recovery. This recommendation is also classified as class I, with level B‐NR evidence.

Modality of Treatment for Posterior Circulation Aneurysms

These guidelines provide specific guidance for aSAH resulting from ruptured aneurysms in the posterior circulation.¹ In cases in which coiling these aneurysms is feasible, it is recommended over surgical clipping to enhance patient outcomes. This partiality is supported by class I evidence with level B‐R (randomized).

Emergency Clot Evacuation

For patients with aSAH considered salvageable but presenting with a depressed level of consciousness due to a large intraparenchymal hematoma, emergency clot evacuation is recommended.¹ This intervention is pivotal in reducing death and is classified as a class I recommendation with level B‐R evidence.

Specialist Evaluation

The guidelines underline the importance of involving specialists with expertise in both endovascular and surgical treatments for evaluating ruptured aneurysm.¹ This assessment is essential for determining the most suitable treatment approach tailored to individual patient and aneurysm characteristics. Although categorized as class IIb, this recommendation is supported by level B‐R evidence.

Age‐Specific Considerations

Age plays a crucial role in treatment decisions for patients with aSAH.¹ The efficacy of coiling or clipping in improving outcomes for individuals aged >70 years is uncertain, marked as a class IIb recommendation with level C‐LD (limited data) evidence. Conversely, for patients aged <40 years, surgical clipping of the ruptured aneurysm may be considered preferable to enhance treatment durability and overall outcome.

Modality of Treatment for Equally Suitable Aneurysms

In cases of good‐grade aSAH stemming from ruptured aneurysms in the anterior circulation, where primary coiling and clipping are both viable, the 2023 AHA guidelines endorse primary coiling for superior 1‐year functional outcomes.¹ Supported by level A evidence, this recommendation holds a class I designation. However, both treatment options are considered reasonable to achieve favorable long‐term outcomes, constituting a class IIa recommendation with level B‐R evidence.

Endovascular Advancements

These guidelines underscore the growing acceptance of advanced techniques in aneurysm treatment, particularly for wide‐neck aneurysms resistant to traditional methods.¹ Notably, stent‐assisted coiling and flow diversion have gained favor.

Use of Flow Diverters for Fusiform/Blister Aneurysms

In cases of aSAH from ruptured fusiform or blister aneurysms, the use of flow diverters is considered reasonable to reduce death, as indicated by a class IIa recommendation with level C‐LD evidence.¹

Stents or Flow Diverters for Saccular Aneurysms

It is crucial to note, however, that for patients with aSAH with ruptured saccular aneurysms suitable for either primary coiling or clipping, the guidelines advise against using stents or flow diverters due to a higher risk of complications.¹ This recommendation is classified as class III, indicating harm, with level B‐NR evidence. In such instances, where coiling is not deemed suitable or when there is a state of equipoise, the guidelines emphasize the importance of comprehensive multidisciplinary discussions. These discussions should carefully weigh the merits of both neurosurgical and neuroendovascular alternatives, considering each patient's unique circumstances and clinical presentation.

In summary, these guidelines represent a significant step forward in tailoring aSAH treatment to individual patient needs. By emphasizing precision and timeliness in intervention, they aim to achieve the best possible outcomes for patients facing this critical medical condition. The growing acceptance of advanced techniques reflects the dynamic nature of aneurysm management, highlighting the importance of staying abreast of evolving treatment options and engaging in thoughtful, multidisciplinary discussions to optimize patient care.

The Rise of Neurocritical Care

The neuro‐ICU has, in recent years, transitioned from a supporting role to taking center stage in aSAH management. This change is not arbitrary; it is substantiated by a growing body of evidence that underscores the importance of specialized critical care for patients with aSAH.² Multidisciplinary teams in neuro‐ICUs have been shown to significantly enhance patient survival and improve overall outcomes. These teams bring together neurointensivists, neurosurgeons, interventionists, nurses, and other specialists, working in concert to provide the highest standard of care.

The rationale behind this shift is also founded on comparative effectiveness research that consistently demonstrates the benefits of specialized neurocritical care.³ High‐volume centers equipped with dedicated neuro‐ICUs have consistently reported lower mortality rates and improved patient outcomes. This is not merely a theoretical concept but a practical reality that demands acknowledgment and implementation.

Ultimately, the 2023 AHA guidelines serve as a call to action for the medical community, urging physicians, hospitals, medical societies, and national organizations to recognize and champion the importance of neuro‐ICUs in aSAH management.¹ With these guidelines, it is recognized that comprehensive care for patients with aSAH encompasses not only surgical prowess but also the intricate and specialized care delivered within the neuro‐ICU.

Refresher on Mechanical Ventilation

The 2023 guidelines sought to reduce the duration of mechanical ventilation and the risk of hospital‐acquired pneumonia, recognizing that optimal outcomes for critically ill ventilated patients are more likely when evidence‐based care bundles are applied.¹ For patients experiencing aSAH who require mechanical ventilation for >24 hours, it is strongly recommended to implement a standardized ICU care bundle. This recommendation underscores the importance of drawing from the extensive research conducted in both medical and surgical ICUs and consistently applying these principles to patients with high‐grade aSAH (HG‐aSAH). The core components of the ventilator bundle, often referred to as “ABCDEF,” encompass the following aspects:

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Assess, prevent, and manage pain

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Both spontaneous awakening trials and spontaneous breathing trials

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Choice of analgesia and sedation

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Delirium: assess, prevent, and manage

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Early mobility and exercise

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Family engagement and empowerment

In practical terms, what this means for patients with HG‐aSAH is 2‐fold. First, there is substantial evidence supporting the reduction in the use of opioid narcotics and a preference for nonsteroidal anti‐inflammatory drugs like acetaminophen, ibuprofen, and ketorolac.⁴ Second, it involves the regular interruption of sedation, at least once daily, to assess the patient's neurological status and prevent excessive sedation.

Effective prevention of delirium, a common challenge after aSAH, is achieved by avoiding benzodiazepine sedation. Instead, dexmedetomidine is recommended for achieving light sedation while also helping to manage the autonomic dysregulation (ie, storming) often seen in these patients.⁵ Finally, systematic early mobilization necessitates a substantial commitment from both physical therapy and nursing teams. For example, every Hunt–Hess grade III patient capable of following commands with an external ventricular drain should be ambulated daily. These initiatives are best organized and led by a dedicated team of neurointensivists.

Advancements in Neuromonitoring

The updated guidelines emphasize the importance of employing advanced monitoring techniques in the management of patients with HG‐aSAH, particularly when their neurological examination is limited.¹ The direction of neurocritical care, especially for severe brain injuries like HG‐aSAH, is undeniably moving toward sophisticated multimodality brain monitoring. The foundation of this approach involves initiating long‐term continuous video electroencephalogram monitoring, a practice that should be maintained for at least 48 hours in all comatose patients, including those with HG‐aSAH.⁶

Studies have indicated that nonconvulsive seizures are more prevalent in this patient population than previously thought, with a frequency ranging from 10% to 30%.⁷ Importantly, there is substantial evidence to suggest that electrographic seizure activity can significantly impact the patient's level of consciousness and exacerbate secondary brain injury. Furthermore, nonconvulsive seizures have been identified as potential mimics of delayed cerebral ischemia (DCI) after aSAH.^{8, 9}

In recent years, there has been a notable surge in interest and research dedicated to neuromonitoring techniques, encompassing both invasive and noninvasive approaches. One particularly intriguing noninvasive method is transcranial Doppler, often likened to a highly sophisticated ultrasound for the brain. It stands out with an impressive sensitivity exceeding 90%, making it a valuable bedside tool for detecting cerebral abnormalities. However, it is equally important to acknowledge the inherent limitations of this technique. While it excels in sensitivity, it exhibits a specificity of 71% and is also limited by a positive predictive value of 57%. These statistics underscore the need for cautious interpretation and consideration of other clinical factors when using transcranial Doppler data.

Quantitative electroencephalogram patterns have emerged as another noninvasive neuromonitoring approach with great potential.¹ These patterns have shown promise in detecting DCI, with supporting evidence from prospective studies suggesting their clinical relevance. The ability to noninvasively identify DCI is a significant step forward in managing patients with complex neurological conditions.

Invasive neuromonitoring tools, such as brain tissue oxygen monitoring, cerebral microdialysis, and electrocorticography, have also found their place in the realm of DCI detection.¹ This assertion is supported by a comprehensive review encompassing 47 studies. These invasive techniques provide valuable insights into cerebral physiology and can be instrumental in tailoring treatment strategies for individual patients.

In summary, it is important to recognize that the optimal indications and best practices for these neuromonitoring methods are still under investigation. The field continues to evolve as researchers refine their understanding of when and how to deploy these techniques most effectively. Moreover, while these tools hold great promise, their ultimate impact on clinical outcomes in the context of subarachnoid hemorrhage and other neurological conditions remains an area of active exploration.

Antiseizure Medication Controversy

One contentious topic within the management of aSAH that the guidelines grapple with is the use of prophylactic antiseizure medications.¹ While the guidelines do recommend against their routine administration, they do so with an understanding that numerous medical centers continue to adopt a universal approach in administering these medications to patients with aSAH. This disparity in practice highlights the ongoing debate surrounding the benefits and risks associated with prophylactic antiseizure medications in this patient population, particularly in relation to cognitive outcomes.

The rationale for administering prophylactic antiseizure medications stems from concerns about the heightened risk of seizures in patients with aSAH due to the brain's exposure to blood and potential irritants from the hemorrhage. Consequently, some medical institutions have chosen to err on the side of caution by providing antiseizure medications to all patients with aSAH, regardless of their individual risk factors. Although antiseizure medications can effectively reduce the risk of seizures, they are not without their own set of adverse effects. These medications may lead to side effects such as sedation, impaired cognition, and even delirium.

There is a growing body of evidence suggesting that long‐term use of certain antiseizure medications, particularly phenytoin, may be associated with negative cognitive outcomes in patients with aSAH.¹ This raises concerns about whether the potential benefits in terms of seizure prevention outweigh the risks, especially when it comes to the patient's overall cognitive function and quality of life. The cumulative risk of convulsive seizures in hospitalized patients with aSAH has been reported to be 4%. Could the risk of delirium or oversedation from routine antiseizure medication use be higher? It has been reported that continued phenytoin use after discharge in patients with aSAH is associated with worse cognitive outcomes that then improve when the medication is stopped. We do not anticipate any change in practice until clinical trials are conducted to address the issue of antiseizure medication use after aSAH.

The guidelines acknowledge this contentious landscape and the need for further clarity.¹ They highlight the importance of conducting additional clinical trials to better understand the impact of prophylactic antiseizure medications on cognitive outcomes in patients with aSAH. This research would aim to provide concrete evidence regarding the risk–benefit balance, potentially informing more precise recommendations in the future.

Caution Against Hemodynamic Prophylaxis and Hypervolemia

The cautionary approach to hemodynamic augmentation and hypervolemia in the 2023 AHA Guidelines for aSAH management signifies another notable departure from previous strategies.¹ This shift aligns with a broader principle in critical care medicine: the recognition that sometimes less intervention can yield better outcomes. It reflects the acknowledgment that excessive medical interventions, even with the best intentions, can lead to unintended complications that may worsen the patient's condition.

One of the critical aspects of this cautionary approach is the recognition of potential complications associated with aggressive hemodynamic management.¹⁰ By attempting to artificially increase blood pressure or volume in patients with aSAH, health care providers may inadvertently trigger an adverse event. In certain circumstances, we may develop a strong fixation on pursuing active interventions, making it quite tempting to deviate from established protocols. For instance, one might consider, “I know that per the guidelines we're only supposed to induce hypertension in the face of symptomatic vasospasm, but I'm concerned about this particular patient.” In addition to potentially fatal complications such as myocardial infarction and pulmonary edema, the guidelines highlight the risk of exacerbating intracranial pressure, which can be detrimental in patients with aSAH, who are already at risk of elevated pressure within the skull. Additionally, there is the practice of prophylactically inducing hypertension to arbitrary blood pressure targets in every patient. This is a common occurrence.

Another noteworthy concern is the possibility of inducing posterior reversible encephalopathy syndrome, a neurological condition characterized by symptoms such as headache, altered mental status, seizures, and visual disturbances. Posterior reversible encephalopathy syndrome can occur when there is a sudden increase in blood pressure, which can result from aggressive attempts to elevate it in patients aSAH. Recognizing the potential harm of such interventions is crucial in avoiding these complications.

As a final deterrent from aggressive hemodynamic management, the guidelines draw attention to the concept of pressor dependence.¹ This phenomenon is thought to occur when patients are subjected to aggressive blood pressure management, resulting in their bodies becoming reliant on medications to sustain blood pressure within a reasonable target range. This can make it challenging to wean patients off these medications without their blood pressure dropping below the desired threshold. Even if only occurring in the thoughts and concerns of the neuro‐ICU team, this phenomenon can lead to prolonged hospital stays and increased health care resource usage.

More Oral Nimodipine?

With a continuance of the 2012 recommendations, the updated guidelines stamp the significance of early enteral nimodipine initiation in preventing DCI and enhancing functional outcomes in cases of aSAH.¹

In clinical practice, the administration of oral nimodipine occurs along a schedule of 60 mg every 4 hours, following the precedent set by the British Nimodipine Trial in 1989.¹¹ Unfortunately, this regimen often gets discontinued as soon as patients with aSAH exhibit symptomatic vasospasm due to its tendency to cause systemic hypotension. As a result, health care providers often resort to halving the dosage or, more commonly, suspending nimodipine altogether.

The question that has persisted over time is whether there might be superior agents or administration protocols for arterial vasodilators that could provide more effective alternatives.¹ Examples include continuous intravenous infusion of nimodipine, a practice prevalent in Europe, or the use of fasudil and clazosentan, which are favored in Japan. However, it is crucial to note that the current body of evidence does not support an immediate shift in US clinical practice. This underscores the dynamic nature of medical practice, with a recognition that as science advances, treatment strategies may evolve to provide better outcomes for patients with aSAH.

Taking the Guidelines Into Practice

In managing cases of aSAH, it is crucial to recognize that there is not a definitive volume threshold that guides treatment decisions. Each patient's condition must be carefully evaluated, highlighting the importance of individualized care. Timely transfer of patients presenting with acute severe headaches or new neurological deficits is paramount to ensure they undergo appropriate diagnostic assessments and receive specialized care as needed. Patients presenting >6 hours after the onset of severe headaches or those with new neurological deficits should undergo a noncontrast head computed tomography. If this initial scan is negative for aSAH, lumbar puncture becomes essential to confirm or exclude the presence of subarachnoid blood. Similarly, for individuals with spontaneous aSAH and a strong suspicion of aneurysmal involvement but inconclusive results from computed tomography angiography, digital subtraction angiography is the recommended diagnostic tool to identify or rule out cerebral aneurysms promptly.

Prompt identification of aneurysmal sources remains a paramount concern for clinical management.¹ Comprehensive use of advanced imaging methods, such as CT angiography, can significantly aid in this regard. Furthermore, using established grading scales can aid in outcome prediction and guide discussions with patients, families, and surrogates regarding treatment choices. Decisions regarding the treatment of ruptured aneurysms should be made by specialists well versed in both endovascular and surgical approaches. Ultimately, the determination to use clipping, coil embolization, or even flow diversion should be tailored to the patient's distinctive characteristics and the aneurysm's unique features. As highlighted by the current guidelines, there is a growing preference for coil embolization for good‐grade aSAH cases originating from anterior circulation ruptured aneurysms.¹

Neuro‐ICU management should encompass preventive measures such as deep vein thrombosis prophylaxis, maintaining euvolemia, and thoughtful fluid management.¹ While invasive neuromonitoring techniques are increasingly valuable for detecting DCI in high‐grade aSAH cases, the specific goals for fluid management require further clarification. Although the risk of rerupture in aSAH cases is relatively low, the use of imaging to guide treatment decisions for survivors in the neuro‐ICU is recommended, particularly in individuals with residual aneurysms. Regular monitoring for the development of new aneurysms is also essential, especially in younger patients with multiple aneurysms or a strong family history of aSAH.

Additionally, considerations such as the timing of cerebrospinal fluid diversion, choice of fluids, sodium goals, temperature management, glucose control, and monitoring of intracranial pressure and multimodal monitoring are important aspects of comprehensive aSAH management that deserve further attention and investigation.¹ Finally, early identification of deficits, especially in behavioral and cognitive domains, is crucial. Interventions for mood disorders can significantly improve long‐term outcomes, and providing counseling on the higher risk of long‐term cognitive dysfunction may prove beneficial for patients recovering from aSAH.

References at link.