Blood pressure and the risk of rebleeding and delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

Elevated Blood Pressure and Culprit Aneurysm Rebleeding During the Unsecured Period of Aneurysmal Subarachnoid Hemorrhage: A Systematic Review

In aneurysmal subarachnoid hemorrhage, rebleeding prior to securing the culprit aneurysm leads to significant morbidity and mortality. Elevated blood pressure has been identified as a possible risk factor. In this systematic review, we evaluated the association between elevated blood pressure and aneurysm rebleeding during the unsecured period. We searched MEDLINE, Embase + Embase Classic, and CENTRAL, from inception to March 8th, 2024. We included studies of adults with aneurysmal subarachnoid hemorrhage reporting at least one blood pressure measurement during the unsecured period and a measure of association with rebleeding. Results were stratified by blood pressure thresholds, effect measure, and adjustment for confounding. Separate meta-analyses were performed for each of these groups. Our search identified 5,209 citations. After screening, 15 studies were included in our review. All studies were observational in design and at moderate or high risk of bias. Meta-analysis of the unadjusted results produced mixed findings across the systolic blood pressure (SBP) thresholds: SBP > 140 mm Hg, unadjusted odds ratio (uOR) 1.03 (95% confidence interval [CI] 0.55-1.93; I2 = 66%); SBP > 160 mm Hg, uOR 3.35 (95% CI 1.44-7.81; I2 = 83%); SBP > 180 mm Hg, uOR 1.52 (95% CI 0.40-5.81; I2 = 89%); and SBP > 200 mm Hg, uOR 7.99 (95% CI 3.60-17.72; I2 = 0%). Meta-analysis of adjusted results was only possible at an SBP > 160 mm Hg; adjusted hazard ratio 1.13 (95% CI 0.98-1.31; I2 = 0%). The overall quality of evidence as assessed by the Grading of Recommendations, Assessment, Development, and Evaluations tool was rated as very low. Based on very low quality evidence, our systematic review failed to determine whether there is an association between elevated blood pressure during the unsecured period and increased risk of culprit aneurysm rebleeding.

Leveraging machine learning algorithms to forecast delayed cerebral ischemia following subarachnoid hemorrhage: a systematic review and meta-analysis of 5,115 participants

It is feasible to predict delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH) using Artificial intelligence (AI) algorithms, which may offer significant improvements in early diagnosis and patient management. This systematic review and meta-analysis evaluate the efficacy of machine learning (ML) in predicting DCI, aiming to integrate complex clinical data to enhance diagnostic accuracy. We searched PubMed, Scopus, Web of science, and Embase databases without restrictions until June 2024, applying PRISMA guidelines. Out of 1498 studies screened, 10 met our eligibility criteria involving ML approaches in patients with confirmed aSAH. The studies employed various ML algorithms and reported differential ML metrics outcomes. Meta-analysis was performed on eight studies, which resulted in a pooled sensitivity of 0.79 [95% CI: 0.63-0.89], specificity of 0.78[95% CI: 0.68-0.85], positive DLR of 3.54 [95% CI: 2.22-5.64] and the negative DLR of 0.28 [95% CI: 0.15-0.52], diagnostic odds ratio of 12.82 [95% CI: 4.66-35.28], the diagnostic score of 2.55 [95% CI: 1.54-3.56], and the area under the curve (AUC) of 0.85. These findings show significant diagnostic accuracy and demonstrate the potential of ML algorithms to significantly improve the predictability of DCI, implying that ML could impart a significant role on improving clinical decision making. However, variability in methodological approaches across studies shows a need for standardization to realize the full benefits of ML in clinical settings.

Relationship between cumulative blood pressure exposure within the early brain injury time window and delayed cerebral ischemia and rebleeding in patients with aneurysmal subarachnoid hemorrhage after aneurysm clipping: a retrospective study

Delayed cerebral ischemia, one of the most common complications following aneurysmal subarachnoid hemorrhage, was strongly related to poor patient outcomes. However, there are currently no clear guidelines to provide clinical guidance for post-craniotomy management. Our research aims to explore the association between cumulative blood pressure exposure during the early brain injury phase and the occurrence of delayed cerebral infarction and rebleeding following surgical aneurysm clipping. All baseline characteristics of the patients were meticulously recorded. We collected blood pressure data 25 times in 48 h after surgery for subsequent analysis. Cumulative blood pressure exposure is calculated by the product of the time spent below a specific blood pressure threshold and the cumulative exposure time. The principal outcome is the incidence of Delayed Cerebral Infarction, while the secondary outcome pertains to postoperative rebleeding. Logistic regression was utilized to examine the relationship. The cumulative exposure to mean arterial pressure at and below 85 mmHg demonstrated a significant association with DCI occurrence. However, no significant statistical correlation was found between hypertensive exposure and rebleeding events. The results from the sensitivity analysis remained consistent, and the lack of significant interactions further supports the robustness of the study findings. The identified threshold of 85 mmHg could potentially represent a critical blood pressure management parameter for post-surgical aneurysm clipping patients. These findings merit further investigation through larger prospective clinical trials.

Blood Pressure Management in Early Aneurysmal Subarachnoid Hemorrhage: A National Cross-Sectional Survey of Canadian Intensivists and Cerebrovascular Neurosurgeons

BACKGROUND

In aneurysmal subarachnoid hemorrhage (aSAH), rebleeding of the culprit aneurysm is associated with significant morbidity and mortality. Blood pressure reduction to specific target levels, with the goal of preventing rebleeding, has been a mainstay of care prior to definitively securing the aneurysm. Clinical practice guidelines have recently changed and no longer recommend specific blood pressure targets. This survey aims to identify the reported practice patterns and beliefs regarding blood pressure management during the early phase of aSAH.

METHODS

We conducted a self-administered, Web-based survey of critical care physicians and cerebrovascular neurosurgeons practicing in Canada. The questionnaire contained 21 items, including 3 case-based scenarios to elicit blood pressure target selection, both before and after aneurysm securing.

RESULTS

In the presecured period, systolic blood pressures of 160 mm Hg (50% [144 of 287]) and 140 mm Hg (42% [120 of 287]) were the most frequently selected upper-limit targets. In the postsecured period, a systolic blood pressure of 180 mm Hg (32% [93 of 287]) was the most frequently selected upper-limit target, but there was a wide distribution of targets selected across all three cases ranging from 100 to > 200 mm Hg. A mean arterial pressure of 65 mm Hg was the most common lower-limit target in both the presecured and postsecured periods. There was little change in blood pressure targets with increasing clinical severity. Predictors of higher or lower blood pressure target selection and barriers to implementation of the desired target were identified.

CONCLUSIONS

During the presecured period, nearly half of the reported upper-limit blood pressure targets are lower than previous guideline recommendations. These targets remain consistent despite increasing clinical severity and could potentially exacerbate cerebral ischemia and negatively impact clinical outcomes. In the postsecured period, there is wide variation in the reported blood pressure targets. A clinical trial is urgently needed to guide decision-making.

Comparison of LVIS and Enterprise stent-assisted coiling embolization for ruptured intracranial aneurysms: a propensity score-matched cohort study

The role of a low-profile visualized intraluminal support stent (LVIS) and Enterprise in the treatment of unruptured intracranial aneurysms is well established. Although previous studies have investigated one single type of stent for the treatment of ruptured intracranial aneurysms (RIA), the safety and efficacy between the two types of stents has not been fully explored. Herein we conducted a study to compare the outcomes of the two stents for treatment of RIA. This is a prospective registry database of aneurysmal subarachnoid hemorrhage (aSAH) patients admitted to a single institution between 2018 and 2021. We collected patient baseline information, secondary complications, follow-up angiographic data, long-term prognostic outcomes, and conducted propensity score matching (PSM) analysis with 1:1 ratio and a multivariable logistic regression to compare the outcomes of the two types of stents. A total of 231 patients with RIAs were included in this study, with 108 treated using the LVIS device and 123 treated using the Enterprise device. Before PSM analysis, only the incidence of poor prognosis after 12 months was higher in the Enterprise group comparing to the LVIS group (20% vs. 10%, P = 0.049). After PSM analysis, there was a higher occurrence of delayed cerebral ischemia (DCI) in the Enterprise group compared to the LVIS group (odds ratio [OR] 3.95, 95% confidence interval [CI] [1.20-13.01], P = 0.024). However, no significant difference in prognosis was observed after PSM adjustment. Furthermore, subgroup analysis revealed that patients with female (P = 0.019), hypertension (P = 0.048), and anterior circulation aneurysms (P = 0.019) receiving the Enterprise device had a higher risk of DCI. The overall efficacy of LVIS and Enterprise in the treatment of RIA is comparable, while the incidence of DCI in the LVIS group is lower than that in the Enterprise group after PSM analysis. Registration number: NCT05738083 ( https://clinicaltrials.gov/ ).

Association between estimation of pulse wave velocity and all-cause mortality in critically ill patients with non-traumatic subarachnoid hemorrhage: an analysis based on the MIMIC-IV database

Background

Estimated pulse wave velocity (ePWV), which measures vascular aging, is an independent predictor of cardiovascular death. Nevertheless, the relationship between ePWV and all-cause mortality among patients suffering from non-traumatic subarachnoid hemorrhages (NSAH) remains obscure. Consequently, the objective of this study is to ascertain whether ePWV exerts influence on the prognosis of individuals afflicted with NSAH.

Methods

Through the Medical Information Mart for Intensive Care IV (MIMIC-IV) database, 644 eligible participants were included. The Kaplan-Meier survival curve method was employed to assess the disparity in survival status between the low and high ePWV cohorts. The Cox proportional hazard model was employed to investigate the association between ePWV and inpatient mortality among critically ill patients diagnosed with NSAH. The Restricted Cubic Spline (RCS) model was employed to examine the dose-response correlation. Subsequently, multivariate Cox regression analysis was performed to identify independent prognostic factors. Lastly, the impact of ePWV on inpatient mortality across various subgroups was evaluated through stratified analysis.

Results

Participants were categorized into two groups, delineated by their ePWV levels: a low ePWV level group and a high ePWV level group. Survival analysis unveiled that individuals with high ePWV exhibited a diminished survival rate compared to their counterparts with low ePWV. Following adjustment, low ePWV was significantly linked with a reduced risk of inpatient mortality among patients with NSAH (HR = 0.54, 95% CI = 0.32-0.89, p = 0.016). Simultaneously, analysis employing the RCS model further substantiated a linear escalation in the risk of inpatient mortality with increasing ePWV values.

Conclusion

Elevated ePWV levels have been identified as an independent risk factor for the rise in inpatient mortality among NSAH patients and as a significant predictor of the clinical outcome of NSAH.

Comparison of the Effects of Blood Pressure Parameters on Rebleeding and Outcomes in Unsecured Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Elevated systolic blood pressure (SBP) has been linked to preprocedural rebleeding risk and poor outcome in patients with aneurysmal subarachnoid hemorrhage (aSAH). This study seeks to compare the effects of SBP and mean arterial pressure (MAP) on rebleeding and functional outcomes in aSAH patients.

METHODS

We performed a retrospective study of a prospectively collected cohort of consecutive patients with aSAH admitted to an academic center in 2016-2023. Binary regression analysis was used to determine the association between BP parameters and outcomes including rebleeding and poor outcome defined as modified Rankin Scale 4-6 at 3 months postdischarge.

RESULTS

The cohort included 324 patients (mean age 57 years [standard deviation 13.4], 61% female). Symptomatic rebleeding occurred in 34 patients (11%). Higher BP measurements were recorded in patients with rebleeding and poor outcome, however, only MAP met statistical significance for rebleeding (odds ratio {OR} 1.02 for 1 mmHg increase in MAP, 95% confidence interval {CI}: 1.001-1.03, P = 0.043; OR 1 per 1 mmHg increase in SBP, 95% CI 0.99-1.01; P = 0.06)) and for poor outcome (OR 1.01 for 1 mmHg increase in MAP, 95% CI: 1.002-1.025, P = 0.025; OR 1 for 1 mmHg increase in SBP, 95% CI: 0.99-1.02, P = 0.23) independent of other predictors.

CONCLUSIONS

MAP may appear to be slightly better correlated with rebleeding and poor outcomes in unsecured aSAH compared to SBP. Larger prospective studies are needed to identify and mitigate risk factors for rebleeding and poor outcome in aSAH patients.

Twelve controversial questions in aneurysmal subarachnoid hemorrhage

Critical care management of aneurysmal subarachnoid hemorrhage (aSAH) remains a major challenge. Despite the recent publication of guidelines from the American Heart Association/American Stroke Association and the Neurocritical Care Society, there are many controversial questions in the intensive care unit (ICU) management of this population. The authors provide an analysis of common issues in the ICU and provide guidance on the daily management of this specific population of neurocritical care patients.