Blood pressure variability and outcome in acute severe stroke: A post hoc analysis of CHASE-A randomized controlled trial

Predicting 24-Hour Blood Pressure Variability Post Thrombectomy Using Machine Learning for Patients with Ischemic Stroke from Anterior Circulation Large Vessel Occlusion

BACKGROUND

Mechanical thrombectomy is the standard of care for patients with ischemic stroke from large vessel occlusion. Blood pressure variability (BPV) in the post thrombectomy period is associated with poor functional outcomes. To determine predictive factors associated with increased BPV, a machine learning algorithm was used to identify factors that are linked with increased BPV indices at 24 hours post thrombectomy.

METHODS

This retrospective study examined all patients from a Comprehensive Stroke Center's registry who underwent mechanical thrombectomy between January 2016 and December 2019. The primary outcome was BPV between patients who had adequate reperfusion post thrombectomy (Thrombolysis in Cerebral Infarction [TICI] grading 2b+) and those who did not. The secondary outcomes were good functional status at 90 days (modified Rankin Scale ≤2) and reperfusion (TICI 2b+). Random forest analysis was leveraged to determine predictors for BPV with reported root mean square error and normalized root mean square error metrics. Multivariable regression analysis was used to determine factors significantly associated with secondary outcomes. P < 0.05 was the threshold for statistical significance.

RESULTS

A total of 395 patients (49%, n = 195 females and 51%, n = 200 males) were included in the final analysis with mean age (± standard deviation) of 65 (±15) years. TICI 2b+ was achieved in 322 (82%) patients. Median Alberta stroke program early CT score and National Institutes of Health Stroke Scale (NIHSS) were 9 and 18, respectively. Higher age, NIHSS, number of passes, and mechanical ventilation were significantly associated with lower likelihood of modified Rankin Scale ≤2 at 90 days in multivariable regression analysis.

CONCLUSIONS

This study identified the interval from last-known-well time-to-groin puncture, age, and NIHSS as factors significantly associated with increased 24-hour BPV in random forest analysis. These predisposing factors in our machine learning analysis allow clinicians to identify patients who are at risk of having increased BPV and opportunities to augment these patients' blood pressure control.

Prognostic value of beat-to-beat blood pressure variability parameters in patients after mechanical thrombectomy

The relationship of beat-to-beat blood pressure variability (BPV) with prognosis after mechanical thrombectomy (MT) is unclear. Consecutive patients with acute ischemic stroke with large vessel occlusion treated with and without MT matched 1:1 by age, sex, and National Institutes of Health Stroke Scale were included. Beat-to-beat BPV was calculated for both systolic (SBP) and diastolic blood pressure (DBP) as standard deviation, coefficient of variation, successive variation (SV), and average real variability (ARV) at 24-72 h after MT. Additionally, hour-to-hour (first 24 h after MT) and day-by-day BPV (first 7 days after MT) were also measured. The outcome was modified Rankin Scale (mRS) at 3 months. Of 168 patients, 84 patients received MT and 84 did not. MT closely correlated with lower beat-to-beat BPV parameters. Beat-to-beat SBP-SV and SBP-ARV were significantly higher in patients with unfavorable outcome than in those with favorable outcome (median 3.40 vs 2.71; P = 0.016; median 2.81 vs 2.20, P = 0.003). After adjusting for confounders, higher beat-to-beat SBP-SV and SBP-ARV were independently associated with unfavorable outcome in patients with MT (all P < 0.05). However, no association was found between hour-to-hour and day-by-day BPV and outcome at 3 months (P > 0.05). The patients with MT had lower beat-to-beat BPV values in the acute phase, which indicated that MT has a positive effect on beat-to-beat BPV. Furthermore, beat-to-beat BPV, rather than hour-to-hour or day-by-day BPV, is an independent risk factor for unfavorable outcome in patients after MT.

Blood Pressure Variability and Outcome Predictors for Traumatic Brain Injury Patients with Diffuse Axonal Injury: A Retrospective Cohort Study

Background

Diffuse axonal injury (DAI), a feature seen in severe traumatic brain injury (TBI), is associated with substantial morbidity and mortality. Although blood pressure variability (BPV) has been shown to impact TBI outcomes overall, its relevance in DAI cases remains uncertain. We investigated whether 24-hour post-injury BPV and other clinical factors were linked to patient outcomes.

Methods

We conducted a retrospective analysis of Level I trauma center-admitted TBI patients with radiographic DAI diagnosis (computed tomography/magnetic resonance imaging). Hospital disposition (home, nursing facility, hospice/death) and Glasgow Coma Scale (GCS) on hospital day 5 (HD5GCS) were outcomes of interest. We assessed associations with clinical factors using ordinal logistic regression.

Results

Among 153 patients (mean age 49 ±20 years, 74% male), median admission GCS was 5.0 (3.0-12.5), HD5GCS was 8.0 (6.0-11), and median hospital stay was 25 (15.5-34.5) days. The BPV, measured as successive variation in systolic blood pressure (SBPSV) and standard deviation in systolic blood pressure (SBPSD), was not significantly associated with hospital disposition. SBPSV and SBPSD were also not associated with our secondary outcome of HD5GCS. Initial international normalized ratio (INR) (Coefficient -3.67, odds ratio [OR] 0.03, 95% confidence interval [CI] 0.00-0.70), cerebral contusion (Coeff -2.39, OR 0.09, 95% CI 0.01-0.75), and HD5GCS (Coeff 0.59, OR 1.80, 95% CI 1.30-2.49) were associated with increased odds of discharge to hospice or death. Administration of blood products (Coeff 1.06, OR 2.89, 95% CI 1.10-7.60), vasopressors (Coeff 1.40, OR 4.05, 95% CI 1.37-11.96), and hyperosmolar therapy (Coeff 1.23, OR 3.41, 95% CI 1.36-8.54), and concurrent intraventricular hemorrhage (Coeff 0.99, OR 2.70, 95% CI 0.86-6.49) were linked to poorer HD5GCS.

Conclusion

Blood pressure variability was not correlated with outcomes in patients with diffuse axonal injury. Low Glasgow Coma Score on hospital day 5, high initial INR, and concomitant cerebral contusion were associated with poorer outcomes.

Assessment of Blood Pressure and Heart Rate Related Variables in Acute Stroke Patients Receiving Intravenous Antihypertensive Medication Infusions

BACKGROUND

We performed an analysis of a large intensive care unit electronic database to provide preliminary estimates of various blood pressure parameters in patients with acute stroke receiving intravenous (IV) antihypertensive medication and determine the relationship with in-hospital outcomes.

METHODS

We identified the relationship between pre-treatment and post-treatment systolic blood pressure (SBP) and heart rate (HR)-related variables and in-hospital mortality and acute kidney injury in patients with acute stroke receiving IV clevidipine, nicardipine, or nitroprusside using data provided in the Medical Information Mart for Intensive Care (MIMIC) IV database.

RESULTS

A total of 1830 patients were treated with IV clevidipine (n = 64), nicardipine (n = 1623), or nitroprusside (n = 143). The standard deviations [SDs] of pre-treatment SBP (16.3 vs. 13.7, p ≤ 0.001) and post-treatment SBP (15.4 vs. 14.4, p = 0.004) were higher in patients who died compared with those who survived, particularly in patients with intracerebral hemorrhage (ICH). The mean SBP was significantly lower post treatment compared with pre-treatment values for clevidipine (130.7 mm Hg vs. 142.5 mm Hg, p = 0.006), nicardipine (132.8 mm Hg vs. 141.6 mm Hg, p ≤ 0.001), and nitroprusside (126.2 mm Hg vs. 139.6 mm Hg, p ≤ 0.001). There were no differences in mean SDs post treatment compared with pre-treatment values for clevidipine (14.5 vs. 13.5, p = 0.407), nicardipine (14.2 vs. 14.6, p = 0.142), and nitroprusside (14.8 vs. 14.8, p = 0.997). The SDs of pre-treatment and post-treatment SBP were not significantly different in patients with ischemic stroke treated with IV clevidipine, nicardipine, or nitroprusside or for patients with ICH treated with IV clevidipine or nitroprusside. However, patients with ICH treated with IV nicardipine had a significantly higher SD of post-treatment SBP (13.1 vs. 14.2, p = 0.0032).

CONCLUSIONS

We found that SBP fluctuations were associated with in-hospital mortality in patients with acute stroke. IV antihypertensive medication reduced SBP but did not reduce SBP fluctuations in this observational study. Our results highlight the need for optimizing therapeutic interventions to reduce SBP fluctuations in patients with acute stroke.

Blood Pressure Variability in Acute Stroke: A Narrative Review

The management of blood pressure variability (BPV) in acute stroke presents a complex challenge with profound implications for patient outcomes. This narrative review examines the role of BPV across various stages of acute stroke care, highlighting its impact on treatment strategies and prognostic considerations. In the prehospital setting, while guidelines lack specific recommendations for BP management, emerging evidence suggests a potential link between BPV and outcomes. Among ischaemic stroke patients who are ineligible for reperfusion therapies, BPV independently influences functional outcomes, emphasising the need for individualised approaches to BP control. During intravenous thrombolysis and endovascular therapy, the intricate interplay between BP levels, recanalisation status, and BPV is evident. Striking a balance between aggressive BP lowering and avoiding hypoperfusion-related complications is essential. Intracerebral haemorrhage management is further complicated by BPV, which emerges as a predictor of mortality and disability, necessitating nuanced BP management strategies. Finally, among patients with acute subarachnoid haemorrhage, increased BPV may be correlated with a rebleeding risk and worse outcomes, emphasizing the need for BPV monitoring in this population. Integration of BPV assessment into clinical practice and research protocols is crucial for refining treatment strategies that are tailored to individual patient needs. Future studies should explore novel interventions targeting BPV modulation to optimise stroke care outcomes.

Risk Factors of Cardiovascular and Cerebrovascular Events in Patients With Uraemia Complicated With Hypertension During Maintenance Haemodialysis Treatment

INTRODUCTION

This study aimed to investigate the risk factors associated with major adverse cardiovascular (group of events that affect heart and blood vessels) and cerebrovascular (events affecting blood vessels supplying the brain) events (MACCE) in patients with uraemia complicated with hypertension who required maintenance haemodialysis (MHD) treatment.

METHODOLOGY

Clinical data and laboratory indicators of 156 uraemia patients complicated with hypertension were collected and retrospectively analysed. The patients were admitted to a tertiary care hospital (Abbas Institute of Medical Sciences AIMS) in Muzaffarabad, Pakistan, from February 2018 to February 2022. The data was collected through consecutive sampling and patients were recruited after following the inclusion and exclusion criteria.

RESULTS

Eighty-one out of 156 patients were not complicated with MACCE, and 75 patients were complicated with MACCE during the MHD treatment cycle, with an incidence of 48.08%. Compared to the non-MACCE group, the MACCE group's diabetes, body mass growth rate, triglyceride (TG), NT-proBNP, standard deviation and coefficient of variance for systolic and diastolic blood pressure (SBP-SD, SBP-CV, DBP-SD, and DBP-CV) showed significant differences (P<0.05) between the groups. Diabetes, body mass growth rate, TG, NT-proBNP, SBP-SD, SBP-CV, DBP-SD, and DBP-CV with odds ratios of 3.074, 3.202, 2.188, 2.512, 2.357, 2.431, 2.299, and 2.062 respectively were risk factors for MACCE in uraemia patients with hypertension.

CONCLUSION

 From the results of this study, we inferred that patients with uraemia and hypertension complicated by MACCE in the treatment cycle of MHD were related to diabetes, body mass growth rate, TG, NT-proBNP, SBP-SD, SBP-CV, DBP-SD, and DBP-CV.

Early Low Pulse Pressure in VA-ECMO Is Associated with Acute Brain Injury

BACKGROUND

Pulse pressure is a dynamic marker of cardiovascular function and is often impaired in patients on venoarterial extracorporeal membrane oxygenation (VA-ECMO). Pulsatile blood flow also serves as a regulator of vascular endothelium, and continuous-flow mechanical circulatory support can lead to endothelial dysfunction. We explored the impact of early low pulse pressure on occurrence of acute brain injury (ABI) in VA-ECMO.

METHODS

We conducted a retrospective analysis of adults with VA-ECMO at a tertiary care center between July 2016 and January 2021. Patients underwent standardized multimodal neuromonitoring throughout ECMO support. ABI included intracranial hemorrhage, ischemic stroke, hypoxic ischemic brain injury, cerebral edema, seizure, and brain death. Blood pressures were recorded every 15 min. Low pulse pressure was defined as a median pulse pressure < 20 mm Hg in the first 12 h of ECMO. Multivariable logistic regression was performed to investigate the association between pulse pressure and ABI.

RESULTS

We analyzed 5138 blood pressure measurements from 123 (median age 63; 63% male) VA-ECMO patients (54% peripheral; 46% central cannulation), of whom 41 (33%) experienced ABI. Individual ABIs were as follows: ischemic stroke (n = 18, 15%), hypoxic ischemic brain injury (n = 14, 11%), seizure (n = 8, 7%), intracranial hemorrhage (n = 7, 6%), cerebral edema (n = 7, 6%), and brain death (n = 2, 2%). Fifty-eight (47%) patients had low pulse pressure. In a multivariable model adjusting for preselected covariates, including cannulation strategy (central vs. peripheral), lactate on ECMO day 1, and left ventricle venting strategy, low pulse pressure was independently associated with ABI (adjusted odds ratio 2.57, 95% confidence interval 1.05-6.24). In a model with the same covariates, every 10-mm Hg decrease in pulse pressure was associated with 31% increased odds of ABI (95% confidence interval 1.01-1.68). In a sensitivity analysis model adjusting for systolic pressure, pulse pressure remained significantly associated with ABI.

CONCLUSIONS

Early low pulse pressure (< 20 mm Hg) was associated with ABI in VA-ECMO patients. Low pulse pressure may serve as a marker of ABI risk, which necessitates close neuromonitoring for early detection.

Blood pressure variability related to early outcome of acute ischemia stroke in a prospective observational study

Hypertension is a well-known risk factor for stroke, but the relationship between blood pressure variation (BPV) and prognosis remains unclear. This prospective observational study assessed the association between BPV and early functional outcomes in acute ischemic stroke patients. A total of 871 patients with acute ischemic stroke within 24 h of symptom onset were recruited from the Third Affiliated Hospital of Qiqihar Medical University between 2013 and 2016. Within 6 days of hospitalization, blood pressure was continuously measured from 8:00 to 9:00 every day, and the coefficient of variation (CV) of blood pressure was calculated (including systolic blood pressure [SBP] and diastolic blood pressure [DBP]). The modified Rankin scale was used to evaluate early functional outcomes at discharge. The coefficients of variation of SBP, DBP, and functional outcomes were included as primary outcome variables. Demographic characteristics and medical history were recorded as secondary outcome variables. We found that a greater CV level of SBP and DBP were associated with the poor early functional outcome at hospital discharge, and the odds ratio (OR) and 95% confidence interval (95%CI) of them were 1.56 (1.04-2.35) and 1.99 (1.31-3.03) respectively. A higher standard deviation (SD) of SBP and DBP significantly increased risk of poor early prognosis, OR (95%CI) was 1.78 (1.17-2.71) and 2.25 (1.47-3.45) respectively. Similar results were observed for SBP and DBP. The larger the range of SBP and DBP, the worse is the prognosis. In conclusion, the present study suggests that high BPV is a risk factor for poor early prognosis in acute ischemic stroke.

Hypertension management in elderly with severe intracerebral hemorrhage

Objective

To explore the effect of individualized blood pressure (BP)‐lowering treatment on the outcomes of elderly patients with severe intracerebral hemorrhage (ICH).

Methods

We performed an exploratory analysis of Controlling Hypertension After Severe Cerebrovascular Event (CHASE) trial, which was a multicenter, randomized, controlled clinical trial. Patients with severe ischemic or hemorrhagic stroke (defined as GCS ≤ 12 or NIHSS ≥ 11) were randomized into individualized versus standard BP‐lowering treatment in CHASE trial. In this exploratory analysis, patients with severe ICH were included. The primary outcome was the percentage of patients with 90‐day functional independence defined as modified Rankin Scale (mRS) ≤2.

Results

We included 242 patients with severe ICH in the present analysis, consisting of 142 patients aged <65 years and 100 patients aged ≥65 years. There were significant differences between patients aged ≥65 years and <65 years in the proportion of functional independence (47.9% vs. 15.0%, P < 0.001) and good outcome (73.9% vs. 50.0%, P < 0.001) at day 90. In patients aged ≥65 years, the adjusted individualized BP‐lowering treatment had an unequivocal effect on the functional independence at day 90 (21.6% vs. 8.2%, odds ratio [OR]: 4.309, 95% confidence interval [CI]: 1.040‐17.859, P = 0.044) and improved the neurological deficits at discharge (∆ NIHSS ≥ 4: 64.7% vs. 34.7%, OR: 4.300, 95% CI: 1.599‐11.563, P = 0.004).

Interpretation

Compared with the younger counterparts, the elderly patients (≥65 years) with acute severe ICH might benefit more from individualized BP‐lowering treatment.