Relationship between blood pressure and outcome changes over time in acute ischemic stroke

Time-varying association between blood pressure and malignant brain edema after large hemispheric infarction: a prospective cohort study

AIM

To investigate the time-varying association between blood pressure (BP) and malignant brain edema (MBE) risk after large hemispheric infarction (LHI).

METHODS

We prospectively enrolled LHI patients (CT hypodensity > 1/3 middle cerebral artery territory within 6 h or > 1/2 within 6-48 h of onset) from registry cohort. BP was recorded hourly and analyzed for 24 h and in two 12-hour epochs after onset: 1-12 h and 13-24 h. MBE was defined as neurological deterioration symptoms with midline shift ≥ 5 mm. Generalized estimating equation (GEE) compared BP patterns by MBE occurrence. Logistic regression and restricted cubic splines (RCS) assessed dose-response associations.

RESULTS

Among 414 included LHI patients (mean age 69 ± 14y, median onset-to-admission interval 3 h [interquartile range, IQR 2-5]), 117(28.3%) developed MBE with a median post-onset interval of 29 h (IQR 15-56). No significant difference in BP level was observed during 1-12 h. Systolic BP (SBP) was significantly higher in MBE group over time during 13-24 h (GEE P = 0.027). The 24-hour mean SBP exhibited a U-shaped association with MBE risk (nonlinear test, P = 0.029), with no significance in 1-12 h and a positive correlation between mean SBP in 13-24 h and MBE risk (aOR 1.02[1.00-1.04]). A threshold effect for 24-hour mean diastolic BP (DBP) was identified (non-linear test, P = 0.039), with DBP increase above 70 mmHg associated with higher MBE risk (aOR 1.03 [1.00-1.07]). Similarly, elevated mean DBP > 75mmHg during 1-12 h was associated with higher MBE risk.

CONCLUSION

In LHI patients, 24-hour mean SBP demonstrated a U-shaped association with MBE risk, with no significant effect during 1-12 h and a positive linear correlation during 13-24 h after onset. DBP exhibited a threshold effect, primarily influencing MBE risk during 1-12 h after onset.

Hemodynamics of distal cerebral arteries are associated with functional outcomes in symptomatic ischemic stroke in middle cerebral artery territory: A four-dimensional flow cardiovascular magnetic resonance study

BACKGROUND

Cerebrovascular hemodynamics are believed to play an important role in the development of ischemic stroke (IS). However, the relationships between hemodynamics and prognosis are not fully understood. Four-dimensional (4D) flow cardiovascular magnetic resonance (CMR) enables comprehensive characteristics of cerebrovascular hemodynamics. This study aims to investigate the associations of the different hemodynamics derived from 4D flow CMR with IS functional outcomes.

METHODS

Ninety-one patients (median age 64 years, 62 males) with unilateral IS in middle cerebral artery (MCA) territory were included. All subjects underwent a CMR scan, including 4D flow, three-dimensional (3D) time-of-flight magnetic resonance angiography, and 3D whole brain black-blood high-resolution vessel wall imaging of the MCA. Six hemodynamic parameters, including flow rate, velocity, pulsatility index, time-averaged wall shear stress (TAWSS), oscillatory shear index, and relative residence time (RRT), were calculated for the lesion site, pre-bifurcation M1 (pM1) segment, and the distal M1 and/or first branches of M2 (dM1/M2) segments. Vessel characteristics, such as lumen area, vessel area, wall area, maximum wall thickness, and the degree of stenosis, were calculated at the most stenotic lesion site. The modified Rankin Scale (mRS) scores were assessed at 90 days and 1 year, and an mRS >2 was considered as a poor functional outcome.

RESULTS

Lower segment-level TAWSS (odds ratio [OR]: 0.24, P = 0.006 and OR: 0.29, P = 0.014), higher RRT (OR: 2.74, P = 0.007 and OR: 2.40, P = 0.011) of dM1/M2 segments, and lower segment- and lesion-level velocity (OR: 0.40, P = 0.019 and OR: 0.41, P = 0.025; OR: 0.41, P = 0.030 and OR: 0.42, P = 0.040) of pM1 segment were observed to be associated with poor functional outcome at both 90 days and 1 year. Using the cut-off value of 3.58 Pa and 0.29, respectively, TAWSS and RRT of dM1/M2 segments showed moderate performance in distinguishing poor functional outcome from favorable outcome (area under the curve ranging from 0.642-0.687) both at 90 days and 1 year.

CONCLUSION

Distal segmental TAWSS and RRT of dM1/M2 segments were associated with poor functional outcomes. Such alterations in hemodynamics might help in the identification of patients with potentially unfavorable prognosis.

Blood pressure variability predicts poor outcomes in acute stroke patients without thrombolysis: a systematic review and meta-analysis

BACKGROUND

Stroke is a significant medical condition, and blood pressure stands out as the most prevalent treatable risk factor associated with it. Researches link blood pressure variability (BPV) with stroke; however, the specific relationship between with the outcomes of stroke patients remains unclear. As blood pressure variability and mean blood pressure are interrelated, it remains uncertain whether BPV adds additional information to understanding the outcome of acute stroke patients.

OBJECTIVE

To systematically review studies investigating the association between blood pressure variability and prognosis in acute stroke patients.

METHODS

Embase, PubMed, Web of Science, and the Cochrane Library were searched for English language full-text articles from the inception to 1 January 2023. Stroke patients aged ≥ 18 years were included in this analysis. Stroke types were not restricted.

RESULTS

This meta-analysis shows that higher systolic blood pressure variability is linked to a higher risk of poor outcome, including function disability, mortality, early neurological deterioration, and stroke recurrence, among acute stroke patients without thrombolysis. A higher diastolic blood pressure variability is linked with to a higher risk of mortality and functional disability.

CONCLUSIONS

This review reveals that blood pressure variability is a novel and clinically relevant risk factor for stroke patients' outcome. Future studies should investigate how best to measure and define BPV in acute stroke. Larger studies are warranted to provide more robust evidence in this area.

European stroke organisation (ESO) guideline on cerebral small vessel disease, part 2, lacunar ischaemic stroke

A quarter of ischaemic strokes are lacunar subtype, typically neurologically mild, usually resulting from intrinsic cerebral small vessel pathology, with risk factor profiles and outcome rates differing from other stroke subtypes. This European Stroke Organisation (ESO) guideline provides evidence-based recommendations to assist with clinical decisions about management of lacunar ischaemic stroke to prevent adverse clinical outcomes. The guideline was developed according to ESO standard operating procedures and Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. We addressed acute treatment (including progressive lacunar stroke) and secondary prevention in lacunar ischaemic stroke, and prioritised the interventions of thrombolysis, antiplatelet drugs, blood pressure lowering, lipid lowering, lifestyle, and other interventions and their potential effects on the clinical outcomes recurrent stroke, dependency, major adverse cardiovascular events, death, cognitive decline, mobility, gait, or mood disorders. We systematically reviewed the literature, assessed the evidence and where feasible formulated evidence-based recommendations, and expert concensus statements. We found little direct evidence, mostly of low quality. We recommend that patients with suspected acute lacunar ischaemic stroke receive intravenous alteplase, antiplatelet drugs and avoid blood pressure lowering according to current acute ischaemic stroke guidelines. For secondary prevention, we recommend single antiplatelet treatment long-term, blood pressure control, and lipid lowering according to current guidelines. We recommend smoking cessation, regular exercise, other healthy lifestyle modifications, and avoid obesity for general health benefits. We cannot make any recommendation concerning progressive stroke or other drugs. Large randomised controlled trials with clinically important endpoints, including cognitive endpoints, are a priority for lacunar ischaemic stroke.

Time-dependent systolic blood pressure within 72 h after endovascular treatment in large vessel occlusion stroke

BACKGROUND

The association of systolic blood pressure (SBP) and ischemic stroke outcome has recently been proved to be varied at different time points within 72 h after acute ischemic stroke onset; however, the specific status of how SBP affects prognosis at different time points within 72 h after endovascular treatment (EVT) among patients with large vessel occlusion (LVO) remains unclear.

METHODS

Consecutive LVO patients treated with EVT were enrolled in our study. BP data were collected at eight time points (1, 2, 4, 8, 16, 24, 48, and 72 h post-EVT). Outcome measure of interest was functional dependence, which was defined as mRS >2 at 90 days.

RESULTS

A total of 406 LVO patients treated with EVT from 2016 to 2022 were included. At 16 h after EVT, the relationship between SBP and functional dependence showed a nonlinear association. At other time points after EVT, SBP had linear relationships with functional dependence. Furthermore, higher SBP, as either a linear or quadratic term, had an adverse effect on functional outcome. In addition, three SBP trajectories were observed, and the high-to-low group was independently associated with functional dependence.

CONCLUSION

Taken together, higher SBP within the first 72 h after EVT has a time-dependent association with adverse clinical outcomes. Optimal blood pressure management during the first 72 h after EVT may be important to improve clinical outcome.

Untreated hypertension and prognosis paradox in acute ischemic stroke

INTRODUCTION

This study is to explore the long-term functional outcome of antihypertensive medication-naïve, untreated hypertension (HTN) patients with acute ischemic stroke compared to those with no prior HTN and those with treated HTN.

PATIENTS AND METHODS

We analyzed a prospectively collected stroke registry of all patients with acute ischemic stroke consecutively admitted to Incheon St. Mary's Hospital. Patients who received reperfusion therapy were excluded. Long-term functional outcomes were assessed at a 3-month follow-up visit using the modified Rankin Scale.

RESULTS

A total of 1044 patients was enrolled. Compared to patients with no or treated HTN, those with untreated HTN had higher odds for more favorable outcomes (adjusted odds ratio (OR): 1.7 [95% CI: 1.0-2.7, p = 0.050*] and 1.7 [95% CI: 1.0-2.8, p = 0.047*], respectively) when the stroke was large vessel atherosclerosis (LAA)/cardioembolic (CE) with large vessel occlusion/stenosis. However, no such association was observed when there was no large vessel occlusion or stenosis, in total patients, or if the index stroke was related to SVO. In untreated HTN patients with LAA/CE and large vessel occlusion/stenosis compared to patients in the lowest mean arterial pressure quartile (< 96.7 mmHg), patients in the second and third highest quartiles had higher odds of favorable outcomes.

CONCLUSIONS

Patients with untreated HTN had significantly more favorable outcomes at 3 months after ischemic stroke compared to those with no or treated HTN when the stroke was LAA/CE with large vessel occlusion/stenosis. Untreated HTN patients also showed an association between higher MAP and favorable outcomes.

Systolic blood pressure trajectories after acute ischemic strokes and clinical outcomes: A systematic review

Blood pressure(BP) varies drastically during the acute phase after stroke onset. BP level and BP variability may have a major impact on acute ischemic stroke (AIS) prognosis. However, the association between trajectories of blood pressure over time and clinical outcomes have not been established. This review sought out existing evidences for associations of systolic blood pressure (SBP) trajectories on outcomes after stroke to determine the connection between SBP trajectories and stroke prognosis. According to a pre‐designed search strategy, literature search was carried out in Embase, Pubmed and Web of Science. Two authors independently evaluated study eligibility and quality, and literature data were extracted. When the literature was eligible, we perform meta‐analysis to determine associations of SBP trajectories with clinical outcomes. Seven studies were finally screened out of 52 studies retrieved. Seven studies received a good risk of bias rating and reported BP measurement methods and intervals, BP trajectories modeling methods, outcome measures, but it was found that final systolic BP trajectories in various papers were significantly different. All studies reported statistically significant associations between systolic blood pressure trajectories and prognosis. Methodological heterogeneity is observed in studies. However, this systematic review suggests that the high SBP group after AIS is related to poor clinical outcomes, while the rapid decline or medium‐to‐low or low SBP group is associated with relatively better clinical outcomes at different period after stroke. More prospective studies are needed to report the full methodology according to standardized criteria and explore relationships between SBP trajectories and prognosis of stroke.

Time-dependent shift of the relationship between systolic blood pressure and clinical outcome in acute lacunar stroke

BACKGROUND AND AIMS

This study explores the relationship between systolic blood pressure during the acute period of stroke and poor functional outcome in patients with lacunar stroke, emphasizing a possible time-dependent nature of the relationship.

METHODS

Based on multicenter stroke registry data, patients with acute lacunar stroke were identified, and systolic blood pressure levels at eight time points (1, 2, 4, 8, 16, 24, 48, and 72 h) after stroke onset were extracted at the 15 participating centers in South Korea. Poor functional outcome was defined as a three-month modified Rankin Scale score of 2-6. Non-linear restricted cubic spline and linear models were used for assessing the relationship at each time point.

RESULTS

A total of 97,349 systolic blood pressure measurements of 3,042 patients were analyzed. At 1 h and 4 h after stroke onset, the relationship between systolic blood pressure and poor outcome showed a non-linear association. The nadir was 155 mmHg at 1 h and 124 mmHg at 4 h. After this time period, a higher systolic blood pressure was associated with a poorer outcome. This linear relationship weakened over time after 12 h (coefficient values of the adjusted linear models: 0.0081 at 8 h, 0.0105 at 12 h, 0.0102 at 24 h, 0.0082 at 48 h, 0.0054 at 72 h).

CONCLUSIONS

Based on our cohort of large number of lacunar stroke patients, our findings suggest that systolic blood pressure levels may follow a time-dependent course in relation to prediction of outcome at three months. The findings may be valuable for hypothesis generation in association with clinical trial development for blood pressure control in acute stroke patients.