Intensive Blood Pressure Lowering and DWI Lesions in Intracerebral Hemorrhage: Exploratory Analysis of the ATACH-2 Randomized Trial

Premorbid Blood Pressure Control Modifies Risk of DWI Lesions With Acute Blood Pressure Reduction in Intracerebral Hemorrhage

BACKGROUND

Hypoperfusion due to blood pressure (BP) reduction is a potential mechanism of cerebral ischemia after intracerebral hemorrhage. However, prior evaluations of the relationship between BP reduction and ischemia have been conflicting. Untreated chronic hypertension is common in intracerebral hemorrhage and alters cerebral autoregulation. We hypothesized that the risk of diffusion-weighted imaging (DWI) hyperintensities from acute BP reduction is modified by premorbid BP control.

METHODS

Individuals enrolled in the ERICH study (Ethnic/Racial Variations of Intracerebral Hemorrhage) from 2010 to 2015 were categorized as untreated, treated, or nonhypertensive based on preintracerebral hemorrhage diagnosis and antihypertensive medication use. The percent reduction of systolic BP (SBP) was calculated between presentation and 24 hours from admission. The primary outcome was the presence of DWI lesions. Using logistic regression, we tested the association between chronic hypertension status, SBP reduction, and their interaction with DWI lesion presence.

RESULTS

From 3000 participants, 877 with available magnetic resonance imaging met inclusion (mean age, 60.5±13.3 years; 42.5% women). DWI lesions were detected in 25.9%. Untreated, treated, and no hypertension accounted for 32.6%, 47.9%, and 19.5% of cases, respectively. SBP reduction was not directly associated with DWI lesions; however, an interaction effect was observed between SBP reduction and chronic hypertension status (P=0.036). Nonhypertensive subjects demonstrated a linear risk of DWI lesion presence with greater SBP reduction, whereas untreated hypertension demonstrated a stable risk across a wide range of SBP reduction (P=0.023).

CONCLUSIONS

Premorbid BP control, especially untreated hypertension, may influence the relationship between DWI lesions and acute BP reduction after intracerebral hemorrhage.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT01202864.

Systematic Review and Meta-Analysis of the Association Between Appearance of Lesions on Diffusion-Weighted Imaging and Poor Outcomes Among Patients with Intracerebral Hemorrhage

OBJECTIVE

Some patients with intracerebral hemorrhage show lesions on diffusion-weighted magnetic resonance imaging, and such lesions have been associated with a greater risk of worse prognosis. Here we meta-analyzed the available evidence for such an association.

METHODS

Studies that reported the presence or absence of lesions on diffusion-weighted imaging (DWI) after intracerebral hemorrhage as well as clinical or radiological outcomes were systematically reviewed and meta-analyzed. Clinical outcome was defined as a score of modified Rankin scale (mRS) at admission to 90 days.

RESULTS

Ten studies involving 3575 patients were included in the meta-analysis, and the incidence of DWI lesions ranged from 11.1% to 49.6%. Lesions were associated with a significantly higher risk of poor outcome (mRS scores 3-6) across 6 studies (odds ratio: 2.91; 95% confidence interval: 1.62-5.23; P < 0.001). In subgroup analysis, mRS scores 4-6 were associated with the presence of lesions on DWI (odds ratio: 2.18; 95% confidence interval: 1.31-3.60; P = 0.003). We observed similar results using 3 different definitions of lesions on DWI. Some studies have reported that recurrence of intracerebral hemorrhage was also related with DWI lesions. But there was controversy on the relationship between mortality, ischemic stroke, and hematoma volume and DWI lesions.

CONCLUSIONS

Lesions on DWI after intracerebral hemorrhage were associated with a higher risk of poor outcome, but large longitudinal studies are needed to verify this association.

Blood Pressure Management in Intracerebral Haemorrhage: when, how much, and for how long?

PURPOSE OF REVIEW

When compared to ischaemic stroke, there have been limited advances in acute management of intracerebral haemorrhage. Blood pressure control in the acute period is an intervention commonly implemented and recommended in guidelines, as elevated systolic blood pressure is common and associated with haematoma expansion, poor functional outcomes, and mortality. This review addresses the uncertainty around the optimal blood pressure intervention, specifically timing and length of intervention, intensity of blood pressure reduction and agent used.

RECENT FINDINGS

Recent pivotal trials have shown that acute blood pressure intervention, to a systolic target of 140mmHg, does appear to be beneficial in ICH, particularly when bundled with other therapies such as neurosurgery in selected cases, access to critical care units, blood glucose control, temperature management and reversal of coagulopathy. Systolic blood pressure should be lowered acutely in intracerebral haemorrhage to a target of approximately 140mmHg, and that this intervention is generally safe in the ICH population.

Suboptimal Cerebral Perfusion is Associated with Ischemia After Intracerebral Hemorrhage

BACKGROUND

Remote ischemic lesions on diffusion-weighted imaging (DWI) occur in one third of patients with intracerebral hemorrhage (ICH) and are associated with worse outcomes. The etiology is unclear and not solely due to blood pressure reduction. We hypothesized that impaired cerebrovascular autoregulation and hypoperfusion below individualized lower limits of autoregulation are associated with the presence of DWI lesions.

METHODS

This was a retrospective, single-center study of all primary ICH with intraparenchymal pressure monitoring within 10 days from onset and subsequent magnetic resonance imaging. Pressure reactivity index was calculated as the correlation coefficient between mean arterial pressure and intracranial pressure. Optimal cerebral perfusion pressure (CPPopt) is the cerebral perfusion pressure (CPP) with the lowest corresponding pressure reactivity index. The difference between CPP and CPPopt, time spent below the lower limit of autoregulation (LLA), and time spent above the upper limit of autoregulation (ULA) were calculated by using mean hourly physiologic data. Univariate associations between physiologic parameters and DWI lesions were analyzed by using binary logistic regression.

RESULTS

A total of 505 h of artifact-free data from seven patients without DWI lesions and 479 h from six patients with DWI lesions were analyzed. Patients with DWI lesions had higher intracranial pressure (17.50 vs. 10.92 mm Hg; odds ratio 1.14, confidence interval 1.01-1.29) but no difference in mean arterial pressure or CPP compared with patients without DWI lesions. The presence of DWI lesions was significantly associated with a greater percentage of time spent below the LLA (49.85% vs. 14.70%, odds ratio 5.77, confidence interval 1.88-17.75). No significant association was demonstrated between CPPopt, the difference between CPP and CPPopt, ULA, LLA, or time spent above the ULA between groups.

CONCLUSIONS

Blood pressure reduction below the LLA is associated with ischemia after acute ICH. Individualized, autoregulation-informed targets for blood pressure reduction may provide a novel paradigm in acute management of ICH and require further study.

Effects of Mobile Stroke Unit dispatch on blood pressure management and outcomes in patients with intracerebral haematoma: Results from the Berlin_Prehospital Or Usual Care Delivery in acute Stroke (B_PROUD) controlled intervention study

INTRODUCTION

In patients with acute intracerebral haemorrhage (ICH) and elevated systolic blood pressure (BP), guidelines suggest that systolic BP reduction to <140 mmHg should be rapidly initiated. Compared with conventional care, Mobile Stroke Units (MSUs) allow for earlier ICH diagnosis through prehospital imaging and earlier BP lowering.

PATIENTS AND METHODS

ICH patients were prospectively evaluated as a cohort of the controlled B_PROUD-study in which MSU availability alone determined MSU dispatch in addition to conventional ambulance. We used inverse probability of treatment weighting to adjust for confounding to estimate the effect of additional MSU dispatch in ICH patients. Outcomes of interest were 7-day mortality (primary), systolic BP (sBP) at hospital arrival, dispatch-to-imaging time, largest haematoma volume, anticoagulation reversal, length of in-hospital stay, 3-month functional outcome.

RESULTS

Between February 2017 and May 2019, MSUs were dispatched to 95 (mean age: 72 ± 13 years, 45% female) and only conventional ambulances to 78 ICH patients (mean age: 71 ± 12 years, 44% female). After adjusting for confounding, we found shorter dispatch-to-imaging time (mean difference: -17.75 min, 95% CI: -27.16 to -8.21 min) and lower sBP at hospital arrival (mean difference = -16.31 mmHg, 95% CI: -30.64 to -6.19 mmHg) in the MSU group. We found no statistically significant difference for the other outcomes, including 7-day mortality (adjusted odds ratio: 1.43, 95% CI: 0.68 to 3.31) or favourable outcome (adjusted odds ratio = 0.67, 95% CI: 0.27 to 1.67).

CONCLUSIONS

Although MSU dispatch led to sBP reduction and lower dispatch-to-imaging time compared to conventional ambulance care, we found no evidence of better outcomes in the MSU dispatch group.

Relationships of Hemoglobin Concentration, Ischemic Lesions, and Clinical Outcomes in Patients With Intracerebral Hemorrhage

BACKGROUND

Hemoglobin concentration and diffusion-weighted imaging (DWI) ischemic lesions are separately known to be associated with poor intracerebral hemorrhage (ICH) outcomes. While hemoglobin concentrations have known relationships with ischemic stroke, it is unclear whether hemoglobin concentration is associated with DWI ischemic lesions after ICH. We sought to investigate the hypothesis that hemoglobin concentrations would associate with DWI lesions after ICH and further investigated their relationships with clinical outcomes.

METHODS

Supratentorial ICH patients enrolled between 2010 and 2016 to a prospective, multicenter, observational cohort study (ERICH study [Ethnic/Racial Variations of Intracerebral Hemorrhage]) were assessed. Patients from this study with baseline, admission hemoglobin, and hospitalization magnetic resonance imaging were analyzed. Hemoglobin was examined as the primary exposure variable defined as a continuous variable (g/dL). Magnetic resonance imaging DWI ischemic lesion presence was assessed as the primary radiographic outcome. Primary analyses assessed relationships of hemoglobin with DWI lesions. Secondary analyses assessed relationships of DWI lesions with poor 3-month outcomes (modified Rankin Scale score, 4-6). These analyses were performed using separate multivariable logistic regression models adjusting for relevant covariates.

RESULTS

Of 917 patients with ICH analyzed, mean baseline hemoglobin was 13.8 g/dL (±1.9), 60% were deep ICH, and DWI lesions were identified in 27% of the cohort. In our primary analyses, increased hemoglobin, defined as a continuous variable, was associated with DWI lesions (adjusted odds ratio, 1.21 per 1 g/dL change in hemoglobin [95% CI, 1.07-1.37]) after adjusting for sex, race, ICH severity, time to magnetic resonance imaging, and acute blood pressure change. In secondary analyses, DWI lesions were associated with poor 3-month outcomes (adjusted odds ratio, 1.83 [95% CI, 1.24-2.69]) after adjusting for similar covariates.

CONCLUSIONS

We identified novel relationships between higher baseline hemoglobin concentrations and DWI ischemic lesions in patients with ICH. Further studies are required to clarify the role of hemoglobin concentration on both cerebral small vessel disease pathophysiology and ICH outcomes.

ANAID-ICH nomogram for predicting unfavorable outcome after intracerebral hemorrhage

OBJECTIVE

Diffusion-weighted imaging lesions (DWILs) are associated with unfavorable outcome in intracerebral hemorrhage (ICH). We proposed a novel predictive nomogram incorporating DWILs.

METHODS

A total of 738 patients with primary ICH in a tertiary hospital were prospectively enrolled as a training cohort. DWILs were defined as remote focal hyperintensities on DWI corresponding to low intensities on apparent diffusion coefficient images and remote from the focal hematoma. The outcome of interest was modified Rankin Scale scores of 4-6 at 90 days after onset. Multivariate logistic regression was used to construct a nomogram. Model performance was tested in the training cohort and externally validated with respect to discrimination, calibration, and clinical usefulness in another institute. Additionally, the nomogram was compared with the ICH score in terms of predictive ability.

RESULTS

Overall, 153 (20.73%) and 23 (15.54%) patients developed an unfavorable outcome in the training and validation cohorts, respectively. The multivariate analysis revealed that age, National Institutes of Health Stroke Scale (NIHSS) score, anemia, infratentorial location, presence of DWILs, and prior ICH were associated with unfavorable outcome. Our ANAID-ICH nomogram was constructed according to the aforementioned variables; the area under the receiver operating characteristic curve was 0.842 and 0.831 in the training and validation sets, respectively. With regard to the 90-day outcome, the nomogram showed a significantly higher predictive value than the ICH score in both cohorts.

CONCLUSIONS

The ANAID-ICH nomogram comprising age, NIHSS score, anemia, infratentorial location, presence of DWILs, and prior ICH may facilitate the identification of patients at higher risk for an unfavorable outcome.

Diffusion-Weighted Lesions After Intracerebral Hemorrhage: Associated MRI Findings

The current study aimed to investigate whether diffusion-weighted imaging-positive (DWI+) lesions after acute intracerebral hemorrhage (ICH) are associated with underlying small vessel disease (SVD) or linked to the acute ICH. We included patients ≥18 years with spontaneous ICH confirmed on neuroimaging and performed 3T MRIs after a median of 11 days (interquartile range [IQR] 6–43). DWI+ lesions were assessed in relation to the hematoma (perihematomal vs. distant and ipsilateral vs. contralateral). Differences in clinical characteristics, ICH characteristics, and MRI markers of SVD between participants with or without DWI+ lesions were investigated using non-parametric tests. We observed 54 DWI+ lesions in 30 (22%) of the 138 patients (median age [IQR] 65 [55–73] years; 71% men, 59 lobar ICH) with available DWI images. We found DWI+ lesions ipsilateral (54%) and contralateral (46%) to the ICH, and 5 (9%) DWI+ lesions were located in the immediate perihematomal region. DWI+ lesion presence was associated with probable CAA diagnosis (38 vs. 15%, p = 0.01) and larger ICH volumes (37 [8–47] vs. 12 [6–24] ml, p = 0.01), but not with imaging features of SVD. Our findings suggest that DWI+ lesions after ICH are a feature of both the underlying SVD and ICH-related mechanisms.

Blood Pressure Management After Intracerebral and Subarachnoid Hemorrhage: The Knowns and Known Unknowns

Blood pressure (BP) elevations often complicate the management of intracerebral hemorrhage and aneurysmal subarachnoid hemorrhage, the most serious forms of acute stroke. Despite consensus on potential benefits of BP lowering in the acute phase of intracerebral hemorrhage, controversies persist over the timing, mechanisms, and approaches to treatment. BP control is even more complex for subarachnoid hemorrhage, where there are rationales for both BP lowering and elevation in reducing the risks of rebleeding and delayed cerebral ischemia, respectively. Efforts to disentangle the evidence has involved detailed exploration of individual patient data from clinical trials through meta-analysis to determine strength and direction of BP change in relation to key outcomes in intracerebral hemorrhage, and which likely also apply to subarachnoid hemorrhage. A wealth of hemodynamic data provides insights into pathophysiological interrelationships of BP and cerebral blood flow. This focused update provides an overview of current evidence, knowledge gaps, and emerging concepts on systemic hemodynamics, cerebral autoregulation and perfusion, to facilitate clinical practice recommendations and future research.