High initial blood pressure after acute stroke is associated with poor functional outcome

Management of arterial hypertension in patients with acute stroke

Management of arterial hypertension in the hyperacute period immediately after stroke ictus remains controversial. Extremes of blood pressure (BP) are associated with poor outcomes in all stroke subtypes. Severely hypertensive patients likely benefit from modest BP reductions, but aggressive BP reduction may worsen outcome. Although little evidence is currently available to definitively establish guideline recommendations for optimal BP goals at stroke presentation, recently published research is shedding some light on how to approach management of BP after stroke. Antihypertensive treatment should probably be deferred in ischemic stroke patients except in cases of severe hypertension or when thrombolytic therapy is warranted and the patient's BP is above acceptable levels. Hypertensive hemorrhagic stroke patients may benefit from modest BP reductions. Relative hypotension causing regional hypoperfusion is an increasingly understood concept immediately following ischemic or hemorrhagic stroke, emphasizing the need for careful titration of appropriate medications to minimize fluctuations in BP for treated patients. Ongoing trials will improve our current knowledge regarding BP management after ischemic and hemorrhagic stroke.

Blood pressure variability in acute ischemic stroke depends on hemispheric stroke location

The relationship between blood pressure (BP) variability and stroke location was examined in 85 patients admitted with acute ischemic stroke. The patients were divided into three groups according to stroke location: right hemisphere (32 patients), left hemisphere (30 patients) and non-localized (23 patients). BP upon admission was 147.94/76.53 +/- 20.72/13.70 mmHg in the right hemisphere group, 151.81/76.10 +/- 25.69/16.23 mmHg in the left hemisphere and 155.23/83.41 +/- 30.45/15.74 in the non-localized group. The left hemisphere group had significantly (p < 0.01) greater variations in systolic and diastolic BP between days 2 and 3 and in systolic BP between days 3 and 4 after stroke compared with the other groups. BP in the left hemisphere group was less stable than in the other two groups. Non-localized patients without pre-existing hypertension had a significantly lower and more stable BP during the week following stroke than non-localized patients with pre-existing hypertension. Non-localized patients with pre-existing hypertension had the highest BP and showed no improvement during the week. Systolic BP tended to be higher and less stable in left hemisphere patients than in right hemisphere, whereas among non-localized ischemic stroke patients BP was higher in those who had a prior diagnosis of hypertension.

Blood pressure management in acute stroke: a long-standing debate

Although elevated blood pressure (BP) levels are a common complication of acute stroke, whether of ischaemic or haemorrhagic type, a long-standing debate exists regarding the management of post-stroke hypertension. In the absence of solid, randomised data from controlled trials, the current observational evidence allows different approaches, since theoretical arguments exist for both lowering BP in the setting of acute stroke (reduce the risk of stroke recurrence, of subsequent oedema formation, of rebleeding and haematoma expansion in patients with cerebral bleeding) as well as leaving raised BP levels untreated (avoid reduction in cerebral perfusion pressure and blood flow to viable ischaemic tissue in the absence of normal autoregulation). The present review will summarize the evidence for and against the therapeutic manipulation of BP in acute stroke provided by the currently available observational studies and randomised trials, consider the ongoing clinical trials in this area and address the present recommendations regarding this conflicting issue.

Systemic inflammation, blood pressure, and stroke outcome

Hypertension is the most important modifiable risk factor for ischemic stroke, and antihypertensive treatment is of paramount importance to reduce the incidence of stroke mortality and morbidity. The significance and best management of hypertension during the first hours after stroke onset, however, are still matters of debate. Cerebral ischemia results in a complex inflammatory cascade; inflammatory mechanisms are also important participants in the pathophysiology of hypertension. There has been a convergence of evidence that is important to consider in managing systemic blood pressure after stroke to ensure an optimal outcome. The identification of useful markers will allow progress in our ability to treat blood pressure in the acute phase of a stroke. The determination of levels of C-reactive protein, an acute-phase inflammation marker, may help to guide our approach in the management of blood pressure in acute ischemic stroke. Whether this target will be useful in the development of risk prediction strategies or therapies for the treatment of stroke in humans is far from clear.

Blood Pressure Evolution After Acute Ischemic Stroke in Patients With and Without Sleep Apnea

Background and Purpose— Sleep apnea (SA) is an independent risk factor for arterial hypertension and is present in 50% to 70% of patients with ischemic stroke. The effects of SA on blood pressure (BP) and stroke outcome in the acute stroke phase are essentially unknown.

Methods— We studied 41 consecutive patients admitted within 96 hours after stroke onset. Stroke severity on admission (National Institutes of Health Stroke Scale [NIHSS]) and stroke outcome at discharge (modified Rankin Disability Scale [mRS]) were assessed. Nocturnal breathing was assessed with an ambulatory device the first night after admission. SA was defined by an apnea-hypopnea-index (AHI) ≥10/hour, and moderate-severe SA (MSSA) was defined by an AHI >30/hour. BP monitoring was performed during the first 36 hours after admission. A nondipping status (NDS) was defined by a ratio >0.9 of mean systolic BP during nights 1 to 2/mean systolic BP during day 2.

Results— SA was found in 28 (68%) and MSSA in 11 (27%) of 41 patients. A correlation was found between AHI and both NIHSS ( r =0.331; P =0.035) and mRS ( r =0.341; P =0.031). Patients with MSSA had higher systolic and diastolic BP values during night 1 ( P =0.003), day 2 ( P =0.004), and night 2 ( P =0.03). NDS was found in 26 (63%) patients. Nondippers had a similar AHI but higher NIHSS ( P =0.004) and mRS ( P =0.005) than dippers. AHI and NDS were confirmed to be independent predictors for both stroke severity and stroke outcome in a multiple stepwise linear regression model.

Conclusions— SA severity is associated with high 24-hour BP values but only weakly with stroke severity and outcome. Conversely, NDS is linked with a more severe stroke and a poorer evolution but not with SA severity. These data suggest different, although overlapping, pathophysiological and clinical implications of circadian and nocturnal BP values in acute stroke.

Characteristics of Blood Pressure Profiles as Predictors of Long-Term Outcome After Acute Ischemic Stroke

Background and Purpose— Most patients have elevated blood pressure (BP) in the early phase after an acute ischemic stroke. Mechanism and effects of this BP elevation are not well understood. The benefits of intervention by lowering the initial BP or waiting for spontaneous return to normal values remain debated. We studied the hypothesis that increased BP level and profile variability will adversely affect long-term outcome after stroke with and without thrombolytic treatment.

Methods— We studied the 615 patients with acute ischemic hemispheric stroke in the first European Cooperative Acute Stroke Study (ECASS). BP was measured at 2-hour intervals during the first 20 hours after randomization, and then every 4 hours, up to 72 hours after admission. Studied features of individual 0- to 72-hour BP profiles were: baseline BP, maximum and minimum BP, mean level, and successive variation in the BP profile. The end point was good functional recovery (modified Rankin Scale [mRS] score of 0 to 1) at 90 days. Logistic regression was used to adjust for known prognostic factors, demographic, initial stroke severity, disease and medication histories, and computed tomography signs.

Results— Higher systolic BP or diastolic BP at baseline were associated with favorable outcome assessed on modified mRS at 90 days (adjusted odds ratio [OR], 1.22; 95% CI, 1.01 to 1.49; and OR, 1.22; 95% CI, 1.01 to 1.49 per 10 mm Hg), lower within-patient 0- to 72-hour average systolic BP (SBP), or DBP implied favorable outcome (OR, 0.74; 95% CI, 0.61 to 0.90; and OR, 0.61; 95% CI, 0.41 to 0.90 per 10 mm Hg). Reduced variability of 0- to 72-hour DBP profile was an independent predictor of favorable outcome (OR, 0.58; 95% CI, 0.39 to 0.85 per 5 mm Hg).

Conclusions— Higher baseline SBP or DBP was associated with favorable outcome after stroke. Other characteristics of first 72-hour BP profiles: lower mean level of SBP or DBP and reduced successive variability of DBP profile were independent predictors of favorable outcome at 90 days.

The effect of admission physiological variables on 30 day outcome after stroke

INTRODUCTION

Potentially modifiable physiological variables may influence stroke prognosis but their independence from modifiable factors remains unclear.

METHODS

Admission physiological measures (blood pressure, heart rate, temperature and blood glucose) and other unmodifiable factors were recorded from patients presenting within 48 hours of stroke. These variables were compared with the outcomes of death and death or dependency at 30 days in multivariate statistical models.

RESULTS

In the 186 patients included in the study, age, atrial fibrillation and the National Institutes of Health Stroke Score were identified as unmodifiable factors independently associated with death and death or dependency. After adjusting for these factors, none of the physiological variables were independently associated with death, while only diastolic blood pressure (DBP) > or = 90 mmHg was associated with death or dependency at 30 days (p = 0.02).

CONCLUSIONS

Except for elevated DBP, we found no independent associations between admission physiology and outcome at 30 days in an unselected stroke cohort. Future studies should look for associations in subgroups, or by analysing serial changes in physiology during the early post-stroke period.

Severe Hypertension in the Emergency Department Patient

Severely elevated blood pressure is a common clinical problem en-countered in the Emergency Department. It is often difficult for physicians to differentiate between patients who need emergent blood pressure reduction, requiring the use of intravenous agents and in-tensive monitoring, and those for whom careful, slow reduction in BP is more appropriate. The optimal assessment and management of these patients is reviewed here, with an emphasis on clinical strategies that will most efficiently identify those at greatest risk.

Blutdruck und Gehirn

During acute cerebral infarction, autoregulation is abolished. Brain perfusion therefore directly depends on perfusion pressure and cardiac output. For this reason, in the early state of stroke, elevated blood pressure improves cerebral blood flow and only values of 210 mmHg systolic or above should be lowered. With the development of a vasogenic brain edema or a dysfunctional blood-brain barrier (usually on day 2 to 4 after infarction), blood pressure must be normalized in order to avoid hemorrhage and to minimize edema. In the presence of space occupying edema or intracranial hemorrhage, only those antihypertensive substances may be used which do not cause a dilatation of brain vessels. Direct vasodilators and calcium antagonists are not suitable in this situation. Furthermore, antihypertensive medication which causes bradycardia (e.g. beta blockers) should be avoided, because in acute stroke, brain perfusion also depends on the cardiac output. For primary and secondary stroke prevention normalization of blood pressure is essential. Efficacy is basically independent of the kind of antihypertensive medication used. Effective normalization of blood pressure probably helps to prevent vascular dementias of all kinds. Convincing studies however are still lacking for most sorts of antihypertensive medication.

Salivary cortisol, a biological marker of stress, is positively associated with 24-hour systolic blood pressure in patients with acute ischaemic stroke

BACKGROUND/AIM

The cause of elevated blood pressure (BP) in acute stroke is unknown. Stress is often suggested as a main contributing factor. We aimed to investigate the relationship between BP and stress in patients with acute stroke.

METHODS

58 patients with clinical symptoms of stroke were recruited prospectively after exclusion of haemorrhage by CT scan within 14 h and 15 min (mean) after symptom onset (range 2 h and 45 min-23 h and 40 min). The mean age of the patients was 66 years (range 39-86 years), and the mean National Institute of Health Stroke Scale score was 7 (range 1-26). BP and pulse rate were recorded by non-invasive automatic monitoring hourly for 24 h. Stress was evaluated by testing the level of salivary cortisol. Four samples of saliva were obtained at inclusion, on the evening of the inclusion day (20.00-22.00 h), on the morning of the next day (7.00-9.00 h) and on the afternoon of the inclusion day/next day (15.00-17.00 h) within 24 h after inclusion in the study. Logarithmic transformation was done for cortisol levels.

RESULTS

The 24-hour mean cortisol level (geometric mean 13.6 nmol/l) was related to 24-hour mean systolic BP [SBP; r = 0.36, p = 0.01, multivariate p = 0.02], mean night-time (22.00-6.00 h) SBP (r = 0.43, p = 0.001, multivariate p < 0.005) and mean night-time diastolic BP (r = 0.31, p = 0.02, multivariate p = 0.02). Cortisol levels at inclusion (r = 0.31, p = 0.02, multivariate p = 0.05 for 24-hour SBP) and in the evening were also statistically significantly related to the above BP variables. The morning cortisol (r = 0.28, p = 0.04, multivariate p = 0.04) was related to night-time SBP.

CONCLUSIONS

Salivary cortisol was positively correlated with 24-hour SBP and night-time BP, suggesting that stress is a contributing factor for high BP in acute stroke.

Blood pressure, nimodipine, and outcome of ischemic stroke

OBJECTIVES

The reduction of blood pressure (BP) caused by nimodipine has been proposed as an explanation for the poor results in ischemic stroke trials. We evaluated further the relationships between BP, nimodipine, and outcome of ischemic stroke, and also searched for other possible explaining mechanisms.

PATIENTS AND METHODS

All 350 participants of an earlier placebo controlled trial on oral nimodipine were included in this study. Among other variables, the admission BP, and the change of BP during the first day were noted. The 3 week and 3 month functional outcome was assessed with a modified Rankin grading.

RESULTS

The severity of stroke was the utmost important predictor of outcome. Visible cerebral infarction on computed tomography (CT) was associated with severe stroke and an early commencement (within 24 h of stroke onset) of nimodipine treatment. In the nimodipine arm, high initial systolic and diastolic BP measured < or =24 h of stroke onset were independent predictors of good functional outcome (Rankin grades 1 and 2), whereas BP change was not. The survivors in the nimodipine arm with mild to moderately severe stroke had higher initial BP than the deceased ones, in severe strokes the situation was the opposite.

CONCLUSIONS

Stroke severity, visible cerebral infarcts on CT, and early commencement of nimodipine treatment were associated. Overall, high initial systolic and diastolic BP predicted a good functional outcome in patients on nimodipine. In severe strokes, the combination of nimodipine and high initial BP was associated with increased risk of death.

U-shaped relationship between mortality and admission blood pressure in patients with acute stroke

OBJECTIVE

To evaluate the relationship between systolic blood pressure (SBP) or diastolic blood pressure (DBP) on admission and early or late mortality in patients with acute stroke.

DESIGN

Prospective study of hospitalized first-ever stroke patients over 8 years.

SETTING

Stroke unit and medical wards in a University hospital.

SUBJECTS

A total of 1121 patients admitted within 24 h from stroke onset and followed up for 12 months.

MAIN OUTCOME MEASURES

Mortality at 1 and 12 months after stroke in relation to admission SBP and DBP.

RESULTS

Early and late mortality in patients with acute ischaemic or haemorrhagic stroke in relation to admission SBP and DBP followed a 'U-curve pattern'. After adjusting for known outcome predictors, the relative risk of 1-month and 1-year mortality associated with a 10-mmHg SBP increase above 130 mmHg (U-point of the curve) increased by 10.2% (95% CI: 4.2-16.6%) and 7.2% (95% CI: 2.2-12.3%), respectively. For every 10 mmHg SBP decrease, below the U-point, the relative risk of 1-month and 1-year mortality rose by 28.2% (95% CI: 8.6-51.3%) and 17.5% (95% CI: 3.1-34.0%), respectively. Low admission SBP-values were associated with heart failure (P < 0.001) and coronary artery disease (P = 0.006), whilst high values were associated with history of hypertension (P < 0.001) and lacunar stroke (P < 0.001). Death due to cerebral oedema was significantly (P = 0.005) more frequent in patients with high admission SBP-values, whereas death due to cardiovascular disease was more frequent (P = 0.004) in patients with low admission SBP-values.

CONCLUSION

Acute ischaemic or haemorrhagic stroke patients with high and low admission BP-values have a higher early and late mortality. Coincidence of heart disease is associated with low initial BP-values. Death due to neurological damage from brain oedema is associated with high initial BP-values.

Association between course of blood pressure within the first 24 hours and functional recovery after acute ischemic stroke

STUDY OBJECTIVE

The relation between course of blood pressure within the first 24 hours after acute stroke and early neurologic outcome remains a matter of dispute. We investigate this relation with adjustment for other influencing variables.

METHODS

Three hundred seventy-two patients with the diagnosis of ischemic stroke were included to evaluate the relation between blood pressure course and early neurologic outcome. The following data were collected: age; sex; history of hypertension, diabetes mellitus, hyperlipidemia, coronary heart disease, peripheral vascular disease, and stroke; smoking habits; preadmission blood pressure, blood pressure on admission, and blood pressure 24 hours later; antihypertensive treatment; and stroke localization. We assessed outcome at day 5 after admission as dependent or independent (Rankin Scale score <or=2) and applied multivariate logistic regression analysis to investigate the effect of blood pressure changes on outcome, with adjustment for other baseline variables.

RESULTS

Relative changes of systolic and diastolic blood pressure within hospital admission to 24 hours after admission revealed significant differences of patients' neurologic outcome only for diastolic blood pressure changes from admission to 24 hours. A diastolic blood pressure decrease more than 25% from admission until 24 hours after admission was associated with a 3.8-fold increased adjusted odds (95% confidence interval 1.2 to 12.1) for poor neurologic outcome on day 5 (Rankin Scale score 3 to 5).

CONCLUSION

Excessive diastolic blood pressure reduction was associated with an increased risk for an impaired neurologic outcome in patients with ischemic stroke. The association between both characteristics was independent from concomitant risk factors, stroke localization, and possible antihypertensive treatment.

European Stroke Initiative Recommendations for Stroke Management – Update 2003

This article represents the update of 'European Stroke Initiative Recommendations for Stroke Management', first published in this Journal in 2000. The recommendations are endorsed by the 3 European societies which are represented in the European Stroke Initiative: the European Stroke Council, the European Neurological Society and the European Federation of Neurological Societies.

Effects of blood pressure lowering in the acute phase of total anterior circulation infarcts and other stroke subtypes

BACKGROUND

Lowering of blood pressure (BP) in the acute phase of stroke is reported both to worsen and to improve the outcome. To investigate whether heterogeneity exists between stroke subtypes in the response to BP lowering, we analysed data from the Intravenous Nimodipine West European Stroke Trial (INWEST).

METHODS

INWEST enrolled acute ischaemic stroke patients within 24 h (n = 295) to the following groups: placebo (n = 100), 1 mg/h nimodipine (n = 101) or 2 mg/h nimodipine (n = 94). Patients were retrospectively classified as total anterior circulation infarct (TACI) (i.e. hemiparesis + hemianopia + dysphasia) and non-TACI (exclusion of any one of these). Main outcome measures were neurological (Orgogozo) and functional (Barthel) scores at day 21.

RESULTS

106 patients were labelled as TACI and 62 as non-TACI. No significant difference in BP was observed between the TACI and non-TACI subtypes at baseline, nor did the subtypes differ in BP course within the treatment groups. A higher proportion of non-TACI patients received postrandomisation antihypertensive agents in addition to the study drug compared with TACI patients (55% non-TACI vs. 26% TACI, p < 0.005). For TACI patients, there was no outcome difference between the placebo- and nimodipine-treated groups. For non-TACI patients, placebo had a significantly better neurological (p = 0.004) and functional (p = 0.04) outcome than the high-dose nimodipine group. In multivariate analysis for TACI patients, BP reduction and nimodipine treatment had no relation with outcome. Baseline stroke severity (p < 0.005) was the only significant predictor of the outcome at day 21. For non-TACI patients, diastolic BP (DBP) reduction (p = 0.03) and nimodipine treatment (p = 0.001) were related to neurological deterioration and nimodipine treatment (p = 0.01) to functional deterioration. Systolic BP reduction was associated with neurological (p < 0.005) and functional improvement (p = 0.01). Baseline stroke severity (p < 0.005) was related to both neurological and functional outcome.

CONCLUSION

BP lowering and nimodipine treatment had no significant effect on outcome for TACI patients. For non-TACI patients, DBP lowering worsened the neurological outcome and high-dose nimodipine worsened both the neurological and functional outcome.

Effects of induced hypertension on intracranial pressure and flow velocities of the middle cerebral arteries in patients with large hemispheric stroke

BACKGROUND AND PURPOSE

Our aim was to prospectively evaluate the effects of induced arterial hypertension in patients with large ischemic stroke.

METHODS

A total of 47 monitoring sessions in 19 patients with acute, complete, or subtotal middle cerebral artery (MCA) territory stroke were performed. Intracranial pressure (ICP) was monitored using a parenchymal catheter. Mean arterial blood pressure (MAP), ICP, and peak mean flow velocity of the middle cerebral arteries (V(m)MCA) were continuously recorded. Patients with acute ICP crises were excluded. After obtaining baseline values, MAP was raised by an infusion of norepinephrine to reach an MAP increase of at least 10 mm Hg. After MAP had reached a peak plateau level, the norepinephrine infusion was stopped.

RESULTS

Baseline MAP was 83.6+/-1.6 mm Hg and rose to 108.9+/-2.0 mm Hg after infusion of norepinephrine. ICP slightly increased from 11.6+/-0.9 mm Hg to 11.8+/-0.9 mm Hg (P<0.05). Cerebral perfusion pressure rose from baseline 72.2+/-2 mm Hg to 97+/-1 mm Hg (P<0.0001). V(m)MCA was already higher on the affected side during baseline measurements. At maximum MAP levels, V(m)MCA rose by 25.5+/-5.5 cm/s on the affected side and by 8.6+/-1.6 cm/s on the contralateral side.

CONCLUSIONS

In patients with large hemispheric stroke without an acute ICP crisis, induced hypertension enhances cerebral perfusion pressure and augments the V(m)MCA(s), more so on the affected side. The ICP slightly increases; however, this is probably not clinically significant.