The course of blood pressure in acute stroke is related to the severity of the neurological deficits

Blood Pressure Management in Acute Stroke

The optimal management of arterial blood pressure in the setting of acute stroke has not been firmly defined. The different types of stroke--ischemic, intracerebral hemorrhage, and subarachnoid hemorrhage--have different pathophysiologies and require different approaches in terms of blood pressure management in the acute setting. This article reviews the current literature and experience at the authors' institution.

Blood pressure in acute ischemic stroke and mortality: a study with noninvasive blood pressure monitoring

BACKGROUND

In acute ischemic stroke, a transient elevation of blood pressure is common; its significance and its relationship with the neurological outcome are still unclear.

METHODS

In 71 consecutive patients with acute ischemic stroke, aged 25-94 years, admitted to our unit, we investigated the relationships between the blood pressure variation during the first 24 h and mortality at 3 months (study endpoint). Neurological status was assessed with the National Institutes of Health Stroke Scale. Blood pressure was measured with bedside noninvasive blood pressure monitoring every 15 min. The mean of four measurements at the emergency department and the mean of 12 measures (during a 3-h interval) at 12 and at 24 h after stroke onset were considered for analysis. Antihypertensive treatment was given in accordance with the Recommendations for Stroke Management of European Stroke Initiative.

RESULTS

In the whole series, 21% were atherothrombotic, 32% cardioembolic, 34% lacunar, and 13% of unknown or other cause. Blood pressure was 160+ or -3/86+ or -2 mmHg at the emergency department, 148+ or -3/82+ or -2 mmHg at 12 h, and 147+ or -3/81+ or -2 mmHg at 24 h (P<0.05). Four patients (11%) of those in whom mean blood pressure decreased >5 mmHg, and 12 (33%) of the others, in whom mean blood pressure decreased < or =5 mmHg or did not decrease, reached the endpoint (P<0.05). According to the multivariate Cox model, NIHSS score at the emergency department (95% confidence interval: 1.025-1.238, P=0.013) and age (95% confidence interval: 1.007-1.259, P=0.038) were predictors of reaching the endpoint, whereas mean blood pressure reduction 24 h after stroke onset had a protective effect (95% confidence interval: 0.845-0.995, P=0.038). Diabetes, mean blood pressure at the emergency department and the need for antihypertensive therapy did not correlate with the outcome.

CONCLUSIONS

Noninvasive blood pressure monitoring during the first 24 h of acute ischemic stroke may be useful in the prognostic stratification by showing moderate blood pressure decrease, either spontaneous or drug induced, which is associated with a favorable prognosis at 3 months.

Relationship between outcome and baseline blood pressure and other haemodynamic measures in acute ischaemic stroke: data from the TAIST trial

BACKGROUND

A poor outcome after stroke is associated independently with high blood pressure during the acute phase; however, relationships with other haemodynamic measures [heart rate (HR), pulse pressure (PP), rate-pressure product (RPP)] remain less clear.

METHODS

The Tinzaparin in Acute Ischaemic Stroke Trial is a randomised, controlled trial assessing the safety and efficacy of tinzaparin versus aspirin in 1484 patients with acute ischaemic stroke. Systolic blood pressure (SBP), diastolic blood pressure (DBP) and HR measurements taken immediately prior to randomization were averaged, and the mid-blood pressure (MBP), PP, mean arterial pressure (MAP), pulse pressure index, and RPP were calculated. The relationship between these haemodynamic measures and functional outcome (death or dependency, modified Rankin Scale > 2) and early recurrent stroke, were studied with adjustment for baseline prognostic factors and treatment group. Odds ratios (OR) and 95% confidence intervals (CI) refer to a change in haemodynamic measure by 10 points.

RESULTS

A poor functional outcome was associated with SBP (adjusted OR; 1.11; 95% CI, 1.03-1.21), HR (adjusted OR; 1.15; 95% CI, 1.00-1.31), MBP (adjusted OR; 1.15, 95% CI, 1.03-1.29), PP (adjusted OR; 1.14; 95% CI, 1.02-1.26), MAP (adjusted OR; 1.15; 95% CI, 1.02-1.31) and RPP (adjusted OR; 1.01; 95% CI, 1.00-1.02). Early recurrent stroke was associated with SBP, DBP, MBP and MAP.

CONCLUSIONS

A poor outcome is independently associated with elevations in blood pressure, HR and their derived haemodynamic variables, including PP and the RPP. Agents that modify these measures may improve functional outcome after stroke.

Circadian blood pressure variation after acute stroke

We aimed to characterise the patterns of circadian blood pressure (BP) variation after acute stroke and determine whether any relationship exists between these patterns and stroke outcome. BP was recorded manually every 4 h for 48 h following acute stroke. Patients were classified according to the percentage fall in mean systolic BP (SBP) at night compared to during the day as: dippers (fall > or = 10-<20%); extreme dippers (> or = 20%); non-dippers (> or = 0-<10%); and reverse dippers (<0%, that is, a rise in mean nocturnal SBP compared to mean daytime SBP). One hundred and seventy-three stroke patients were included in the study (83 men, 90 women; mean age 74.3 years). Four patients (2.3%) were extreme dippers, 25 (14.5%) dippers, 80 (46.2%) non-dippers and 64 (36.9%) reverse dippers. There was a non-significant trend in the proportion of patients who were dead or dependent at 3 months in the extreme dipper (p=0.59) and reverse dipper (p=0.35) groups. Non-dipping and reverse-dipping were relatively common patterns of circadian BP variation seen in acute stroke patients. These patterns were not clearly associated with outcome.

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.

High blood pressure in early acute stroke: a sign of a poor outcome?

OBJECTIVE

To evaluate the prognostic value of admission blood pressure in patients with acute ischemic stroke by determining whether it contributes to clinical outcome and vascular death.

METHODS

We studied 230 consecutive patients admitted within the first 24 h after the onset of ischemic stroke. We used the first systolic and diastolic blood pressure measurements recorded on admission. The functional outcome was assessed on the basis of mortality or dependency (Rankin Scale > 3) at the 10-day and 6-month visits.

RESULTS

High systolic blood pressure on admission was associated with poor outcome at the 10-day and 6-month visits, independent of the baseline risk factors but not of the severity of the initial stroke (odds ratio, 1.39; 95% confidence interval, 0.50-3.87). The spontaneous decrease in systolic blood pressure within the first 10 days was higher in patients with functional improvement. The admission blood pressure was not significantly associated with total and vascular deaths, except for a threshold effect of diastolic blood pressure.

CONCLUSIONS

After an acute stroke, the relationship between blood pressure and clinical outcome depended on the severity of the stroke on presentation, and on the level and trend of the systolic blood pressure during the first 24 h.

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.

Epidemiological Evaluation of Stroke in Babol, Northern Iran (2001–2003)

This retrospective descriptive analytical study was performed on 250 patients (130 males and 120 females) diagnosed to have stroke in the Department of Neurology, Babol, Iran, from April 2001 to April 2003.The risk factors for stroke were recorded. The frequencies of hypertension, diabetes mellitus, cardiac diseases and hyperlipidemia were 54, 24, 43.2 and 26%, respectively. All these epidemiological factors were associated with stroke (p < 0.05). The incidence of stroke was 50/100,000 population during 2 years. It happened more often in females than males, and ischemic stroke (67%) was twice as frequent than hemorrhagic stroke (33%). The mortality rate was 32%. The most common epidemiological risk factors for stroke in our region were hypertension, cardiac diseases and diabetes mellitus.

Abnormalities on ECG and telemetry predict stroke outcome at 3 months

BACKGROUND

ECG is a useful tool in monitoring vital functions in patients with acute stroke; however, fairly little evidence is available concerning the prevalence and the prognostic impact of ECG findings in patients with acute cerebral infarction and acute intracerebral haemorrhage (ICH).

METHODS

This analysis was based on data from 692 patients with acute cerebral infarction, 155 patients with intracerebral haemorrhage (ICH), and 223 patients with transient ischaemic attack (TIA), who were admitted to hospital within 6 h of symptom onset. A 12 lead ECG was obtained on admission, and the patient was on telemetry for the first 12-24 h of hospitalisation.

RESULTS

ECG abnormalities were observed in 60% of patients with cerebral infarction, 50% of patients with ICH, and 44% of patients with TIA. In multivariate analyses 3-month mortality in patients with ischaemic stroke was predicted by atrial fibrillation OR 2.0 (95% CI 1.3-3.1), atrio-ventricular block OR 1.9 (95% CI 1.2-3.9), ST-elevation OR (2.8, 95% CI 1.3-6.3), ST-depression OR 2.5 (95% CI 1.5-4.3), and inverted T-waves OR 2.7 (95% CI 1.6-4.6). This was independent of stroke severity, pre-stroke disability and age. In patients with ICH, sinus tachycardia OR 4.8 (95% CI 1.7-14.0), ST-depression OR 5.2 (95% CI 1.1-24.9), and inverted T-wave 5.2 (95% CI 1.2-22.5) predicted poor outcome. None of the changes reached significance in patients with TIA. In patients with severe cerebral infarction or ICH, heart rate did not decrease within the first 12 h after admission, which was the case in patients with mild to moderate stroke. Rapid heart rate predicted 3-month mortality in multivariate testing OR 1.7 (95% CI 1.02-2.7).

CONCLUSIONS

ECG abnormalities are frequent in acute stroke and may predict 3-month mortality.

Blood pressure course in acute ischaemic stroke in relation to stroke subtype

OBJECTIVES

Blood pressure (BP) management in acute stroke remains a matter of little consensus. Data on BP changes during the first hours of ictus are lacking. We aimed to evaluate the early spontaneous time course of BP in different ischaemic stroke (IS) subtypes.

METHODS

Twenty-four h BP monitoring was performed in 200 first-ever hyper-acute IS patients. The recording was initiated and terminated at 3 h and 27 h of ictus respectively. All IS patients were classified on admission into the following subgroups of different etiology: large artery atherosclerotic stroke (LAA), cardio-embolic stroke (CE), lacunar stroke (LAC) and infarct of undetermined cause (IUC). Statistical comparisons between stroke subgroups were performed using one-way ANOVA and linear regression analyses were used to evaluate the influence of different factors in BP course.

RESULTS

Although there were no significant differences in 24 h systolic (SBP) and diastolic (DBP) BP values between IS subgroups, a distinctly different SBP course was observed. The SBP dropped sharply in the LAA and LAC subgroups, while a more gradual decrease was monitored in the CE subgroup. Throughout the BP-recording, a SBP decrease of 10.1% (95% CI: 8.6-11.5) and 10.4% (95% CI: 9.0-11.8) was documented in patients with LAA and LAC respectively, while a milder drop was recorded in CE (3.7%, 95% CI: 2.4-5.0) and IUC (5.5%, 95% CI: 4.1-6.8). Increasing stroke severity (p<0.001) and brain oedema (p=0.013) was independently associated with a milder spontaneous SBP reduction.

CONCLUSIONS

Spontaneous SBP course varies in acute ischaemic stroke subtypes of different etiology. This may have implications in the optimal management of post-stroke hypertension.

C-reactive protein and white blood cell count increases in the first 24 hours after acute stroke

Levels of C-reactive protein (CRP) and white blood cell count (WBC) in acute stroke may reflect the stroke lesion itself or pre-existing factors such as infections, smoking or atherosclerosis. The aim of this study was to investigate the relation between CRP and WBC levels and time from onset of stroke, stroke severity and outcome.

PATIENTS AND METHODS

The analyses were based on 719 patients in whom WBC test material was obtained within 9 h of stroke onset and CRP test material within 24 h of stroke onset. Stroke severity was assessed by the Scandinavian Stroke Scale Score on admission and outcome by death 7 days, 3 months and 1 year after symptom onset as well as modified Rankin Scale 3 months after stroke onset.

RESULTS

CRP and WBC levels correlated significantly with time from symptom onset as well as with stroke severity and outcome. Levels of CRP and WBC were higher in later determinations in severe stroke. In multivariate logistic regression analysis, CRP(+10 mg/l) was independently related to 1-year mortality (OR 1.1, 95% CI 1.02-1.2).

CONCLUSION

Levels of WBC and CRP increase within the first 24 h in patients with severe stroke. CRP but not WBC is related to long-term mortality possibly by reflecting the vascular risk profile.

Factors influencing acute blood pressure values in stroke subtypes

The aim of this prospective observational study was to determine the association of acute blood pressure values with independent factors (demographic, clinical characteristics, early complications) in stroke subgroups of different aetiology. We evaluated data of 346 first-ever acute (<24 h) stroke patients treated in our stroke unit. Casual and 24-h blood pressure (BP) values were measured. Stroke risk factors and stroke severity on admission were documented. Strokes were divided into subgroups of different aetiopathogenic mechanism. Patients were imaged with CT-scan on admission and 5 days later to determine the presence of brain oedema and haemorrhagic transformation. The relationship of different factors to 24-h BP values (24-h BP) was evaluated separately in each stroke subgroup. In large artery atherosclerotic stroke (n=59), history of hypertension and stroke severity correlated with higher 24-h BP respectively. In cardioembolic stroke (n=87), history of hypertension, stroke severity, haemorrhagic transformation and brain oedema were associated with higher 24-h BP, while heart failure with lower 24-h BP. History of hypertension and coronary artery disease was related to higher and lower 24-h BP, respectively, in lacunar stroke (n=75). In patients with infarct of undetermined (n=57) cause 24-h BP were mainly influenced by stroke severity and history of hypertension. An independent association between higher 24-h BP and history of hypertension and cerebral oedema was documented in intracerebral haemorrhage (n=68). In conclusion, different factors influence acute BP values in stroke subtypes of different aetiology. If the clinical significance of these observations is verified, a differentiated approach in acute BP management based on stroke aetiology may be considered.

Association Between Blood Pressure and C-Reactive Protein Levels in Acute Ischemic Stroke

Among patients with acute stroke, high blood pressure (BP) and higher levels of circulating C-reactive protein (CRP) at the entry are often associated with poor outcome, although the reason is unclear. If the link between BP and stroke outcome is indeed mediated by inflammatory response, one would expect to see positive associations between BP and CRP. In a prospective observational stroke data bank involving 535 first-ever ischemic stroke patients, we studied the association between BP and baseline concentrations of CRP within 24 hours after stroke onset. The association between BP components and the odds of having an elevated CRP level (> or =1.5 mg/dL) was assessed by logistic regression analysis. An increase in systolic BP (SBP), diastolic BP (DBP), mean arterial pressure (MAP), or pulse pressure (PP) was significantly associated with an increase in the odds of having an elevated CRP level, independent of other associated study factors. For each 10 mm Hg increase in SBP, DBP, MAP, or PP, the odds of having a high CRP level increased by 72% (P<0.0001), 10% (P<0.0001), 21% (P<0.0001), and 10% (P<0.0001), respectively. When the same model was rerun, adjusting for all considered BP components, only SBP significantly increased the odds of an elevated CRP level by 77% (P<0.0001). Increased SBP was significantly associated with elevated levels of circulating CRP in ischemic stroke patients. These findings support a possible role of acute hypertension after stroke as an inflammatory stimulus contributing to ischemic brain inflammation.