Angiotensin Receptor Blockade in Acute Stroke. the Scandinavian Candesartan Acute Stroke Trial: Rationale, Methods and Design of a Multicentre, Randomised- and Placebo-Controlled Clinical Trial (NCT00120003)

Transcriptomic Analysis of Mouse Brain After Traumatic Brain Injury Reveals That the Angiotensin Receptor Blocker Candesartan Acts Through Novel Pathways

Traumatic brain injury (TBI) results in complex pathological reactions, where the initial lesion is followed by secondary inflammation and edema. Our laboratory and others have reported that angiotensin receptor blockers (ARBs) have efficacy in improving recovery from traumatic brain injury in mice. Treatment of mice with a subhypotensive dose of the ARB candesartan results in improved functional recovery, and reduced pathology (lesion volume, inflammation and gliosis). In order to gain a better understanding of the molecular mechanisms through which candesartan improves recovery after controlled cortical impact injury (CCI), we performed transcriptomic profiling on brain regions after injury and drug treatment. We examined RNA expression in the ipsilateral hippocampus, thalamus and hypothalamus at 3 or 29 days post injury (dpi) treated with either candesartan (0.1 mg/kg) or vehicle. RNA was isolated and analyzed by bulk mRNA-seq. Gene expression in injured and/or candesartan treated brain region was compared to that in sham vehicle treated mice in the same brain region to identify genes that were differentially expressed (DEGs) between groups. The most DEGs were expressed in the hippocampus at 3 dpi, and the number of DEGs reduced with distance and time from the lesion. Among pathways that were differentially expressed at 3 dpi after CCI, candesartan treatment altered genes involved in angiogenesis, interferon signaling, extracellular matrix regulation including integrins and chromosome maintenance and DNA replication. At 29 dpi, candesartan treatment reduced the expression of genes involved in the inflammatory response. Some changes in gene expression were confirmed in a separate cohort of animals by qPCR. Fewer DEGs were found in the thalamus, and only one in the hypothalamus at 3 dpi. Additionally, in the hippocampi of sham injured mice, 3 days of candesartan treatment led to the differential expression of 384 genes showing that candesartan in the absence of injury had a powerful impact on gene expression specifically in the hippocampus. Our results suggest that candesartan has broad actions in the brain after injury and affects different processes at acute and chronic times after injury. These data should assist in elucidating the beneficial effect of candesartan on recovery from TBI.

Effects of Candesartan in the Acute Phase of Intracerebral Hemorrhage

BACKGROUND AND PURPOSE

Uncertainty persists over the effects of blood pressure-lowering treatment in acute intracerebral hemorrhage (ICH). We assessed the effects of treatment with candesartan in acute ICH and according to different types of hematoma.

METHODS

Post-hoc analysis of the Scandinavian Candesartan Acute Stroke Trial, a randomized- and placebo-controlled, double-masked trial of candesartan in patients with any stroke within the acute phase (<30 hours) and high systolic blood pressure (≥140 mm Hg). We collected baseline computed tomography scans of participants with ICH, and characterized hematoma volume (planimetric approach), location (deep versus lobar or infratentorial), hemisphere side, and presence of intraventricular hemorrhage. The trial's 2 coprimary effect variables were the composite endpoint of vascular death, stroke or myocardial infarction, and functional outcome at 6 months according to the modified Rankin scale. We used Cox, ordinal, and binary logistic regression for analysis and adjusted for key, predefined prognostic variables.

RESULTS

Of 274 participants with ICH, computed tomography scans were available in 205 patients (74.8%). There were no significant differences between the candesartan and placebo groups with respect to hematoma volume (median 15.6 mL versus 13.5 mL, P = .96), deep location (77% versus 72%, P = .64), right hemisphere (49% versus 51%, P = .46), and presence of intraventricular hemorrhage (18% versus 11%, P = .22). Candesartan was associated with a significant increase in poor functional outcome in patients with deep hematoma (adjusted common odds ratio 2.27, 95% confidence interval 1.23-4.18, P = .009, P for interaction .015), but there was no differential effect on functional outcome or vascular events in any of the other imaging subgroups.

CONCLUSIONS

Candesartan was not associated with any beneficial effect when initiated in the acute phase of ICH, a possible adverse effect on functional outcome in patients with deep hematomas cannot be ruled out by this study alone.

Effects of candesartan in acute stroke on activities of daily living and level of care at 6 months

OBJECTIVE

The Scandinavian Candesartan Acute Stroke Trial (SCAST) indicated that blood pressure-lowering treatment with candesartan in the acute phase of stroke has a negative effect on functional outcome at 6 months, measured by the modified Rankin scale. We wanted to see if similar effects can be observed on activities of daily living and level of care.

METHODS

SCAST was an international multicentre, randomized and placebo-controlled trial of candesartan in 2029 patients recruited within 30  h of acute ischaemic or haemorrhagic stroke. Treatment lowered blood pressure by 5/2  mmHg from day 2 onwards, and was administered for 7 days. At 6 months, activities of daily living were assessed by the Barthel index, and categorized as 'dependency' (≤55 points), 'assisted dependency' (60-90), or 'independency' (≥95). Level of care was categorized as 'living at own home without public help', 'living at home with public help, or in institution for rehabilitation', or 'living in institution for long or permanent stay'. We used ordinal and binary logistic regression for statistical analysis, and adjusted for predefined key variables.

RESULTS

Data were available in 1825 patients, of which 1559 (85%) patients had ischaemic and 247 (13%) had haemorrhagic stroke. There were no statistically significant effects of candesartan on the Barthel index or on level of care (adjusted common odds ratio for poor outcome 1.09, 95% confidence interval 0.88-1.35, P = 0.44; and odds ratio 1.05, 95% confidence interval 0.82-1.34, P = 0.69, respectively). In the individual Barthel index domains, there were also no statistically significant differences.

CONCLUSION

Blood pressure-lowering treatment with candesartan had no beneficial effect on activities of daily living and level of care at 6 months. This result is compatible with the results of the main analysis of the modified Rankin scale, and supports the conclusion that there is no indication for routine blood pressure treatment with candesartan in the acute phase of stroke.

Effects of candesartan in acute stroke on vascular events during long-term follow-up: results from the Scandinavian Candesartan Acute Stroke Trial (SCAST)

BACKGROUND

Randomized-controlled trials have shown no beneficial short-term effects of blood pressure lowering treatment in the acute phase of stroke.

AIM

We aimed to see whether blood pressure lowering treatment with candesartan in the acute phase can lead to benefits that become apparent over a longer period of follow-up.

METHODS

The Scandinavian Candesartan Acute Stoke Trial was a randomized- and placebo-controlled trial of candesartan in 2,029 patients with acute stroke and systolic blood pressure ≥140 mmHg. Trial treatment was given for seven-days, and the primary follow-up period was six-months. We have used the national patient registries and the cause of death registries in the Scandinavian countries to collect data on vascular events and deaths up to three-years from randomization. The primary end-point was the composite of stroke, myocardial infarction, or vascular death, and we used Cox proportional hazards regression model for analysis.

RESULTS

Long-term data were available for 1,256 of the 1,286 patients (98%) from Scandinavia. The risk of the primary composite end-point did not differ significantly between the groups (candesartan 178/632 events, placebo 203/624 events, hazard ratio = 0·87, 95% confidence interval 0·71-1·07). There were also no statistically significant differences for the secondary end-points stroke and all-cause death, or in any of the pre-specified subgroups.

CONCLUSIONS

Treatment with candesartan in the acute phase of stroke was not associated with clear long-term clinical benefits. This result supports the conclusion from trials with short-term follow-up, that blood pressure lowering treatment with candesartan should not be given routinely to patients with acute stroke and raised blood pressure.

Effects of blood pressure lowering in patients with acute ischemic stroke and carotid artery stenosis

BACKGROUND

The Scandinavian Candesartan Acute Stroke Trial (SCAST) showed no beneficial clinical effects of blood pressure lowering with the angiotensin receptor blocker candesartan in the acute phase of stroke. In the present analysis we wanted to see if the effects of blood pressure lowering are harmful in the subgroup of patients with carotid artery stenosis.

METHODS

SCAST was a randomized- and placebo-controlled, double-masked trial of 2029 patients with acute stroke and high systolic blood pressure (≥ 140 mmHg). Of 1733 patients with ischemic stroke 993 underwent carotid artery imaging, and the degree of stenosis was categorized as no/insignificant (0-49%, n = 806), moderate (50-69%, n = 97) or severe (≥ 70%, n = 90). The trial's two co-primary effect variables were the composite end-point of vascular death, stroke or myocardial infarction, and functional outcome at six-months, according to the modified Rankin Scale.

RESULTS

Among patients with moderate or severe carotid artery stenosis the vascular end-point occurred in 9 of 87 patients (10.3%) treated with candesartan and in 17 of 100 controls (17.0%), and there was no evidence of a different risk in patients with severe stenosis (adjusted hazard ratio 0.74, 95% confidence interval 0.28-1.96, P = 0.54). For functional outcome there was also no clear difference, although in patients with severe stenosis the risk of a poor outcome was somewhat higher than in any of the other groups (adjusted odds ratio 2.24, 95% confidence interval 0.71-7.09, P = 0.16). Progressive stroke also occurred more often in patients with carotid artery stenosis treated with candesartan (10 of 87 patients (11.5%) vs. 4 of 100 patients (4.0%)), with a trend towards an increased risk with increasing severity of stenosis (P-value for linear trend = 0.04).

CONCLUSIONS

There is no clear evidence that the effect of candesartan is qualitatively different in patients with carotid artery stenosis, but there are signals that patients with severe stenosis are at particularly high risk of stroke progression and poor functional outcome.

Interventions for deliberately altering blood pressure in acute stroke

BACKGROUND

It is unclear whether blood pressure should be altered actively during the acute phase of stroke. This is an update of a Cochrane review first published in 1997, and previously updated in 2001 and 2008.

OBJECTIVES

To assess the clinical effectiveness of altering blood pressure in people with acute stroke, and the effect of different vasoactive drugs on blood pressure in acute stroke.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (last searched in February 2014), the Cochrane Database of Systematic reviews (CDSR) and the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2014, Issue 2), MEDLINE (Ovid) (1966 to May 2014), EMBASE (Ovid) (1974 to May 2014), Science Citation Index (ISI, Web of Science, 1981 to May 2014) and the Stroke Trials Registry (searched May 2014).

SELECTION CRITERIA

Randomised controlled trials of interventions that aimed to alter blood pressure compared with control in participants within one week of acute ischaemic or haemorrhagic stroke.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied the inclusion criteria, assessed trial quality and extracted data. The review authors cross-checked data and resolved discrepancies by discussion to reach consensus. We obtained published and unpublished data where available.

MAIN RESULTS

We included 26 trials involving 17,011 participants (8497 participants were assigned active therapy and 8514 participants received placebo/control). Not all trials contributed to each outcome. Most data came from trials that had a wide time window for recruitment; four trials gave treatment within six hours and one trial within eight hours. The trials tested alpha-2 adrenergic agonists (A2AA), angiotensin converting enzyme inhibitors (ACEI), angiotensin receptor antagonists (ARA), calcium channel blockers (CCBs), nitric oxide (NO) donors, thiazide-like diuretics, and target-driven blood pressure lowering. One trial tested phenylephrine.At 24 hours after randomisation oral ACEIs reduced systolic blood pressure (SBP, mean difference (MD) -8 mmHg, 95% confidence interval (CI) -17 to 1) and diastolic blood pressure (DBP, MD -3 mmHg, 95% CI -9 to 2), sublingual ACEIs reduced SBP (MD -12.00 mm Hg, 95% CI -26 to 2) and DBP (MD -2, 95%CI -10 to 6), oral ARA reduced SBP (MD -1 mm Hg, 95% CI -3 to 2) and DBP (MD -1 mm Hg, 95% CI -3 to 1), oral beta blockers reduced SBP (MD -14 mm Hg; 95% CI -27 to -1) and DBP (MD -1 mm Hg, 95% CI -9 to 7), intravenous (iv) beta blockers reduced SBP (MD -5 mm Hg, 95% CI -18 to 8) and DBP (-5 mm Hg, 95% CI -13 to 3), oral CCBs reduced SBP (MD -13 mmHg, 95% CI -43 to 17) and DBP (MD -6 mmHg, 95% CI -14 to 2), iv CCBs reduced SBP (MD -32 mmHg, 95% CI -65 to 1) and DBP (MD -13, 95% CI -31 to 6), NO donors reduced SBP (MD -12 mmHg, 95% CI -19 to -5) and DBP (MD -3, 95% CI -4 to -2) while phenylephrine, non-significantly increased SBP (MD 21 mmHg, 95% CI -13 to 55) and DBP (MD 1 mmHg, 95% CI -15 to 16).Blood pressure lowering did not reduce death or dependency either by drug class (OR 0.98, 95% CI 0.92 to 1.05), stroke type (OR 0.98, 95% CI 0.92 to 1.05) or time to treatment (OR 0.98, 95% CI 0.92 to 1.05). Treatment within six hours of stroke appeared effective in reducing death or dependency (OR 0.86, 95% CI 0.76 to 0.99) but not death (OR 0.70, 95% CI 0.38 to 1.26) at the end of the trial. Although death or dependency did not differ between people who continued pre-stroke antihypertensive treatment versus those who stopped it temporarily (worse outcome with continuing treatment, OR 1.06, 95% CI 0.91 to 1.24), disability scores at the end of the trial were worse in participants randomised to continue treatment (Barthel Index, MD -3.2, 95% CI -5.8, -0.6).

AUTHORS' CONCLUSIONS

There is insufficient evidence that lowering blood pressure during the acute phase of stroke improves functional outcome. It is reasonable to withhold blood pressure-lowering drugs until patients are medically and neurologically stable, and have suitable oral or enteral access, after which drugs can than be reintroduced. In people with acute stroke, CCBs, ACEI, ARA, beta blockers and NO donors each lower blood pressure while phenylephrine probably increases blood pressure. Further trials are needed to identify which people are most likely to benefit from early treatment, in particular whether treatment started very early is beneficial.

Blood pressure-lowering treatment with candesartan in patients with acute hemorrhagic stroke

BACKGROUND AND PURPOSE

Early and intensive blood pressure-lowering treatment seems to be beneficial in patients with acute hemorrhagic stroke and high blood pressure. We wanted to see if similar benefits can be shown from a later and more gradual blood pressure lowering, using data from the Scandinavian Candesartan Acute Stroke Trial (SCAST).

METHODS

SCAST was a randomized- and placebo-controlled, double-masked trial of candesartan given for 7 days, in 2029 patients with acute stroke and systolic blood pressure ≥140 mm Hg. We assessed the effects of candesartan in the 274 patients with hemorrhagic stroke, using the trial's 2 coprimary effect variables: the composite vascular end point of vascular death, stroke or myocardial infarction, and functional outcome at 6 months, according to the modified Rankin Scale. We used Cox proportional hazards models and ordinal regression for analysis and adjusted for key, predefined prognostic variables.

RESULTS

There was no association between treatment with candesartan and risk of vascular events (17 of 144 [11.8%] versus 13 of 130 [10.0%]; hazard ratio, 1.36; 95% confidence interval, 0.65-2.83; P=0.41). For functional outcome we found evidence of a negative effect of candesartan (common odds ratio, 1.61; 95% confidence interval, 1.03-2.50; P=0.036).

CONCLUSIONS

There was no evidence that blood pressure-lowering treatment with candesartan is beneficial during the first week of hemorrhagic stroke. Instead, there were signs that such treatment may be harmful, but this needs to be verified in larger studies.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT00120003.

Effects of candesartan in acute stroke on cognitive function and quality of life: results from the Scandinavian Candesartan Acute Stroke Trial

BACKGROUND AND PURPOSE

High blood pressure is common in the acute phase of stroke and is associated with poor outcome. We examined whether blood pressure-lowering treatment with candesartan in the acute phase affects long-term cognitive function and quality of life.

METHODS

Scandinavian Candesartan Acute Stroke Trial was a randomized-controlled and placebo-controlled trial of candesartan in 2029 patients with acute stroke and raised blood pressure. At 6 months, cognitive function was assessed by the Mini Mental State Examination and quality of life by the EuroQol instrument. We used ordinal logistic and multiple linear regression for statistical analysis, adjusting for predefined key variables.

RESULTS

Median Mini Mental State Examination score was 28 in both groups, and there was no significant difference between the distribution of Mini Mental State Examination scores in the 2 groups (common odds ratio, 1.11; 95% confidence interval, 0.91-1.34; P=0.32). Median EuroQol-5D index were 0.74 and 0.78 (P=0.034), and the mean EuroQol-visual analogue scale scores were 66.0 and 67.3 in the candesartan and placebo groups, respectively (P=0.11).

CONCLUSIONS

Candesartan did not improve cognitive function or quality of life. Rather, there were signs of harmful effects. These findings support the conclusion from our previous report that there is no indication for routine blood pressure-lowering treatment with candesartan in the acute phase of stroke.

CLINICAL TRIAL REGISTRATION URL

www.clinicaltrials.gov. Unique identifier: NCT00120003.

Relation Between Change in Blood Pressure in Acute Stroke and Risk of Early Adverse Events and Poor Outcome

Background and Purpose—

The Scandinavian Candesartan Acute Stroke Trial (SCAST) found no benefits of candesartan in acute stroke. In the present analysis we aim to investigate the effect of change in blood pressure during the first 2 days of stroke on the risk of early adverse events and poor outcome.

Methods—

SCAST was a multicenter, randomized controlled, double-blind trial of candesartan in acute stroke. The trial recruited 2029 patients presenting within 30 hours of acute stroke and with systolic blood pressure (SBP) ≥140 mm Hg. Treatment was given for 7 days. Change in blood pressure was defined as the difference in SBP between baseline and Day 2 and was used to divide patients into groups with increase/no change, a small decrease, moderate decrease, or large decrease in SBP. The primary effect parameter was early adverse events (recurrent stroke, stroke progression, and symptomatic hypotension) during the first 7 days, analyzed using logistic regression, with the group with a small decrease in SBP as the reference group. Secondary effect parameters were neurological status at 7 days and functional outcome at 6 months.

Results—

Patients with a large decrease or increase/no change in SBP had a significantly increased risk of early adverse events relative to patients with a small decrease (OR, 2.08; 95% CI, 1.19–3.65 and OR, 1.96; 95% CI, 1.13–3.38, respectively). Patients with an increase/no change in SBP had a significantly increased risk of poor neurological outcome as compared with the other groups ( P =0.001). No differences were observed in functional outcome at 6 months.

Conclusions—

Our findings support the suggestion from SCAST that blood pressure reduction may be harmful and that routine blood pressure-lowering treatment should probably be avoided in the acute phase.

Clinical Trial Information—

Clinical Trial Registration: www.clinicaltrials.gov . Unique identifier: NCT00120003.

Hemodynamic findings in patients with brain stroke

INTRODUCTION

Standard procedures carried out at a stroke department in patients after a cerebral event may prove insufficient for monitoring hemodynamic indices. Impedance cardiography enables hemodynamic changes to be monitored non-invasively. The aim of the work was to describe hemodynamic parameters in patients with acute phase of ischemic and hemorrhagic stroke and to analyse the correlation between the type of hemodynamic response and long-term prognosis.

MATERIAL AND METHODS

The 45 consecutive subjects with ischemic stroke and 16 with a hemorrhagic stroke were examined additionally with impedance cardiography during the first day of hospitalization. The heart contractility, pump performance, afterload and preload indices were recorded and calculated automatically and the data analyzed in terms of 6-month mortality.

RESULTS

We found a significant association between the systemic vascular resistance index, Heather index, stroke index, heart rate, systolic and diastolic and mean arterial blood pressure and mortality in patients with ischemic stroke (p = 0.002, p = 0.008, p = 0.012, p = 0.005, p = 0.007, p = 0.009, p = 0.002 respectively). Logistic regression analysis identified the thoracic fluid content as the most significant variable correlating with the non-survival of the patients with ischemic stroke and in the whole group (ischemic and hemorrhagic stroke). The significant parameters were also mean arterial pressure and stroke index in ischemic stroke (the correct answer ratio was 86.67%) and heart rate in the whole group (the correct answer ratio was 80.33%). There were no significant associations in hemorrhagic stroke.

CONCLUSIONS

The hemodynamic parameters correlate with long term prognosis in patients with ischemic brain stroke.

Hospital-based management of acute ischemic stroke following intravenous thrombolysis

Timely administration of proven therapies remains the primary goal in acute stroke care. Following reperfusion therapy with intravenous thrombolysis, medical and neurological complications may develop in the hospitalized patient with acute ischemic stroke. Medical complications may include deep venous thrombosis, pulmonary embolism, aspiration, systemic infections and neuropsychiatric disturbances. Neurologic complications may include symptomatic intracranial hemorrhage, cerebral edema with elevated intracranial pressure, and post-stroke seizures. Early initiation of preventative strategies and proper management of common complications may improve both short-term and long-term outcomes. Here we review evidence-based management strategies for hospitalized acute ischemic stroke patients following intravenous thrombolysis.

The angiotensin-receptor blocker candesartan for treatment of acute stroke (SCAST): a randomised, placebo-controlled, double-blind trial

BACKGROUND

Raised blood pressure is common in acute stroke, and is associated with an increased risk of poor outcomes. We aimed to examine whether careful blood-pressure lowering treatment with the angiotensin-receptor blocker candesartan is beneficial in patients with acute stroke and raised blood pressure.

METHODS

Participants in this randomised, placebo-controlled, double-blind trial were recruited from 146 centres in nine north European countries. Patients older than 18 years with acute stroke (ischaemic or haemorrhagic) and systolic blood pressure of 140 mm Hg or higher were included within 30 h of symptom onset. Patients were randomly allocated to candesartan or placebo (1:1) for 7 days, with doses increasing from 4 mg on day 1 to 16 mg on days 3 to 7. Randomisation was stratified by centre, with blocks of six packs of candesartan or placebo. Patients and investigators were masked to treatment allocation. There were two co-primary effect variables: the composite endpoint of vascular death, myocardial infarction, or stroke during the first 6 months; and functional outcome at 6 months, as measured by the modified Rankin Scale. Analyses were by intention to treat. The study is registered, number NCT00120003 (ClinicalTrials.gov), and ISRCTN13643354.

FINDINGS

2029 patients were randomly allocated to treatment groups (1017 candesartan, 1012 placebo), and data for status at 6 months were available for 2004 patients (99%; 1000 candesartan, 1004 placebo). During the 7-day treatment period, blood pressures were significantly lower in patients allocated candesartan than in those on placebo (mean 147/82 mm Hg [SD 23/14] in the candesartan group on day 7 vs 152/84 mm Hg [22/14] in the placebo group; p<0·0001). During 6 months' follow-up, the risk of the composite vascular endpoint did not differ between treatment groups (candesartan, 120 events, vs placebo, 111 events; adjusted hazard ratio 1·09, 95% CI 0·84-1·41; p=0·52). Analysis of functional outcome suggested a higher risk of poor outcome in the candesartan group (adjusted common odds ratio 1·17, 95% CI 1·00-1·38; p=0·048 [not significant at p≤0·025 level]). The observed effects were similar for all prespecified secondary endpoints (including death from any cause, vascular death, ischaemic stroke, haemorrhagic stroke, myocardial infarction, stroke progression, symptomatic hypotension, and renal failure) and outcomes (Scandinavian Stroke Scale score at 7 days and Barthel index at 6 months), and there was no evidence of a differential effect in any of the prespecified subgroups. During follow-up, nine (1%) patients on candesartan and five (<1%) on placebo had symptomatic hypotension, and renal failure was reported for 18 (2%) patients taking candesartan and 13 (1%) allocated placebo.

INTERPRETATION

There was no indication that careful blood-pressure lowering treatment with the angiotensin-receptor blocker candesartan is beneficial in patients with acute stroke and raised blood pressure. If anything, the evidence suggested a harmful effect.

FUNDING

South-Eastern Norway Regional Health Authority; Oslo University Hospital Ullevål; AstraZeneca; Takeda.