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Clinical Review Extracts from “Clinical Evidence”

Acute ischaemic stroke

BMJ 2000; 320 doi: https://doi.org/10.1136/bmj.320.7236.692 (Published 11 March 2000) Cite this as: BMJ 2000;320:692

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Management of blood pressure in acute stroke

EDITOR - Gubitz and Sandercock review the question of blood pressure
reduction in acute stroke, quoting an ongoing collaboration and systematic
review which we manage 1,2. In addition to pointing out that this question
has yet to be tested in a large scale randomised controlled trial, they
suggest that lowering blood pressure may be harmful, largely as a result
of trials utilising calcium channel blockers (especially intravenous
nimodipine) or ß-adrenoceptor antagonists. However, it is inappropriate to
extrapolate the results from these trials to all antihypertensive agents
and suggest that any form of blood pressure lowering may be detrimental.

Firstly, CCBs and ß- adrenoceptor antagonists may be harmful for class-
specific reasons, e.g. they are both negatively inotropic, whilst CCBs may
cause dysrhythmias and cerebral steal, all of which can reduce cerebral
blood flow.

Secondly, acute stroke trials often utilise drugs at doses
which, whilst safe in younger, fit, often male, adults, may be excessive
in sick, frail, older, often female stroke patients - this criticism can
certainly be levelled at some CCB studies. Importantly, it is possible to
give antihypertensive agents, e.g. angiotensin converting enzyme
inhibitors or nitric oxide donors, at doses which causes relatively small
reductions in blood pressure (<_15 without="without" reducing="reducing" cerebral="cerebral" perfusion="perfusion" _34.="_34." p="p"/>Lastly, trials of agents in acute stroke which raised blood pressure
(and which may, therefore, have increased cerebral blood flow in the
absence of cerebral autoregulation) have also been unsuccessful, e.g.
aptiganel and diaspirin cross-linked haemoglobin.

In the absence of definitive trial data, we are planning a large
multicentre RCT, the 'Efficacy of Nitric Oxide in Stroke' (ENOS) trial, to
test the question of whether it is safe and efficacious to lower blood
pressure with transdermal glyceryl trinitrate during the acute phase of
stroke; further information is given at

http://www.nottingham.ac.uk/stroke-medicine/enossummary.htm
.

Philip Bath
professor

Fiona Bath scientist

Parveen Rashid
clinical research fellow

Chris Weaver
research nurse

Division of Stroke Medicine, University of Nottingham, City Hospital
campus, Nottingham NG5 1PB

1 Bath FJ, Bath PMW. What is the correct management of blood pressure
in acute stroke? The Blood pressure in Acute Stroke Collaboration.
Cerebrovasc Dis 1997;7:205-213.

2 Blood pressure in Acute Stroke Collaboration (BASC) . Interventions
for deliberately altering blood pressure in acute stroke (Cochrane
Review). In: The Cochrane Library. Oxford: Update Software, 1999;

3 Dyker AG, Grosset DG, Lees K. Perindopril reduces blood pressure
but not cerebral blood flow in patients with recent cerebral ischemic
stroke. Stroke 1997;28:580-583.

4 Butterworth RJ, Cluckie A, Jackson SHD, Buxton-Thomas M, Bath PMW.
Pathophysiological assessment of nitric oxide (given as sodium
nitroprusside) in acute ischaemic stroke. Cerebrovasc Dis 1998;8:158-165.

Competing interests: No competing interests

06 April 2000
Philip Bath
Professor of Stroke Medicine
University of Nottingham