Stroke

1
Stroke

• Issues prevention

2
Agenda

• Impact of Stroke
• Definitions
• Epidemiology
• Risk factors
• Management of Stroke
• Acute management
• Primary Secondary Prevention
• Guidelines
• Future Directions

3
Definitions

• Stroke
• a clinical syndrome characterised by an acute
  loss of focal cerebral function with symptoms
  lasting over 24 hours or leading to death, and
  which is thought to be due to either spontaneous
  haemorrhage into the brain or inadequate cerebral
  blood supply to a part of the brain as a result
  of low blood flow, thrombosis, or embolism
  associated with diseases of the blood vessels,
  heart, or blood
• Taken from Stroke - A Practical Guide to
  Management - 2nd Edition, Edited by Warlow C et
  al, Blackwell 2001

4
Definitions

• Transient Ischaemic Attack (TIA)
• a clinical syndrome characterised by an acute
  loss of focal cerebral function with symptoms
  lasting less than 24 hours and which is thought
  to be due to inadequate cerebral or occular blood
  flow, arterial thrombosis, or embolism associated
  with disease of the arteries, heart or blood
• Taken from Stroke - A Practical Guide to
  Management - 2nd Edition, Edited by Warlow C et
  al, Blackwell 2001

5
Incidence of Stroke

• 125,000 strokes / year in UK
• 100,000 population (PCO average)
• 240 strokes / year
• 50 TIA / year
• 33 of strokes are secondary events
• Average GP
• 2-5 strokes/year
• 20-40 stroke / TIA survivors

that come to medical attention
6
Stroke Case Fatality
Data from Oxford Community Stroke Project
7
Survival with first and recurrent strokes
Proportion surviving
Survival first stroke
Survival recurrent stroke
Plt0.001
0
100
200
300
400
500
600
700

• Days since stroke

adapted from Samsa G et al. Stroke.
199930338-349.
8
Impact of stroke

• Majority of strokes are not fatal
• Real burden of stroke is disability
• Stroke is most common cause of disability
• There are approximately 250,000 disabled stroke
  survivors in UK
• Stroke is 2nd leading cause of dementia
• Stroke is most common cause of epilepsy in the
  elderly
• Stroke is a frequent cause of depression

9
Risk Factors for Stroke

• Age
• Blood Pressure
• History of Stroke / TIA
• Atrial Fibrillation
• Smoking
• Cholesterol
• Alcohol
• Homocysteine
• Social Class
• Birth Weight

10
Incidence of Stroke by Age

• By age of 85, 1 in 4 men and 1 in 5 women will
  have
• experienced a stroke

11
BP and risk of first stroke
7 prospective observational studies 843 events,
405,500 individuals
RelativeRisk of Stroke
76
84
91
98
105
mm Hg
Approximate mean usual DBP
MacMahon S, Peto R, Cutler J, et al. Lancet.
1990335765-774.
12
BP and risk of recurrent stroke
Stroke and usual BP among 2435 individuals with a
history of TIA or minor stroke
Relative risk of stroke
Relative risk of stroke
Usual Diastolic BP (mm Hg)
Usual Systolic BP (mm Hg)
Rogers A. et al. BMJ 1996313147
13
History of Stroke / TIA
Adapted from Stroke - A Practical Guide to
Management - 2nd Edition, Edited by Warlow C et
al, Blackwell 2001, P655
14
Atrial Fibrillation Stroke

• About 20 of patients with primary stroke are in
  atrial fibrillation
• AF confers an approximate 5 fold increase in
  stroke risk
• Absolute risk however can vary from lt1 to gt12
  per annum depending on presence or absence of
  clinical / echocardiographic risk factors
• Patients with atrial fibrillation should be
  stratified according to absolute risk of future
  CVA events prior to any clinical decision to
  prescribe anticoagulants or antiplatelet agents

15
Absolute risk stratification for patients with
atrial fibrillation
16
Management of stroke
17
Stroke prevention

• Key issues
• Identification of patients
• Stroke / vascular disease registers
• Evidence for intervention
• Blood pressure reduction
• Antiplatelet agents
• Anticoagulants
• Cholesterol reduction
• Carotid endartectomy
• Effective management in practice

18
Summary of secondary prevention
Estimated effect of long term treatments for
secondary prevention of stroke in the 12,000
patients with a history of previous stroke or TIA
in a population of 1 million people
in the 12,000 patients with history of stroke /
TIA in an average 1 million population BP
reduction may be equally relevant to all patients
which would double the number of strokes avoided
Number of extra events avoided compared to
aspirin
Adapted from Hankey Warlow Lancet 1999
3541457-1463
19
Summary of secondary prevention
Estimated effect of long term treatments for
secondary prevention of stroke in the 12,000
patients with a history of previous stroke or TIA
in a population of 1 million people
in the 12,000 patients with history of stroke /
TIA in an average 1 million population BP
reduction may be equally relevant to all patients
which would double the number of strokes avoided
Adapted from Hankey Warlow Lancet 1999
3541457-1463
20
Guidelines for secondary prevention of stroke