Stroke Epidemiology-2001

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Stroke Epidemiology-2001

• Aurora K. Pajeau, M.D., MPH
• Stroke Director
• LSUHSC-Shreveport

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Stroke-2001

• 3rd leading cause of death in the United States
• A major cause of disability among adults.
• Estimated 750,000 annual incident strokes.
• gt4 million stroke survivors.

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Well-Documented Modifiable Stroke Risk Factors
Factor Prevalence PAR RR Risk? /c
Tx

• HTN (Age 50-80) 20-55 40-20 4.0-1.4 38
• Smoking 25 12-18 1.8 50 /c 1yr
• DM 20 14-58 1.8-6 /c BP ?
• Asxto Carotid Stn 2-8 2-7 2.0 50
• ?TC men 55y 25 25 1.8/ 240-279 20-30
  women 65y 40 2.6/gt280 /c statins
• A Fib 0.5-8.8 1.5-23 5 2.6-4.5 68 A/C
• 21ASA
• Adapted from Goldstein et al Stroke
  200132280-299

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Hyperlipidemia

• 36 (60x106) adults in U.S.
• Mean TC levels increase in men till age 55-64
  then decline.
• 25 of American men and 28 of women have TC
  levels gt240mg/dl (6.21mm/l)
  
  
  
  
  
  
  
  
  

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Normal Endothelium
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Fibrous Plaque
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Stimuli Initiating Atherosclerosis

• Hypertension Mechanical forces, sheer stress
  response
• Oxidized LDL Adhesion, permeability,
  deposition
• Homocysteine O LDL, vascular toxin
• Cigarettes Toxic, oxidizing glycation products
• Hyperglycemia Arterial retention of Trigl
• Infection Vessel wall injury

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Novel Risk Factors

• Hyperhomocysteinemia
• Infection and inflammation
• Additional genetic factors
• Hemostatic and coagulation disorders
• Leisure time inactivity and obesity
• Fast food restaurant abuse
• Second hand smoke

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Hyperhomocysteinemia

• HC is a highly reactive amino acid toxic to
  vascular endothelium
• Pro-atherogenic and pro-thrombotic effect on
  blood vessels
• HC can potentiate the auto-oxidation of LDL
• HC is emerging as a potentially modifiable risk
  factor for atherosclerosis

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Infection and Inflammation

• Infectious agents contribute to initiation and
  chronic formation, progression and activation of
  atherosclerotic plaques.
• Infectious agents can be seen as triggers

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Infection and Inflammation

• Chlamydia pneumoniae
• Helicobacter pylori
• Cytomegalovirus
• Herpes virus
• Periodontal disease
• Genetic influence

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Chlamydia Pneumoniae

• Obligate intracellular parasite Infects
  mononuclear phagocytes
• Macrophages derived from them localize in
  atherosclerotic plaque to provide mechanism for
  entry of organism into vessel wall

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Helicobacter pylori

• Thought to be a potential factor in causing
  pathophysiology of atherosclerosis
• One strain was found to be associated with
  increased cytokine expression.

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Periodontal Disease

• A mechanism for chronic systemic inflammation
  from Gm (-) organisms
• Advanced disease estimated prevalence
• 15 -60-64 yo
• gt45 in gt65 y.o.
• One study showed a significant ?ischemic stroke
  risk (RR 2.1) among those with periodontitis.

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Genetic Inflammatory Disorders

• Genetic mutations gene polymorphisms
• Associated with inflammatory pathways
• May lead to increased susceptibility to develop
  atherosclerosis
• Particular HLA types

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Genetic Inflammatory Disorders

• Continuing research in linkage analysis studies
  and association studies with genetic influence
  based on risk factor exposure are needed.

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Genetic Hemostatic Coagulation Factors

• Sickle cell disease
• CADASIL
• Coagulation disorders
• Connective tissue disorders
• Vasculopathies
• Metabolic disorders

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CADASIL

• Cerebral autosomal dominant arteriopathy with
  subcortical infarcts and leukoencephalopahty
• monogenic inherited small vessel disease
• Notch 3 gene on chromosome 19q12
• Migraines, TIAs, lacunar strokes
• Stroke and dementia in early middle age

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Fast Food Restaurant Abuse

• Increased trans fatty acid intake from foods
  fried in partially hydrogenated fats at fast food
  restaurants
• Trans unsaturated fatty acids ?LDL and ?HDL
• Major contributor is hydrogenated fats
• Builds plaque in arteries

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Leisure Time Inactivity and Obesity

• Obesity defined as BMIgt30kg/m2
• ? with age
• Associated with ? BP,
• ? glucose, lipids
• Walker et al Am J Epi 1996

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Guidelines for Stroke Prevention

• Antiplatelets anticoagulation
• HTN control
• Statin agents
• RAAS inhibition
• Leisure time activity
• Dietary guidelines

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Guidelines for Stroke Prevention

• Aspirin and Sub Q heparin for inpatient with
  acute stroke
• IV heparin for TIA from symptomatic carotid
  stenosis, until CEA
• Bottom line ASA/ext. release dipyridamole
  better than aspirin alone, may be better than
  clopidogrel

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Use of Anticoagulant Therapy

• Coagulopathies (INR 2-3), prosthetic heart
  valves( INR 2.5-3.5)
• Nonvalvular atrial fibrillation (INR 2-3)
• Age lt65, no risk factors Aspirin
• Age lt65, /c risk factors Warfarin
• Age 65-75, no risk factors Aspirin or Warfarin
• Age 65-75 /c risk factors Warfarin
• Age gt75, /c or /s Warfarin

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Hypertension Control

• SBPlt140mmHg DBPlt90mmHG
• lt135/lt85 if target organ damage
• Antihypertensive medications
• Lifestyle modification

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Leisure Time Inactivity and Obesity

• Walking AM PM ?1.8 mi/d most days of week will
  modify risk of cardiovascular disease and
  stroke.
• Walker et al Am J Epi 1996 Rexrode et
  alJAMA 1997.Abbott RD et al Am J Epi 1994

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Leisure Time Activity

• Leisure Time Activity
• Exercise will ? insulin resistance, fibrinogen,
  LDL and weight and will ? HDL
• There is no dose relationship with level of
  activity

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Novel Approaches to Stroke Prevention

• Statin agents used for hyperlipidemia may reduce
  risk of stroke.
• Antihypertensive agents that inhibit the
  renin-angiotensin aldosterone system (RAAS) may
  reduce risk by non-hypertensive lowering
  mechanisms.
• Plehn et al Circ 1999 LIPID Study Gp N Engl
  J Med 1998
• Van Bortel et al Am J Card 1995 Thybo et al
  HTN 1995

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Stroke Prevention Therapy

• AHA Dietary Guidelines, 2000
• General population
• Special populations
• Ancillary lifestyle issues
• BMI
• ?120 of ideal body weight for height

Krauss et al, Stroke 2000.
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Physician-Community Knowledge Gap

• Well-defined stroke prevention measures
  underutilized, misapplied
• Knowledge of risk factors for primary stroke
  prevention
• CME, physician recertification
• Promote stroke prevention legislation

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U.S. Legislative Measures

• Public education and awareness of stroke
• Improved stroke care
• Kennedy Bill
• Establish a national clearinghouse on stroke
  treatment research
• Authorize a national public awareness and
  education plan
• Provide state grants to ensure stroke patients
  have access to high quality care

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STOP Stroke Act

• Stroke Treatment and Ongoing Prevention
• Public awareness campaign
• Grant program
• Ensure training in prevention treatment for
  medical personnel
• Create comprehensive research for best practices,
  barriers, disparities measure effect of public
  awareness efforts.

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STOP Stroke Act

• Stroke legislation hot line
• www.stroke.org/strokesmart.cfm