II. Epidemiology
- Modifiable risk factors are responsible for 87% of stroke risk (e.g. Obesity, diabetes, Hypertension, Hyperlipidemia)
- Behavioral factors are responsible for 47% of modifiable factors (e.g. smoking, sedentary, unhealthy diet)
III. Risk Factors
-
Hypertension (increased systolic Blood Pressure)
- Hypertension Management (with Diuretic or ACE Inhibitor) significantly lowers the risk of CVA
- (2001) Lancet 358(9287):1033-41 [PubMed]
- African American or Hispanic Race
- Hypothyroidism
- Obesity
- Sedentary lifestyle
- Family History of CVA or Hyperlipidemia
- Age over 65 years
- Diabetes Mellitus
- Coronary Artery Disease (esp. Myocardial Infarction in last month)
- Increased Apolipoprotein-a
- Congestive Heart Failure with ejection fraction <30%
- Atrial Fibrillation or Atrial Flutter
- Bioprosthetic or mechanical Heart Valve Replacement
- Patent Foramen Ovale
- Hypercoagulable state
- Fibromuscular dysplasia
- Polycythemia Vera
- Thrombocytosis
- Arteritis or Vasculitis
-
Obstructive Sleep Apnea
- Consider Sleep Study in cryptogenic stroke if suspected Sleep Apnea
-
Migraine Headache with aura
- Especially in women over age 35, Tobacco Abuse or Oral Contraceptive use
-
Cigarette smoking (Tobacco Abuse)
- Particularly if Oral Contraceptive use age >35 years
- Aortic Arch Plaque
- Evaluated by TEE Echocardiogram
- Measured aortic arch wall thickness
- Risk increased 4 fold with thickness >3 mm
- Any vascular event
- Recurrent Ischemic CVA
- Reference
-
Hypercholesterolemia or Hypertriglyceridemia
- Meta-analysis on Cholesterol and Stroke: No effect
- Eleven trials, total N=36,000
- Cholesterol reduction: 6 to 23%
- No significant reduction in fatal or non-fatal CVA
- No decrease CVA for selected high risk CAD patients
- Reference
- Meta-analysis on Cholesterol and Stroke: No effect
IV. Prevention: Protective factors
- Lower CVA risk with moderate Alcohol use
V. Causes
- Vessel wall embolus (most common)
- Carotid Artery most often the source
- Related to thrombus formation distal to stenosis
- Cardiac source (Hemispheric attack >60 minutes)
- Atrial Fibrillation
- Underlying cause of 1 in 7 strokes
- For those with crypogenic CVA, consider insertable cardiac monitor (or non-invasive monitor)
- Paroxymsal Atrial Fibrillation episodes >2.5 minutes may be significant CVA risk
- Mitral valve stenosis
- Mitral Valve Prolapse
- Calcified mitral annulus
- Ventricular aneurysm or Dyskinesia
- Atrial or ventricular clot
- Valvular vegetation or Bacterial Endocarditis
- Atrial Septal Defect or Patent Foramen Ovale
- Atrial Fibrillation
- Other vascular sources
- Intracranial artery thrombus (esp. African-Americans)
- Aortic arch atherosclerotic Plaque
- Transient Hypotension with Carotid Stenosis >75%
- Arteritis or Vasculitis
- Less common etiologies (age <45 years)