ISCHEMIC STROKE / PREVENTION
Vascular risk factors
Created 26/03/2021, last revision 22/12/2022
Vascular risk factors |
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Non-modifiable risk factors (cannot be changed) |
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Modifiable risk factors (can be reduced or controlled with altered behavior) |
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Vascular risk factors
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Manifest cardiovascular diseases (CVD)
stroke/TIA, coronary artery disease (CAD), peripheral artery disease (PAD), aneurysm
Cardiovascular risk
The overall cardiovascular risk depends on:
- risk factors control → ASCVD Risk Estimator Plus
- a value of > 5% is considered as high risk (probability of death from cardiovascular disease in the next 10 years > 5%)
- subclinical damage of target organs
- clinical manifestation of CVD
- people with overt CVD or renal disease have a high (> 5%) or very high (> 10%) risk of vascular death in the next 10 years
- type 1 diabetes (T1D) with microalbuminuria and type 2 diabetes (T2D) have a high cardiovascular risk (> 5%)
- the Ankle-Brachial Pressure Index (ABPI) is a quick, non-invasive way to check peripheral artery disease (PAD)
- the disease occurs when narrowed arteries reduce the blood flow to the limbs
- an abnormal ABPI may be an independent predictor of mortality, as it reflects the burden of atherosclerosis
- it is a ratio of the blood pressure at the ankle to the blood pressure in the upper arm (brachial BP)
- the patient must be in the supine position, without the head or any extremities dangling over the edge of the table
- the brachial BP is measured in both arms, and the higher value is used
- a low ABPI index indicates narrowing or occlusion of peripheral arteries in the legs
ankle BP
ABPI = ———————————
brachial BP
Interpretation of ABPI | ||
> 1.3 | abnormal (vessel hardening due to calcifications) | |
1-1.2 | normal | |
0.9-0.99 |
acceptable |
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0.8-0.89 | mild PAD |
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0.8 – 0.5 | moderate PAD | |
< 0.5 | severe PAD |
- the standard measurement is performed in B-mode on the far wall of the CCA, 10 mm proximal to the bifurcation
- use high-resolution images
- optimize the insonation angle (90° to the vessel wall)
- measure the distance between the 2 echogenic lines
- the 1st line is the lumen-intima interface
- the 2nd line is the media-adventitia interface
- obtain at least five measurements on each side and get an average value (“average IMT”); specialized software may be helpful
[Baldassare, 2000]
- avoid atherosclerotic plaques when measuring IMT (lesions > 1.5 mm are already considered plaque)
- echogenicity, especially of the media, may be increased in the presence of fatty infiltration and thickening
- IMT > 95th. percentile for age and sex is considered abnormal (usually IMT >1 mm is abnormal)
Female (95. percentile) |
Male (95. percentile) |
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45 y
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55 y |
65 y |
45 y | 55 y |
65 y |
0.73
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0.91 | 1.04 |
0.89
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1 | 1.3 |
95.th percentile [Howard, 1993]
Age |
P25 | P50 |
P75 |
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Men <30 | 0.39 | 0.43 | 0.48 |
Men 31-40 | 0.42 | 0.46 | 0.50 |
Men 41-50 | 0.46 | 0.50 | 0.57 |
Men >50 | 0.46 | 0.52 | 0.62 |
Women <30 | 0.39 | 0.40 | 0.43 |
Women 31-40 | 0.42 | 0.45 | 0.49 |
Women 41-50 | 0.44 | 0.48 | 0.53 |
Women >50 | 0.50 | 0.54 | 0.59 |
Prognostic value of IMT measurement
- not only atherosclerotic plaques but also IMT can quantify atherosclerosis burden in asymptomatic patients
- IMT should be assessed in each extracranial ultrasound examination
- increased IMT is the first stage of atherosclerosis and, if left untreated, is followed by plaque formation
- clinical and epidemiological studies have shown an association between IMT and coronary artery disease (CAD), stroke, and peripheral vascular disease (PAD) (ROTTERDAM, ACAPS trials ) [Lorenz, 2007]
- thickening of IMT correlates with the presence of traditional vascular risk factors (BMI, hypertension, hypercholesterolemia, diabetes, smoking)
- some authors recommend including IMT and the presence of AS plaques among the classic vascular risk factors [Chambless, 2010]
- some publications question the importance of IMT in predicting CV events [Costanzo, 2010] [Ruijter, 2012]
- detection of subclinical atherosclerosis is important in patients with borderline risk and multiple risk factors, as it moves the patient into the high-risk category (SCORE ≥ 5%) with all therapeutic consequences
- pharmacological studies have shown a reduction in the rate of progression of IMT with hypolipidemic therapy and antihypertensive drugs (ACAPS, METEOR)
- rosuvastatin did not induce disease regression
- on the other hand, a meta-analysis of 41 randomized trials showed regression of cardiovascular events with hypolipidemic drugs but did not show a relationship between a decrease in CV events and a regression of IMT [Costanzo, 2010]
- an increase in IMT can also be found in non-atherosclerotic diseases (e.g., Takayasu´s arteritis)
I. Risk factors used to stratify CV risk according to ASCVD Risk Estimator Plus
- sex
- race
- blood pressure
- total cholesterol, LDL, HDL
- history of diabetes and smoking
- therapy (antithrombotic therapy, statins, antihypertensive drugs)
II. Target organs subclinical damage
- left ventricular hypertrophy
- sonographically proven thickening of the arterial wall (carotid IMT ≥ 0.9 mm) or the presence of atherosclerotic plaques (atherosclerosis)
- ankle-brachial pressure index (ABPI) ratio < 0.9
- slight increase in serum creatinine (115-133 μmol / l)
- microalbuminuria (30-300 mg / 24hrs)
- ↓ glomerular filtration rate (< 60ml / min / 1.73 m3)
III. Clinical manifestation
- cerebrovascular disease
- stroke / TIA
- intracerebral hemorrhage
- heart disease
- myocardial infarction
- angina pectoris
- chronic congestive heart failure (CHF)
- aneurysms
- a serious complication that can occur anywhere in your body
- besides sudden life-threatening rupture, a slow leak is possible. If a blood clot within an aneurysm dislodges, it may block an artery ostium and cause hypoperfusion
- renal impairment
- diabetic/non-diabetic nephropathy
- decrease in renal function (serum creatinine > 133 μmol/L)
- peripheral vascular disease (PAD)
- advanced retinopathy
- with hemorrhage or exudates
- papilledema (optic disc swelling)