Circulatory internist clinic of specializing in heart
From Sengawa Station about 4 minute
〒182-0002 東京都調布市仙川町2-12-6 メディカルモール仙川
インターネット予約の枠に空きがない場合は、お電話もしくは〈お問い合わせ〉、チャットからご相談ください
"Why the arteriosclerosis is so danger?"
-Relationship with cardiovascular disease and stroke-
Arteriosclerosis is a condition in which vascular endothelial cells are damaged due to high blood pressure, inflammation occurs, cholesterol accumulates in the walls of blood vessels, and the lumen of blood vessels narrows. Fat-rich lesions can collapse and suddenly clog blood vessels, causing myocardial infarction or stroke. There is more than one cause of arteriosclerosis. There are included hypertension, hyperlipidemia, smoking, diabetes and obesity. These causes are called "risk factors for arteriosclerosis."
Index for evaluating arteriosclerosis
Arteriosclerosis has no subjective symptoms in the early stages and it is unknown how far it has progressed. To the assess, CVIC can perform cardiac CT and carotid echography.
Cardiac CT
Initially, arteriosclerotic plaques are mainly cholesterol, but over time they change to calcium-based lime. This is called coronary artery calcification. It is rarely seen in the early stages of arteriosclerosis and is seen in relatively advanced cases.
Coronary artery calcification is also detected by routine chest CT scan. However, accurate measurement of coronary artery calcification score requires synchronized electrocardiogram and heart-focused CT scans. With CVIC, coronary artery calcification can be visualized as follows.
Image of coronary artery calcification using cardiac CT
Coronary artery
3D image
The calcified part
Shining white
Calcified coronary arteries
Youssef G. et al. Curr Cardiol Rep. 2013; 15: 325
The calcification score is calculated by measuring the area that glows white on the CT screen. In the above image, in the leftmost image, there is no white shining part in the coronary artery and the calcification score is 0, whereas in the center and right images, calcification of the coronary artery is observed and the calcification score. It can be seen that also increases according to the degree of calcification (CACS; coronary artery calcium score).
Calcification analysis
The calcified part of the coronary artery is calculated as the calcification score. If the score is higher, the risk of coronary artery disease be high.
If the Agatston score is higher, the risk of developing coronary artery disease will be high. For example, if the above calcification score is 400 or higher, there is a 90% or higher probability that significant coronary artery stenosis is present. In this way, we will explain it to each patient's about calcification score.
Clinical significance of coronary artery calcification
The calcification score is considered to be a very sensitive marker of arteriosclerosis and is more predictive of future myocardial infarction than previous risk factors for arteriosclerosis such as hypertension, diabetes, hyperlipidemia, smoking and family history. A lot of data has been published that it is excellent in. Therefore, the calcification score is used as an independent prognostic predictor of cardiovascular events. The guidelines of the American Heart Association recommend that coronary artery calcification scores be measured in the moderate risk group of coronary artery disease, even in asymptomatic patients.
In a retrospective analysis of the MESA study published in 2015, of the 6722 patients, 162 had cardiovascular events during the 3.9-year central observation period. In this study, it was reported that the higher the calcification score, the more cardiovascular events, for example, the group with a calcification score of 300 or more had 6.8 times more cardiovascular events than the group with a calcification score of 0.
Incidence of cardiovascular events (%)
Observation period (year)
Detrano R et al. N Engl J Med 2008; 358: 1336-1345.
Carotid echo
By observing the cross section of the blood vessel in the neck using ultrasonic waves, it is possible to observe the presence or absence of cholesterol plaque on the blood vessel wall, the shape and the thickening of the blood vessel wall. Carotid echo is a test that allows you to directly observe the degree of arteriosclerosis without invading the body.
The items that can be observed using carotid echo are as follows.
IMT (Inner Media Thickness)
It refers to the maximum medial media thickness in the observable area of both walls, such as the left and right common carotid arteries, carotid sinus, and internal carotid artery. In addition, the average IMT value is also measured.
Plaque
The intima thickened and arteriosclerotic plaques form. Plaques to watch out for include ulcer-type plaques on the surface, low-brightness plaques on brightness, and mobile plaques.
IMT measurement
Carotid sinus
Common carotid artery
Plaque
Clinical Significance of Carotid Echo (IMT)
IMT is important as a quantitative evaluation of early stage arteriosclerosis before the appearance of plaque.
Average IMT (mm)
Japanese IMT
Homma S et al. Stroke. 2001; 32: 830-5.
In addition, IMT is said to be associated with the development of arteriosclerosis, independent of the various major risk factors for arteriosclerosis. According to Japanese data, 1289 men aged 60 to 74 years were prospectively followed up, and after 4-5 years of follow-up, the group with the largest CCA (common carotid artery) IMT≥1.07 mm. it was reported that the incidence of stroke was 3.5 times higher than that in the group with the smallest IMT (<0.78 mm).
Observation period (year)
Average IMT (mm)
Maximum CCA <0.78mm
Maximum CCA ≥ 1.07mm
Kitamura A et al. Stroke. 2004; 35: 2788-94.