European Journal of Cardiovascular Medicine

An exploratory analysis of data showed that the chance of atherosclerosis was more than 10 times higher in the 40– 49 years age group than in the younger group, and that this chance was even higher in people aged 50 years or over. 1 Atherosclerotic vascular disease begins in childhood and progresses over decades.2 Symptomatic, clinical cardiovascular disease (CVD) events generally occur when atherosclerosis progresses to flow limiting disease that causes ischemia, or when a thrombus forms on an existing plaque as a result of rupture or erosion.3 Although not everyone with underlying atherosclerotic plaque will experience a clinical CVD event, the greater the degree of subclinical atherosclerosis, the greater the risk for future cardiovascular events.4-7

Ultrasonograghy is reliable & accurate technique to determine IMT in superficial arteries. High resolution sonography seems promising for detection, quantification of atherosclerotic plaque & in structural alterations of arterial wall. An intima-media thickness of 0.9 mm or more is abnormal and is likely to be associated with sonographically visible plaque.8 Several conventional cardiovascular risk factors are associated with IMT in both men and women.8

To prevent death and morbidity from CVD, there is great interest in identifying asymptomatic patients at high risk who would be candidates for more intensive, evidence-based medical interventions that reduce CVD risk.7 Imaging of arteries to identify and quantify the presence of subclinical vascular disease has been suggested to further refine CVD risk assessment.7 As a screening test, imaging must be safe, be sensitive, be affordable, and lead to interventions that can favourably alter the natural history of CVD. Measurement of carotid intima-media thickness (CIMT) with B-mode ultrasound is a non-invasive, sensitive, and reproducible technique for identifying and quantifying atherosclerotic burden and CVD risk. It is a well-validated research tool that has been translated increasingly into clinical practice.9

This was an observational study. The present study was carried out on 120 individuals in the department of Radio- diagnosis.

Inclusion criteria

·         Age criteria for study are 40 years and above for both sexes.

·         All patients and volunteers, otherwise asymptomatic (No known H/O CVA, STROKE, IHD, MI) above 40 years of age.

Exclusion criteria

·         Patients below 40 years.

·         Patients who have known history of CVA, STROKE, IHD, MI.

·         Patients who have undergone carotid procedures/surgery.

Appropriate consent from the Institutional Ethical Committee and Research Cell was obtained for this study

The ultrasound and colour Doppler being a non-invasive and safe method of investigation, the consent was taken orally as per approval by the Institutional Ethical Committee And Research Cell.

This study included total of 120 subjects, hypertensive & diabetics were the patients attending the outpatient of medicine department for follow-up and without any symptoms.

Table No.1: Age wise distribution of plaque cases

Majority of carotid plaques were found in 71-80 years of age group i.e. 7.5 % of total individuals. The second largest groups were from 51-60 & 61-70 years of age group i.e. 5.8 % of total individuals

Table No.2: Sex wise distribution of plaque

The above table shows that 87.5% males had plaques while 12.5% females had plaques.

Table 3: Plaque Characterization

The above table shows that maximum no. of plaques i.e. 81.25% were homogenous on ultrasound.

Table 4: Distribution of risk factors in total individuals (n=120)

By applying Z test of difference between two proportions the proportion of hypertension and smoking is significantly more as compared to other risk factors (i.e. p<0.05).

Table 5: Distribution of risk factors males (n=62)

Above table shows smoking was found to be the most powerful risk factor in males responsible for development of atherosclerotic plaque in carotid arteries.

Following risk factors are overlapping.

• Only Hypertensive = Non-diabetic, non-smoker and non-
• Only Diabetic = Normotensive, non-smoker and non-
• Only Smoker = Normotensive, non-diabetic and non-

Table 6: Distribution of Plaque considering the individual risk factor in females (n=58)

Above table shows hypertension was found to be the most powerful risk factor in males responsible for development of atherosclerotic plaque in carotid arteries.

Table 7: Distribution of risk factors in females (n=58)

Above table shows, majority of the females in the study who had a plaque in their carotid arteries were hypertensive followed by diabetics i.e. 65.51 % and 22.41 % respectively.

This study was an observational study done on asymptomatic individuals above 40 years of age without any known H/O Cerebrovascular Accident/Coronary Artery Disease, to study the prevalence of carotid artery disease in asymptomatic individuals, to correlate various risk factors associated with development of carotid artery disease & to know the effect of these factors on Intima Media Thickness [IMT] of carotid arteries which can be effectively done using high frequency ultrasound and Color Doppler sonography.

The risk factors for CAD in Asian Indians as in other races are high blood pressure, high cholesterol smoking, diabetes, family history of CAD, male gender and menopause in women.1 High frequency ultrasound transducers have made the better visualization of the various layers of arteries [intima, media and adventitia] particularly of superficial arteries like carotid arteries with good resolution. With this, the accurate measurement of intima media thickness is possible. The risk factors for CAD in Asian Indians as in other races are high blood pressure, high cholesterol, smoking, diabetes, family history of CAD, male gender and menopause in women.11 So, the challenge for all health care professionals is to implement comprehensive method for identification of initial atherosclerotic events in high risk patients and also in general public so that more vigorous preventive measures can be taken. For this, various non-invasive markers of early arterial wall alteration are currently available such as arterial wall thickening and stiffening, endothelial dysfunction and coronary artery calcification.12 Of them, Intima Media Thickness (IMT) of large artery walls, especially carotid, can be assessed by B-Mode ultrasound in a relatively simple way and represents a safe, inexpensive, precise and reproducible measure.13 Intima Media Thickness [IMT] is thus far the best-studied sonographic parameter.

An increase in IMT in relation to vascular risk factors or manifestation of atherosclerosis has been demonstrated many times. In clinical practice the measurement of Intima

media thickness [IMT] is done as a routine investigation. The predictive value of Intima Media Thickness [IMT] with regards to cardiovascular complications has been established in several prospective studies and suggests that Intima Media Thickness [IMT] measurement might participate in future in the stratification of cardiovascular risk of asymptomatic patients in primary prevention.14,15 This explains why IMT is more and more widely used in clinical research:

[1]           For testing the value of new or emerging risk factors by means of observational or epidemiological studies in

groups of patients or in general populations and

[2]           For evaluating effects of risk factor modifications by various drugs on the progression of early arterial wall alteration in therapeutic trials.14

The proportion of hypertension and smoking is significantly more as compared to other risk factors in asymptomatic individuals (i.e. p<0.05).

Considering individual risk factors in asymptomatic individuals, hypertension was found to be the most powerful risk factor in males as well as females responsible for development of plaque in carotid arteries.

1.       Albuquerque V, Zírpoli J, Miranda-Filho D, Albuquerque M, Montarroyos U, Alencar Ximenes R and Lacerda H. Risk factors for subclinical atherosclerosis in HIV-infected patients under and over 40 years :a case–control study.BMC Infectious Diseases 2013, 13:274

2.       McGill HC Jr, McMahan CA, Herderick EE, Tracy RE, Malcom GT,Zieske AW, et al. Effects of coronary heart disease risk factors on atherosclerosis of selected regions of the aorta and right coronary artery: PDAY research group, Pathobiological Determinants of Atherosclerosis in Youth. Arterioscler Thromb Vasc Biol 2000; 20:836-45.

3.       Virmani R, Burke AP, Farb A, Kolodgie FD. Pathology of the vulnerable plaque. J Am Coll Cardiol 2006; 47:C13-8.

4.       Greenland P, Abrams J, Aurigemma GP, Bond MG, Clark LT, Criqui MH,et al. Prevention conference V: beyond secondary prevention, identifying the high-risk patient for primary prevention, non-invasive tests of atherosclerotic burden, writing group III. Circulation 2000; 101:E16-22.

5.       Taylor AJ, Merz CN, Udelson JE. 34th Bethesda conference: executive summary–can atherosclerosis imaging techniques improve the detection of patients at risk for ischemic heart disease? J Am Coll Cardiol 2003; 41:1860-2.

6.       Chambless LE, Heiss G, Folsom AR, Rosamond W, Szklo M, Sharrett AR,et al. Association of coronary heart disease incidence with carotid arterial wall thickness and major risk factors: the Atherosclerosis Risk in Communities (ARIC) study, 1987-1993. Am J Epidemiol 1997; 146:483-94.

7.       Zwiebel W ,Pellerito J . Chapter 8. In: (eds.) Introduction to Vascular Ultrasonography. 5th ed. Philadelphia: Saunders; 2005. p156

8.       Salonen R & Salonen JT .Progression of carotid atherosclerosis and its determinants: a population-based ultrasonography study. Atherosclerosis 1990; 81:3340.

9.       O’Leary DH, Polak JF, Kronmal RA, Manolio TA, Burke GL, Wolfson SK Jr. Carotid-artery intima and media thickness as a risk factor for myocardial infarction and stroke in older adults: Cardiovascular Health Study Collaborative Research Group. N Engl J Med 1999; 340:14-22.

10.    Mohan V. Intimal medial thickness of the carotid artery in south Indian diabetic and non-diabetic subjects: the Chennai Urban Population Study (CUPS). Diabetologia 2000; 43: 494-499.

11.    Hoeks AP, Brands PJ, Smeets FA, Reneman RS. Assessment of the distensibility of superficial arteries. Ultrasound Med Biol 1990; 16:121X.

12.    Su TC, Jeng JS, Chien KL, Torng PL, Sung FC, Lee YT. Measurement reliability of common carotid artery Intima- media thickness by ultrasonographic assessment. J Med Ultrasound 1999; 7: 73Á.

13.    Salonen JT. Salonen R. Ultrasound B-mode imaging in observational studies of atherosclerotic progression. Circulation 1993; 87 (supp III): 56--65.

14.    Mercuri M. Devi K. Quantitative ultrasonographic evaluation of the carotid arteries in hypertension. J Cardiovasc Risk 1995; 2: 27-33.