3.P.341 Carotid artery ultrasonography and aortic pulse wave velocity as the predictors of coronary artery disease

270 3 .P.341

Wednesday 8 October 1997 . Posters Vascular imaging Carotid artery ultrasonography and aortic pulse wave velocity as the predictors of coronary artery disease

Masafumi Kusaka, Tomotake Suzuki, Masako Nagata, Nobuyuki Furutani, Noriaki Ohyama, Kiyoshi Kanae, Reijiro Watanabe. Department of General Internal Medicine, Kashiwa Hospital, The Jikei University School of Medicine, Chiba, Japan Purpose : To evaluate the efficacy of carotid artery ultrasonography and aortic pulse wave velocity (PWV) as the predictors of coronary artery disease (CAD) . Setting : 128 patients hospitalized for coronary angiography (CAG) from March 1994 to December 1996 . Intervention : The thickness of intima-media (IMT) is measured at 1 cm below the bifurcation of internal and external carotid artery by 7 .5 MHz ultrasonography . PWV are measured at carotid and femoral artery and made blood pressure correction . Atherosclerotic lesion of coronary artery is determined when the stenosis is over 25% . We count the number of stenotic vessels and lesions of 15 segments of American Heart Association . Analysis : Logistic regression is used to compare IMT and PWV with number of vessels and lesions . Receiver Operator Characteristic curve is used to decide the cut-off points . Result : IMT has correlation with number of vessels (right ; p = 0 .0045, left ; p = 0 .0097) and number of segments (right ; p = 0 .0032, left; p = 0 .0049). PWV also has with number of vessels (p = 0 .0146) and number of segments (p = 0.0292). The sensitivity and specificity of the cut off point of 1 .0 mm IMT with existence of CAD are 26 .2% and 90 .5% in right and 35 .5% and 95.2% in left . These of 10 m/sec PWV are 15 .0% and 100 .0% respectively . Conclusion : IMT and PWV are high specificity method to predict CAD . They are effective to discuss the needs of CAG .

3 .P.342

Prevalence of peripheral vascular disease (PVD) among haemodialysis : Contribution of non-invasive explorations

P. Leger, C . Goudable, A . Cadene, P. Cabrol, D. Lefebvre, J .M . Sue, H . Boccalon . Angiology and Nephrology CHU Rangueil 1 Ave J . Poulhes 31403 cedex 4 Toulouse, France The atheromatous disease is frequent in haemodialysis patients (HP) . However, prevalence of PVD is still not well known . The aim of this study is to evaluate the prevalence of PVD in HP, and the contribution of non invasive explorations in the diagnosis of PVD . Diagnosis criteria of PVD are : palpation of peripheral pulses (PPP), ROSE questionnaire (RQ) for intermittent claudication, ankle brachial pressure index (ABPI), blood flow measure by electromagnetic blood flowmeter (EMF) and nuclear magnetic resonance blood flowmeter (NMRF) . 42 HP have been examinated (21 women and 21 men), mean age was 55 .19 years old . Mean duration of haemodialysis is 7 .9 years 28% of patients had previous cardiovascular events . 76% had cardiovascular risk factors (26% were diabetic patients) . According to the different diagnosis methods the prevalence of PVD was : RQ : 24%, PPP: 47%, ABPI 50%, EMF 55%, NMRF 45% . The use of ABPI and of EMF correct the results of peripheral pulses : 6 false positive (FP) and 7 false negative (FN) are diagnosed with ABPI and 6 FN by the EMF. The use of the EMF correct the result of the ABPI, finding 4 FP and 7 FN . The prevalence of PVD in this study is very high whatever the method used for the diagnosis is . Clinical examination with PPP is inadequate to diagnose PVD . ABPI gives better results but is still insufficient because of the arterial rigidity in HP. EMF and NMRF take then an important place as they are correcting errors of diagnosis .

3 .P.343

Postoperative monitoring of lower extremity arterial bypass grafts with duplex and color Doppler sonography

M.J. Morton, R .A. Lee, B .D . Lewis, E .M . James, T.J. Vrtiska . Mayo Clinic, Rochester MN 55905, USA A wide variety of graft procedures are currently used to bypass lower extremity atherosclerotic disease . Many studies have shown that postoperative surveillance and early repair of graft abnormalities can increase the long-term patency of these grafts. Although angiography is considered the reference standard for the postoperative evaluation of lower extremity bypass grafts, duplex imaging is being used more frequently because of the ability of this sonographic technique to provide both anatomic and hemodynamic information noninvasively and at a relatively low cost . Numerous investigators have shown that the combined technique of duplex and color Doppler sonography is sensitive and specific for detecting and grading stenoses and predicting graft failure . When angiography is used as the reference standard, the re-

ported sensitivity of duplex sonography in this setting is 86-100% and the specificity is 87-100% . In addition, this technique enables accurate detection of other postoperative complications such as arteriovenous fistulae, perigraft fluid collections, and pseudoaneurysms . The purpose of this teaching exhibit is to describe our technique of examination and illustrate the spectrum of normal and abnormal findings and diagnostic pitfalls in the duplex and color Doppler sonographic evaluation of lower extremity arterial bypass grafts . Cases for this exhibit were selected from over 800 duplex studies performed for postoperative monitoring of lower extremity bypass grafts at our institution over a two-year period.

13 .P.344

Coronary artery calcification and coronary atherosclerosis in familial hypercholesterolemia: Electron beam computed tomographic study

A. Nohara', K . Kajinami 2 , N. Takekoshit, H . Mabuchi 2 .'Kanazawa Cardiovascular Hospital ; 2 The Second Department of Internal Medicine, School of Medicine, Kanazawa University, Kanazawa, Japan Atherosclerotic calcification is an organized process invariably associated with atherosclerotic plaque . However, its precise mechanism is still unclear . Electron beam computed tomography (EBCT) can noninvasively detect coronary calcification with high sensitivity, and can quantitate its amount. To investigate the effects of hyper-LDL-cholesterolemia on the onset and the development of coronary calcification, we performed prospective EBCT study for patients with familial hypercholesterolemia (FH) who underwent elective coronary angiography, and compared their results with those of non-FH subjects . The total coronary calcification score (TCS) was calculated by multiplying the area (>_2 pixels) of calcification (peak density >130 HU) by density-based score (0 to 4) . Fifty five heterozygous FH patients (M/F = 39/16) and 187 non-FH patients (M/F = 128/59) were studied . The amount of coronary calcification of FH patients [TCS = 3 .69 ± 2 .45 (mean f SD)) was significantly larger than that of controls (TCS = 2.67 f 2.61, p = 0 .011), especially in men (p = 0.048) . This difference decreased with age in both gender, whereas it was still observed even when patients showed no significant stenosis on angiography . The amount of calcification was significantly correlated with cholesterol-year score (mg/dl x yr) (R = 0 .356 p = 0 .0076) . These results suggested that genetically determined high levels of LDL-cholesterol promote early coronary calcification in FH .

3.P.345*

In situ perfusion of fluorescently labelled chylomicron-

remnants in rabbit carotid artery visualised by 3D-confocal microscopy S .D . Proctor, J .C.L. Mamo . University Department of Medicine, Royal Perth Hospital, Perth, Western Australia Atherosclerotic plaques are characterised by the accumulation of cholesterol within the subendothelial space . Plaque cholesterol is thought to be derived from circulating lipoproteins, possibly low density lipoproteins (LDL) . However, there is increasing evidence to suggest that remnants of post prandial lipoproteins (chylomicrons) are atherogenic and may be a significant source of plaque cholesterol . We have previously shown (utilising a residual radiolabel) that chylomicron-remnants rapidly penetrate the arterial wall, efflux poorly and are preferentially retained in arterial fatty streaks compared to other lipoproteins (including LDL) . In order to visually characterize arterial uptake of chylomicron-remnants we report here perfusion of fluorescently labelled chylomicron-remnants through the rabbit common carotid . Fluorescently labelled chylomicron-remnants were perfused (in-situ) through carotid arteries for various lengths of time (2-60 mins) under physiological conditions of flow rate, pressure and oxygen tension . Histological sections of perfused artery were fixed and chylomicron-remnant delivery identified as fluorescence, by digital image microscopy (confocal laser scanning microscopy-CSLM) . The precise sites of chylomicron remnant arterial delivery and retention were obtained by three dimensional image processing. The 3D constructs were generated by merging fluorescent and morphological images (obtained by transmission microscopy) . We found that arterial uptake of chylomicron-remnants occurred within minutes of perfusion . At longer periods of perfusion chylomicron remnants appeared to penetrate deeper segments of the arterial media . Arterial uptake of chylomicron remnants occurred as focal accumulations within the subendothelium, consistent with the random appearance of atherosclerotic lesions . This study represents the first time CSLM has been utilized to visually assess arterial uptake of lipoproteins and supports earlier studies which showed that chylomicron-remnants may be directly involved in atherogenesis as a consequence of lipid delivery,

11th International Symposium on Atherosclerosis, Paris, October 1997