Andrew N. Nicolaides

Carotid plaque, intima media thickness, cardiovascular risk factors, and prevalent cardiovascular disease in men and women : The British Regional Heart Study

BACKGROUND AND PURPOSE B-mode ultrasound is a noninvasive method of examining the walls of peripheral arteries and provides measures of the intima-media thickness (IMT) at various sites (common carotid artery, bifurcation, internal carotid artery) and of plaques that may indicate early presymptomatic disease. The reported associations between cardiovascular risk factors, clinical disease, IMT, and plaques are inconsistent. We sought to clarify these relationships in a large, representative sample of men and women living in 2 British towns. METHODS The study was performed during 1996 in 2 towns (Dewsbury and Maidstone) of the British Regional Heart Study that have an approximately 2-fold difference in coronary heart disease risk. The male participants were drawn from the British Regional Heart Study and were recruited in 1978-1980 and form part of a national cohort study of 7735 men. A random sample of women of similar age to the men (55 to 77 years) was also selected from the age-sex register of the general practices used in the original survey. A wide range of data on social, lifestyle, and physiological factors, cardiovascular disease symptoms, and diagnoses was collected. Measures of right and left common carotid IMT (IMTcca) and bifurcation IMT (IMTbif) were made, and the arteries were examined for plaques 1.5 cm above and below the flow divider. RESULTS Totals of 425 men and 375 women were surveyed (mean age, 66 years; range, 56 to 77 years). The mean (SD) IMTcca observed were 0. 84 (0.21) and 0.75 (0.16) mm for men and women, respectively. The mean (SD) IMTbif were 1.69 (0.61) and 1.50 (0.77) mm for men and women, respectively. The correlation between IMTcca and IMTbif was similar in men (r=0.36) and women (r=0.38). There were no differences in mean IMTcca or IMTbif between the 2 towns. Carotid plaques were very common, affecting 57% (n=239) of men and 58% (n=211) of women. Severe carotid plaques with flow disturbance were rare, affecting 9 men (2%) and 6 women (1.6%). Plaques increased in prevalence with age, affecting 49% men and 39% of women aged <60 years and 65% and 75% of men and women, respectively, aged >70 years. Plaques were most common among men in Dewsbury (79% affected) and least common among men in Maidstone (34% affected). IMTcca showed a different pattern of association with cardiovascular risk factors from IMTbif and was associated with age, SBP, and FEV1 but not with social, lifestyle, or other physiological risk factors. IMTbif and carotid plaques were associated with smoking, manual social class, and plasma fibrinogen. IMTbif and carotid plaques were associated with symptoms and diagnoses of cardiovascular diseases. IMTbif associations with cardiovascular risk factors and prevalent cardiovascular disease appeared to be explained by the presence of plaques in regression models and in analyses stratified by plaque status. CONCLUSIONS IMTcca, IMTbif, and plaque are correlated with each other but show differing patterns of association with risk factors and prevalent disease. IMTcca is strongly associated with risk factors for stroke and with prevalent stroke, whereas IMTbif and plaque are more directly associated with ischemic heart disease risk factors and prevalent ischemic heart disease. Our analyses suggest that presence of plaque, rather than the thickness of IMTbif, appears to be the major criterion of high risk of disease, but confirmation of these findings in other populations and in prospective studies is required. The association of fibrinogen with plaque appears to be similar to its association with incident cardiovascular disease. Further work elucidating the composition of plaques using ultrasound imaging would be helpful, and more data, analyzed to distinguish plaque from IMTbif and IMTcca, are required to understand the significance of thicker IMT in the absence of plaque.

Carotid Plaque Echolucency Increases the Risk of Stroke in Carotid Stenting The Imaging in Carotid Angioplasty and Risk of Stroke (ICAROS) Study

Background—Carotid artery stenting (CAS) has recently emerged as a potential alternative to carotid endarterectomy. Cerebral embolization is the most devastating complication of CAS, and the echogenicity of carotid plaque has been indicated as one of the risk factors involved. This is the first study to analyze the role of a computer-assisted highly reproducible index of echogenicity, namely the gray-scale median (GSM), on the risk of stroke during CAS. Methods and Results—The Imaging in Carotid Angioplasty and Risk of Stroke (ICAROS) registry included 418 cases of CAS collected from 11 international centers. An echographic evaluation of carotid plaque with GSM measurement was made preprocedurally. The onset of neurological deficits during the procedure and the postprocedural period was recorded. The overall rate of neurological complications was 3.6%: minor strokes, 2.2%, and major stroke, 1.4%. There were 11 of 155 strokes (7.1%) in patients with GSM ≤25 and 4 of 263 (1.5%) in patients with GSM >25 (P=0.005). Patients with severe stenosis (≥85%) had a higher rate of stroke (P=0.03). The effectiveness of brain protection devices was confirmed in those with GSM >25 (P=0.01) but not in those with GSM ≤25. Multivariate analysis revealed that GSM (OR, 7.11; P=0.002) and rate of stenosis (OR, 5.76; P=0.010) are independent predictors of stroke. Conclusions—Carotid plaque echolucency, as measured by GSM ≤25, increases the risk of stroke in CAS. The inclusion of echolucency measured as GSM in the planning of any endovascular procedure of carotid lesions allows stratification of patients at different risks of complications in CAS.

Deep vein thrombosis of the leg: Is there a “high risk” group?

Summary Two hundred and three patients undergoing elective surgery were investigated to determine the group of patients who are at a “great risk” of developing deep vein thrombosis. It was found that the patients who formed this group included those who had a history of previous deep vein thrombosis or pulmonary embolism, those who had varicose veins or underwent operation for malignant disease, and elderly patients (over sixty-one years) having major operations. All of these patients are at a “great risk” of developing thrombosis during the postoperative period.

ESVS Guidelines. Invasive Treatment for Carotid Stenosis: Indications, Techniques

The European Society for Vascular Surgery brought together a group of experts in the field of carotid artery disease to produce updated guidelines for the invasive treatment of carotid disease. The recommendations were rated according to the level of evidence. Carotid endarterectomy (CEA) is recommended in symptomatic patients with >50% stenosis if the perioperative stroke/death rate is <6% [A], preferably within 2 weeks of the patients last symptoms [A]. CEA is also recommended in asymptomatic men <75 years old with 70-99% stenosis if the perioperative stroke/death risk is <3% [A]. The benefit from CEA in asymptomatic women is significantly less than in men [A]. CEA should therefore be considered only in younger, fit women [A]. Carotid patch angioplasty is preferable to primary closure [A]. Aspirin at a dose of 75-325 mg daily and statins should be given before, during and following CEA. [A] Carotid artery stenting (CAS) should be performed only in high-risk for CEA patients, in high-volume centres with documented low peri-operative stroke and death rates or inside a randomized controlled trial [C]. CAS should be performed under dual antiplatelet treatment with aspirin and clopidogrel [A]. Carotid protection devices are probably of benefit [C].

Air-plethysmography and the effect of elastic compression on venous hemodynamics of the leg***

Leg volume changes during exercise have been measured in absolute units (milliliters) by means of a new method of air-plethysmography. Venous volume (VV), venous filling time, and venous filling index on standing from the recumbent position, ejected volume (EV) and ejection fraction (EF = EV x 100/VV) with one tiptoe movement, and residual volume (RV) and residual volume fraction (RVF = RV x 100/VV) after 10 tiptoe movements were measured in normal limbs, limbs with superficial venous incompetence, and limbs with deep venous disease. The same measurements were repeated with a graduated medium compression stocking in limbs with SVI and graduated high compression stockings in limbs with DVD. Ambulatory venous pressure was measured at the same time, with a needle in a vein in the foot. The results indicate that this method of air-plethysmography is not only of diagnostic value but offers a new and unique technique to assess and study the hemodynamic effects of different forms of elastic compression. The lower ambulatory venous pressure, produced by the elastic compression, was the result of a reduction in reflux and an improvement in the calf muscle ejecting ability during rhythmic exercise.

Classification and Grading of Chronic Venous Disease in the Lower Limbs-A Consensus Statement-

Classification and grading of chronic venous disease in the lower limbs : A consensus statement

The origin of deep vein thrombosis: a venographic study

Abstract A venographic technique has been described which demonstrates the soleal veins in addition to the rest of the deep veins of the lower limb consistently in the presence or absence of thrombosis. In 127 consecutive patients, the soleal veins were demonstrated in all but three. In 97 surgical and medical patients with clinically suspected deep vein thrombosis, the presence of thrombi was confirmed by venography only in 51 (52 per cent); the remainder had normal deep veins. In nine patients the soleal veins were the only site of thrombosis. Only one patient was found with thrombosis proximally and normal soleal veins. In the remaining patients whenever there were thrombi proximally they were also present in the soleal and intervening veins. It is concluded that in the majority of patients thrombi start in the soleal veins in the calf. It has also been shown that the clinical diagnosis of deep vein thrombosis is unreliable and no patient should be given anticoagulant therapy without first confirming t...

The relation of venous ulceration with ambulatory venous pressure measurements.

Two hundred thirty-six limbs of 220 unselected patients who were admitted with venous problems (83 with ulcers) were studied with continuous-wave Doppler ultrasonography, duplex scanning, and ambulatory venous pressure measurements. Patients with evidence of deep venous disease because of reflux or obstruction in the deep veins on Doppler and duplex ultrasonic examination or with an ambulatory venous pressure greater than 45 mm Hg despite the ankle cuff had venography. One hundred fifty-three limbs had superficial venous disease (reflux in the superficial veins with competent popliteal valves), and 83 limbs had deep venous disease (popliteal reflux on duplex examination or deep venous obstruction on venography). No ulceration occurred in limbs with ambulatory venous pressure < 30 mm Hg, and there was a 100% incidence with ambulatory venous pressure > 90 mm Hg. A linear increase occurred from 14% in limbs with ambulatory venous pressure between 31 and 40 mm Hg to 100% in limbs with ambulatory venous pressure greater than 90 mm Hg (r = 0.79). In the groups studied, an increased incidence of ulceration was associated with an increase in ambulatory venous pressure irrespective of whether the venous problem was the result of superficial or deep venous disease. Ambulatory venous pressure has both diagnostic and prognostic significance in patients with venous disease.

Cardiovascular Outcomes in Type 2 Diabetes: A double-blind placebo-controlled study of bezafibrate: the St. Mary's, Ealing, Northwick Park Diabetes Cardiovascular Disease Prevention (SENDCAP) Study

OBJECTIVE To determine whether serum lipid intervention, in addition to conventional diabetes treatment, could alter cardiovascular outcomes in type 2 diabetes. RESEARCH DESIGN AND METHODS There were 164 type 2 diabetic subjects (117 men, 47 women) without a history of clinical cardiovascular disease randomized to receive either bezafibrate or placebo daily on a double-blind basis in addition to routine diabetes treatment and followed prospectively for a minimum of 3 years. Serial biochemical and noninvasive vascular assessments, carotid and femoral artery B-mode ultrasound measurements, and those pertaining to coronary heart disease (CHD)—clinical history, the World Health Organization (WHO) cardiovascular questionnaire, and resting and exercise electrocardiogram (ECG)—were recorded. RESULTS Bezafibrate treatment was associated with significantly greater reductions over 3 years in median serum triglyceride (−32 vs. 4%, P = 0.001), total cholesterol (−7 vs. −0.3%, P = 0.004), and total−to-HDL cholesterol ratio (−12 vs. −0.0%, P = 0.001), and an increase in HDL cholesterol (6 vs. −2%, P = 0.02) as compared with placebo. There was a trend toward a greater reduction of fibrinogen (−18 vs. −6%, P = 0.08) at 3 years. No significant differences between the two groups were found in the progress of ultrasonically measured arterial disease. In those treated with bezafibrate, there was a significant reduction (P = 0.01, log-rank test) in the combined incidence of Minnesota-coded probable ischemic change on the resting ECG and of documented myocardial infarction. CONCLUSIONS Improving dyslipidemia in type 2 diabetic subjects had no effect on the progress of ultrasonically measured arterial disease, although the lower rate of “definite CHD events” in the treated group suggests that this might result in a reduction in the incidence of coronary heart disease.

Superficial venous insufficiency: Correlation of anatomic extent of reflux with clinical symptoms and signs

PURPOSE The aim of this study was to assess the distribution and extent of valvular incompetence in patients with reflux confined to the superficial venous system and correlate the extent of such reflux with clinical symptoms and signs. METHODS Two hundred fifty-five limbs of 217 patients with superficial venous insufficiency and normal perforating and deep veins were examined with color-flow duplex imaging. One hundred twenty-three limbs (48.2%) of 102 patients had reflux confined to the long saphenous system, 83 limbs (32.6%) of 72 patients had reflux confined to the the short saphenous system, and 49 limbs (19.2%) of 43 patients had reflux in both long and short saphenous systems. RESULTS In the long saphenous system the commonest pattern of reflux was that which extended throughout the length of long saphenous vein (LSV) (47%). Ache, swelling, and skin changes were common in the presence of below knee reflux irrespective whether the thigh segment was involved. Ulceration (8%) was found only in limbs with reflux extending throughout the length of LSV. In the short saphenous system the most common pattern of reflux extended throughout the length of short saphenous vein (SSV) (57%) without involvement of Giacomini or gastrocnemial veins. Ache and swelling were present in 62% and 72% of the limbs, but this incidence was not related to the extent of reflux. Swelling, skin changes, and ulceration occurred only when the whole of the SSV was involved. In the limbs with reflux in both the long and short saphenous systems, the most common pattern of reflux extended throughout the length of both systems (45%). In these limbs the incidence of swelling was 80%. The incidence of skin changes went from 44% when the below-knee segment of the LSV was involved to 73% when reflux occurred throughout the LSV and SSV. Ulceration (14%) was found only in the latter situation. Variable patterns of saphenogastrocnemial termination were seen. In 57.8% of the limbs SSV joined the popliteal vein just above the popliteal crease, whereas the SSV terminated in the thigh in 26.6%. CONCLUSIONS We conclude that ache, ankle edema, and skin changes in limbs with reflux confined to the superficial venous system are predominantly associated with reflux in the below-knee veins. Ulceration is found only when the whole of the LSV is involved (8%) or when reflux is extensive in both LSV and SSV (14%).