Impact of atherosclerotic risk factors on the extent of arterial occlusive disease among Arabian patients: a hospital based study

AIM

Although the risk factors for atherosclerosis have been identified, their impacts on the extent of arterial occlusive disease among Arabian population have never been studied before.

METHODS

A case control study was undertaken on consecutive series of Arabian patients over one year. The study comprised 2 patients groups: atherosclerotic group which included patients aged 40 years and older admitted with peripheral, carotid or coronary artery disease and the control group, including patients admitted to one of the general surgical units who were free from atherosclerotic disease. All patients underwent evaluation of risk factors for atherosclerotic and systemic study of the vascular tree. Correlation and association were checked between prevalence of these factors and the extent of atherosclerotic disease into different territories.

RESULTS

Two hundred and fifteen patients in the atherosclerotic group and 191 patients in the control group were included. The incidence of diabetes mellitus (DM) was very high in the atherosclerotic group (67.8%). There was significant correlation between incidence of risk factors and risk and extent of atherosclerosis. In age, sex and nationality-adjusted logistic regression analysis, combination of some risk factors augmented the risk and extent of atherosclerosis e.g. diabetes alone increased the risk of atherosclerosis slightly in one affected system (OR 2.28, 95% CI 1.9-2.7) while combination of diabetes, smoking and dyslipidemia enhanced this risk (OR 7.4, 95% CI 2.5-22.4).

CONCLUSIONS

The risk factors of atherosclerosis increase its incidence and extent into different territories.

Alanine aminotransferase is associated with atherothrombotic risk factors in a British South Asian population

BACKGROUND

Alanine aminotransferase (ALT) predicts the development of Type 2 diabetes mellitus and cardiovascular disease in Caucasian subjects.

OBJECTIVES

This study aimed to determine the incidence of an elevated ALT and its relationship to metabolic and atherothrombotic risk factors in a healthy British South Asian population.

PATIENTS/METHODS

One hundred and forty-three participants from the West Yorkshire community were recruited randomly from general practice registers and were grouped according to whether their ALT was above or within the normal range (cut-off 35 IU L(-1)) and examined for differences in metabolic and atherothrombotic risk factors. All participants were originally from South Asia, with their grandparents being born in India, Pakistan, or Bangladesh.

RESULTS

The incidence of a raised ALT was 24%. Those with a raised ALT had a more adverse metabolic profile, with significantly higher body mass index, waist/hip ratio, fasting insulin, glucose, homeostasis model assessment homeostasis model assessment insulin resistance (HOMA-IR), and triglycerides, and lower high-density lipoprotein (HDL) cholesterol. Fifty per cent had the metabolic syndrome [International Diabetes Federation (IDF) criteria]. They also had a more adverse atherothrombotic profile, with higher tissue-type plasminogen activator and plasminogen activator inhibitor-1 (PAI-1) antigen. In accordance, the group as a whole showed a positive correlation of ALT (age-adjusted) with waist/hip ratio, insulin, glucose, triglycerides, PAI-1 antigen, factor XIII B subunit, and FXII, and a negative correlation with HDL cholesterol.

CONCLUSION

Raised ALT is common in apparently healthy British South Asians, and is significantly associated with an adverse metabolic and atherothrombotic risk profile.

Diagnosis of Congenital Obstructive Aortic Arch Anomalies in Chinese Children by Contrast-Enhanced Magnetic Resonance Angiography

OBJECTIVE

The purpose of this study was to evaluate the accuracy of contrast-enhanced magnetic resonance angiography for the diagnosis of congenital obstructive aortic arch anomalies in children and compare it with transthoracic echocardiography and other MR imaging techniques (ECG gated T1-weighted spin-echo imaging and gradient-echo cine imaging).

MATERIALS AND METHODS

Contrast-enhanced magnetic resonance angiography, ECG gated T1-weighted spin-echo imaging, and gradient-echo cine imaging were performed for the diagnosis of congenital obstructive aortic arch anomalies in 416 patients from April 1999 to March 2005 (age range, 3 days to 12 years; mean age, 2.4 years) using a GE 1.5T MR scanner. Transthoracic echocardiography was performed in all patients prior to MR examination. Surgery and/or conventional X-ray angiocardiography were done in all patients to determine the final diagnosis.

RESULTS

The population consisted of 416 patients. Congenital obstructive aortic arch anomalies were diagnosed in 213 patients and ruled out in 203 patients by operation and/or conventional X-ray angiocardiography. Among the 213 patients with anomalies, coarctation of aorta was diagnosed in 174, interruption of aortic arch was diagnosed in 35, and persistent fifth aortic arch with fourth aortic arch interruption was diagnosed in 4 patients. Among the 35 patients with interruption of aortic arch, 21 were of type A, and 14 were of type B. The diagnostic sensitivity, specificity and accuracy of contrast-enhanced magnetic resonance angiography for congenital obstructive aortic arch anomalies were 98% (208/213), 99% (201/203) and 98% (409/416), respectively. The diagnostic sensitivity, specificity and accuracy of transthoracic echocardiography were 88% (187/213), 92% (186/203) and 90% (373/416), respectively. The diagnostic sensitivity, specificity and accuracy of other MR imaging techniques (ECG gated T1-weighted spin-echo imaging and gradient-echo cine imaging) were 89% (189/213), 84% (170/203) and 86% (359/416), respectively.

CONCLUSION

Contrast-enhanced magnetic resonance angiography is a reliable, noninvasive imaging technique for the diagnosis of congenital obstructive aortic arch anomalies in children. Occasionally, even more information can be obtained from this technique than from conventional X-ray angiocardiography. Contrast-enhanced magnetic resonance angiography is superior to transthoracic echocardiography and other MR imaging techniques (ECG gated T1-weighted spin-echo imaging and gradient-echo cine imaging) for diagnosis of congenital obstructive aortic arch anomalies in children.

Comparative analysis of autogenous infrainguinal bypass grafts in African Americans and Caucasians: The association of race with graft function and limb salvage

OBJECTIVE

African Americans (AAs) are at risk for developing diabetes mellitus and atherosclerosis. Whether race influences the results of infrainguinal arterial reconstruction is unclear. The purpose of this study was to compare the results of autogenous infrainguinal bypasses in AAs and Caucasians to determine the association of race with graft function and limb salvage.

METHODS

This was a retrospective, comparative cohort study of AA and Caucasian patients who had undergone autogenous infrainguinal bypass surgery. Only single-limb bypasses in each patient cohort were considered in this analysis. In patients who had undergone bilateral lower limb bypasses, the first limb bypass was chosen as the index bypass procedure.

RESULTS

From January 1985 to December 2003, 1459 autogenous infrainguinal bypasses were performed in 1459 patients for lower limb ischemia. Within this group, 89 AA patients/vein grafts formed the study cohort. The control group comprised 1370 Caucasian patients/vein grafts. Compared with the Caucasian cohort, AA patients were significantly younger (median age, 65 vs 70 years, respectively; P = .001) and predominantly female (57% vs 41%, respectively; P = .002). AA patients also had a higher prevalence of diabetes mellitus, hypertension, cerebrovascular disease, congestive heart failure, and dialysis-dependent renal failure. More AA than Caucasian patients presented with gangrene (34% vs 16%, respectively; P = .001), and more underwent bypass surgery for limb salvage indications (91% vs 81%, respectively; P = .01). The venous conduit used was predominantly the greater saphenous vein (AA, 83%; Caucasian, 85%), and the site of distal anastomosis was at the tibial/pedal level in 67% of AA and 61% of Caucasian patients. Overall morbidity (AA, 28%; Caucasian, 23%) and 30-day mortality (AA, 3%; Caucasian, 3%) were similar. Thirty-day graft failure was significantly greater in AAs than Caucasians (12% vs 5%, respectively; P = .003). The overall 5-year primary graft patency (+/-SE) was significantly worse in AA patients (AA, 52% +/- 6%; Caucasian, 67% +/- 2%; P = .009). The 5-year limb salvage rate (+/-SE) was also significantly worse in AA patients (AA, 81% +/- 5%; Caucasian, 90% +/- 1%; P = .04). With the Cox proportional hazard model, significant risk factors associated with primary graft failure were AA race, age younger than 65 years, female sex, secondary reconstructions, tibial bypasses, and critical limb ischemia. Significant risk factors associated with limb loss were age younger than 65 years, female sex, absence of coronary disease, presence of critical limb ischemia, and secondary reconstructions.

CONCLUSIONS

Autogenous infrainguinal bypass surgery in AAs is associated with poorer primary graft patency and limb salvage rates compared with those of Caucasians. This may partially account for the higher rate of limb loss in AA patients with peripheral arterial occlusive disease.

Independent association of uric acid levels with peripheral arterial disease in Taiwanese patients with Type 2 diabetes

AIMS

Hyperuricaemia may be a risk factor for atherosclerotic disease. Its association with peripheral arterial disease (PAD) has not been studied in Taiwanese patients with Type 2 diabetes.

METHODS

Uric acid (UA) levels and PAD were evaluated in 508 Taiwanese outpatients with Type 2 diabetes (210 men, 298 women; mean age +/- sd, 63.8 +/- 10.6 years). PAD was diagnosed when the ankle-brachial index was < 0.9. Patients with an ankle-brachial index of > or = 1.3 were excluded because of possible medial arterial calcification. Potential confounding variables with P < 0.10 were adjusted for in multivariate analyses.

RESULTS

In univariate analyses, UA levels were higher in patients with PAD than in those without PAD (345.0 +/- 95.2 vs. 309.3 +/- 89.2 micromol/l; P < 0.0005). Prevalences of PAD for quintiles of UA levels were 6.8, 8.9, 10.2, 13.1 and 16.5%, respectively (P-trend < 0.05). With UA level as a continuous variable, the multivariate-adjusted odds ratio (95% confidence interval) for PAD was 1.005 (1.001-1.008) (P < 0.01). The optimal cut-off point for UA as determined by the receiver operating characteristic curve was 264.7 micromol/l. The sensitivity and specificity at this cut-off point was 82.6 and 33.3%, respectively. The area under curve was 0.60 (95% confidence interval: 0.53-0.68). The multivariate-adjusted odds ratio for PAD for UA above this level was 2.736 (1.239-6.043) (P < 0.05). The results after excluding 56 cases using diuretics were similar.

CONCLUSIONS

Elevated uric acid level is a significant and independent risk factor for PAD in Taiwanese patients with Type 2 diabetes.

Lower extremity nontraumatic amputation among veterans with peripheral arterial disease: is race an independent factor?

OBJECTIVES

To determine if race/ethnicity is independently associated with an increased risk for nontraumatic lower extremity amputation versus lower extremity bypass revascularization among patients with peripheral arterial disease (PAD).

METHODS

Data were analyzed from the National VA Surgical Quality Improvement Program (NSQIP) and from the Veterans Affairs Patient Treatment File (PTF). Race/ethnicity was defined as non-Hispanic white, black, or Hispanic. Variables that were univariately associated (P < or = 0.05) with the outcome of amputation were placed into a multiple logistic regression model to determine independent predictors for the dependent variable, lower extremity amputation versus lower extremity bypass revascularization.

RESULTS

Three thousand eighty-five lower extremity amputations and 8409 lower extremity bypass operations were identified. Among all cases included, there were 416 Hispanic patients (3.6%), 2337 black patients (20.3%), and 8741 non-Hispanic white patients (76.1%). Among all variables within the model, Hispanic and black race were each associated with a greater risk for amputation than a history of rest pain/gangrene (Hispanic race 1.4, 95% CI 1.1, 1.9; black race 1.5, 95% CI 1.4, 1.7; rest pain/gangrene 1.1, 95% CI 1.0, 1.3). The final model had a c statistic of 0.83.

CONCLUSION

Hispanic race and black race were independent risk factors for lower extremity amputation in patients with PAD. Although the burden of certain atherosclerotic risk factors (eg, diabetes and hypertension) is higher in minority patients, the impact of this burden does not account for the increased risk for the outcome of lower extremity amputation in these two populations. Further research is needed to better understand the reason(s) why race/ethnicity is independently associated with poor outcomes in PAD.

Aorto-iliac occlusive disease in the different population groups--clinical pattern, risk profile and results of reconstruction

BACKGROUND

It has previously been accepted that atherosclerotic disease is uncommon among blacks worldwide; however, recent studies have increasingly reported atherosclerotic disease in this group.

STUDY DESIGN

Prospective study of hospital patients with aorto-iliac occlusive disease presenting to the vascular service of the Durban metropolitan hospitals. The study was designed to assess clinical pattern, risk profile and results of reconstruction in these patients.

METHODS

This is a study of 688 patients with aorto-iliac occlusive disease managed over 9 years in Durban, with clinical pattern and risk factors compared in the different population groups. A subgroup of 492 patients underwent aortobifemoral bypass, providing material for comparison of the results of reconstruction in the different population groups.

RESULTS

More black patients presented with gangrene and threatened limb, whereas whites tended to present early with claudication. All groups had hypertension and diabetes as risk factors. In addition, whites and Indians had ischaemic heart disease, which was not found among blacks. Mortality was 5% (blacks 1.8%, whites 8.5%, Indians 5%). Medium-term occlusion rates were 19% in blacks, 13% in Indians and 5% among whites. Five-year cumulative patency rates were 92% for whites, 77% for Indians and 74% for blacks.

CONCLUSION

Whites do significantly better than blacks, who tend to present at an advanced stage of the disease. The presence of ischaemic heart disease among whites and Indians contributes to the higher mortality in these groups.

Prevalence of coronary artery disease, atherothrombotic brain infarction, and peripheral arterial disease: associated risk factors in older Hispanics in an academic hospital-based geriatrics practice

OBJECTIVE

To investigate the prevalence of coronary artery disease (CAD), atherothrombotic brain infarction (ABI), and peripheral arterial disease (PAD) in older Hispanics and the association with risk factors in this population.

DESIGN

A retrospective analysis of charts from all Hispanics seen during January 1996 through July 1997 at an academic hospital-based geriatrics practice.

SETTING

An academic, hospital-based, primary care geriatrics practice staffed by fellows in a geriatrics training program and by full-time faculty geriatricians.

PATIENTS

One hundred sixty women and 53 men, mean age 80 +/- 8 years (range 64 to 100), were included in the study.

MEASUREMENTS AND MAIN RESULTS

Of 213 Hispanics in the study, 59 (28%) had documented CAD, 43 (20%) had ABI, 34 (16%) had PAD, and 90 (42%) had either CAD, ABI, or PAD. Serum total cholesterol and triglycerides were measured in 202 of 213 subjects (95%). Serum high-density lipoprotein cholesterol was measured in 137 of 213 patients (64%). Other risk factor data were documented in all patients. Multiple logistic regression analysis performed in 202 patients using the variables age, gender, cigarette smoking, hypertension, diabetes mellitus, obesity, serum total cholesterol, and serum triglycerides showed statistically significant associations between prevalent CAD, ABI, or PAD and age (P = .002, odds ratio (OR) = 1.083), cigarette smoking (P = .002, (OR) = 3.865), hypertension (P = .007, (OR) = 2.749), diabetes mellitus (P = .028, (OR) = 2.386), obesity (P = .014, (OR) = 2.608), serum total cholesterol (P < 0.001, (OR) = 1.025), and serum triglycerides (P = .017, (OR) = .993).

CONCLUSIONS

Either CAD, ABI, or PAD was present in 42% of 213 older Hispanics. There were statistically significant associations between prevalent CAD, ABI, or PAD in older Hispanics and risk factors, including age, cigarette smoking, hypertension, diabetes mellitus, obesity, and serum total cholesterol.

Intracranial stenosis in Chinese patients with acute stroke

We studied 100 consecutive acute stroke patients in a Chinese population with transcranial Doppler and CT. Twenty patients had intracerebral hemorrhage and 14 patients did not have adequate temporal windows for transcranial Doppler examination. Among the remaining 66 patients, 22 patients (33%) had intracranial occlusive diseases and 3 (6%) had extracranial carotid stenosis. Our data showed that intracranial occlusive disease is the most commonly found vascular lesion in our acute stroke patients.

Racial differences in operation for peripheral vascular disease: results of a population-based study

Operation for non-coronary atherosclerotic peripheral vascular occlusive disease may vary among race and gender groups. Using a state-wide registry, the authors identified all operations performed for infrarenal peripheral vascular disease over a 12-month period in a single south-eastern state. Procedures performed included reconstruction for aortoiliac (n=641) and infrainguinal (n=1129) disease and major amputation (n=1077). The incidence for patients over age 50 was calculated using census data. Operation for aortoiliac disease was significantly more likely for white patients (relative risk 3.79, 95% C.I. 2.84-5.15), but less likely for infrainguinal peripheral vascular disease (relative risk 0.64, 95% C.I. 0.56-0.73) and amputation (relative risk 0.17, 95% C.I. 0.15-0.19). Trends toward lower operative mortality in blacks with aortoiliac disease (10.6% versus 12.0%), PVD (3.2% versus 3.5%), and amputation (5.5 versus 8.7%) failed to attain statistical significance. Patient race was associated with the type and location of operation performed for peripheral vascular disease.

Total occlusion of left main coronary artery in Orientals: profile of 4 cases

The authors report 4 Oriental cases of total occlusion of the left main coronary artery (LMCA) with differing presentations. The first patient had a twelve-year history of stable angina pectoris. The second patient had angina for a year, which became unstable two months prior to diagnosis. The third patient had myocardial infarction seven years ago and presented with a one-month history of rest angina. The fourth patient had stable effort angina for six years but presented with accelerated angina three months prior to diagnosis. The incidence of total occlusion of the LMCA is rare and survival depends on the existence of collateral circulation. In LMCA disease, there is usually disease in other parts of the coronary arterial tree, and hence, the need for urgent coronary bypass surgery.