Cost of routine screening for carotid and lower extremity occlusive disease in patients with abdominal aortic aneurysms

Asymptomatic carotid intraplaque hemorrhage is associated with a high risk of cerebral infarction and death after cardiovascular surgery

BACKGROUND

There is a lack of information on the natural history of asymptomatic carotid artery stenosis (AsymCS) associated with cardiovascular diseases that require surgery. The aim of this study was to investigate risk factors for postoperative ipsilateral ischemic stroke and all-cause mortality after cardiovascular surgery in patients with AsymCS.

METHODS

Among 2158 patients who underwent cardiovascular surgery, 150 patients with AsymCS who didn't undergo carotid revascularization were included. The relationships between preoperative factors, including carotid intraplaque hemorrhage (IPH), and postoperative ipsilateral ischemic stroke and all-cause mortality were analyzed retrospectively.

RESULTS

During the median follow-up of 1087 days of 150 patients with 19 IPH, 12 (8.0%) and 21 (14.0%) encountered ipsilateral infarction and all-cause mortality, respectively. Multivariable Cox regression analyses indicated that IPH was significantly predictive of both ipsilateral infarction (hazard ratio [HR] 21.31, 95% confidence interval [CI], 4.98-91.17; P ≤.001) and all-cause mortality (HR 4.64, 95% CI, 1.61-13.34; P = .004). Another significant factor was peak systolic velocity for ipsilateral infarction with the cutoff velocity of 227 cm/s by the receiver-operating characteristic curve.

CONCLUSIONS

In this cohort of patients with AsymCS undergoing cardiovascular surgery, IPH had a close connection with a high risk of both postoperative ischemic stroke and mortality after cardiovascular surgery.

Outcomes and Risk Prediction Model for Peripheral Arterial Disease in Patients with Stable Coronary Artery Disease

We used the National Heart, Lung, and Blood Institute Limited Access Dataset of Prevention of Events with Angiotensin-Converting Enzyme Inhibition (PEACE) Trial (n = 8290) which included patients with stable coronary artery disease (CAD) and preserved ejection fraction (>40%). We identified risk factors for the development of critical peripheral arterial disease (PAD; those needing angioplasty, bypass grafting, or aneurysm repair) and formulated a risk score by multivariate analyses. A total of 220 patients (2.8%) developed critical PAD over a mean follow-up of 4.7 years. Significant predictors of critical PAD were history of intermittent claudication, smoking, hypertension (HTN), coronary-artery bypass grafting (CABG), diabetes, age, serum cholesterol, and body mass index (BMI). Incident critical PAD was associated with increased composite outcome of cardiovascular death, myocardial infarction, percutaneous transluminal coronary angioplasty, or CABG (hazard ratio 1.82, 95% CI 1.50-2.22, P < .001). Risk assessment using our score may identify CAD patients at risk for critical PAD events.

Haemostatic and fibrinolytic factors in men with a small abdominal aortic aneurysm

BACKGROUND

: The presence of an abdominal aortic aneurysm (AAA) independently predicts cardiovascular disease (CVD) and its complications. Levels of plasma markers of fibrin turnover are raised in men with a large AAA (at least 5.5 cm) and predict CVD risk in healthy subjects. This study examined fibrin turnover in men with a small AAA.

METHODS

: Seventy-five men with a small AAA (30-55 mm) were compared with 90 controls matched for age, sex and race. Haemostatic and fibrinolytic parameters were assessed.

RESULTS

: Men with a small AAA had higher mean levels of fibrinogen (2.92 versus 2.59 g/l; P = 0.019), thrombin-antithrombin (TAT) complex (4.57 versus 1.89 ng/ml; P < 0.001), prothrombin F1 + 2 (1.13 versus 0.82 ng/ml; P = 0.004) and D-dimer (346.7 versus 120.2 ng/ml; P < 0.001). All markers correlated with maximum aortic diameter determined by ultrasonography. On multivariable regression the association between presence of an AAA and fibrinogen, TAT complex, prothrombin F1 + 2 and D-dimer levels remained significant after adjustment for confounding influences.

CONCLUSION

: Fibrin turnover was increased in these men with a small AAA, independently of concomitant CVD, conventional risk factors and inflammatory markers. Enhanced fibrin turnover may contribute to the risk of cardiac complications in this group.

Guidelines for Screening of Extracranial Carotid Artery Disease: A Statement for Healthcare Professionals from the Multidisciplinary Practice Guidelines Committee of the American Society of Neuroimaging; Cosponsored by the Society of Vascular and Interventional Neurology

The aim of this new statement is to provide comprehensive and timely evidence-based recommendations on the screening for asymptomatic carotid artery stenosis in the general population and selected subsets of patients. Recommendations are included for high-risk persons in the general population; patients undergoing open heart surgery including coronary artery bypass surgery; patients with peripheral vascular diseases, abdominal aortic aneurysms, and renal artery stenosis; patients after radiotherapy for head and neck malignancies; patients following carotid endarterectomy, or carotid artery stent placement; patients with retinal ischemic syndromes; patients with syncope, dizziness, vertigo or tinnitus; and patients with a family history of vascular diseases and hyperhomocysteinemia. The recommendations are based on prevalence of disease, anticipated benefit, and concurrent guidelines from other professional organizations in selected populations.

First-year results of a community peripheral vascular screening program at an academic community hospital

Disease associated with the vascular system, including peripheral arterial disease, poses a serious health problem with incidence growing annually. Recognizing this, several health care organizations across the United States have developed programs for public education and community awareness, and for screening individuals at risk for vascular disease. Lehigh Valley Hospital developed and implemented a screening program that evaluated more than 160 individuals during a 12-month period. Results suggest that screening should be limited to patients at high risk; however, the intrinsic value of patient education and patient peace of mind is worth proceeding with the screening effort because patients reported a positive experience.

Estenose carotídea acima de 70% em pacientes no pré-operatório de cirurgia da aorta abdominal: freqüência e fatores de risco

OBJETIVO: Analisar a freqüência e os fatores de risco associados à estenose carotídea acima de 70% em pacientes que serão submetidos a cirurgias de aorta abdominal. MATERIAL E MÉTODO: Foram analisados 94 pacientes que realizaram ultra-som Doppler de carótidas no pré-operatório de cirurgias de aorta abdominal entre janeiro de 2000 e janeiro de 2003, pela disciplina de Cirurgia Vascular da Santa Casa de São Paulo. RESULTADOS: Sessenta e sete pacientes (71%) eram homens. Dentre os 94 pacientes, 42 (44,6%) tinham doença oclusiva aorto-ilíaca, e 52 (53,4%), aneurismas da aorta abdominal (AAA). A análise dos dados mostrou uma prevalência de estenose de carótidas acima de 70% em 8,33% dos pacientes com AAA e em 13,51% dos pacientes com doença oclusiva aorto-ilíaca, diferença esta sem significância estatística (P = 0,5). Nos pacientes que apresentavam antecedente de isquemia cerebral - acidente vascular cerebral (AVC) ou ataque isquêmico transitório (AIT) -, houve uma prevalência estatisticamente maior de estenose carotídea entre 70 e 99%. Outros fatores de risco para aterosclerose, como sexo masculino, diabetes, hipertensão arterial e tabagismo, não foram preditivos da presença de estenose carotídea acima de 70%. CONCLUSÃO: A freqüência de estenose da carótida acima de 70% em pacientes no pré-operatório de cirurgia de aorta foi de 9,57%, e a presença de antecedente de AVC ou AIT na história foi preditiva de estenose acima de 70% neste grupo de pacientes.

Prevalence of coronary artery disease, lower extremity peripheral arterial disease, and cerebrovascular disease in 110 men with an abdominal aortic aneurysm

Of 110 men (mean age 66 years) with an abdominal aortic aneurysm, 78 (71%) had coronary artery disease (CAD), 50 (46%) had lower extremity peripheral arterial disease (PAD), and 30 (27%) had cerebrovascular disease. Twenty-four percent of the patients with an abdominal aortic aneurysm had CAD plus lower extremity PAD plus cerebrovascular disease, 22% had CAD plus lower extremity PAD and no cerebrovascular disease, 22% had only CAD, 4% had CAD plus cerebrovascular disease and no lower extremity PAD, and 29% had no CAD, lower extremity PAD, or cerebrovascular disease.

Focused screening for occult carotid artery disease: patients with known heart disease are at high risk

OBJECTIVES

Stroke puts a major financial burden on our healthcare system. However, carotid duplex scanning performed as a screening test for occult carotid artery stenosis (CAS) currently is not reimbursed by Medicare. The goals of this study were to develop a cost-effective stroke screening program, to determine the prevalence of potential causes of stroke in this population, and to define a population at high risk in which screening would be most effective.

METHODS

In a community-based stroke screening program, patients were eligible if they were older than 60 years and had a history of either hypertension, heart disease, or cigarette smoking, or a family history of stroke. Screening included blood pressure determination, an electrocardiographic rhythm strip, and a previously validated modified carotid duplex ultrasound examination to detect CAS 50% or greater. The relationships between standard demographic risk factors and screening outcomes were analyzed.

RESULTS

Screening was performed in 610 patients. Unilateral or bilateral CAS was detected in 66 patients (10.8%). The finding of occult CAS was more prevalent than that of new hypertension (2.6%) or new atrial fibrillation (0.5%). Patients with known hypertension were significantly more likely to have CAS than were those without hypertension (12.7% vs 7.8%; P =.05). Patients with heart disease were significantly more likely to have CAS than were those without heart disease (18.2% vs 8%; P <.0001). Patients with both risk factors were significantly more likely to have occult carotid artery disease than were patients without either risk factor (22.1% vs 8.5%; P <.0001). Multivariate analysis with logistic regression revealed a history of heart disease as an independent predictor of occult carotid artery disease (odds ratio 95% confidence interval, 1.4-4.4). Type of heart disease was not a significant factor in predicting occult CAS. Direct cost of the screening, including community outreach, nurses, technicians, support staff, and miscellaneous expenses, was less than $75 per patient.

CONCLUSIONS

In a screening program for treatable causes of potential stroke, CAS was the most commonly diagnosed disease. More than one of every five patients with known hypertension and heart disease had occult CAS. Known heart disease of any type was a significant independent predictor of occult CAS. Screening for treatable causes of potential stroke can be cost-effective. This information could help to further target populations to screen for occult CAS and to justify reimbursement for screening carotid duplex scanning examinations.

Reliability of extracranial carotid artery duplex ultrasound scanning: value of vascular laboratory accreditation

OBJECTIVES

The purpose of this study was to evaluate the reliability of carotid duplex ultrasound scanning performed by nonaccredited vascular laboratories and to assess the clinical effect on patient management.

METHODS

We retrospectively reviewed concordance of findings of carotid duplex ultrasound scanning between laboratories accredited by the Intersocietal Commission for Accreditation of Vascular Laboratories and nonaccredited laboratories in 174 patients with asymptomatic disease referred to tertiary care community hospitals for surgical evaluation for carotid endarterectomy (CEA) between January 2001 and December 2002, and evaluated changes in clinical management made on the basis of repeat examinations.

RESULTS

Concordant findings were noted in 171 of 348 arteries (49%), predominantly those with minimal or mild disease (114 arteries; 67%). Discordant findings of no clinical significance were found in 54 arteries (16%). Clinically significant discordant findings were noted in 123 arteries (35%) in 107 patients (61%). In 104 arteries (88 patients) stenosis was overestimated by the nonaccredited laboratory secondary to technical error (19 arteries), use of B-mode imaging data alone (36 arteries), and use of inappropriate velocity criteria (49 arteries). None of these patients underwent CEA. Stenosis was significantly underestimated in 19 arteries (19 patients); all of these patients underwent uncomplicated CEA.

CONCLUSIONS

Incorrect physician interpretation of data is the most common cause of error in carotid duplex ultrasound scanning performed in nonaccredited vascular laboratories. Results of carotid duplex ultrasound scanning from nonaccredited laboratories should be considered with extreme caution, and do not appear reliable in planning treatment of obstructive disease.

Risk for stroke after elective noncarotid vascular surgery

INTRODUCTION

Patients undergoing operations to treat peripheral vascular disease have systemic atherosclerosis and are at risk for stroke. However, the incidence and effect of cerebrovascular events on noncarotid vascular surgical outcomes are not well-defined.

METHODS

Patients undergoing common operations for vascular disease from 1997 to 2000 were examined with data from the Veterans Affairs (VA) National Surgery Quality Improvement Project and the VA patient treatment files. Operations studied included abdominal aortic aneurysmectomy (n = 2551), aortobifemoral bypass (n = 2616), lower extremity bypass (n = 6866), and major lower extremity amputation (n = 7442). The incidence of perioperative stroke was determined, and logistic regression analysis was used to identify independent risk factors for stroke. Logistic and linear regression analyses were used to quantify the effect of postoperative stroke on adjusted mortality and length of stay. Odds ratio (OR) and 95% confidence interval (CI) were defined. P <.05 was considered significant.

RESULTS

Stroke was uncommon after noncarotid vascular procedures, occurring in only 0.4% to 0.6% of patients. Independent risk factors for stroke include preoperative ventilation (OR, 11; 95% CI, 5.0-22.3; P <.001), previous stroke or transient ischemic attack (OR, 4.2; 95% CI, 2.7-6.4; P <.001), postoperative myocardial infarction (OR, 3.3; 95% CI, 1.3-8.7; P =.009), and need to return to the operating room (OR, 2.2; 95% CI, 1.4-3.5; P =.001). Factors that did not appear to be associated with stroke risk included procedure type, diabetes, renal failure, dialysis dependence, number of transfused units of blood, and hypertension. After controlling for other postoperative complications and comorbid conditions, postoperative stroke significantly increased the risk for perioperative mortality (OR, 6.3; 95% CI, 3.4-11.4; P <.001), with similar magnitude as postoperative myocardial infarction (OR, 6.3; 95% CI, 3.9-10.1; P <.001). Stroke was also associated with a 48% increase in overall length of stay.

CONCLUSIONS

Stroke after noncarotid peripheral vascular surgery is uncommon, but results in markedly increased mortality and length of stay. Stroke risk is most strongly associated with previous stroke history and greater degree of illness. Patients with these associated conditions deserve particular attention to assessing and medically managing modifiable risk factors.

A model for predicting occult carotid artery stenosis: screening is justified in a selected population

OBJECTIVES

The diagnosis and treatment of carotid artery disease is an integral part of stroke prevention. However, a population of patients who would benefit from screening for carotid artery stenosis has not been well defined. As part of an institutional stroke-screening program, a modified, rapid duplex scan was developed to evaluate patients for occult carotid stenosis. The goal of this study was to evaluate risk factors predictive of carotid stenosis in a selected population, and to identify patients who would benefit from carotid screening.

METHODS

Patients were eligible for the study if they were >60 years of age and had a history of hypertension, heart disease, current smoking, or family history of stroke. A modified carotid duplex scan that had been previously validated against formal duplex scanning was utilized; this involved visualization of the carotid bulb and proximal internal carotid artery where Doppler flow velocities were obtained and recorded.

RESULTS

Screening was performed on 394 patients. Thirty-eight patients (9.6%) had either unilateral or bilateral carotid stenosis of > or =50%. Risk factors evaluated included smoking, hypertension, cardiac disease, or hypercholesterolemia. If none of these risk factors was present, the incidence of carotid stenosis was 1.8%. This increased to 5.8% with one risk factor, 13.5% with two risk factors, and 16.7% with three risk factors. Two of three patients with all four risk factors had carotid stenosis (66.7%). Logistic regression and prespecified contrast statements for multiple comparisons were used to assess the relationship between the presence of risk factors and occult carotid artery stenosis. The presence of any one of these risk factors was associated with a statistically significant increase in the presence of occult carotid stenosis (P <.01). This was also statistically significant for the presence of any two risk factors (P <.01) or three risk factors (P <.05).

CONCLUSION

The prevalence of carotid stenosis significantly increases with the presence of one or more identifiable demographic risk factors in a selected population. Assuming the diagnosis and treatment of carotid stenosis are fundamental to stroke prevention, screening for carotid artery disease is justified in this group of patients.