Noninvasive studies for the peripheral artery disease patient.

Numerous noninvasive diagnostic tests can be performed to detect peripheral arterial disease (PAD), and these can be separated into direct and indirect examinations. The test chosen is determined on the basis of both the presenting symptoms of the patient and the needs of the health care provider. A simple pressure measurement is often used to screen an asymptomatic patient for PAD, and a more specific and detailed test, such as ultrasound, is required to determine disease within a stent or bypass. Indirect testing types include the measurement of systolic pressures within a limb or digit and acquisition of waveforms. The combination of quantitative data from pressures and qualitative data from waveforms is used to provide an accurate assessment of global perfusion in a limb. Direct noninvasive testing is performed with duplex ultrasound techniques. With ultrasound, specific anatomic features can be visualized directly. Spectral waveforms obtained with duplex ultrasound can be characterized and velocities can be measured. Criteria exist to categorize disease on the basis of velocities and velocity ratios and by using this objective hemodynamic data, progression of disease may be followed. The focus of this review was to describe the various types of direct and indirect arterial noninvasive testing for detection and management of PAD. The advantages and disadvantages of each will be explained, as well as common applications for these tests. Direct, indirect, or a combination of direct and indirect testing may be required to accurately determine the presence, level, and severity of PAD.

Tima nigroannulata (Cnidaria: Hydrozoa: Eirenidae), a New Species of Hydrozoan from Japan.

Tima nigroannulata sp. nov. is described from medusae collected in shallow waters of four prefectures on the Pacific coast of Japan (Miyagi, Fukushima, Kanagawa, and Miyazaki), as well as from cultures maintained at two aquaria (Enoshima Aquarium, Kanagawa Prefecture; Tsuruoka City Kamo Aquarium, Yamagata Prefecture). Adult medusae differ from those of other known species of the genus Tima Eschscholtz, 1829 in the following combination of characters: (1) umbrella usually hemispherical or higher, (2) marginal tentacles up to 50 or more in number; and (3) black pigment granules form a ring around the umbrella rim, and sometimes extend onto the tentacles and radial canals. Their hydroids, from aquarium cultures, have stolonal colonies with pedicels of varied length, vestigial hydrothecae, slender and vase- to club-shaped hydranths, and a whorl of about 20 filiform tentacles with an intertentacular web basally. Medusa buds develop singly within gonothecae that arise from the hydrothecal pedicels. The cnidomes of both hydroid and medusa stages comprise heteronemes, provisionally identified as microbasic mastigophores. Medusae of T. nigroannulata are confirmed as a unique, cohesive lineage by comparing mtDNA COI sequence fragments with those from two congeners, resulting in three well-supported reciprocally monophyletic clades, one representing each species. Records of the western Atlantic medusa Tima formosa L. Agassiz, 1862 from Japan overlap those of T. nigroannulata, and are believed to have been based on the new species described herein.

Utility of unilateral versus bilateral venous reflux studies for venous insufficiency.

OBJECTIVE: Duplex ultrasonography is the reference standard for diagnosing chronic venous insufficiency. Bilateral venous reflux ultrasound studies are among the most time-consuming and physically demanding tests for vascular ultrasound technologists to perform. Furthermore, if a venous procedure is required, many insurance policies require that a diagnostic venous ultrasound scan for reflux must be performed within 1 year of the procedure. If the intervention is scheduled for >1 year after the ultrasound scan, the insurance company might require a repeat venous ultrasound scan before granting insurance authorization. Hence, ordering bilateral venous duplex ultrasound scans to evaluate for reflux when an intervention might only be performed on one limb within the year could be a waste of time and resources. The aim of the present study was to determine the utility of ordering bilateral vs unilateral studies to evaluate for reflux in patients with suspected chronic venous insufficiency and to determine whether a resource-saving potential exists for vascular laboratories through optimization of the process of ordering venous duplex ultrasound studies. METHODS: A retrospective review of all patients who had undergone bilateral lower extremity ultrasound scanning to evaluate for reflux from January 1, 2016 to December 31, 2016 at the Massachusetts General Hospital vascular laboratory was performed. The demographics, indications for ultrasound scanning, comorbidities, time required to perform the ultrasound study, and interval to intervention were documented. The data were analyzed using SPSS statistical software (IBM Corp, Armonk, NY). RESULTS: During the study period, 13,854 ultrasound studies had been performed in our vascular laboratory, of which 606 (4.4%) had been bilateral ultrasound scans for venous insufficiency. The time allotted for a bilateral study was 2 hours. Of the 606 studies evaluated, 152 (25.1%) showed no evidence of reflux, 284 (46.9%) showed bilateral lower extremity reflux, and 170 (28.1%) showed only venous insufficiency in one leg. Venous ablation, phlebectomy, and/or sclerotherapy were performed for 28.7% of the patients. However only 6.2% of patients had undergone venous procedures on both legs within 1 year after the ultrasound studies. Ablation was the most common procedure performed (54.6%), followed by phlebectomy (27.%) and sclerotherapy (17.9%). Overall, 94.7% of patients had not undergone a venous procedure on both legs within 1 year after the ultrasound studies and, hence, would have required a repeat duplex ultrasound scan to ensure insurance coverage for future procedures. CONCLUSIONS: Most bilateral ultrasound scans for venous insufficiency will not result in an intervention. Thus, most patients (95%) could have undergone a unilateral scan before the initial intervention instead of bilateral duplex ultrasound scanning.

Carotid artery plaque and progression of coronary artery calcium: the multi-ethnic study of atherosclerosis.

BACKGROUND: Carotid and coronary atherosclerosis are associated with each other in imaging and autopsy studies. The aim of this study was to evaluate whether carotid artery plaque seen on carotid ultrasound can predict incident coronary artery calcification (CAC). METHODS: Agatston calcium score measurements were repeated in 5,445 participants of the Multi-Ethnic Study of Atherosclerosis (MESA; mean age, 57.9 years; 62.9% women). Internal carotid artery lesions were graded as 0%, 1% to 24%, or >25% diameter narrowing, and intima-media thickness (IMT) was measured. Plaque was present for any stenosis >0%. CAC progression was evaluated with multivariate relative risk regression for CAC scores of 0 at baseline and with multivariate linear regression for CAC score > 0, adjusting for cardiovascular risk factors, body mass index, ethnicity, and common carotid IMT. RESULTS: CAC was positive at baseline in 2,708 of 5,445 participants (49.7%) and became positive in 458 of 2,837 (16.1%) at a mean interval of 2.4 years between repeat examinations. Plaque and internal carotid artery IMT were both strongly associated with the presence of CAC. After statistical adjustment, the presence of carotid artery plaque significantly predicted incident CAC with a relative risk of 1.37 (95% confidence interval, 1.12-1.67). Incident CAC was associated with internal carotid artery IMT, with a relative risk of 1.13 (95% confidence interval, 1.03-1.25) for each 1-mm increase. Progression of CAC was also significantly associated (P < .001) with plaque and internal carotid artery IMT. CONCLUSIONS: In individuals free of cardiovascular disease, subjective and quantitative measures of carotid artery plaques by ultrasound imaging are associated with CAC incidence and progression.

Changes in carotid intima-media thickness during the cardiac cycle: the multi-ethnic study of atherosclerosis.

BACKGROUND: Common carotid artery intima-media thickness (IMT), a measure of subclinical cardiovascular disease, changes during the cardiac cycle. The magnitude of this effect and its implications have not been well studied. METHODS AND RESULTS: Far-wall IMT measurements of the right common carotid artery were measured at end diastole and peak systole in 5633 individuals from the Multi-Ethnic Study of Atherosclerosis (MESA). Multivariable regression models were generated with end-diastolic IMT, peak-systolic IMT, and change in IMT during the cardiac cycle as dependent variables and traditional cardiovascular risk factors as independent variables. The average age of our population was 61.9 (45 to 84) years. Average change in carotid IMT during the cardiac cycle was 0.041 mm (95% confidence interval: 0.039 to 0.042 mm), with a mean IMT of 0.68 mm. End-diastolic IMT and peak-systolic IMT were similarly associated with risk factors. In a fully adjusted model, change in carotid IMT during the cardiac cycle was associated with ethnicity and pulse pressure (P=0.001) and not age, sex, or other risk factors. Chinese and Hispanics had less of a change in IMT than did non-Hispanic whites. With peak-systolic IMT reference values used as normative data, 31.3% more individuals were classified as being in the upper quartile of IMT and at high risk for cardiovascular disease than would be expected when IMT is measured at end diastole. CONCLUSIONS: Measurable differences in IMT are seen during the cardiac cycle. This affects the interpretation of IMT measurements used for cardiovascular risk assessment, given published normative data with IMT measured at peak systole. CLINICAL TRIAL REGISTRATION: URL: www.ClinicalTrials.gov. Unique identifier: NCT00063440. (J Am Heart Assoc. 2012;1:e001420 doi: 10.1161/JAHA.112.001420.).

Associations of cardiovascular risk factors, carotid intima-media thickness and left ventricular mass with inter-adventitial diameters of the common carotid artery: the Multi-Ethnic Study of Atherosclerosis (MESA).

BACKGROUND: Common carotid artery inter-adventitial diameter (IAD) and intima-media thickness (IMT) are measurable by ultrasound. IAD may be associated with left ventricular mass (LV mass) while IMT is a marker of subclinical atherosclerosis. It is not clear if IAD is associated with LV mass after accounting for IMT and traditional cardiovascular risk factors. METHODS: IAD and IMT were measured on participants of the Multi-Ethnic Study of Atherosclerosis (MESA) IMT progression study. A total of 5641 of the originally enrolled 6814 MESA participants were studied. LV mass was measured by magnetic resonance imaging. Multivariable linear regression was used with IAD as the outcome and adjustment for risk factors, as well as IMT and LV mass. RESULTS: Traditional cardiovascular risk factors, height, weight and ethnicity were significantly associated with IAD. After adjustment for risk factors, a 1mm difference in IMT was associated with a 1.802mm (95% CI: 1.553, 2.051) higher mean IAD. A 1g difference in LV mass was associated with a 0.006mm (95% CI: 0.005, 0.007) higher mean IAD. After adjusting for cardiovascular risk factors and IMT, a 1g difference in LV mass was associated with a 0.006mm (95% CI: 0.005, 0.008) higher mean IAD for women and 0.004mm (95% CI: 0.003, 0.005) higher IAD for men. CONCLUSIONS: Inter-adventitial diameters are associated with left ventricular mass after adjusting for cardiovascular risk factors and IMT. IAD might serve as a surrogate for left ventricular mass and have predictive value for cardiovascular outcomes.

HIV infection and progression of carotid and coronary atherosclerosis: the CARE study.

BACKGROUND: Progression of carotid intima-media thickness (c-IMT) and coronary artery calcium (CAC) are increasingly used as surrogates for vascular risk. We assessed the predictors of c-IMT and CAC progression in a large longitudinal cohort of HIV-infected adults. METHODS: c-IMT, CAC scores, and vascular and HIV risk factors were evaluated at baseline and at 3-year follow-up in 255 HIV-infected adults. Multivariate regression was used to determine the predictors of atherosclerotic progression. RESULTS: The mean change in c-IMT per year of follow-up was 0.016 mm for the common and 0.020 mm for the internal. Significant predictors of yearly progression were age, systolic blood pressure, triglycerides, and insulin for common c-IMT and triglycerides >=150 mg/dL, glucose >126 mg/dL, use of glucose-lowering medications, quantitative insulin sensitivity check index, high waist circumference, and current smoking for internal c-IMT. Twenty-eight percent had CAC progression. Of those with zero CAC at baseline, 32% had detectable scores at follow-up. Of those with detectable CAC at baseline, 26% had progression at follow-up. For CAC score, quantitative insulin sensitivity check index, apolipoprotein B, and triglycerides predicted progression. Those with abnormal surrogate markers at baseline were more likely to have the metabolic syndrome reversed and be started on antihypertensive medications over the 3-year follow-up period than those who had no abnormalities at baseline. CONCLUSIONS: Although c-IMT and CAC progression rates in HIV-infected patients appear higher than expected for this age and risk groups, traditional cardiovascular risk factors remain the strongest determinants of carotid and coronary atherosclerotic disease progression in HIV-infected patients. Aggressive cardiovascular risk reduction is effective at slowing the atherosclerotic progression in those with preexisting disease.

Progression of carotid artery intima-media thickness during 12 years in the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) study.

OBJECTIVE: This study investigated the long-term effects of intensive diabetic treatment on the progression of atherosclerosis, measured as common carotid artery intima-media thickness (IMT). RESEARCH DESIGN AND METHODS: A total of 1,116 participants (52% men) in the Epidemiology of Diabetes Interventions and Complications (EDIC) trial, a long-term follow-up of the Diabetes Control and Complications Trial (DCCT), had carotid IMT measurements at EDIC years 1, 6, and 12. Mean age was 46 years, with diabetes duration of 24.5 years at EDIC year 12. Differences in IMT progression between DCCT intensive and conventional treatment groups were examined, controlling for clinical characteristics, IMT reader, and imaging device. RESULTS: Common carotid IMT progression from EDIC years 1 to 6 was 0.019 mm less in intensive than in conventional (P < 0.0001), and from years 1 to 12 was 0.014 mm less (P = 0.048); but change from years 6 to 12 was similar (intensive - conventional = 0.005 mm, P = 0.379). Mean A1C levels during DCCT and DCCT/EDIC were strongly associated with progression of IMT, explaining most of the differences in IMT progression between DCCT treatment groups. Albuminuria, older age, male sex, smoking, and higher systolic blood pressure were significant predictors of IMT progression. CONCLUSIONS: Intensive treatment slowed IMT progression for 6 years after the end of DCCT but did not affect IMT progression thereafter (6-12 years). A beneficial effect of prior intensive treatment was still evident 13 years after DCCT ended. These differences were attenuated but not negated after adjusting for blood pressure. These results support the early initiation and continued maintenance of intensive diabetes management in type 1 diabetes to retard atherosclerosis.

Segment-specific associations of carotid intima-media thickness with cardiovascular risk factors: the Coronary Artery Risk Development in Young Adults (CARDIA) study.

BACKGROUND AND PURPOSE: We propose to study possible differences in the associations between risk factors for cardiovascular disease (myocardial infarction and stroke) and carotid intima-media thickness (IMT) measurements made at 3 different levels of the carotid bifurcation. METHODS: We conducted a cross-sectional study of a cohort of whites and blacks of both genders with a mean age of 45 years. Traditional cardiovascular risk factors were determined in cohort members. Carotid IMT was measured from high-resolution B-mode ultrasound images at 3 levels: the common carotid artery, the carotid artery bulb (bulb), and the internal carotid artery. Associations with risk factors were evaluated by multivariate linear regression analyses. RESULTS: Of 3258 who underwent carotid IMT measurements, common carotid artery, bulb, and internal carotid artery IMT were measured at all 3 separate levels in 3023 (92.7%). A large proportion of the variability of common carotid artery IMT was explained by cardiovascular risk factors (26.8%) but less so for the bulb (11.2%) and internal carotid artery (8.0%). Carotid IMT was consistently associated with age, low-density lipoprotein cholesterol, smoking, and hypertension in all segments. Associations with fasting glucose and diastolic blood pressure were stronger for common carotid artery than for the other segments. Hypertension, diabetes, and current smoking had qualitatively stronger associations with bulb IMT and low-density lipoprotein cholesterol with internal carotid artery IMT. CONCLUSIONS: In our cohort of relatively young white and black men and women, a greater proportion of the variability in common carotid IMT can be explained by traditional cardiovascular risk factors than for the carotid artery bulb and internal carotid arteries.