Carotid artery Doppler ultrasonography in patients with chronic kidney disease

Interleukin 37; a possible marker of arterial stiffness in Behçet's disease

BACKGROUND

Interleukin 37 (IL-37) is an anti-inflammatory cytokine previously studied in Behçet's disease (BD) and atherosclerosis. However, little is known about its relation to macro and microcirculations in BD. Previous studies relied mainly on common carotid artery (CCA) intima-media thickness (IMT) and ankle brachial index (ABI) to study atherosclerosis in BD with conflicting results. This study evaluated flow parameters of CCA, ABI and nailfold videocapillaroscopy in relation to serum IL-37 in BD.

METHODS

Forty BD patients and 30 healthy controls were included. IMT, peak-systolic, end-diastolic velocities, resistivity index of CCA and ABI were measured by duplex ultrasound. Capillary loop, length, diameter and morphology were recorded by nailfold videocapillaroscopy. Serum IL-37 levels were measured using enzyme-linked immunosorbent assay (ELISA).

RESULTS

Compared to controls, patients had higher mean CCA IMT (p < 0.0001), resistivity index (p < 0.001) and peak-systolic velocity (p=0.09) and lower mean CCA end-diastolic velocity (p=0.002), capillary loop, length, arterial, venous limbs diameter and serum IL-37 (p < 0.001). Patients with ABI ≥ 1.4 "indicating stiff arteries" had higher serum IL-37 (p < 0.05 on left, p>0.05 right sides). Serum IL-37 correlated negatively with left CCA end-diastolic velocity "denoting atherosclerosis" and positively with left posterior tibial artery ABI and CRP (p < 0.03) "denoting inflammation". Multiple regression analysis showed only association with left CCA end-diastolic velocity.

CONCLUSIONS

IL-37 may be related to arterial stiffness in BD and could be used as a possible marker of arteriosclerosis in the disease for further investigations. Changes of CCA peak-systolic, end-diastolic velocities, resistivity index and IMT refer to increased atherosclerosis in larger elastic arteries. In smaller muscular "crural" arteries, vasculitis with possible medial disease may be more evident.

Cardiovascular risk factors and the impact on prognosis in patients with chronic kidney disease secondary to autosomal dominant polycystic kidney disease

BACKGROUND

Autosomal dominant polycystic kidney disease (ADPKD) is the most frequent hereditary renal disease. There is an increased rate of cardiovascular disease (CVD) in ADPKD. In this study, we evaluate the prevalence of cardiovascular risk factors, the achievement rates for treatment goals and cardiovascular events (CVE) in ADPKD and their relations with asymptomatic CVD in CKD from other etiologies (CKDoe) and controls.

METHODS

We evaluated 2445 CKD patients (2010-2012). The information collected was: clinical, anthropometric and analytical parameters, treatments and CVD evaluation (intima-media thickness (IMT), atheromatous plaque presence and ankle-brachial index (ABI)). Laboratory, vital status, CVE and hospitalizations were collected for 4 years.

RESULTS

ADPKD patients had a worse renal function and worst achievement of blood pressure, higher parathormone levels but lower proteinuria compared to CKDoe. ADPKD patients presented lower IMT values than other groups, however, an intermediate rate of pathologic ABI and atheromatous plaque was present. More than half of the patients received statins, achieving LDL-c levels < 100 only in 50 and 39.8% of them (ADPKD and CKDoe respectively). The number of CVE during the follow-up period was low. In adjusted Cox regression model, ADPDK had the lowest occurrence of CVE of all three groups (HR:0.422, 95%CI 0.221-0.808, p = 0.009).

CONCLUSION

ADPKD patients show intermediate control rates of CVD. A better control of CVD risk seems to be related with a lower load of CVD compared to other groups, which may lead in the long term to a better prognosis. Further investigation is necessary to determine cardiovascular prognosis in ADPKD.

The Relationship between Carotid and Femoral Artery Intima-Media Thickness and Histopathologic Grade of Atherosclerosis in Patients with Chronic Kidney Disease

BACKGROUND/AIMS

Variability in the grade of atherosclerosis among patients with chronic kidney disease (CKD) could affect the ultrasound measurements of intima media thickness (IMT). We sought to investigate IMTs of carotid (cIMT) and femoral (fIMT) arteries in CKD patients and assess the degree of their correlation with histopathological atherosclerosis.

METHODS

Eighty-nine out of 99 enrolled subjects completed this study. The subjects were divided into 3 groups: 34 patients with CKD (Case group), 31 with coronary artery disease undergoing coronary artery bypass graft (CABG, positive control group), and 24 healthy kidney donors (negative control group). For histopathological assessment of atherosclerosis, arterial tissue samples were obtained from the patients in each study group. The cIMT and fIMTs were measured by ultrasonography.

RESULTS

Histopathological atherosclerosis was present in 82.3, 100, and 20.8% of CKD, CABG, and donor groups respectively (p < 0.001). CKD patients had higher values of cIMT and fIMT than the donor group (p = 0.01 and 0.004, respectively). cIMT was positively correlated with the grade of atherosclerosis in the CKD group only (p < 0.001), while fIMT was correlated with the grade of atherosclerosis in both CKD and donor groups (p < 0.001 and p = 0.009 respectively). In CKD patients, cIMT >0.65 mm and femoral values >0.57 mm predicted the presence of histopathological atherosclerosis with sensitivities of 96 and 92% respectively.

CONCLUSION

Higher values of cIMT and fIMT in CKD patients are associated with higher rates and degrees of histopathological atherosclerosis. Additionally, when compared to fIMT, cIMT has a higher sensitivity for detecting atherosclerosis in CKD patients.

Appraisal of different ultrasonography indices in patients with carotid artery atherosclerosis

In this study a semi-automated image-processing based method was designed in which the parameters such as intima-media thickness (IMT), resistive index (RI), pulsatility index (PI), dicrotic notch index (DNI), and mean wavelet entropy (MWE) were evaluated in B-mode and Doppler ultrasound in patients presenting with carotid artery atherosclerosis. In a cross-sectional design, 144 men were divided into four groups of control, mild, moderate and severe stenosis subjects. In all individuals, far wall IMT, RI, PI, DNI, and MWE of the left common carotid artery (CCA) were extracted using the proposed method. Our findings showed that the maximum far wall IMT, RI, PI, DNI in the CCA were significantly different in the patients with mild, moderate, and severe stenosis compared to control group (p-value < 0.05), however, there were no significant differences in MWE among the four groups (p-value > 0.05). The proposed method can help physicians to better identify patients at risk of cardiovascular diseases.

Association Between Conjunctival and Corneal Calcification and Atherosclerotic Changes in the Carotid Artery in Maintenance Hemodialysis Patients

PURPOSE

We aimed to investigate the association between atherosclerotic changes in the common carotid artery (CA) and conjunctival and corneal calcification (CCC) in maintenance hemodialysis (MHD) patients.

METHODS

Fifty eyes of MHD patients with the highest CCC scores were enrolled. CCCs were scored according to the method described by Tokuyama et al. The eyes with the highest CCC scores were selected for further analysis. According to their CCC scores, the patients were classified into 3 groups: mild (0-2 score), moderate (3-5), and severe (6-10 score). Atherosclerosis of the common CA was evaluated by determination of intima-media thickness (IMT), peak systolic (PSV) and end diastolic (EDV) flow velocities, pulsatility index, and resistive index values by using Doppler ultrasonography.

RESULTS

The mean IMT of the CA was 0.61 ± 0.09 mm in the mild group, 0.82 ± 0.16 mm in the moderate group, and 1.21 ± 0.32 mm in the severe group (P < 0.001). The PSV and EDV were significantly higher in the severe group than in the mild and moderate groups (all, P < 0.001). The CCC score was positively correlated with the duration of hemodialysis, ocular surface disease index score, IMT, PSV, EDV, lymphocyte, calcium, and sedimentation rate. In multiple stepwise linear regression analysis, IMT was the best predictive factor for the CCC score (R = 0.812, β = 9.526 ± 1.05, and P < 0.001).

CONCLUSIONS

Our results suggest that chronic ocular ischemia due to atherosclerotic changes may have a role in the formation or progression of CCC in MHD patients.

Observational multicenter study to evaluate the prevalence and prognosis of subclinical atheromatosis in a Spanish chronic kidney disease cohort: baseline data from the NEFRONA study

BACKGROUND

Cardiovascular events (CVE) are more prevalent in chronic kidney disease (CKD) than in general population, being the main cause of morbimortality. Specific risk factors related to CKD have been suggested, because traditional factors do not fully explain this increase in cardiovascular disease rates. However, the role of atheromatosis, its pathogenesis and evolution are still unclear. The potential use of diagnostic tests to detect subclinical atheromatosis has to be determined.

METHODS

NEFRONA is a prospective multicenter cohort study. 2445 CKD subjects were enrolled from 81 Spanish hospitals and dialysis clinics, from 2010 to 2012. Eligibility criteria included: 18 to 74 years old, CKD stage 3 or higher, and no previous CVE. 559 non-CKD controls were also recruited. Demographical, clinical and analytical data were collected. Carotid and femoral ultrasounds were performed by a single trained team to measure carotid intima-media thickness (cIMT) and detect atheromatous plaques. Ankle-brachial index (ABI) was measured.

RESULTS

Differences in age, sex and prevalence and control of cardiovascular risk factors were found between controls and CKD patients. These differences are similar to those described in epidemiological studies.No difference was found regarding cIMT between controls and CKD (when subjects with plaques in common carotid arteries were omitted); earlier CKD stages had higher values. CKD patients had a higher rate of atheromatous plaques, with no difference between stages in the unadjusted analysis. A group of patients had plaques in femoral arteries but were plaque-free in carotid arteries, and would have gone underdiagnosed without the femoral study. The percentage of pathologic ABI was higher in CKD, with higher prevalence in more advanced stages, and a higher rate of ABI >1.4 than <0.9, suggesting more vascular calcification.

CONCLUSIONS

NEFRONA is the first large study describing the actual prevalence of subclinical atheromatosis across different CKD stages. There is a very high rate of atheromatous plaques and pathologic ABI in CKD. Prospective data will add important information to the pathogenesis and evolution of atheromatosis in CKD, compared to non-CKD subjects.