Evaluation Of Arterial And Left Ventricular Alterations In Patients With Chronic Kidney Disease By Ultrasonography

Chronic kidney disease(CKD) is a general term for heterogeneous disordersaffecting the structure and function of the kidney. Chronic kidney disease is aworldwide public health problem with an increasing incidence and prevalence, pooroutcomes, and high cost. In February2002, the Kidney Disease Outcomes QualityInitiative (K/DOQI) of the National Kidney Foundation (NKF) published clinicalpractice guidelines on chronic kidney disease. CKD is defined as either are duction inthe glomerular filtrationrate (GFR) to values below60ml/min/1.73m2or thepresence of kidney damage as reflected in an abnormal urine sediment (proteinuria,hematuria, and casts) or abnormalities in renal architecture even if the GFR ispreserved within normal levels. Because of the central role of GFR in thepathophysiology of complications, the disease is classifi ed into five stages on thebasis of GFR: more than90mL/min per1·73m2(stage1),60–89mL/min per1·73m2(stage2),30–59mL/min per1·73m2(stage3),15–29mL/min per1·73m2(stage4),and less than15mL/min per1·73m2(stage5). Complications can occur at any stage,which often lead to death with no progression to kidney failure.Individuals with CKD are at extremely high cardiovascular risk than generalpopulation, the major cardiovascular complications including: coronary artery disease（prevalence16.5%）, left ventricular hypertrophy（58.5%）, congestive heart failure (27.7%), stroke (5.6%). Cardiovascular disease is the leading cause of death for endstage renal disease(ESRD) patients.Increased arterial stiffness associated with arterial calcification is found inpatients with ESRD and is associated with increased cardiovascular mortality in thesepatients. Aortic pulse wave velocity(PWV), a standard method to measure arterialstiffness, has been reported to be a strong independent predictor of overall andcardiovascular mortality in patients with ESRD. A close correlation between PWVand the extent of coronary artery, aortic and valvular calcificati ons has been observed.In fact, patients with a reduced glomerular filtration rate (GFR) are more likely to dieof cardiovascular disease than they are to develop ESRD. Several, but not all,previous studies suggested that mild-to-moderate elevations in serum creati-ninelevels are associated with increased rates of death from any cause and fromcardiovascular causes. It is important to note that many patients with chronic renalinsufficiency (CRI) die before ever reaching ESRD. However, to our knowledge, littleis known about cardiovascular changes in adult CKD patients without dialysis.Ultrasound technology can detect and visualize the structure and functionchanges of the cardiovascular. Modern high-resolution ultrasound scanners candemonstrate that the inner layers of the arterial wall exhibit considerable movementsin the longitudinal direction and show extent of atherosclerotic plaque. Echotrackingsystems provide optimal conditions for a precise determination of local arterialstiffness, which is directly determined and requires no assumption from models of thecirculation. ET can assess arterial flexibility by determining systolic arterial diameterdialation combied with blood pressure, thus quantitative of arteries stiffness at eartlystag. ET provide local vascular stiffness parameters as well as the segmental vascularstiffness parameters, resulting in an overall assessmet of the changes in vascularstructure and function.The purpose of this study is to evaluate arterial and left ventrical structure and function changes in different stages of chronic kidney diseas by ultrasonography,while explore the related factors of the alterations of the arterial stiffness and leftventricule, which may provide some information for the clinicians so that moreappropriate and sufficient clinica interventions can be applied to CKD patients. Thisstudy is divided into two parts:Part1. Evaluation of Arterial Alterations And Associated Factors OfChronic Kidney Disease by ultrasonographyThe aim of part1was to evaluate the structural and elastic changes of thearteries, as well as the factors related with arterial stiffness patients with chronickidney disease(CKD) predialysisas by echo-tracking technique. Thirty-nine CKDpatients predialysis enrolled the study and were subdivided into CKD stage2-3group(n=19) and stage4-5group (n=20). Forty healthy subjects were selected as the controlgroup. The carotid and femoral arteries were assessed by high resolution ultrasound.The parameters of arterial structural and stiffness measured by echo-trackingtechnique were compared among groups: Intima-media thickness(IMT), stiffnessparameter(β)， pressure strain elastic modulus(Ep)， arteria1compliance(AC)，augmentation index(AI), carotid pulse wave velocity(PWVβ), carotid-femoralpulse-wave velocity(PWVcf), carotid diameter(D). Stepwise multiple linearregression analysis the associated factors of arterial stiffness.RESULTS①The SBP、PP were significantly higher in the stage CKD4-5group than those inthe other groups. Compared with the control group, Serum creatinine, Serumphosphorus, Serum triglycerides were significantly increased and the level ofestimated creatinine clearance(eGFR), Serum calcium, Hemoglobin of CKD2-3andCKD4-5group were significantly decreased. Compare with CKD2-3group, Serum creatinine, Serum phosphorus were significanty increased of CKD4-5group, andeGFR, Serum calcium, Hemoglobin were significantly decreased.②Compared with control group, PWVcf and D in stage2-3group weresignificantly increase (P<0.05，P<0.001), while PWVβ significantly increase instage4-5（P<0.05）; compared with CKD2-3group, PWVcf and D were significantlyincrease in stage4-5(P<0.05，P<0.001).③Correlation analysis showed that the diameter of left common carotid wascorrelated with age, pulse pressure, eGFR（r=0.478，P=0.002；r=0.419，P=0.008;r=-0.623，P=0.000） and PWVcf was correlated with age, pulse pressure, eGFR（r=0.436,P=0.023；r=0.415，P=0.032; r=-0.526，P=0.005）.Stepwise multipleregression analysis demonstrated that age, estimated glomerular filtration rate (eGFR)per1.73m2were independent impact factors of PWVcf．Part2. Evaluation of Left Ventricular Alterations in Patients withChronic Kidney DiseaseThe aim of part2was to evaluate the structural and functional changes of the leftventricular in patient with chronic kidney disease(CKD), and to investigate the riskfactos related to changes of left ventricle. Aterial stiffness parameters were measuredwith echo-tracking technology. According to the ASE guidelines, LV mass(LVM), LVmass index(LVMI), relaive wall thickness(RWT), as well as the LV systolic anddiastolic function was measured. These indexes were compared between CKD2-3group, CKD4-5group and the control group. Correlation analysis were carried out toevaluate the risk fators correlated to the RWT and E/e’.RESULTS①LV structures and function changes: Compare with control group, LVM, RWT,LAD were significantly increased of CKD2-3group, and LVID, LVMI, E, E/Em, DTE were increased of CKD4-5group. Compare with CKD2-3group, andLVM,,LAD, LVID, LVMI, E, E/Em, DTE of CKD4-5were increased significantly.DTE in CKD group was significantly decreased. Among the patients of CKD4-5group,85%(n=17) had alteration of left ventricular configuration,45%（n=9）had LVconcentric hypertrophy,10%(n=2) had LV eccentric hypertrophy,30%(n=6) had LVconcentric remodeling; while among CKD2-3group,26.3%(n=5) had LV remodeling,15.8%(n=3) had LV concentric hypertrophy,10%(n=2) had LV concentricremodeling.②Univariable correlation analysis showed that RWT was correlated to SBP, PP,E/Em, D, PWVcf, eGFR(P<0.05-0.01). After controlling age, heart rate, SBP, PP, thecorrelation between RWT and eGFR, PWVcf, E/Em remained significant in partialcorrelation analysis(P<0.05-0.01,r’=-0.477、0.397、0.338). Multivariable analysisshowed that eGFR, PWVcf were factors independently correlated with RWT.③Univariable correlation analysis showed that E/Em was correlated to PP, RWT,D, PWVcf, eGFR(P<0.05-0.01). After controlling age, heart rate, SBP, PP, thecorrelation between E/Em and eGFR, RWT, PWVcf remained significant in partialcorrelation analysis(P<0.05, r’=-0.477、0.397、0.338). Multivariable analysis showedthat PWVcf were factors independently correlated with E/Em.CONCLUSIONS①Patients in CKD4-5group had higher SBP and PP, abnormal lipidmetabolism, calcium and phosphorus metabolism and anemia performance in mild tomorderate CKD, and mor pronounced in patients with severe CKD.②The carotid artery had increases diameter in patients with mild tomoderate CKD and more pronounced in severe CKD, while IMT has no significantchange. The carotid artery was distensively reconstructed. PWVcf increased at earlystage of CKD, and was a sensitive indicator of arterial stiffness. ③The increase carotid diameter and aortic stiffness of the CKD patients wascorrelated with age, blood pressre, and eGFR, with age, eGFR as independentcorrelated factors.④LV remodeling was performance in mild-morderate CKD patients, andpronounced in severe CKD patients, with LV hyperthophy.⑤The LV systolic function was reserved, while the diastolic function wasdecreased in mild-morderate CKD patients CKD. LV remodeling and diastolicdesfunction in CKD patients were closely related to arterial stiffness and eGFR.