Evaluation Of Left Ventricular Myocardial Work In Patients Of Chronic Kidney Disease With Renal Hypertension By Two-dimensional Speckle Tracking Imaging

BackgroundChronic kidney disease(CKD)and hypertension both have varying degrees of damage to the shape and function of the heart,which significantly increases the risk of cardiovascular disease.Left ventricular ejection fraction(LVEF)is widely used to evaluate left ventricular systolic function,two-dimensional speckle tracking imaging(2D-STI)is recommended for observing early-stage myocardial damage.The myocardial work method based on 2D-STI can more objectively reflect the left ventricular myocardial function because it has no load dependeny.This study intends to use 2D-STI and its derived myocardial work method to evaluate the intrinsic systolic function and left ventricular myocardial work in patients with simple CKD(without hypertension)and that of renal hypertension,aiming to explore the damage of CKD with renal hypertension to the left ventricular myocardium.MethodsParticipants: patients with CKD diagnosed in the Department of Nephrology of the first affiliated Hospital of Fujian Medical University from March 2020 to January2021 were divided into two groups according to the presence of secondary hypertension: Simple chronic kidney disease group(CKD group,n = 31),18 males and 13 females,with an average age of 44.0±16.2years;And renal hypertension disease group(RHD group,n = 47),29 males and 18 females,with an average age of46.9±15.0years.Patients with hypertension,coronary heart disease and cardiomyopathy were excluded.41 healthy volunteers matched with sex and age were selected as control group(NC group).Echocardiography observation index:(1)Routine index: left ventricular end-diastolic diameter and wall thickness,LVEF(obtained by Simpson method),transmitral diastolic inflow velocities(E 、 A),mitral annuluar lateral and septum velocities in late diastole and its average value,and the ratio was calculated.(2)Two-dimensional strain index: left ventricular systolic peak longitudinal strain(GLS),circumferential strain(GCS)and radial strain(GRS);(3)Myocardial work index of left ventricle: myocardial work index(GWI),myocardial constructive work(GCW),myocardial wasted work(GWW)and myocardial work efficiency(GWE).Results1.Parameters of left ventricular structure and routine cardiac function: compared with NC group,left atrial volume index(LAVI),left ventricular end-diastolic volume(LVEDV),wall thickness and left ventricular mass index(LVMI)increased significantly in RHD group(all P < 0.05),but there was no significant change in CKD group(all P>0.05).In RHD group,LVEF and e’ decreased while E/e’ increased(all P < 0 05),and the above functional indexs did not change significantly in CKD group(all P>0.05).2.Left ventricular global myocardial strain and work: compared with NC group,only left ventricular longitudinal strain(GLS)decreased in CKD group,while GLS and GRS decreased in RHD group,and GLS was lower than that in CKD group(all P< 0.05),but there was no significant change in GCS in both groups(all P > 0.05).In terms of work index,myocardial wasted work(GWW)increased and myocardial work efficiency(GWE)decreased in both CKD group and RHD group,especially in RHD group,but there was no significant change in myocardial work index(GWI)and myocardial constructive work(GCW)(all P > 0.05).3.Correlation analysis:(1)In nephrotic patients,myocardial wasted work(GWW)was negatively correlated with LVEF and GLS(r=-0.37,-0.65,p<0.05),Other myocardial work indexes such as GWI、GCW and GWE were correlated with LVEF(r = 0.43～0.60)and GLS(r = 0.65～0.81)(all P < 0 05);(2)there was a negative correlation between myocardial wasted work(GWW)and glomerular filtration rate(GFR)in patients with nephropathy(r =-0.48),and other myocardial work indexes、LVEF and GLS were all correlated with GFR(r = 0.31～0.53)(all P < 0 05).(3)In patients with nephropathy,SBP and the course of renal hypertension are positively correlated with myocardial wasted work(GWW)(r = 0.52,0.43),and negatively correlated with myocardial work efficiency(GWE)(r =-0.34,-0.42)(all p<0.05).ConclusionsWhen CKD induce secondary hypertension,the severity of left ventricular systolic strain disorder increases,which aggravates the decrease of myocardial work efficiency,and finally leads to cardiac insufficiency.In addition to further deterioration of renal function(such as decreased glomerular filtration rate),this change may also be related to secondary myocardial damage caused by secondary hypertension.