| Uremia is the end-stage of chronic kidney disease (CKD), which increases risk of cardiovascular disease and death. Cardiovascular events are the leading causes of mortality for patients with uremia. Approximately58%of uremia patients died from cardiovascular diseases, commonly sudden cardiac death and heart failure. Cardiac remodeling mainly included changes in heart size, shape and function due to heart damage or increased cardiac load. Left ventricular (LV) hypertrophy is the most common cardiovascular complication indicating poor prognosis in patients with CKD. Left ventricular hypertrophy exists in75%of adult patients with uremia at the beginning of dialysis. Cardiac pathologic changes in uremia include myocardial fibrosis, hypertrophy, and coronary perfusion decrease.Kidney transplantation and dialysis are main therapy of uremia. Compared with dialysis, kidney transplantation reduces mortality, and is considered the standard treatment for uremia. Dzemidzic found out that post-transplantation LV mass regression is related to reduce of the risk factors of uremia. Therefore, evaluation of LV mass changes is critical for assessment of the condition of patients after renal transplantation. However, it is controversial whether there is a regression of LV mass after renal transplantation. Early studies showed improved cardiac function and mitigated LV hypertrophy after renal transplantation. Montanaro found out that LV mass decreased, while Patel found out that there was no significant change in LV mass after renal transplantation. Recently, Vaidya found out that majority of patients had reduced LV mass, while still a few patients express no significant change of LV mass. This study also indicated that LV mass regression was associated with the extent of hypertrophy before the surgery.The survival rates of patients with renal transplant are higher than those with hemodialysis. USRDS data showed that patients with renal transplant had significantly lower mortality compared with those with dialysis. However, the rate of cardiac failure is10times and the annual rate of nonfatal cardiovascular events is50times in patients with renal transplant compared with the general population. Several studies indicate that patients with systolic dysfunction had a greatly increased mortality of cardiovascular events compared with normal systolic function patients after renal transplant. Therefore, it is important to evaluate LV systolic function after renal transplantation.Various techniques have been used for assessment, including magnetic resonance imaging (MRI), radionuclides, angiography, CT, cardiac catheter, and echocardiography. MRI is the gold standard for evaluating the LV structure and function, but it’s expensive and time consuming with certain contraindications, which limit its clinical application. Radionuclides, angiography, and cardiac catheter are invasive. CT is radioactive. Echocardiography is non-invasive, non-radioactive, low-cost, and reproducible. It is the preferred examination for monitoring of cardiac morphology and function, with clear observation of the cardiac structure and convenient evaluation of cardiac function. In this study, we detected the structure and function of left ventricular by using two-dimensional echocardiography and speckle tracking technique to explore the changes in cardiac structure and function of renal transplant patients after operation. This article aimed to reveal the changes in structure and function ofgraft and to provide useful information for the treatment of these patients.This study included three parts as follows:Part1Echocardiographic Assessment of Left Ventricular Remodeling and Systolic Function in Uremia PatientsThe aim of this part was to assess LV remodeling and systolic function in uremia patients by echocardiography. Sixty-seven uremia patients were enrolled in this study and divided into normal EF group and reduced EF group according to left ventricular ejection fraction (EF) value. Left ventricular end-diastolic diameter (LVEDD), interventricular septal wall thickness (SWT), posterior wall thickness (PWT), left ventricular mass (LVM), left ventricular mass index (LVMI) were measured and calculated by two-dimensional echocardiography from the parasternal long-axis view. The global left ventricular circumferential strain (GCS), global radial strain (GRS), global longitudinal strain (GLS) were measured by speckle tracking imaging (STI) from the parastemal short-axis view at the mitral papillary muscle and the apical four-chamber view. Result①Compared with, systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP) and heart rate were significantly increased in uremia patients. Heart rate, SBP were greater in reduced EF group than those in normal EF group (p<0.05).②Compared with the control group, LVEDD, SWT, PWT, LVM, LVMI were increased in uremia patients, which was more significant in reduced EF group than normal EF group(p<0.05).③Compared with controls, GCS, GRS, GLS were decreased in uremia patients, which was more significant in reduced EF group (p<0.05).Part2Echocardiographic Assessment of Left Ventricular Remodeling in Renal Transplant PatientsThe aim of this part is to assess LV remodeling in patients before and after operation by echocardiography, and to explore the factors affecting LV mass. Thirty renal transplant patients were enrolled in this study. Echocardiography was performed before,3months after,6months after, and1year after the renal transplantation. Left ventricular end-diastolic diameter (LVEDD), left ventricular interventricular septal wall thickness (SWT), posterior wall thickness (PWT), left ventricular mass (LVM), and left ventricular mass index (LVMI) were measured and calculated by two-dimensional echocardiography from the parasternal long axis view. LV ejection fraction was calculated by biplane method (modified Simpson’s rule). Result①SBP,DBP, PP were significantly reduced to normal level at3months,6months,1year (p<0.05). EF was increased to normal level at3months,6months,1year (p<0.05).②SWT, PWT, LVEDD, LVM, LVMI were significantly reduced after the surgery(p<0.05).③LVMI was correlated positively with SBP (r=0.734, p=0.000), DBP (r=0.550, p=0.015), PP (r=0.507, p=0.000), serum creatinine (Cr)(r=0.539, p=0.017). LVMI was not correlated with arteriovenous fistula (r=0.071, p=0.774), duration of dialysis and EF before surgery (r=0.008, p=0.975). SBP was the independent predictor of LVMI (β=0.734, p=0.000).Part3Assessment of Left Ventricular Global Systolic Function in Renal Transplant Patients by Speckle Tracking ImagingThe aim of this part is to assess LV systolic function in renal transplant patients before and after operation by STI. Thirty renal transplant patients were enrolled in this study. Echocardiography was performed before,3months after,6months after, and1year after the renal transplantation. The global left ventricular circumferential strain (GCS), global radial strain (GRS), global longitudinal strain (GLS) were measured by speckle tracking imaging (STI) from the parasternal short-axis view at the mitral papillary muscle and the apical four-chamber view. LV ejection fraction was measured by two-dimensional echocardiography. Result①Compared with controls, EF, GCS, GRS, GLS were reduced in patients before surgery (p<0.05), EF was increased to normal level at6months and1year after operation (p<0.05). There was no statistically significant difference of these indexes between before and3months after operation. GCS, GRS, GLS were increased at3months,6months and1year after the surgery, but were still lower than those of control (p<0.05).③GCS, GLS and GRS were negatively correlated with SBP, DBP, PP, Cr, duration of dialysis before surgery, and arteriovenous fistula (AVF).Conclusions1.The left ventricle in uremia patients was reconstructed and LV systolic function was decreased. STI can detect LV systolic dysfunction in uremia patients with preserved left ventricular ejection fraction.2.LV structure, mass and systolic function can be improved after renal transplantation for uremia patients. LV structure, mass and systolic function gradually restored over time after surgery, although they were not completely restored to normal level. Postoperative LVMI was correlated with blood pressure, serum creatinine. SBP was the independent predictor of LVMI. LV systolic function was correlated with blood pressure, serum creatinine, duration of dialysis, and AVF.3.Echocardiography is a useful tool for follow-up evaluation of LV structure and function after renal transplantation. |
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