Correlation between Left Atrial Diameter and Renal Outcomes in Chronic Kidney Disease Patients

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1 Acta Nephrologica 27(1): 23-30, DOI: /AN Original Article Correlation between Left Atrial Diameter and Renal Outcomes in Chronic Kidney Disease Patients Tsung-Kun Yang 1, Szu-Chia Chen 1, 2, Jer-Chia Tsai 1, 3, Shang-Jyh Hwang 1, 3, Jer-Ming Chang 1, 2, 3, and Hung-Chun Chen 1, 3 1 Division of Nephrology, Kaohsiung Medical University Hospital 2 Department of Internal Medicine, Kaohsiung Municipal Hsiao-Kang Hospital 3 Faculty of Renal Care, College of Medicine, Kaohsiung Medical University Kaohsiung, Taiwan, Republic of China Abstract BACKGROUND: An enlarged left atrium is frequently noted in chronic kidney disease (CKD) patients, and left atrial enlargement has been documented to be an independent predictor of adverse cardiovascular outcomes in CKD patients. However, little is known about the relation between left atrial diameter (LAD) and renal outcomes in this kind of patient. We assessed whether LAD was independently associated with renal function progression in patients with CKD stages 3-5. METHODS: This study is a prospective cohort study. We enrolled 398 patients, who were classified into three groups according to the degrees of LAD. The change in renal function was measured by the estimated glomerular filtration rate (egfr) slope. Rapid renal progression was defined as an egfr slope of 3 ml/min/1.73 m 2 /year decrease or more. The renal end point was defined as commencement of dialysis. Multiple forward linear regression analysis was used to identify the factors associated with LAD. The associations between the tertile of LAD and the egfr slope and rapid renal progression and progression to dialysis were assessed by a modified stepwise procedure in 3 modeling steps. RESULTS: Increased LAD was significantly associated with hypertension, obesity, high left ventricular mass index, low left ventricular ejection fraction, and high transmitral E wave velocity to early diastole mitral velocity ratio. Further, the highest tertile of LAD (vs. lowest tertile of LAD) was independently associated with egfr slope (β = , P = 0.005) and rapid renal progression (odds ratio, 2.115; 95% confidence interval, to 4.389; P = 0.044), but not to risks for progression to dialysis after adjustment of demographic, clinical, and biochemical parameters. CONCLUSION: Our findings show increased LAD is independently associated with a faster rate of renal function decline and rapid renal progression, but not with dialysis in CKD patients. Assessment of LAD by echocardiography might be useful to predict the risk of adverse renal outcomes. KEY WORDS: left atrial diameter, chronic kidney disease, estimated glomerular filtration rate slope, renal function progression, dialysis Introduction Chronic kidney disease (CKD) is an increasingly acknowledged worldwide public health problem associated with increased morbidity and mortality (1). Progressive decline in renal function has also been shown to be significantly associated with high cardiovascular morbidity and mortality (2, 3). Therefore, identifying patients with rapid renal function progression for more aggressive treatment interventions is important for disease attenuation and prolonged survival. Corresponding author: Dr. Jer-Ming Chang, Department of Internal Medicine, Kaohsiung Municipal Hsiao-Kang Hospital, (Operated by Kaohsiung Medical University), No. 482, San-Ming Rd., Hsiao-Kang District, Kaohsiung 81267, Taiwan, R.O.C. Tel: ext. 3441, Fax: , jemich@kmu.edu.tw Received: May 16, 2012; Revised: July 31, 2012; Accepted: September 24, 2012.

2 24 Yang, Chen, Tsai, Hwang, Chang and Chen The risk of progression of renal function is contributed by traditional risk factors, such as hypertension, diabetes, dyslipidemia, proteinuria, and non-traditional risk factors including structural and functional abnormalities of the heart (4, 5). Echocardiography is a noninvasive and useful method of assessing abnormal heart structure and function. Heart failure may accelerate renal function progression through various patho-physiological mechanisms, including hemodynamic factors, systemic neurohormonal factors, drug treatment, and anemia (6, 7). Previous studies have discussed various echocardiographic findings of cardiovascular risk monitoring and outcomes, including left ventricular hypertrophy (LVH), left ventricular systolic and diastolic dysfunction, mitral annular calcification and left atrial (LA) enlargement (8-11). LA enlargement, including increased LA volume and LA diameter (LAD), is frequently noted in patients with CKD because of persistent pressure and volume overload (12). Recently, an enlarged left atrium has been considered as a marker of adverse cardiovascular outcomes in CKD patients (9, 13). However, published data related to the effects of LA size on renal outcomes in CKD are limited and inconsistent. One study found LA volume index, calculated by dividing LA volume by body surface area, was an independent risk factor for the period of time before dialysis in patients with CKD stages 4-5 (14), whereas another study suggested only a weak association between LA size and renal outcome in CKD subjects (15). Thus, the status of LA enlargement as an independent risk marker for renal progression remains controversial. Accordingly, in this study, we evaluate the determinants of LAD in patients with CKD stages 3-5. Further, we also assess whether LAD is independently associated with progressive decline in renal function and progression to dialysis in CKD patients. Patients and Study Design Materials and Methods We consecutively enrolled 505 pre-dialysis patients, who were evaluated for heart disease with stages 3 to 5 of CKD by our Outpatient Department of Internal Medicine from January 2007 to May 2010 (16). This study is a prospective cohort study. We classified our patients with kidney damage lasting for more than 3 months into CKD stages 3, 4, and 5 based on their estimated glomerular filtration rate (egfr) levels (ml/min/1.73 m 2 ) of 30 to 59, 15 to 29, and < 15, respectively. Fifty-one patients with fewer than three egfr measurements during the followup period were excluded. In addition, those patients who died (n = 9) or entered dialysis therapy (n = 27) within 3 months after enrollment were also excluded to avoid incomplete observation of changes in renal function. Because atrial fibrillation influences LAD, patients with atrial fibrillation (n = 20) were also excluded. Finally, 398 patients (mean age 66.3 ± 12.1 years, 251 males) were included in this study. The protocol was approved by our Institutional Review Board and all enrolled patients gave written informed consent. Evaluation of Cardiac Structure and Function The echocardiographic examinations were performed by two experienced cardiologists with a VIVID 7 (General Electric Medical Systems, Horten, Norway), and the participants remained in the left decubitus position. The cardiologists were not aware of the patients data. Two-dimensional and twodimensionally guided M-mode images were recorded from the standardized views. The echocardiographic measurements included LAD, left ventricular internal diameter in diastole (LVIDd), left ventricular posterior wall thickness in diastole (LVPWTd), inter-ventricular septal wall thickness in diastole (IVSTd), peak early transmitral filling wave velocity (E), peak late transmitral filling wave velocity (A) and early diastolic mitral velocity (Ea). The protocol specified recording two-dimensional parasternal long- and short-axis LA views with optimal orientation of the cursor beam used to derive additional M-mode recordings. Each patient underwent M-mode measurements of the inferior vena cava in inspiration and expiration and LAD in end systole using the standards of the American Society of Echocardiography (17). Left ventricular systolic function was assessed by left ventricular ejection fraction (LVEF). Left ventricular mass was calculated using the Devereux-modified method, i.e. left ventricular mass = 1.04 [(IVSTd + LVIDd + LVPWTd) 3 LVIDd 3 ] 13.6 g (18). Left ventricular mass index (LVMI) was calculated by dividing left ventricular mass by body surface area. LVH was defined as suggested by the 2007 European Society of Hypertension/European Society of Cardiology guidelines (19). Collection of Demographic, Medical, and Laboratory Data Demographic and medical data including age, gender, smoking history (ever versus never), and comorbid conditions were obtained from medical records or interviews with patients. Coronary artery disease was defined as a history of angina, ischemic electrocardiogram change, old myocardial infarction, or having undergone coronary bypass surgery or angioplasty. The body mass index (BMI) was calculated

3 LAD with Renal Outcomes in CKD 25 Table 1. Clinical characteristics of patients by tertile of left atrial diameter (LAD) Characteristics All Tertile 1 Tertile 2 Tertile 3 (n = 398) (n = 136) (n = 138) (n = 124) egfr slope (ml/min/1.73 m 2 /year) ± ± ± ± 0.29* Age (years) 66.3 ± ± ± ± 12.4 Male gender (%) Smoking history (%) Diabetes mellitus (%) * Hypertension (%) * 91.9* Coronary artery disease (%) Stage of CKD Stage 3 (%) * Stage 4 (%) Stage 5 (%) Mean arterial pressure (mmhg) 99.4 ± ± ± ± 14.2 Pulse pressure (mmhg) 61.7 ± ± ± ± 18.9* Body mass index (kg/m 2 ) 25.4 ± ± ± 3.3* 27.2 ± 4.1* Laboratory parameters Albumin (g/dl) 4.06 ± ± ± ± 0.39* Fasting glucose (mg/dl) ± ± ± ± 58.0 Triglyceride (mg/dl) 140 (97-201) ( ) 137 ( ) 156 ( ) Total cholesterol (mg/dl) ± ± ± ± 49.6 Hemoglobin (g/dl) 11.7 ± ± ± ± 2.3 Baseline egfr (ml/min/1.73 m 2 ) 27.1 ± ± ± ± 14.0* Calcium-phosphorous product (mg 2 /dl 2 ) 38.2 ± ± ± ± 8.6 Uric acid (mg/dl) 8.1 ± ± ± ± 2.0 Proteinuria (%) Echocardiographic data LAD (cm) 3.73 ± ± ± 0.17* 4.46 ± 0.30* LVMI (g/m 2 ) ± ± ± 48.3* ± 48.5* LVH (%) * 83.9* LVEF (%) 68.9 ± ± ± ± 12.2 E/A < 1 (%) E/Ea 10.2 ± ± ± ± 5.5 Abbreviations: egfr, estimated glomerular filtration rate; CKD, chronic kidney disease; LAD, left atrial diameter; LVMI, left ventricular mass index; LVH, left ventricular hypertrophy; LVEF, left ventricular ejection fraction; E, peak early transmitral filling wave velocity; A, peak late transmitral filling wave velocity; Ea, early diastolic velocity of lateral mitral annulus. *P < 0.05 compared with tertile 1; P < 0.05 compared with tertile 2. as the ratio of weight in kilograms divided by the square of height in meters. Laboratory data were measured from fasting blood samples using an autoanalyzer (Roche Diagnostics GmbH, D Mannheim COBAS Integra 400). Serum creatinine was measured by the compensated Jaffé (kinetic alkaline picrate) method in a Roche/Integra 400 Analyzer (Roche Diagnostics, Mannheim, Germany) using a calibrator traceable to isotope-dilution mass spectrometry (20). The value of egfr was calculated using the 4-variable equation in the Modification of Diet in Renal Disease (MDRD) study (21). Proteinuria was examined by dipsticks (Hema-Combistix, Bayer Diagnostics). A test result of 1+ or more was defined as positive. Blood and urine samples were collected within 3 months of the echocardiographic examination. Assessment of Rate of Renal Function Decline and Definition of Rapid Renal Progression The rate of renal function decline was assessed by the egfr slope, defined as the regression coefficient between egfr and time in unit of ml/min/ 1.73 m 2 /year. At least three egfr measurements after echocardiographic examination were required to estimate the egfr slope. Any reduction greater

4 26 Yang, Chen, Tsai, Hwang, Chang and Chen than 3 ml/min/1.73 m 2 /year, i.e. slope more negative than -3 ml/min/1.73 m 2 /year (< -3), was considered to be rapid renal progression (3). Definition of Renal End Point The renal end point was defined as commencement of dialysis. In patients reaching renal end point, renal function data were censored at the start of renal replacement therapy. The other patients were followed until February The commencement of dialysis was determined according to the National Health Insurance regulations for dialysis therapy based on laboratory data, nutrition status, and uremic symptoms and signs. Statistical Analysis Statistical analysis was performed using SPSS version 15.0 (SPSS Inc., Chicago, IL, USA) for windows. Data are expressed as percentages, means ± standard deviation, means ± standard error of mean for egfr slope, or median (25 th -75 th percentile) for triglyceride and the number of serum creatinine measurements. The study patients were stratified into three groups according to the tertiles of LAD. The cutoff values of the tertiles of LAD were 3.4, > 3.4 to 4, and > 4 cm, respectively. Tertile 1 was taken as a reference category. Multiple comparisons among the study groups were performed by one-way analysis of variance (ANOVA) followed by a post hoc test adjusted with a Bonferroni correction. The relationship between two continuous variables was assessed by a bivariate correlation method (Pearson s correlation). Multiple forward linear regression analysis was used to identify the factors associated with LAD. Significant variables in univariate analysis were selected for multivariate analysis. The associations between the tertile of LAD and egfr slope and rapid renal progression and progression to dialysis were assessed by a modified stepwise procedure in three modeling steps. The first model consisted of age and sex. The second model consisted of additional clinical risk factors. The final step added biochemical factors. Time to commencement of dialysis and covariates of risk factors were modeled using the Cox proportional hazards model. A difference was considered significant if the P value was less than Results Characteristics of Study Subjects A total of 398 non-dialyzed CKD patients were included. The mean age was 66.3 ± 12.1 years and Change of egfr (ml/min/1.73 m 2 /year) Tertil 1 Fig. 1. The estimated glomerular filtration rate (egfr) slopes among 4 study groups. The egfr slope was the lowest in the group with the highest tertile of left atrial diameter (LAD) (tertile 3). *P < 0.05 compared with the group with the lowest tertile of LAD (tertile 1); P < 0.05 compared with the group with middle tertile of LAD (tertile 2). there were 251 males and 147 females. The average egfr slope of all patients was ± 0.14 ml/min/ 1.73 m 2 /year. The average number of serum creatinine measurements during the follow-up period was eight times (25 th -75 th percentile: ). The study patients were stratified into three groups according to the tertile of LAD ( 3.4, > 3.4 to 4, > 4 cm). Comparison of clinical characteristics among the study groups is shown in Table 1. There were 136, 138, and 124 patients in the 3 groups, respectively. The egfr slopes were ± 0.21, ± 0.22 and ± 0.29 ml/min/1.73 m 2 /year, respectively. The egfr slope was the lowest in the group with the highest tertile of LAD (P < 0.001). Fig. 1 illustrates the egfr slopes of the three study groups. Determinants of LAD Table 2 shows the determinants of LAD in our study patients. LAD correlated positively with diabetes mellitus (DM), hypertension, coronary artery disease, mean arterial pressure, pulse pressure, BMI, fasting glucose, log triglyceride, calcium-phosphorous product, LVMI, and E/Ea, but negatively with albumin, baseline egfr, and LVEF. Further forward multivariate analysis showed increased LAD was correlated with hypertension (β = 0.112, P = 0.026), high BMI (β = 0.280, P < 0.001), high LVMI (β = 0.360, P < 0.001), low LVEF (β = , P = 0.006), and high E/Ea (β = 0.145, P = 0.007). Determinants of egfr Slope Tertil 2 * + Tertil 3 Faster renal function decline went along with a greater negative value of the slope. Table 3 displays the relation of tertile of LAD to egfr slope with and

5 LAD with Renal Outcomes in CKD 27 Parameter Table 2. Determinants of left atrial diameter in study patients Standardized coefficient β Multivariate (Forward) P value Hypertension Body mass index (per 1 kg/m 2 ) < LVMI (per 1 g/m 2 ) < LVEF (per 1%) E/Ea (per 1) Abbreviations are same as Table 1. Adjusted for diabetes mellitus, hypertension, coronary artery disease, mean arterial pressure, pulse pressure, body mass index, albumin, fasting glucose, log triglyceride, baseline egfr, calcium-phosphorous product, LVMI, LVEF and E/Ea. Table 3. Relation of tertile of LAD to egfr slope LAD Unadjusted Age and sex adjusted Multivariate Multivariate adjusted (1) adjusted (2) Standardized P value Standardized P value Standardized P value Standardized P value coefficient β coefficient β coefficient β coefficient β Tertile Tertile Tertile < < Multivariate model (1): adjusted for age, sex, diabetes mellitus, hypertension and coronary artery disease. Multivariate model (2): model (1) + mean arterial pressure, pulse pressure, albumin, log triglyceride, total cholesterol, hemoglobin, baseline egfr, calcium-phosphorous product, uric acid and proteinuria. without adjustment for demographic, clinical, and biochemical parameters. The group with the highest tertile of LAD (versus the lowest tertile of LAD) was associated with egfr slope in the age-and sexadjusted model (β = , P < 0.001) and in the multivariable model adjusting for age, sex, DM, hypertension, and coronary artery disease (β = , P = 0.002). This relation remained significant after further adjusting for mean arterial pressure, pulse pressure, albumin, log triglyceride, total cholesterol, hemoglobin, baseline egfr, calcium-phosphorous product, uric acid, and proteinuria (β = , P = 0.005). We further performed egfr slope analysis using the cutoff value of 4 cm of LAD, and found similar results, i.e., LAD > 4 cm (β, ; P = versus LAD 4 cm) was independently and negatively associated with egfr slope after fully adjusting for age, sex, DM, hypertension, coronary artery disease, mean arterial pressure, pulse pressure, albumin, log triglyceride, total cholesterol, hemoglobin, baseline egfr, calcium-phosphorous product, uric acid, and proteinuria. Risk of Rapid Renal Progression The odds ratios (OR) of the tertile of LAD for rapid renal progression are shown in Table 4. The group with the highest tertile of LAD (versus the lowest tertile of LAD) was associated with rapid renal progression in the multivariable model after adjusting for age and sex (OR, 2.794; 95% confidence interval [CI], to 5.072; P = 0.001) and in the multivariable model after adjusting for age, sex and clinical factors (OR, 2.296; 95% CI, to 4.264; P = 0.009). The relation was still significant after further adjusting for biochemical factors (OR, 2.115; 95% CI, to 4.389; P = 0.044). We further performed egfr slope analysis using the cutoff value of 4 cm of LAD, and found LAD > 4 cm (versus LAD < 4 cm) was associated with rapid renal progression in the multivariable model after adjusting for age, sex and clinical factors (OR, 2.060; 95% CI, to 3.403; P = 0.005), and there was a trend after the full multivariate analysis (OR, 1.809; 95% CI, to 3.275; P = 0.050). Risk of Progression to Dialysis The mean follow-up period was 27.3 ± 11.1 months. During the period of follow-up, seventyfour patients (18.6%) began hemodialysis. The Cox proportional hazards regression analysis of the tertile of LAD for progression to dialysis is shown in

6 28 Yang, Chen, Tsai, Hwang, Chang and Chen Table 4. Relation of tertile of LAD to rapid renal progression (egfr slope < -3 ml/min/1.73 m 2 ) LAD Unadjusted Age and sex adjusted Multivariate Multivariate adjusted (1) adjusted (2) OR (95% CI) P value OR (95% CI) P value OR (95% CI) P value OR (95% CI) P value Tertile Tertile ( ) ( ) ( ) ( ) Tertile ( ) ( ) ( ) ( ) Values expressed as odds ratio (OR) and 95% confidence interval (CI). Multivariate model (1): adjusted for age, sex, diabetes mellitus, hypertension and coronary artery disease. Multivariate model (2): model (1) + mean arterial pressure, pulse pressure, albumin, log triglyceride, total cholesterol, hemoglobin, baseline egfr, calcium-phosphorous product, uric acid and proteinuria. Table 5. Relation of tertile of LAD to progression to dialysis LAD Unadjusted Age and sex adjusted Multivariate Multivariate adjusted (1) adjusted (2) HR (95% CI) P value HR (95% CI) P value HR (95% CI) P value HR (95% CI) P value Tertile Tertile ( ) ( ) ( ) ( ) Tertile < ( ) ( ) ( ) ( ) Values expressed as hazard ratio (HR) and 95% confidence interval (CI). Multivariate model (1): adjusted for age, sex, diabetes mellitus, hypertension and coronary artery disease. Multivariate model (2): model (1) + mean arterial pressure, pulse pressure, albumin, log triglyceride, total cholesterol, hemoglobin, baseline egfr, calcium-phosphorous product, uric acid and proteinuria. Table 5. The group with the highest tertile of LAD (versus the lowest tertile of LAD) was associated with progression to dialysis in the multivariable model after adjusting for age and sex (hazard ratio [HR], 2.906; 95% CI, to 5.221; P < 0.001) and in the multivariable model after adjusting for age, sex and clinical factors (HR, 2.362; 95% CI, to 4.294; P = 0.005), but the association disappeared after the multivariate analysis (HR, 1.025; 95% CI, to 1.967; P = 0.941). We further performed egfr slope analysis using the cutoff value of 4 cm of LAD, and found LAD > 4 cm (versus LAD 4 cm) was associated with progression to dialysis in the multivariable model after adjusting for age, sex and clinical factors (HR, 2.374; 95% CI, to 3.788; P < 0.001), but the association disappeared after the full multivariate analysis (HR, 1.276; 95% CI, to 2.120; P = 0.348). Discussion In the present study, we evaluated the determinants for LAD and the association between LAD and renal outcomes in patients with CKD stages 3-5. We found high LVMI, low LVEF and high E/Ea ratio were independently associated with increased LAD. In addition, compared with the group with the lowest tertile of LAD, the group with the highest tertile of LAD was independently associated with egfr slope, rapid renal progression, but not progression to dialysis. LA enlargement, including increased LA volume and LAD, is a potent predictor of adverse clinical events such as stroke, congestive heart failure, atrial fibrillation, and cardiovascular death in various pathologic conditions (9, 13, 22, 23). LA acts as a volume sensor in the heart and its dilatation reflects a sustained elevation in left ventricular filling pressure and LA size, which is directly proportional to the left ventricular filling pressure (24, 25). Moreover, LA enlargement is closely related to LVH (25). Our study also revealed increased LAD was correlated with high LVMI, low LVEF and high E/Ea ratios. This finding is consistent with previous reports. The mechanisms of progressive renal function decline in patients with cardiac abnormalities are

7 LAD with Renal Outcomes in CKD 29 multi-factorial, including chronic renal hypoperfusion, malnutrition, subclinical inflammation, endothelial dysfunction, accelerated atherosclerosis, increased renal vascular resistance, systemic neuro-hormonal factors, pharmacotherapies, and anemia (6, 7). Previous studies have reported an association between renal function decline and echocardiographic findings. Levin et al. (26) found the incidence of LVH increased with a progressive decline in renal function. Liu et al. (27) revealed left ventricular systolic function decrease was associated with worsening renal function in CKD patients. Kim et al. (28) demonstrated left ventricular diastolic dysfunction and LA volume index are predictors of rapid decline of residual renal function in patients with peritoneal dialysis. Shlipak et al. (3) defined a rapid decline in estimated GFR as > 3 ml/ min per 1.73 m 2 /year, and found declining kidney function is associated with higher risk of heart failure, myocardial infarction, and peripheral artery disease among patients with CKD. Therefore, we chose the decreasing egfr > 3 ml/min/year as a cut-off point of rapid progression of CKD in our study, and found increased LAD was also independently associated with faster rates of renal function decline and rapid renal progression. This implies patients with an increased LAD might have a high volume status and left ventricular filling pressure; thereby, it might increase renal efferent pressure and decrease renal blood flow and finally cause a faster renal function decline (6). In our study, compared with the group with the lowest tertile of LAD, the group with the highest tertile of LAD showed a increased risk for renal morbidity, such as higher prevalence of DM, higher prevalence of hypertension, advanced CKD stages, higher pulse pressure, lower albumin, and lower baseline egfr. Even after adjusting for these confounding factors, the group with the highest tertile of LAD was still associated with faster renal function decline and rapid renal progression. Furukawa et al. (14) evaluated the power of LA volume index in progression to hemodialysis in 140 patients with CKD stages 4-5. They found LA volume index was an independent risk factor for the period of time before dialysis. However, our study demonstrated, compared with the group with the lowest tertile of LAD, the group with the highest tertile of LAD did not show increased risk for end-stage renal disease. The follow-up period was relatively short in our study. The average follow-up time was around 2.3 years. Moreover, 73.1% of our study subjects were stage 3-4 CKD patients who might have needed more time to progress to dialysis. This relatively insufficient follow-up period might explain the lack of significant association between the group with the highest tertile of LAD and progression to dialysis in our study. There were limitations to our study. LAD may not accurately reflect the true LA chamber in most patients. LA volume may be more precise, but LAD is a valid surrogate of LA size. LAD is more easily obtained than LA volume and measurement of LAD has already been the part of a routine echocardiographic evaluation. Some large population-based cohort studies, such as Strong Heart Study (23) and the Losartan Intervention For End point (29), have used LAD as a surrogate of LA size. In addition, since our subjects were already being evaluated for heart disease, this study is susceptible to selection bias, potentially making findings less generalizable. In conclusion, our study demonstrated hypertension, obesity, LVH, and left ventricular systolic and diastolic dysfunction were independently associated with LAD. Moreover, increased LAD was independently associated with faster renal function decline and rapid renal progression, but not progression to dialysis. Assessment of LAD by echocardiography might be useful to identify high-risk groups for renal function progression in patients with CKD. Disclosure There is no conflict of interest in the information contained in the manuscript. References 1. Johnson CA, Levey AS, Coresh J, Levin A, Lau J, Eknoyan G. Clinical practice guidelines for chronic kidney disease in adults: Part i. Definition, disease stages, evaluation, treatment, and risk factors. 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