Factors Associated with Echocardiographic Abnormalities in Patients with Chronic Kidney Disease in a Tertiary Hospital in Ivory Coast

Background: Cardiovascular risk factors (CVRF) are very frequent in patients with chronic kidney disease (CKD) and impose a new environment to which the heart must adapt. Cardiac ultrasound is a non-invasive and easyto-perform examination that allows quantitative and qualitative assessment of the anatomy and function of the heart. The objectives of this study were to describe abnormalities observed on trans-thoracic Doppler-echocar-diography and to investigate the factors associated with them. Materials and Method: This was a monocentric retrospective cross-sectional study conducted in CKD patients hospitalized in a hospital center in Côte d'Ivoire from January 2017 to December 2018. Results: One hundred and four cases were collected with a mean age of 48.87 ± 14.47 years and a sex ratio of 1.7. Patients with end-stage-renal-disease (ESRD) represented 83.7% with 55.8% of cases of chronic glomerulonephritis. Cardiovascular risk factors were 100% anemia, 84.6% inflammatory profile, 77.9% hypertension, 76.9% hypocalcemia and in 67.3% oedema. Cardiac abnormalities were observed in 78.8% of patients. Left ventricular hypertrophy (LVH), accounting for 20.2% of cases, was associated with male gender (OR 0.127 CI 0.025 0.643; p = 0.013) and hypertensive nephropathy (OR 0.189 CI 0.056 0.637; p = 0.007). History of hypertension (OR 0.297 CI 0.084 1.050; p = 0.060) and diabetes (OR 5.315 CI 1.260 22.419; p = 0.023), hypertensive nephropathy (OR 0.174 CI 0.052 0.585; p = 0.005) and hypocalcemia (OR 6.094 CI 1.723 21.559; p = 0.005) are incriminated in the development of left ventricular dilatation (LVD) which accounted for 38.5% of cases. Conclusion: Left ventricular hypertrophy and dilatation are the main echocardiographic abnormalities observed in our population. How to cite this paper: Tia, W.M., Togo, A., Wognin, M.A., Koffi, R.M., Kpan, J., Ouattara, B. and Gnionsahe, D.A. (2022) Factors Associated with Echocardiographic Abnormalities in Patients with Chronic Kidney Disease in a Tertiary Hospital in Ivory Coast. Open Journal of Nephrology, 12, 3647. https://doi.org/10.4236/ojneph.2022.121004 Received: January 3, 2022 Accepted: February 8, 2022 Published: February 11, 2022 Copyright © 2022 by author(s) and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY 4.0). http://creativecommons.org/licenses/by/4.0/ Open Access


Introduction
Chronic kidney disease remains a public health challenge because of its increasing frequency, its fatal cardiovascular consequences and its very costly management for public authorities. A subject suffering from CKD has a mortality risk multiplied by 20 to 30 compared to the general population of identical age [1]. One out of two deaths is related to the occurrence of cardiovascular complications [2]. The spectrum of cardiovascular diseases observed in CKD includes ischemic heart disease, congestive heart failure and cardiac arrhythmias. The prevalence of these complications is 69.8% and the risk of cardiovascular events increases exponentially with decreasing glomerular filtration rate (GFR) [3]. There are several ways to assess cardiovascular complications, including transthoracic cardiac ultrasound. It is a non-invasive examination with a reliable degree of accuracy, routinely used to explore the heart chambers. Left ventricular hypertrophy (LVH), found in 60% -80% of patients with CKD, is the most common morphological abnormality [4]. Dilated cardiomyopathy and calcifying valvulopathy may also be found [5]. Most of the patients in sub-Saharan Africa die because of lack of treatment for both CKD and the associated cardiovascular abnormalities [6]. There is paucity of local studies on cadiovascular abnormalities in patients with CKD in Cote d'Ivoire. Therefore, we initiated this work in order to evaluate the prevalence of echocardiographic abnormalities in patients with chronic renal failure not yet treated by hemodialysis and to identify the associated factors.

Patients and Methods
The study took place in the hospitalization unit of the Hemodialysis Nephrology Department of the University Teaching Hospital (CHU) of Yopougon in Abidjan in the Republic of Ivory Coast (RCI). It was a retrospective observational survey that was conducted over a period of two (2) years from January 1, 2017 to December 31, 2018. Were included patients aged more than 15 years, both sex, with established chronic kidney disease who have not received any form of renal replacement therapy, and who had a resting trans-thoracic echocardiography performed during their hospitalization. We excluded people less than 15 yars old or with acute kidney injury and patients with a history of cardiac disease followed by a cardiologist. From the hospitalization medical records, we collected on an individual survey form, socio-demographic parameters (age, sex, occupation, and educational level), clinical data (initial kidney disease, GFR, cardiovascular risk factors, and physical examination data), biological data (hemoglobin level, C-reactive protein (CRP), blood calcium, phosphorus, and creatinine levels), and echocardiographic data (functional abnormalities (hypokinesia, hyperkinesia), morphological abnormalities (hypertrophy, dilatation, pericardial detachment or effusion), and left ventricular systolic ejection fraction). We adopted the following operational definitions: -Glomerular filtration rate (GFR) was estimated using the simplified MDRD formula.
-Hypertensive nephropathy was the combination of past history of hypertension, moderate proteinuria 1 -2 g/24h, LVH on electrocardiogram and on echocardiography, hypertensive retinopathy and CKD.
-Chronic tubulointerstitial nephropathy (CTIN) was defined by the absence of hypertension, edema and hematuria, the presence of leukocyturia>10,000/ml without germs, and a history of urological disease.
-Fluid retention was characterized by the presence of limb edema, facial puffiness or ascites.
-HBP was defined as systolic blood pressure higher than or equal to 140 mmHg and/or diastolic blood pressure higher than and/or equal to 90 mmHg or regular use of antihypertensive drugs.
-Pericarditis was the presence of pericardial friction on physical examination, fluid effusion or pericardial detachment on cardiac ultrasound.
-Systolic dysfunction when the left ventricular ejection fraction was less than 50%; it was said to be severe if less than 30%.
-Left ventricular dilation was left ventricular telediastolic diameter indexed to body surface area > 31 mm/m 2 in men, > 32 mm/m 2 in women.
-Diastolic dysfunction was defined by a left ventricular ejection fraction ≤ 50% associated with mitral flow ≥ 2 and an A-wave deceleration time < 150 ms.
-Left ventricular hypertrophy (LVH) was reflected by left ventricular mass ≥ 110 g/m 2 in women and ≥135 g/m 2 in men.
-Hyperphosphoremia in case of phosphorus levels above 68 mg/l.
-Inflammatory profile when CRP was above 20 mg/l.
-Anemia if the hemoglobin (Hb) level was below 12 g/dl; anemia was said to W. M. Tia et al. be severe if the Hb level was below 6 g/dl.
Data analysis was performed using Stata16 software. First, we performed a descriptive analysis. Quantitative variables were described as average when their distribution was normal or otherwise as median. In bivariate analysis, the dependent variables were left ventricular dilatation and left ventricular hypertrophy, and the proportions of the qualitative variables were compared among patients with or without one of the above-mentioned echocardiographic abnormalities by a chi-square test or Fisher's exact test when the numbers were less than 5. For quantitative variables, averages and medians were compared by a STUDENT test, and relative quantitative variables were transformed into categorical variables according to pathological standards. The threshold of p < 0.05 was considered significant.  were associated with the occurrence of LVH (Table 5)

Discussion
Declining GFR is accompanied by an exponential increase in cardiovascular risk.
We conducted this study to evaluate echocardiographic abnormalities in a population of chronic renal failure patients from black Africa. In our study, the age group 36 -54 years represented 47.1% of the population and the average age was   [8]. The predominance of chronic renal failure in relatively young males can be explained in part by the role of environmental factors, notably smoking, alcoholism and occupational exposure, in the occurrence and progression of renal pathologies [9]. The frequency of chronic end-stage renal disease (GFR < 15 ml/mn/1.73m 2 ) in our series was 83.7%. It was reported 51.2% in Uganda [10]. The causes of chronic renal failure were dominated by chronic glomerulonephritis (55.8%) and hypertensive nephropathy (39.1%) In Nepal, hypertensive (35%) and diabetic (31%) nephropathy were the main causes of chronic failure followed by chronic glomerulonephritis (14%) [7]. CKD due to the progression of hypertensive disease, is more frequent in black subjects than in Caucasians. There is a genetic predisposition of the black race to develop CKD more rapidly. The association of HBP and CKD is very frequent and most chronic kidney diseases are complicated by hypertension at the terminal stage [11]. In addition to the socalled classical risk factors (sedentary lifestyle, dyslipidemia, arterial hypertension, diabetes, chronic alcoholism, chronic smoking and obesity) that patients with CKD share with the general population, they have risk factors that are spe-cific to them such as anemia, chronic inflammatory profile, fluids retention, arteriovenous fistula and phosphocalcic disorders [12]. In our series, we reported arterial hypertension (77.9%), smoking (26%), diabetes (20.2%) and drug abuse (1%). Indeed, all kidney diseases can be complicated by hypertension at the terminal stage, probably due to chronic stimulation of the renin-angiotensinaldosterone system [10]. During CKD, the left ventricle undergoes structural and functional changes secondary to pressure and volume overload and cell apoptosis [13]. Out of 104 chronic renal failure patients who performed transthoracic echocardiography, 82 patients (78.8%) had an abnormality. Our data is comparable to those of some authors which reported 74% of abnormalities [7].
Regarding the functional data, in our series we reported 26% of hypokinesia and  [14]. Dilatation permits to increase cardiac output at a comparable level of energy spending, whereas wall thickening redistributes the increased wall tension over a wider area [4]. A history of hypertension and diabetes, hypertensive nephropathy, and hypocalcemia are incriminated in the development of left ventricular dilatation. The analysis of left ventricular systolic function by cardiac ultrasound is done by measuring the percentage of shortening and the left ventricular ejection fraction [18]. The average left ventricular ejection fraction was 57.24% ± 13.47% with extremes of 20 and 87%. Thirty patients, which is 28.8% had an ejection fraction of less than 50%. In Open Journal of Nephrology Uganda, the left ventricular ejection fraction was lower than 50% in 18.9% of patients [10]. This dysfunction is multifactorial including coronary insufficiency, anemia, hyperparathyroidism, uremic toxins, malnutrition and prolonged hemodynamic overload [15].

Conclusion
Our study demonstrates the high frequency of LVH and LVD on trans-thoracic echocardiography of advanced chronic renal failure in an Ivorian hospital. Left ventricular hypertrophy (LVH) was associated with male gender and hypertensive nephropathy. History of hypertension and diabetes, hypertensive nephropathy and hypocalcemia were incriminated in the development of LVH. These left ventricular abnormalities were thus associated with traditional cardiovascular risk factors and severe renal impairment. Echocardiographic evaluation studies should be performed in the early stage of chronic kidney disease for early detection of cardiac abnormalities.