Prevalence of Ventricular Systolic Cardiac Dysfunction Among Paediatric Patients With Chronic Kidney Disease at Kenyatta National Hospital - a Hospital Based Cross-sectional Study

Abstract

Study Background: Chronic Kidney Disease is currently coming to light as a global issue, and with heightened awareness about kidney diseases there is a greater detection of children living with CKD. The risk of developing cardiovascular complications is increased due to the early onset of the disease and longevity of the children. Prevalence of cardiovascular complications in these children with CKD is reported to be low, <3% in Africa. Cardiovascular disease, if not detected and treated early, correlates with worsening morbidity and poor life quality. Increased mortality has also been noted in these children. Primary objective: To determine the prevalence of ventricular systolic cardiac dysfunction in paediatric patients with Chronic Kidney Disease aged 3 months to 18 years at Kenyatta National Hospital. Study design and site: Hospital based cross-sectional study. Participants and Methods: The study population comprised of 49 children recruited from the Kenyatta National Hospital peadiatric and adult renal units, renal clinics and wards. The Inclusion criteria was any child aged 3months-18 years with chronic kidney disease as per the NFK/KDIGO criteria and whose consent and assent (where applicable) was obtained. The exclusion criterion was any child with cardiac disease that was diagnosed prior to the chronic kidney disease diagnosis. Sampling was by consecutive recruitment and once screened and enrolled, data was collected using a structured questionnaire. The blood pressure and anthropometric measurements were then taken and Basal surface area calculated. Transthoracic Echocardiogram and Electrocardiogram was then done for each patient. The outcomes of interest on echocardiogram were left ventricular hypertrophy defined as LVMI> the 95th percentile for age, gender and BSA. Ventricular systolic dysfunction defined as left ventricular systolic dysfunction measured by ejection fraction<54% and fractional shortening <28%.; right ventricular systolic dysfunction measured by Tricuspid annular plane systolic excursion (TAPSE)<1.6cm adjusted for age gender and BSA, Fractional area change (%FAC) < 35%. All measurements taken were adjusted for age gender and BSA using the Bostons’ childrens hospital Z score charts. Outcome of interest on electrocardiogram were Corrected QT interval >0.44sec, Left Ventricular Hypertrophy (sV1+rV6/V5)>35mm, QRS duration <3yrs > 70ms, 3-8 yrs> 80ms, 8-12 yrs> 90ms, >12 yrs> 100ms. xiv Data Management and Analysis: Data collected was entered into a case record from. Analysis was done using STATA version 15. Descriptive characteristics will be analysed and summarized into tables and charts. Statistical associations and amount of risk between a patient’s time of diagnosis, hypertensive state and renal replacement therapy and developing ventricular systolic dysfunction was analysed using the chi-square test and binary logistic regression. Results: 49 children with chronic kidney disease were enrolled into the study, with 28 male and 21 female with a male to female ratio of 1.3:1. The age ranged from 7-216 months, with a median age of 132 months (IQR 72,192). Majority of the children were aged between 12-18 years (40.82%). Many of the children 35(74.4%) had a duration of illness of <3years. Most of the children were on hypertensive treatment 39(81.3%) while 36(73.47) were found to be hypertensive. A total of 16(32.7%) were on renal replacement therapy, with 12(75%) of these being on hemodialysis. The Prevalence of Ventricular Systolic Cardiac Dysfunction on ECHO and or ECG was 44 (89.8% (95%CI 77.1,95.8)) with 42% (87.71%) being diagnosed on ECHO. Left Ventricular hypertrophy was found in 38(77.5%) of the children. Conclusion: Cardiac dysfunction was highly prevalent in children with CKD. Left ventricular hypertrophy was found to be high (78% (95%CI,63.3,87.4)) in our patients. Right Ventricular systolic dysfunction was higher in our patients with CKD than left ventricular systolic dysfunction. Most of the patients studied were found to be hypertensive (73.5%) despite being on blood pressure medication (81%)