Prevalence of pulmonary hypertension in adult patients with chronic kidney disease at Moi Teaching and Referral Hospital, Eldoret Kenya

Abstract

Background:Pulmonary hypertension is defined as systolic pulmonary artery pressure (SPAP) > 35 mmHg at rest as estimated by Doppler echocardiographywhile Chronic Kidney Disease (CKD) isthe presence of kidney damage or decreased kidney function for three or more months, with eGFR<60mls/min irrespective of the cause. The prevalence of pulmonary hypertension (PHTN) is much higher among patients on hemodialysis in studies done in Non African population and has been associated with a worse outcome. However, theextent of PHTN has not been established in Kenyan patients withCKD on and without hemodialysis. Objective:To determine the prevalence of pulmonary hypertension among CKD patients with and without dialysis and to compare their clinical, hemodynamic and metabolic variablesat the Moi Teaching and Referral Hospital (MTRH). Methods: This cross-sectional hospital based study was conducted among adult patients with Chronic Kidney Disease with or without dialysis in the renal and adult medical wards in MTRH, Eldoret, Kenya.Pulmonary hypertension was defined as systolic pulmonary artery pressure (SPAP) > 35 mmHg at rest as estimated by Doppler echocardiography and CKD as the presence of kidney damage or decreased kidney function for three or more months with eGFR<60mls/min irrespective of the cause.All patients who met the inclusion criteria were enrolled by prospective consecutive sampling. Demography(age, gender), clinical (history and physical examination), transthoracic Doppler echocardiography and laboratory (hemoglobin,hematocrit, BUN, creatinine, potassium, phosphate and calcium levels, albumin, AST and ALT levels, HIV test and RBS) were done. Data were collected using a structured interviewer administered questionnaire, keyed into Microsoft Excel® database and analyzed using STATA version 13 ® . Descriptive statistics were summarized in tables and graphs and correlations were done using Pearson’s Chi Square test. Results: Among the 132 participants included in the final analysis, 82(62%) were male, median age 47 years (IQR 31-59).Only 8% and 2% of the participants reported current history of alcohol use and smoking respectively.Majority (82%) of the participants were hypertensive with a median blood pressure of 150/90 mmHg (IQR 131/75-168/100). An estimated 81% of the participants were on antihypertensives. An estimated 28% of the participants were diabetic, with approximately 15% and 11 % of them being on oral hypoglycemics and insulin respectively. Majority of the participants (78%) were on dialysis, with most (71%) having only one session of dialysis per week. The most common venous access site was subclavian/internal jugular catheter (87%), compared with arteriovenous fistula (11%) and tunneled catheter (2%) respectively.Overall 70/132 participants (53%) had pulmonary hypertension. The prevalence of pulmonary hypertension was higher among participants on dialysis 63/100 (63%) compared to those not on dialysis 7/32 (22%). Patients on dialysis had higher odds of having pulmonary hypertension (OR 5.9; 95%CI 2.4-15.2; p 0.0001) compared with patients not on dialysis.All other factors assessed (such as gender, age, weight, hemoglobin, hematocrit, calcium and potassium) were not significantly associated with pulmonary hypertension. Conclusion:The prevalence of pulmonary hypertension in CKD patients is high at MTRH and it is higher in those on dialysis compared to those not on dialysis. Recommendations:Due to the high prevalence of PHTN in CKD patients, routine screening is recommended for early detection and management. Large prospective studies using right heart catheterization are needed to establish the true prevalence of pulmonary hypertension in CKD.