Prevalence and co-variates of left ventricular dysfunction among patients with chronic kidney disease attending Muhimbili National Hospital.

Abstract

Background: Chronic kidney disease (CKD) is at least 3–4 times more frequent in sub Saharan Africa than in developed countries, affecting mainly young adults in their productive years. The disease is a significant cause of mortality in the region, which may be a result of death from kidney failure or from congestive heart failure - a frequent complication of CKD. There is however scarcity of documented literature on the magnitude of LV dysfunction among CKD patients in Tanzania. Objective: To determine the prevalence and covariates of LV dysfunction in patients with CKD attending Muhimbili National Hospital. Methodology: A descriptive cross-sectional study was conducted between March and October 2014 at the Nephrology Unit, Muhimbili National Hospital. Patients with CKD were consecutively enrolled into the study, if they fulfilled the inclusion criteria and had consented to take part in the study. A structured questionnaire was used to gather information on patient’s clinical characteristics as well as cardiovascular risk profile. Laboratory tests included a blood sample for serum creatinine, urea, and cholesterol levels. A urine dipstick was tested for proteinuria. Echocardiograms were performed to assess the LV systolic and diastolic functions. LV systolic dysfunction was defined as ejection fraction <55% and LV diastolic dysfunction as mild (impaired relaxation), moderate (pseudonormal pattern) and severe (restrictive pattern), based on transmitral pulsed-wave Doppler inflow recordings and tissue Doppler imaging of the medial mitral annulus. Data management and analysis was performed using SPSS software, version 18. A p-value of <0.05 was considered to indicate a significant statistical difference. Results: In total 197 CKD patients were enrolled but only 191 (96.9%) had complete data and were analyzed. The mean±SD age was 48±13 years, and 45.5% were females. The mean blood pressure was 154±24/92±14mmHg and 98.4% were hypertensive, with a mean duration of hypertension of 4.7years. Diabetes was present in 22.8%, smoking in 10.7% and 3.7% were obese. The mean serum creatinine levels were very high (1173±688 μmol/l) and 97.9% had end stage renal disease. The prevalence of LV systolic and diastolic dysfunction was 16.2% and 68.6% respectively in the total population. A clinical finding of heart failure was the only independent predictor of an echocardiographic finding of LV systolic dysfunction (OR = 2.9, p = 0.012), while independent predictors of LV diastolic dysfunction were anemia (OR = 4.9, p = 0.01) and severe hypertension (OR = 9.2, p = 0.001). Males were 70% less likely to have LV diastolic dysfunction when compared to females, p = 0.002. Conclusion and Recommendation: Left ventricular dysfunction is prevalent among patients with CKD attending Muhimbili National Hospital and is associated with modifiable and non-modifiable factors. Echocardiography should be performed in patients with CKD in order to detect overt or sub-clinical LV dysfunction.