Anemia and renal dysfunction in patients with ambulatory heart failure at the Kenyatta national hospital

Abstract

Background. Many patients with chronic heart failure (CHF) fail to respond to maximal heart failure therapy and progress to end stage heart failure with frequent hospitalizations, poor quality of life and chronic renal insufficiency which leads to progressive chronic kidney disease (CKD) due to long standing renal vasoconstriction. These patients may also die of cardiovascular complications within a short time. Anemia is common in both heart failure and chronic kidney disease and is associated with a marked increase in mortality and morbidity in both conditions. Greater CHF severity has been observed in patients with lower hemoglobin. A decrease in hemoglobin over time is associated with an increase in left ventricular mass and higher mortality. Each of these conditions, that is, anemia, chronic renal insufficiency and heart failure can cause or worsen the other and this vicious circle is known as the Cardio Renal Anemia syndrome (CRAS). This study proposed to document the prevalence of anemia and renal dysfunction in patients with ambulatory heart failure at the cardiac clinic at Kenyatta National hospital. Objective of the study. We set out to determine the prevalence and severity of anemia and renal dysfunction in patients attending the outpatient cardiac clinic at the Kenyatta National Hospital. Methods. The study was a cross sectional descriptive study carried out at the outpatient cardiac clinic at the Kenyatta National Hospital over a 4 month period. Adults and minors over 13 years of age who had a confirmed diagnosis of heart failure were interviewed and information recorded in a study proforma. Every participant was examined and blood samples taken for total blood count and peripheral blood film, creatinine levels and blood sugar levels. An eGfR was then calculated from the creatinine levels, and this was also entered into the study proforma. Data analysis'was then done using statistical package for social scientists (SPSS) version 17. Results. The study was conducted between January and April 2012, at the Kenyatta National Hospital outpatient cardiac clinic. A total of 360 patients on follow up at the clinic were screened to identify those with a diagnostic label of heart failure. 167 patients were recruited into the study after meeting the inclusion criteria. There was a female preponderance with a male to female ratio of 1:1.9. The mean age was 51.5 (SD) 20years, while the mean age at diagnosis of heart failure was 44.6 (SD) 21.2 years giving a mean duration of heart failure of 6.9years. Majority of the patients were literate with 39.5% having post primary education. Hypertension was the most common co - morbidity at 37.1 %, while 9.6% of the patients had diabetes mellitus. 82.6% were in cardiac functional class I and II, while cardiomyopathy was the most common etiology of heart failure at 60%. The prevalence of anemia was 36%, with 71.7% having anemia of chronic disease, that is normocytic normochromic anemia, 23.3% had microcytic anemia while 5.0% had macrocytic anemia. Majority, 80%, had mild anemia while 15% had moderate anemia and 3.3% had severe anemia. Only one patient had life threatening anemia. The prevalence of renal dysfunction was 53.3% with 40.7% in CKD stage 3 disease. 10.8% and 2.4% were in CKD stage 4 and 5 respectively. 22.3% of the patients had CRAS. Patients with renal dysfunction were more likely to be older, and have HHD as the etiology of heart failure (p< 0.001 and p = 0.011 respectively). Conlusion. In conclusion, we report a high prevalence of anemia, renal dysfunction and CRAS in our sample population. Majority had mild anemia, of chronic disease, and were in stage III CKD disease. Since anemia, CHF and CKD have an additive effect on morbidity and mortality, earlier detection and correction of anemia and renal dysfunction in patients with CHF may prove beneficial.