PATTERN OF ANAEMIA AND ITS CORRELATES IN NIGERIANS WITH HEART FAILURE

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A.A. Akintunde^1,3 and O.W. Aworanti²

1. Cardiology Unit, Department of Medicine, LAUTECH Teaching Hospital, Ogbomoso & Department of Medicine, Faculty of Clinical Sciences, LAUTECH, Osogbo, Nigeria.
2. Department of Haematology & Blood Transfusion, LAUTECH Teaching Hospital, Ogbomoso, Nigeria.
3. Goshen Heart Clinic, Osogbo, Nigeria.

Abstract

Background: Heart failure often coexists with many comorbidities, including anaemia. However, the pattern of anaemia in heart failure and its clinical and echocardiographic associations have not been adequately studied among Nigerians.

Objective: To describe the pattern of anaemia, its clinical characteristics, and its echocardiographic associations among heart failure subjects in Nigeria

Methods: One hundred and forty subjects with heart failure were recruited from the cardiology clinics of two teaching hospitals in southwest Nigeria: Ladoke Akintola University of Technology and Bowen University Teaching Hospitals, Ogbomoso. Complete blood analyses, among other tests, were done. Statistical analysis was done with Statistical Package for the Social Sciences (SPSS) 20.0. P <0.05 was taken as statistically significant.

Result : Anaemia, as defined by the World Health Organisation, occurred in 106 (75.7%) of the heart failure patients. The patterns of anaemia among participants include combined anaemia of chronic diseases (ACD) with iron deficiency in 64 (45.7%) patients, and ACD alone in 40 (28.6%). Anaemia was more significantly associated with previous diagnosis of diabetes mellitus, presence of pulmonary hypertension, and heart failure with reduced ejection fraction. Mean systolic and diastolic blood pressures, ejection fraction, and fractional shortening were significantly lower among heart failure subjects with anaemia, while serum creatinine, left atrial dimension, left ventricular end diastolic dimension, and left ventricular mass index were significantly higher among heart failure subjects with anaemia compared to those without anaemia.

Conclusion: Anaemia occurs very frequently among heart failure patients in southwest Nigeria. It is associated with many poor prognostic factors, including diabetes mellitus, pulmonary hypertension, and kidney failure.

Keywords: Anaemia, Heart failure, Left ventricular geometry, Nigeria, Echocardiography.

Introduction

Increased frequency of acute events and comorbidities in advanced heart failure is a template for increased mortality and morbidity.^1,2 Hospital admission of patients with heart diseases across Africa is often due to acute decompensated heart failure,³ and notwithstanding the availability of a plethora of disease-modifying medical therapy, patients with heart failure are at high risk of poor clinical outcomes.^4-6 A significant number of deaths in heart failure patients is due to sudden cardiac death, which may be caused by arrhythmias which can further be worsened by anaemia.^7,8

Several factors, including immunological, neurohormonal and metabolic factors, have been implicated in the progression of heart failure.⁹ In addition, anaemia and renal failure seem to be the major risk factors for adverse cardiovascular outcome.¹⁰ In a vicious triad called cardio-renal anaemia syndrome (CRAS), primary heart failure with secondary dysfunction in the kidneys, without primary structural kidney damage, causes development of anaemia.¹¹ The major factors contributing to anaemia in heart failure include nutritional deficiencies such as iron deficiency, inflammation, chronic kidney dysfunction, and haemodilution.^9,10 Anaemia is associated with several structural, functional, and geometric cardiac abnormalities, some of which may initially be compensatory of the anaemia but may eventually be counterproductive in the progression of heart failure. Echocardiography in heart failure can be used to assess various structural, functional, and geometric abnormalities, including those that are associated with anaemia. However, the prevalence of anaemia in several registries from the African continent varies in most cases due to varied definitions of anaemia and emphasis on severe anaemia.^12-15

Despite the wide use of echocardiography in most tertiary centres in Nigeria, the pattern of anaemia in heart failure and its clinical and echocardiographic associations have not been adequately studied among Nigerians. This study therefore aimed at describing the different patterns of anaemia among Nigerians with heart failure, its clinical and echocardiographic associations, and its determinants among heart failure subjects attending the cardiology clinics of two Nigerian tertiary health care settings.

METHODS
This was a cross-sectional study done at the cardiology clinics of Ladoke Akintola University of Technology Teaching Hospital, Ogbomoso, and Bowen University Teaching Hospital, Ogbomoso, Nigeria. One hundred and forty patients with heart failure were included in the study by simple randomization technique. The study was conducted from August 2018 to February 2019.

At study entry, each potential candidate was screened and recruited if they fulfilled the inclusion criteria. The data collection form was used to record the patients’ data. Blood samples were collected and analysed for various haematological parameters, including packed cell volume, haemoglobin concentration (Hb), mean corpuscular haemoglobin concentration, serum transferrin, total iron, total iron binding capacity, transferrin saturation, ferritin, white cell count, platelet count, and peripheral blood film appearance. All the samples were centrally analysed at LAUTECH Teaching Hospital, Ogbomoso. Anaemia was defined as Hb <12g/dl in women and <13g/dl in men according to the World Health Organisation (WHO) criteria. Heart failure was diagnosed based on the 2016 updated guidelines of the European Society of Cardiology on the diagnosis and management of heart failure.¹⁶ The inclusion criteria included subjects (1) who were >18 years of age; (2) who had primary diagnosis of heart failure of more than 6 months duration; (3) who were attending the cardiology clinics of Ladoke Akintola University of Technology Teaching Hospital, Ogbomoso, and Bowen University Teaching Hospital, Ogbomoso, Nigeria; (4) who willingly gave their consent to participate; and (5) who were willing to be followed up.

Exclusion criteria included patients with comorbid illness such as advanced chronic kidney disease (with estimated glomerular filtration rate (eGFR) <15 ml/ min); patients with history of recent blood transfusion, pregnancy, mental diseases, and abuse of non-steroidal anti-inflammatory drugs; patients with ongoing infection; or patients who had been admitted for any illness in the last two weeks prior to recruitment. The Kansas City Cardiomyopathy Questionnaire (KCCQ) score was used to assess quality of life, while six-minute walk test (the distance covered in six minutes of supervised walk in the clinic setting under observation) was used to describe the functional status of eachparticipant.

Information that were obtained include name, age, gender, occupation, marital status, address, and tribe. Histories of hypertension, diabetes, smoking, and alcohol intake, and family history of hypertension/ diabetes were also taken. Investigations that were done include trans-thoracic echocardiography, serum electrolytes, urea and creatinine, and urinalysis. Body mass index (BMI) was determined and categorized appropriately. ¹⁷