Aetiology, pharmaco-therapeutic interventions and clinicaloutcome in acute decompensated heart failure admissions to Kenyatta National Hospital

Abstract

Objective: To characterize heart failure in patients admitted to medical ward at Kenyatta National Hospital, Nairobi. Design: Prospective clinical observational register. Setting: Medical ward, Kenyatta National Hospital. Subjects: Two hundred and sixty one patients with acute decompensated heart failure were studied over a period of six months. Results: 261 patients with an age range of 13-94 years and most were between 20-60 years with 59.1% females. 91% of ADHF cases were in classes III and IV. Noncompliance was the precipitating factor in 83.1% of the cases, followed by infective endocarditis at 8.5%. Out of these 40.9%,27%,18.9%,18.1%, and 7.3% had dilated cardiomyopathy, rheumatic heart disease, Cor-Pulmonale, hypertensive heart disease, and Ischaemic heart disease respectively. The prevalence of heart failure with normal ejection fraction was 39.5% at an ejection fraction cut-off of 40%, average age was 49.3 ± 21.35 years with a statistical significance of p<0.006, with predominantly systolic heart failure in males at 61.7%. Among all the cases, 21 had a QRS duration of more than 120 milliseconds and 19 when rheumatic disease was excluded. Increase in QRS duration was noted with increase in age, with average age being 44.6 years, 62.1 years and 64·7 years in group less than 120 ms, 120 ms-160 ms and more than 160 ms, respectively (p<0.01) and ejection fractions were 38.5%, 43.8% and 30.05% respectively. The mean serum level of NT-proBNP among 50 cases at admission was l3752.36 pg/ml, and 369.3 pg/ml at discharge (p<0.01). At admission 49 out of 50 cases had serum level of more than 1800 pg/ml. At discharge, based on age related cut-offs, 10 patients were in the 'acute congestive cardiac failure likely' likely group while, 10 cases were in the 'less likely' group. On admission, Frusemide was used in 89% of cases, Digoxin in 77% and Spironolactone in 56.5% and on discharge Frusemide was used in 84.8% of cases, Digoxin in 72.3% and Spironolactone in 56% of the cases. Enalapril, Captopril and Carvedilol were used in less than 50% of the cases. The overall case fatality rate was 14.1%. The mean length of hospital stay was 7.1 days, the median was 6 days while the range was 2-29 days. The case fatality rates according to disease aetiologies were: rheumatic heart disease 14.5%; hypertensive heart disease 19.1%; ischaemic heart disease 26.3%; and dilated cardiomyopathy 9.7%. Conclusion: Dilated cardiomyopathy was the most common cause of heart failure at 42.7%. 39.5% of the cases had heart failure with normal ejection fraction, more prevalent among older patients. Prolonged QRS duration was evident in older age groups. Enalapril, Captopril, and Carvedilol were used in less than 50% of heart failure cases. At discharge, 20% of the cases were in heart failure with a raised NTproBNP level.