Epidemiology of acutely decompensated systolic heart failure over the 2003-2013 decade in Douala General Hospital, Cameroon

Abstract

Aims: Acutely decompensated heart failure (HF) (ADHF) is a common cause of hospitalization and mortality worldwide. This study explores the epidemiology and prognostic factors of ADHF in Cameroonian patients.

Methods and results: This was a retrospective study conducted between January 2003 and December 2013 from the medical files of patients followed at the intensive care and cardiovascular units of Douala General Hospital in Cameroon. Clinical, electrocardiographic, echocardiographic, and biological data were collected from 142 patients (58.5% men; mean age 58 ± 14 years) hospitalized for ADHF with reduced ejection fraction (HFrEF), whose left ventricular ejection fraction was <50%, or alternatively whose shortening fraction was <28%, both assessed by echocardiography. The commonest risk factors associated with HFrEF were hypertension (59.2%), diabetes mellitus (16.2%), tobacco use (14.1%), and dyslipidaemia (7.7%), respectively. The major causes of HF in hospitalized patients were hypertensive heart disease (40%, n = 57); hypertrophic cardiomyopathy (33.8%, n = 48); and ischemic heart disease (21.8%, n = 31). The most frequent comorbid conditions were atrial fibrillation (25.4%, n = 36) and chronic kidney disease (18.3%, n = 26). Major biological abnormalities included increased bilirubinemia >12 mg/L (87.5%, n = 124); hyperuricaemia >70 mg/L (84.9%, n = 121); elevated serum creatinine (65.6%, n = 93); anaemia (59.1%, n = 84); hyperglycaemia on admission >1.8 g/L (42.3%, n = 60); and hyponatraemia <135 mEq/L (26.8%, n = 38). At admission, 33.8% (n = 48) of patients had no pharmacological treatment for HF. The most frequently used therapies upon admission included furosemide (50%, n = 71), angiotensin-converting enzyme inhibitors (ACEIs; 40.1%, n = 57); spironolactone (35.2%, n = 50); digoxin (26%, n = 37); beta-blockers (17.7%, n = 25); angiotensin-receptor blockers (ARBs; 7%, n = 10); and nitrates (7.0%). The overall in-hospital mortality rate was 20.4%. Factors associated with poor prognosis were systolic blood pressure <90 mmHg [odds ratio (OR) 3.88; confidence interval (CI) 1.36-11.05, P = 0.011], left ventricular ejection fraction <20% (OR 7.48; CI 2.84-19.71, P < 0.001), decreased renal function (OR 1.03; CI 1.00-1.05, P = 0.026), dobutamine use for cardiogenic shock (OR 2.74;CI 1.00-7.47, P = 0.049), pleural fluid effusion (OR 3.46; CI 1.07-11.20, P = 0.038), and prothrombin time <50% (OR 3.60; CI 1.11-11.68, P = 0.033). The use of ACEIs/ARBs was associated with reduced in-hospital mortality rate (OR 0.17; CI 0.02-0.81, P = 0.006).

Conclusions: Hypertensive heart disease, hypertrophic cardiomyopathy, and ischemic heart disease are the commonest causes of HF in this Cameroonian population. ADHF is associated with high in-hospital mortality in Cameroon. Hypotension, severe left ventricular systolic dysfunction, renal function impairment, and dobutamine administration were associated with worst acute HF outcomes. ACEIs/ARBs use was associated with improved survival.

Keywords: Acute heart failure; Cameroon; Epidemiology; Prognosis.