Validity of Heart Failure Diagnoses in Administrative Databases: A Systematic Review and Meta-Analysis
AIMS Co-morbidities frequently accompany heart failure (HF), contributing to increased morbidity and mortality, and an impairment of quality of life. We assessed the prevalence, determinants, regional variation, and prognostic implications of co-morbidities in patients with chronic HF in Europe. METHODS AND RESULTS A total of 3226 European outpatients with chronic HF were included in this analysis of the European Society of Cardiology (ESC) Heart Failure Pilot Survey. The following co-morbidities were considered: diabetes, hyper- and hypothyroidism, stroke, COPD, sleep apnoea, chronic kidney disease (CKD), and anaemia. Prognostic implications of co-morbidities were evaluated using population attributable risks (PARs), and patients were divided into geographic regions. Clinical endpoints were all-cause mortality and HF hospitalization. The majority of patients (74%) had a least one co-morbidity, the most prevalent being CKD (41%), anaemia (29%), and diabetes (29%). Co-morbidities were independently associated with higher age (P < 0.001), higher NYHA functional class (P < 0.001), ischaemic aetiology of HF (P < 0.001), higher heart rate (P = 0.011), history of hypertension (P < 0.001), and AF (P < 0.001). Only diabetes, CKD, and anaemia were independently associated with a higher risk of mortality and/or HF hospitalization. There were marked regional differences in prevalence and prognostic implications of co-morbidities. Prognostic implications of co-morbidities (PARs) were: CKD = 41%, anaemia = 37%, diabetes = 14%, COPD = 10%, and <10% for all other co-morbidities. CONCLUSION In this pilot survey, co-morbidities are prevalent in patients with chronic HF and are related to the severity of the disease. The presence of diabetes, CKD, and anaemia was independently related to increased mortality and HF hospitalization, with the highest PAR for CKD and anaemia.