Prevalence and treatment of patients with heart failure with special emphasis on diuretics

Abstract

Background: Heart failure (HF) is a major health problem worldwide with an estimated prevalence of about 1-2% in the Western world. The temporal trend for prevalence of HF has never been investigated in a nationwide population. In patients with HF diuretic treatment is recommended for relief of congestive symptoms. Over 80% of all patients with HF are estimated to be treated with diuretics. However, information about the temporal trend for diuretic treatment in a nationwide population is lacking and the prognostic effect of diuretic treatment in patients with HF has never been studied in a randomized clinical trial. Diuretics have been associated with increased mortality in selected populations with HF but the association of diuretics with mortality in unselected Western world patients discharged from a hospitalization for HF or in unselected outpatients with HF has not been studied.

Aim: The aims of this thesis was to study trends for prevalence of patients hospitalized with HF 1990-2007, trends for diuretic treatment in patients hospitalized for HF 2004-2011, the association of diuretic treatment at hospital discharge from a hospitalization for HF with short- and long-term mortality, and to evaluate diuretic treatment as a prognostic predictor for long-term mortality in outpatients with HF.

Methods and results: Data from several different Swedish registries were linked in these studies. Patients hospitalized with a primary or secondary diagnosis of HF aged 19-99 years 1990-2007 were included in Paper I. An increase in age-adjusted prevalence of HF until 1995 and a decrease from 2002 to 2007 was observed. Prevalence of HF in people aged less than 55 years increased throughout the observational period. In absolute num-bers, patients with HF older than 85 years increased by 77% from 1990 to 2007 (Paper I). Patients with a fi rst-time hospitalization for HF that survived for 18 months or more after discharge were included in Paper II. Post-discharge diuretic treatment and doses decreased 2005-2014 and coincided with increased neuro-hormonal antagonist treatment rates (Paper II). Patients recorded in the Swedish HF registry 2004-2011 with known diuretic treatment status were included in Paper III and IV. Diuretic treatment at hospital discharge had a neutral association with short-term mortality but was associated with in-creased long-term mortality (Paper III). Diuretic treatment in unselected outpatients with HF was independently associated with increased long-term mortality but did not improve a previously known model for prediction of 3-year mortality (Paper IV).

Conclusions: The prevalence of HF decreased 2002-2007 but may increase in the future due to increased prevalence in young persons and the demographic transition. If the observed trend for decreased post-discharge diuretic treatment rates and doses in patients with HF 2005-2014 was related to the observed coinciding increase of treatment with neuro-hormonal antagonists was not answered by this study. If the observed associations of diuretic treatment with increased long-term mortality in real-life patients with HF was related to a direct prognostic effect of diuretic treatment or to diuretic treatment as a marker for HF disease severity remains unknown.