Who has advanced heart failure?: definition and epidemiology

Abstract

Summarizing current guidelines and advanced heart failure (AHF) clinical trials/registries, this review focuses on the current definition of AHF and emphasizes the secular trends in this definition over the last two decades. Further, clinical, imaging, hemodynamic, functional capacity and biomarker parameters that may aid clinicians to better recognize patients with AHF are reviewed. Finally, we review the limited data concerning the epidemiology of AHF which to date has been poorly characterized.

Figure 1. Natural History of HF defines advanced HF

The stages in the natural history of HF clarify the relationship between cardiovascular disease (Stage A), asymptomatic abnormalities in cardiac structure and function (Stage B), overt symptomatic HF (Stage C) and advanced HF (Stage D). The natural history of over HF is further characterized in the insert where the fluctuating but progressive clinical course after HF presentation and commencement of optimal medical therapy (OMT) or later, with cardiac resynchronization therapy (CRT) or advanced HF therapies such as cardiac transplantation or ventricular assist devices (LVAD) is shown. Progression to poorer functional status associated with higher risk of hospitalization and overall health care resource utilization occurs over time. The potential modes of death over the course of the natural history of HF are emphasized where patients may die of non-HF related cardiovascular or non-cardiovascular causes (non-HF death, NHFD) or sudden cardiac death (SCD) at any time with the risk of SCD increasing as HF worsens. Patients who avoid NHFD or SCD die of progressive HF (HF).

Figure 2. Health care resource utilization over life after a HF diagnosis in the community

The average monthly cost of health care is shown for patients over their lifetime after a diagnosis of HF. Note that resource utilization is most intense at the time of diagnosis (often made during a hospitalization) and again years after the diagnosis, where the advanced HF patient is at high risk for repeated hospitalizations for HF or other conditions.

Figure 3. Causes of death and hospitalization for HF patients in the community

The “epidemic” of HF occurs in elderly patients where the progression to advanced HF does not occur in isolation from a host of other cardiovascular and non-cardiovascular comorbidities. While HF clinical trials usually exclude patients with other cardiovascular and non-cardiovascular comorbidities, these conditions potently contribute to mortality (A) and hospitalizations (B) in the community as demonstrated in studies from a community based HF surveillance study in Olmsted County, Minnesota. In B, the cause of all hospitalizations over the patients life after a HF diagnosis (excluding the index HF hospitalization in patients in whom the diagnosis was made during a hospitalization for HF) were assessed.