Understanding the 'epidemic of heart failure': a systematic review of trends in determinants of heart failure

We conducted a systematic review of recent studies investigating trends in the epidemiology of heart failure (HF). We fitted simple linear regression models of rates against calendar year for mortality and hospital admission. Based on Population Attributable Fractions (PAFs) from the NHANES I Epidemiological Follow-up Study and self-reported prevalences of risk factors for HF, the estimated changes in numbers of new cases of HF in Australia were calculated from 1995 to 2005. A clear decline in mortality from HF and some data on decreases in admissions to hospitals for HF, as well as the lack of reports showing an increase in the incidence of HF, all argue against the existence of an 'epidemic' of HF. However, most reports on trends in HF survival have shown a secular improvement. The latter, together with population aging, are major factors that may increase the caseload of HF. Against this background of conflicting influences, we estimate that in Australia, the inflow into the caseload of HF decreased by 1.6% among people aged >= 55 years in 2005 relative to 1995. Available evidence does not support an increase in the caseload of HF over recent years. Taking all of the influences on the epidemiology of HF together, it is likely that the number of new cases of HF will rise over the next few years, even if the incidence rate falls, chiefly because the elderly population is expanding so quickly.