Age-specific trends in incidence, mortality and comorbidities of heart failure in Denmark 1995-2012

BACKGROUND: -The cumulative burden and importance of cardiovascular risk factors have changed over the last decades. Specifically, obesity rates have increased among younger people, whereas cardiovascular health has improved in the elderly. Little is known regarding how these changes have impacted the incidence and the mortality rates of heart failure. Therefore, we aimed to investigate the age-specific trends in the incidence and 1-year mortality rates following a first time diagnosis of heart failure in Denmark between 1995 and 2012.

METHODS: -We included all Danish individuals over the age of 18 years with a first-time in-hospital diagnosis of heart failure. Data was collected from 3 nationwide Danish registries. Annual incidence rates of heart failure and 1-year standardized mortality rates were calculated under the assumption of a Poisson distribution.

RESULTS: -We identified 210,430 individuals with a first-time diagnosis of heart failure between 1995 and 2012; the annual incidence rates per 10,000 person-years declined among older individuals (rates in 1995 vs. 2012: 164 vs. 115 in >74 years, 63 vs. 35 in 65-74 years, and 20 vs. 17 in 55-64 years, p<0.0001 for all) but increased among the younger (0.4 vs. 0.7 in 18-34 years, 1.3 vs. 2.0 in 35-44 years, and 5.0 vs. 6.4 in 45-54 years, p<0.0001 for all). The proportion of patients with incident heart failure below 51 years doubled from 3% in 1995 to 6% in 2012 (p<0.0001). Sex- and age-adjusted incidence rate ratios for 2012 vs. 1996 were 0.69 (95%CI 0.67-0.71; p <0.0001) among people >50 years, and 1.52 (95%CI 1.33-1.73; p<0.0001) among individuals ≤50 years; it remained essentially unchanged upon additional adjustment for diabetes, ischemic heart disease, and hypertension. Standardized 1-year mortality rates declined for middle-aged patients with heart failure but remained constant for younger (<45 years) and elderly (≥65 years). The prevalence of comorbidities (including diabetes, hypertension, and atrial fibrillation) increased, especially in younger patients with heart failure.

CONCLUSIONS: -Over the last two decades, the incidence of heart failure in Denmark declined among older (>50 years), but increased among younger (≤50 years) individuals. These observations may portend a rising burden of heart failure in the community.