<strong>A register study of incidence and prevalence during 1997-2006</strong>
Background The incidence and fatality of acute myocardial infarction (MI) has decreased during the last decade - due to both improved medical treatment and a shift toward a healthier lifestyle. The consequence of the improved treatment is likely to be a falling incidens of heart failure following MI. Yet, the treatment of heart failure has also improved. It is unknown to what extent the incidence, prevalence and survival with heart failure in the general population and among patients with ischemic heart disease has changed over time. Aim The aim of this study is to estimate incidence and prevalence of heart failure (HF) in the Danish population and among individuals with ischemic heart disease (IHD) during 1996-2006, applying register data from the national patient register (NPR) and the national dispensing register (NDR). Data and methods All Danish inhabitants (aged >15) by January 1996, the cohort, were followed on the individual level in NPR, NRR and in socio-demographic registers (year of birth, gender, eventual date of death or emigration, household income and origin). From NPR information (diagnoses, performed coronary procedures and date of admission) on individuals admitted with cardiovascular disease was retrieved during 1978-2006. From NDR information on dispensed prescriptions on cardiac vasodilators was retrieved during 1996-2006. After a run-in period all individuals were each year categorized of being or not prevalent or incident according to IHD and HF with and without previous/co-existing IHD. Trends of prevalence and incidence of HF in the population and in IHD patients during 1997-2006 was estimated, applying logistic and Poisson regression analyses, adjusting for gender, age, income and origin (Danish, foreign (western non-western)). Survival time without subsequent or contemporary diagnosis of HF among patients with first myocardial infarction was estimated applying Cox regression analyses (competing risk: Death and emigration), comparing three calendar years.