Population trends and inequalities in incidence and short-term outcome of acute myocardial infarction between 1998 and 2007

Abstract

We studied time trends in acute myocardial infarction (AMI) incidence, including out-of-hospital mortality proportions and hospitalized case-fatality rates. In addition, we compared AMI trends by age, gender and socioeconomic status. We linked the national Dutch hospital discharge register with the cause of death register to identify first AMI in patients ≥ 35 years between 1998 and 2007. Events were categorized in three groups: 178,322 hospitalized non-fatal, 43,210 hospitalized fatal within 28 days, and 75,520 out-of-hospital fatal AMI events. Time trends were analyzed using Joinpoint and Poisson regression. Since 1998, age-standardized AMI incidence rates decreased from 620 to 380 per 100,000 in 2007 in men and from 323 to 210 per 100,000 in 2007 in women. Out-of-hospital mortality decreased from 24.3% of AMI in 1998 to 20.6% in 2007 in men and from 33.0% to 28.9% in women. Hospitalized case-fatality declined from 2003 onwards. The annual percentage change in incidence was larger in men than women (-4.9% vs. -4.2%, P<0.001). Furthermore, the decline in AMI incidence was smaller in young (35-54 years: -3.8%) and very old (≥ 85 years: -2.6%) men and women compared to middle-aged individuals (55-84 years: -5.3%, P<0.001). Smaller declines in AMI rates were observed in deprived socioeconomic quintiles Q5 and Q4 relative to the most affluent quintile Q1 (P=0.002 and P=0.015). Substantial improvements were observed in incidence, out-of-hospital mortality and short-term case-fatality after AMI in the Netherlands. Young and female groups tend to fall behind, and socioeconomic inequalities in AMI incidence persisted and have not narrowed.