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

Objective: 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.

Methods: 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.

Results: 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).

Conclusions: 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.