Trends in incidence and outcome of out-of-hospital cardiac arrest among people with validated myocardial infarction

To describe trends in incidence, outcome, and background characteristics among people who suffered an out-of-hospital cardiac arrest with validated myocardial infarction aetiology (OHCA-V).

People from the northern Sweden MONICA myocardial registry (1989–2007) with OHCA-V (n = 2977) were divided in two age groups (25–64 and 65–74 years). Both those who were resuscitated outside hospital and those who died before resuscitation was started were included in the study. The younger age group was studied during 1989–2007 and the older group during 2000–2007. The incidence of OHCA-V decreased in both the younger group (men p < 0.0001, women p = 0.04) and the older group (men p < 0.0001, women p < 0.0007, respectively). The proportion with a history of ischaemic heart disease prior to the event decreased (p < 0.0001). The proportion of previous myocardial infarction decreased (p < 0.0001), diabetes mellitus increased (p = 0.001), coronary interventions increased (p < 0.0001), and survival after OHCA-V increased (p < 0.0001) in the younger group but not in the older group. Long-term survival after OHCA-V was better in the younger than in the older group (p = 0.026).

The incidence of OHCA-V decreased in both sexes. The proportion surviving after OHCA-V was small but increased, and long-term survival (≥28 days) was better in the younger age group. Primary preventive measures may explain most of the improvements. However, the effects of secondary preventive measures cannot be excluded.