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

Abstract

Aims: 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).

Methods and results: 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).

Conclusion: 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.