A substantial proportion of people experiencing sudden cardiac death have no history of coronary artery disease (CAD) but many show signs of a previously undetected MI at autopsy, according to Finnish and US researchers.

To examine the prevalence of silent MI in those with sudden cardiac death and autopsy-defined CAD, the team analysed data on more than 5800 people who had experienced sudden cardiac death. Most (78.8%) were men.

The underlying cause of death was CAD in 4392 (74.8%) of cases. However, of these, a large number (3122, or 71.1%) had no previous history of CAD.

After exclusions because of missing information, it was found that 1322 subjects (42.4%) showed old myocardial scarring.