Trends in sudden cardiac death in the northern Sweden MONICA area 1985-99

To describe time trends in sudden cardiac death (SCD) occurrences between 1985 and 1999.

Cohort study with analysis of a database of all symptomatic and/or fatal acute myocardial infarctions (AMI) in the two northernmost counties in Sweden, partly north of the Arctic Circle.

A total of 1139 cases of SCD amongst men and women aged 35-64 years.

Sudden cardiac death.

Amongst men the proportion of SCD to all AMI deaths (within 28 days of an AMI) was 38% and for women 31%. The mean yearly incidence of SCD in this age group was 65 per 100,000 men and 12 per 100,000 women. Amongst men the mean yearly incidence decreased by 1.8% (95% confidence interval -3.2 to -0.3) and amongst women the decrease was 1.0% (95% confidence interval -4.4 to 2.4). Diabetes mellitus was more common in women compared with men (24% vs. 14%, P = 0.001). Men suffered an SCD more often around noon and on Saturdays, whereas women suffered their SCD on Mondays and Fridays. For season, men and women behaved similarly with a winter peak, although statistical significance was reached only for men.

The SCD decreased amongst men between 1985 and 1999. There was also a decrease amongst women during the same time period but not to a statistically significant degree, possibly caused by lack of statistical power due to small numbers.