Proportion of ischemic and nonischemic sudden cardiac death by age and sex
Authors: Eskuri M A E , Holmstrom L , Vahatalo J , Kentta T V , Tikkanen J , Pakanen L , Kortelainen M L , Perkiomaki J , Huikuri H V , Junttila M J 
Published: November 2023

Abstract

Background
Among women the incidence of sudden cardiac death (SCD) is significant, but lower than in men. During the last decades the proportion of nonischemic SCD seems to have increased in both sexes. Coronary artery disease (CAD) have changed to be sickness of elderly women rather than middle-aged men as in women the prevalence and incidence of CAD starts to increase after the menopause.

Purpose
The aim of this study was to illustrate how the amount and the proportions of ischemic and nonischemic SCD vary between women and men in different age groups.

Methods
The Fingesture study has systematically collected clinical and autopsy data from SCD victims in Northern Finland between 1998 and 2017. The cohort consists of 5,869 SCD victims.

Results
Approximately one fifth of the SCD victims were women (21.1%; P&lt;0.001). Three out of four SCDs were ischemic (74.8%; P&lt;0.001) and majority of the ischemic SCD victims were men (79.8%; P=0.005). The mean age of female victims was 70.1±13.1 years and 63.5±11.8 years among male victims (P&lt;0.001). Amongst women one SCD out of 15 occurred to the subject under 50 years of age (6.7%; P&lt;0.001) whereas in men one SCD victim out of nine was under 50 years old (11.4%; P&lt;0.001).
A nonischemic SCD was observed in 350 women and in 1,127 men (P&lt;0.001). The proportion of nonischemic death was higher among women than in men in every age group from under 30 years of age to subjects of 84 years old studied in five year periods (Figure 1). Only age group of 65-69 years in women and 60-64 years in men were not statistically significant, otherwise all the P-values were ≤0.003. The difference in proportion of ischemic and non-ischemic SCD was the smallest among subjects of 40-49 years of age amongst the proportion of ischemic SCD increased rapidly both in women and in men as the prevalence of non-ischemic SCD started to decrease (Figure 1).
Amongst SCD victims aged 40-44 years 47.9% of the deaths of men (P&lt;0.001) and 41.7% of the deaths of women (P&lt;0.001) were ischemic etiology. Among women aged 50-54 years over half of the SCDs were ischemic (53.1%; P&lt;0.001). The gender difference in proportion of ischemic SCD was actually the smallest in age groups 40-49 years and after 70 years of age, and its largest in the middle in favor of men. (Figure 1). After the age of 70 years the total amount of SCDs started to plateau in men and decrease in the amount of SCDs was seen in men after the age of 75 years as in women the plateau phase was not reached until the age of 80 years (Figure 2).

Conclusion
Minority of the SCDs occur under the age of 50 years, especially among women. The proportion of nonischemic SCD was higher in women than in men despite the age. However, already in pre- and perimenopausal age the proportion of ischemic SCD in women was remarkable and the amount of ischemic SCD increased until the age of 80 years emphasizing the need of early primary and secondary prevention of CAD also in women not only in men.Figure 1.Figure 2.