Sex specific lifetime risk of incident cardiovascular events. Results from a large British population-based cohort study
Authors: Pana T A , Mamas M A , Wareham N J , Khaw K T , Dawson D K , Myint P K 
Published: November 2023

Abstract

Background
There are marked sex differences in cardiovascular (CV) disease, most characteristically with men having a higher risk of coronary heart disease and myocardial infarction (MI). The sex differences in the absolute lifetime risk of CV disease as well as the different profiles of first incident CV events remain poorly described.

Purpose
Using data from a large British population-based cohort study with long follow-up, we aimed to compare the sex differences in the lifetime risk of incident CV events (MI, stroke, atrial fibrillation (AF), heart failure (HF), peripheral artery disease (PAD) and CV mortality).

Methods
Eligible participants at the study baseline (1993-1998) were included and followed up until March 2018. Cause-specific hazard ratios were ascertained using Weibull regressions. The sex-specific lifetime risks of each outcome were ascertained using Weibull regressions accounting for the competing risk of death. All models were adjusted for time-updated covariates: ethnicity, Townsend index of deprivation, systolic blood pressure, hypercholesterolaemia, diabetes, smoking, alcohol intake, physical activity, body mass index, fruit/vegetable intake, non-cardiovascular conditions and medication.

Results
8975 men and 11,330 women aged ≥40 and free of CV disease at baseline were included. The median follow-up was 22.3 years. Compared to women, men were more likely to be older, have higher systolic blood pressure, higher BMI and be less physically active. Men were less likely to have prevalent non-cardiovascular comorbidities. The adjusted cumulative incidence of a CV event ranged between 13.8%-28.2% for men and 7.5%-21.2% for women (Figure 1). The lifetime risk of CV mortality was 28.7% for men and 22.9% for women. Compared to women, the relative risk of incident CV events for men was two-fold higher for MI (cause specific hazard ratio (95% confidence interval) – 2.05 (1.83-2.30)) and PAD (2.02 (1.83-2.23)), 50% higher for HF (1.52 (1.39-1.66)) and AF (1.51 (1.40-1.62)), 42% for cardiovascular mortality (1.42 (1.32-1.53)) and 12% for stroke (1.12 (1.03-1.22)). There were also sex differences in the lifetime incidence of different types of first CV event (Figure 2). Amongst men, MI had the highest incidence as a first CV event throughout lifetime. The earliest incidence rise in MI occurred by 50 years and was followed by AF, PAD, stroke and heart failure over the following decades. In women, the incidence of MI as a first CV event was highest between 50-60 years but was overtaken by AF by 65 years and stroke by 70 years.

Conclusions
Men had a higher risk of incident cardiovascular disease throughout their lifetime than women, but these sex differences were most pronounced for MI and PAD, followed by AF, HF and CV mortality. These were also reflected in the different sex profiles characterising the type of first incident CV event. These differences highlight the importance of tailoring sex-specific primary preventative strategies.Figure 1Figure 2