The influence of biological age and sex on long-term outcome after percutaneous coronary intervention for ST-elevation myocardial infarction

Abstract

Background: Outcome following ST-segment elevation myocardial infarction (STEMI) is thought to be worse in women than in age-matched men. We assessed whether such differences occur in the UK Pan-London dataset and if age, and particularly menopause, influences upon outcome.

Methods: We undertook an observational cohort study of 26,799 STEMI patients (20,633 men, 6,166 women) between 2005-2015 at 8 centres across London, UK. Patient details were recorded at the time of the procedure into local databases using the British Cardiac Intervention Society (BCIS) PCI dataset. Primary outcome was all-cause mortality at a median follow-up of 4.1 years (IQR: 2.2-5.8 years).

Results: Kaplan-Meier analysis demonstrated a higher mortality rate in women versus men (15.6% men vs. 25.3% women, P<0.0001). Univariate Cox analysis revealed that female sex was a predictor of all-cause mortality (HR: 1.69 95% CI: 1.59-1.82). However, after multivariate adjustment, this effect of female sex diminished (HR: 1.05 95% CI: 0.90-1.25). In a sub-group analysis, we compared the sexes separated by age into the ≤55 and the >55 year olds. Age-stratified Cox analysis revealed that female sex was a univariate predictor of all-cause mortality (HR: 1.60 95% CI: 1.25-2.05) in the ≤55 group and in the >55 group (HR: 1.38 95% CI: 1.28-1.47). However, after regression adjustment incorporating the propensity score into a proportional hazard model as a covariate, whilst female sex was not a significant predictor of all-cause mortality in the ≤55 group it was a predictor in the >55 group. Moreover, whilst age did not influence outcome in <55 group, this effect in the >55 group was correlated with age.

Conclusions: Overall women have a worse all-cause mortality following primary PCI for STEMI compared to men. However, this effect was driven predominantly by women >55 years of age since after adjusting for co-morbidities the risk in younger women did not differ significantly from that in men. These observations support the view that as women advance past the menopausal years their risk of further events following revascularization increases substantially and we suggest that routine assessment of hormonal status may improve clinical decision-making and ultimately outcome for women post-PCI.

Keywords: Primary PCI; myocardial infarction; sex.

Conflict of interest statement

None.

AJCD Copyright © 2021.

Figures

Figure 1

Survival rates in patients over the study period: Kaplan Meier curves showing cumulative probability of all-cause mortality after PCI according to group at 5 years, (A) landmark analysis up to 30 days in the whole cohort, (B) from 30 days to 5 years in the whole cohort, (C) landmark analysis up to 30 days in the less than 55 age group, (D) from 30 days to 5 years in the less than 55 age group, (E) landmark analysis up to 30 days in the greater than 55 age group, (F) from 30 days to 5 years in the greater than 55 age group.

Figure 2

Kaplan Meier curves showing cumulative probability of all-cause mortality after PCI according to men versus women (A), men versus women ≤55 (B) and men versus women >55 (C).

Figure 3

Spline plot for a non-linearly related risk factor. Association between age and log hazard (of overall all-cause mortality). The cut-points used are the age at procedure (40, 50, 60, 70, 80 and 90). The shaded regions show 95% CIs.