Prognostic impact of gender and young age in patients with acute myocardial infarction undergoing primary PCI

Abstract

Abstract Background Previous studies showed higher unadjusted mortality rates in female patients with acute myocardial infarction (AMI) undergoing primary percutaneous coronary intervention (PCI). However, after adjusting for differences in baseline characteristics, including age, female gender was not consistently associated with higher mortality. Purpose Our aim was to investigate the impact of gender on short- and long-term mortality in patients aged 18 to 55 years with AMI undergoing primary PCI. Methods We included 11 288 patients admitted for primary PCI during 2009–2019, from a prospectively kept, electronic registry of a high-volume tertiary center. Adjusted Cox regression models were used to assess 30-day and 5-year mortality hazard. Median follow up was 1 507 days. Results 3 505 patients were younger than 55 years (31%). In this age group, 18.9% were female patients (n=661). Baseline characteristics were similar for females vs. males below the age of 55 years, including similar reperfusion times (338 min. vs. 341 min., p=0.8), with only exceptions being a higher rate of previous hypertension (64% vs. 58%, p=0.002) and stroke (3.6% vs. 2.2%, p=0.049), as well as lower ejection fraction (48% vs. 51%, p<0.001), in female patients. MINOCA (Myocardial Infarction with Nonobstructive Coronary Arteries) was more frequently present in female vs. male patients aged ≤55 years (10.1% vs. 5.0%, p<0.001). In the overall population, crude mortality was higher in female patients at 30 days (9.8% vs. 6.0%, p<0.001) and 5 years (38.4% vs. 30.2%, p<0.001). In younger patients (≤55 years), mortality rates were low and similar between the sexes at both 30 days (3.6% in females vs. 2.5% in males, p=0.136) and 5 years (14.5% vs. 13.4%, p=0.58). On the contrary, in patients aged >55 years, crude mortality was higher in female patients at both 30 days (11.3% vs. 7.9%, p<0.001) and 5 years (43.9% vs. 39.4%, p=0.02), albeit mainly driven by the differences in baseline characteristics between the sexes in this older age group (adjusted HR for female sex 1.220, CI95% 0.920–0.617, p=0.17, at 30 days; and adjusted HR 1.033, CI95% 0.908–0.175, p=0.62, at 5 years). Conclusion Differences in crude mortality rates between sexes in patients with AMI admitted for primary PCI appear to be mainly dependent on age, with similar rates of both short- and long-term mortality in younger patients (≤55 years). The observed excess in mortality in older (>55 years) female vs. male patients could be explained by the differences in baseline clinical characteristics. Funding Acknowledgement Type of funding source: None