Pre-hospital delay, clinical characteristics, angiographic findings, and in-hospital mortality in young and middle-aged adults with acute coronary syndrome: a single-centre registry analysis.

There are several differences between younger and older adults with acute coronary syndrome (ACS). However, few studies have evaluated these differences. We analysed the pre-hospital time interval [symptom onset to first medical contact (FMC)], clinical characteristics, angiographic findings, and in-hospital mortality in patients aged ≤50 (group A) and 51-65 (group B) years hospitalised for ACS. We retrospectively collected data from 2010 consecutive patients hospitalised with ACS between 1 October 2018 and 31 October 2021 from a single-centre ACS registry. Groups A and B included 182 and 498 patients, respectively. ST-segment elevation myocardial infarction (STEMI) was more common in group A than group B (62.6 and 45.6%, respectively; P < 0.001). The median time from symptom onset to FMC in STEMI patients did not significantly differ between groups A and B [74 (40-198) and 96 (40-249) min, respectively; P = 0.369]. There was no difference in the rate of sub-acute STEMI (symptom onset to FMC > 24 h) between groups A and B (10.4% and 9.0%, respectively; P = 0.579). Among patients with non-ST elevation acute coronary syndrome (NSTE-ACS), 41.8 and 50.2% of those in groups A and B, respectively, presented to the hospital within 24 h of symptom onset (P = 0.219). The prevalence of previous myocardial infarction was 19.2% in group A and 19.5% in group B (P = 1.00). Hypertension, diabetes, and peripheral arterial disease were more common in group B than group A. Active smoking was more common in group A than group B (67 and 54.2%, respectively; P = 0.021). Single-vessel disease was present in 52.2 and 37.1% of participants in groups A and B, respectively (P = 0.002). Proximal left anterior descending artery was more commonly the culprit lesion in group A compared with group B, irrespective of the ACS type (STEMI, 37.7 and 24.2%, respectively; P = 0.009; NSTE-ACS, 29.4 and 21%, respectively; P = 0.140). The hospital mortality rate for STEMI patients was 1.8 and 4.4% in groups A and B, respectively (P = 0.210), while for NSTE-ACS patients it was 2.9 and 2.6% in groups A and B, respectively (P = 0.873). No significant differences in pre-hospital delay were found between young (≤50 years) and middle-aged (51-65 years) patients with ACS. Although clinical characteristics and angiographic findings differ between young and middle-aged patients with ACS, the in-hospital mortality rate did not differ between the groups and was low for both of them.