Distinct clinical profiles and outcomes in young versus older adults with acute coronary syndrome: a comparative cohort study

BACKGROUND: Acute coronary syndrome (ACS) in young adults (≤ 40 years) exhibits distinct characteristics compared with older populations, yet detailed comparative data in Chinese cohorts remain limited. METHODS: This comparative retrospective cohort study analyzed 112 consecutive ACS patients aged ≤ 40 years (Young Group) and 112 matched non-young ACS patients (age > 40 years, Non-Young Group) undergoing coronary angiography at a tertiary center between September 2018 and November 2024. We evaluated clinical profiles, angiographic features, revascularization strategies, and 12-month major adverse cardiac events (MACE). RESULTS: Compared with the Non-Young Group, young patients exhibited a higher male predominance (p < 0.001) and a lifestyle related risk profile characterized by significantly higher rates of current smoking (p < 0.001) and obesity (p < 0.001). Young patients more frequently presented with STEMI (p = 0.009) and single vessel disease (p = 0.011), with thrombotic lesions being the dominant etiology (p = 0.005). Regarding treatment, the Young Group had a significantly higher utilization of drug coated balloons (p < 0.001) and lower stent implantation rates (p < 0.001). At 12 months, the MACE rate was significantly lower in the Young Group (p = 0.038). Within the young cohort, multivessel disease (aHR 2.89), LVEF < 50% (aHR 3.25), and stent non-implantation (aHR 2.30) were independent MACE predictors. Clustering of ≥ 2 key modifiable risk factors (dyslipidemia, obesity, smoking) conferred a 3 to 5 fold higher MACE risk in young adults (p < 0.001). CONCLUSIONS: Young ACS patients possess a distinct clinical and angiographic profile characterized by a higher thrombotic burden and lifestyle related risk factors compared with older patients. While they exhibit more favorable short term survival and respond well to stent-less revascularization strategies, their long term prognosis is heavily dependent on the aggressive modification of synergistic modifiable risk factors.