Premature acute coronary syndrome: understanding the early onset

INTRODUCTION: Acute coronary syndrome (ACS) is less frequent in young adults, but it has become a significant health problem, associated with the increasing prevalence of modifiable risk factors. OBJECTIVES: To characterize patients admitted with premature ACS, comparing with those with nonpremature ACS. METHODS: We performed a retrospective study encompassing patients of the Portuguese Registry (ProACS), comparing two groups: one composed of men less than 55 and women less than 65 years old; and other with men ≥55 and women ≥65 years old at the ACS admission. The primary endpoint was the composite of in-hospital mortality, stroke and myocardial reinfarction (re-MI). RESULTS: A total of 29 870 patients were enrolled and 25% had premature ACS, with a mean age of 50 ± 7 years old. They had a larger prevalence of smoking habits, obesity and dyslipidemia. ST-segment elevation MI (STEMI) was the main admission diagnosis in young patients and coronary angiogram mainly revealed one vessel disease in this subgroup. They had a lower Killip-Kimball (KK) class and mostly preserved left ventricular ejection fraction (LVEF). Composite endpoint was more frequent in nonpremature ACS patients. Nonpremature age, presentation with syncope or cardiac arrest, KK class >1, multivessel disease and LVEF <40% were independent predictors of the primary endpoint ( P < 0.001). Younger patients had lower rates of in-hospital all-cause mortality, re-MI and stroke. One-year all-cause mortality and 1-year cardiovascular and non-cardiovascular readmissions were also lower. CONCLUSIONS: Premature ACS affects 25% of the ACS population, mostly presenting with STEMI, but generally associated with better clinical evolution. Nevertheless, prevention measures are essential to correct modifiable cardiovascular risk factors and reduce coronary events.