Lipoprotein(a) levels above 70 mg/dL are an independent predictor for long-term major adverse cardiovascular events in patients with premature (<40 years) acute coronary syndrome

Background There are few data regarding the long-term prognosis of young survivors of acute coronary syndrome (ACS) according to lipoprotein(a) [Lp(a)] levels. We explored whether Lp(a) ≥70 mg/dL or ≥175 nmol/L, i.e. the cut off level applied by the ongoing phase 3 Lp(a) HORIZON trial, is associated with adverse cardiovascular outcome. Methods We recruited 410 consecutive patients who had survived their first ACS <40 years of age. Clinical end points included all major adverse cardiovascular events (MACE): cardiac death, readmission for ACS, arrhythmias requiring hospital admission, ischaemic stroke or coronary revascularization due to clinical deterioration. Cox regression and Kaplan-Meier analyses were used to assess study outcomes. Results The most prevalent risk factor at presentation was smoking (92.4%) and the majority of patients were men (84.5%). Follow-up data were obtained from 380 patients (age: 33.7± 4.3 years). The median follow-up period was 8 (5.2-12.5) years. One hundred fifty-eight (41.6%) patients reported continuation of smoking during follow-up and 139 (36.6%) had a MACE (18 cardiac death, 89 ACS, 23 revascularization due to clinical deterioration, 8 arrhythmias and one ischaemic stroke). Univariate Cox regression analysis showed that continuation of smoking, left ventricular ejection fraction (LVEF), and Lp(a) levels ≥70 mg/dL were predictors of MACE. Lp(a) levels ≥70 mg/dL remained an independent predictor of MACE after adjustments for LVEF, smoking persistence and traditional risk factors (sex, diabetes mellitus, hypercholesterolaemia, hypertension and family history of premature coronary artery disease) [hazard ratio 2.013, 95% CI 1.199-3.381, p=0.008]. Figure 1 presents the unadjusted event-free Kaplan-Meier survival curves according to Lp(a) levels (≥ 70 mg/dL vs <70 mg/dL) [log-rank=0.005]. Conclusions Lp(a) ≥70 mg/dL is an independent long-term predictor for MACE among young survivors of premature ACS.