Impact of Lipoprotein(a) as a Residual Risk Factor in Long-Term Cardiovascular Outcomes in Patients With Acute Coronary Syndrome Treated With Statins

Abstract

The association between lipoprotein(a) (Lp[a]) levels and cardiovascular disease has been reported. However, it is still uncertain whether Lp(a) concentration could be a residual risk factor for cardiovascular events after acute coronary syndrome (ACS). The aim of the present study is to evaluate the impact of Lp(a) on long-term cardiovascular outcomes in patients with ACS treated with statins. We studied 1,758 consecutive patients with ACS who underwent emergency percutaneous coronary intervention between 2008 and 2017. We finally enrolled 1,131 patients for whom Lp(a) data were available and who were treated with statins at discharge. Patients were divided into 2 groups according to Lp(a) levels (median Lp(a) 15.0 mg/100 ml). The primary end points were major adverse cardiac events (MACEs), composite of all-cause death, and myocardial infarction up to 5 years. Overall, 107 MACEs (9.5%) were identified. The cumulative incidence of MACE was significantly higher in the high Lp(a) group than the low Lp(a) group (log-rank p=0.01). After adjustment for other cardiovascular risk factors, the high Lp(a) group had a significantly higher risk of MACE (hazard ratio 1.66, 95% confidence interval 1.05 to 2.61, p=0.03). Multivariate Cox hazard analysis also showed that increasing Lp(a) as a continuous variable was associated with the incidence of MACE (hazard ratio 1.35 per log Lp[a] 1 increase, 95% confidence interval 1.07 to 1.72, p=0.01). In conclusion, high Lp(a) level is significantly associated with long-term cardiovascular outcomes in patients with ACS treated with statins after primary percutaneous coronary intervention and is likely to be a potential biomarker for residual risk prediction of future clinical events.