Lipoprotein(a) as a Risk Factor for Recurrent Acute Myocardial Infarction and Mortality: Insights from Routine Clinical Practice

Abstract Background Lipoprotein(a) [Lp(a)] is a well-established risk factor for incident atherosclerotic cardiovascular (CV) disease. However, evidence regarding its association with recurrent events is limited. To address this gap, we conducted a retrospective analysis of routine clinical data, focusing on patients hospitalized for acute myocardial infarction (AMI) between 2000 and 2022 with available admission Lp(a) results. Methods Patients were stratified into three groups based on their Lp(a) level (≤50 mg/dL, 51–90 mg/dL, and >90 mg/dL). A multivariable-adjusted Cox regression analysis was performed to assess the associations of Lp(a) with recurrent AMI, CV mortality, and all-cause mortality. Results A total of 2248 patients (31.5% women), with a mean age of 64.7 ± 12.2 years, were retrospectively followed until December 31, 2022, or death. The multivariable-adjusted hazard ratios (HRs) for recurrent AMI were 1.01 (p=0.921) for levels 51–90 mg/dL and 1.51 (p=0.013) for levels >90 mg/dL, compared with levels ≤50 mg/dL. The corresponding HRs for CV mortality were 1.13 (p=0.300) and 1.14 (p=0.348), and those for all-cause mortality were 1.09 (p=0.310) and 1.20 (p=0.090), respectively. Stratification by sex and age revealed a significant association of Lp(a) with recurrent AMI only in women aged >65 years, with adjusted HRs of 2.34 (p=0.013) for levels 51–90 mg/dL and 3.94 (p90 mg/dL, compared with levels ≤50 mg/dL. Conclusions We observed a significant association of Lp(a) with recurrent AMI only in patients with Lp(a) levels >90 mg/dL. No associations were found between Lp(a) and CV or all-cause mortality. Notably, the association with recurrent AMI was most pronounced in women aged >65 years.