Lipoprotein(a) and long-term recurrent infarction after an episode of ST-segment elevation acute myocardial infarction

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

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 31 December 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 (p < 0.001) for levels > 90 mg/dL, compared with levels ≤ 50 mg/dL.

CONCLUSIONS

In the presented study, Lp(a) was associated with a significantly higher risk of recurrent AMI only in women aged > 65 years with Lp(a) levels > 50 mg/dL. We found no significant associations between Lp(a) and CV or all-cause mortality.

Lipoprotein(a) and Long-Term Recurrent Infarction After an Acute Myocardial Infarction

Lipoprotein(a) (Lp[a]) is an emerging risk factor for incident ischemic heart disease. However, its role in risk stratification in in-hospital survivors to an index acute myocardial infarction (AMI) is scarcer, especially for predicting the risk of long-term recurrent AMI. We aimed to assess the relation between Lp(a) and very long-term recurrent AMI after an index episode of AMI. It is a retrospective analysis that included 1,223 consecutive patients with an AMI discharged from October 2000 to June 2003 in a single-teaching center. Lp(a) was assessed during index admission in all cases. The relation between Lp(a) at discharge and total recurrent AMI was evaluated through negative binomial regression. The mean age of the patients was 67.0 ± 12.3 years, 379 (31.0%) were women, and 394 (32.2%) were diabetic. The index event was more frequently non-ST-segment elevation myocardial infarction (66.0%). The median Lp(a) was 28.8 (11.8 to 63.4) mg/100 ml. During a median follow-up of 9.9 (4.6 to 15.5) years, 813 (66.6%) deaths and 1,205 AMI in 532 patients (43.5%) occurred. Lp(a) values were not associated with an increased risk of long-term all-cause mortality (p = 0.934). However, they were positively and nonlinearly associated with an increased risk of total long-term reinfarction (p = 0.016). In the subgroup analysis, there was no evidence of a differential effect for the most prevalent subgroups. In conclusion, after an AMI, elevated Lp(a) values assessed during hospitalization were associated with an increased risk of recurrent reinfarction in the very long term. Further prospective studies are warranted to evaluate their clinical implications.

Predictors of Recurrent Ischemic Events in Patients With ST-Segment Elevation Myocardial Infarction

Little is known about the predictors recurrent ischemic events in patients with ST-segment elevation myocardial infarction (STEMI). This study aimed at investigating the predictors of recurrent myocardial infarction (MI) at long-term follow-up in a real-world STEMI cohort. All consecutive STEMI patients who underwent emergent coronary angiography and primary percutaneous coronary intervention between February 2013 and June 2019 at our institution were included. The primary outcome was recurrent MI; secondary outcomes were all-cause death, target vessel revascularization (TVR), in-stent restenosis, definite stent thrombosis (ST) and non-TVR. The study population included 724 STEMI patients; at median follow-up of 803 (324 to 1,394) days, the primary outcome was reported in 70 patients (10.1%). All-cause death occurred in 6.8%, TVR in 4.2%, in-stent restenosis in 2.5%, and ST in 1.9% of cases. At multivariable analysis, diabetes (hazard ratio [HR] = 1.18), serum level of lipoprotein(a) [Lp(a), HR = 1.01], and angiographic evidence of restenotic lesion (HR = 2.98) resulted independent predictors of recurrent MI. Kaplan-Meier analysis confirmed that diabetes, restenotic lesion, and differential Lp(a) risk range values, identified patients with lower long-term survival free from recurrent MI. Lp(a) level ≥ 30 mg/dL had an incremental prognostic stratification capability in patients with diabetes (HR = 5.34), and in patients with both diabetes and restenotic lesion (HR = 17.07). In conclusion, in this contemporary cohort of STEMI patients, diabetes, Lp(a) serum levels and restenotic lesions were independently associated with recurrent MI at long term. The coexistence of Lp(a) level ≥ 30 mg/dL showed an incremental risk stratification capability, supporting its implementation for long-term prognostic assessment in this high-risk clinical setting.