Elevated Lipoprotein(a) Predicts Recurrent Myocardial Infarction in Diabetic Patients Following Acute Coronary Syndromes

Background Patients with type 2 diabetes mellitus (T2DM) who experience acute coronary syndromes (ACS) remain at high risk for recurrent ischemic events despite secondary prevention. Lipoprotein(a) [Lp(a)] contributes to residual cardiovascular risk, but its prognostic impact on recurrent myocardial infarction (MI) and repeat revascularization in diabetic patients after ACS or percutaneous coronary intervention (PCI) remains unclear. Hypothesis We hypothesized that elevated Lp(a) is associated with increased risk of recurrent MI and repeat coronary revascularization in patients with diabetes after ACS or PCI. Methods We conducted a PRISMA‐guided systematic review and meta‐analysis. PubMed, EBSCOhost, and Cochrane Library were searched for studies evaluating Lp(a) and recurrent cardiovascular outcomes in patients with diabetes after ACS or PCI. Observational studies reporting hazard ratios (HRs) with 95% confidence intervals (CIs) were included. Pooled HRs were calculated using random‐effects models. Results Seven studies comprising 7887 patients with diabetes and prior ACS or PCI were included. Elevated Lp(a) was associated with increased risk of recurrent MI (pooled HR 2.17, 95% CI 1.02–4.62; I 2 = 75%) but not repeat coronary revascularization (pooled HR 1.68, 95% CI 0.79–3.57; I 2 = 78%). Conclusions Elevated Lp(a) was associated with increased risk of recurrent MI in patients with diabetes after ACS or PCI. Findings should be interpreted considering the observational study designs, substantial heterogeneity, and limited evidence for repeat revascularization. These findings support Lp(a) as a contributor to residual cardiovascular risk and its potential role in post‐ACS risk stratification. Trial Registration: This study was prospectively registered in the International Prospective Register of Systematic Reviews (PROSPERO; registration number CRD420261296821).