Background <p>In recent years, the impact of lipoprotein(a) (Lp(a)) on the prognosis of coronary heart disease has been increasingly recognized. Lp(a) is an independent risk factor for cardiovascular disease, and studies have shown that homocysteine (HCY) may influence the association between Lp(a) and the risk of recurrent cardiovascular events. This study investigates the association between Lp(a) levels and recurrent cardiovascular events in patients with varying HCY concentrations.</p> Methods <p>We conducted a 36-month follow-up on 530 patients with coronary heart disease and divided them into low-Lp(a) and high-Lp(a) groups based on Lp(a) levels. The incidence rates of major adverse cardiovascular events (MACE) and acute coronary events (ACE) were compared between the two groups. The association between elevated Lp(a) and cardiovascular risk in different subgroups(based on HCY concentration) was analyzed using Kaplan-Meier curves and Cox proportional hazards models.</p> Results <p>Elevated Lp(a) remained a significant risk factor for both MACE (HR = 2.07, 95% CI = 1.37–3.12, <i>P</i> = 0.001) and ACE (HR = 2.83, 95% CI = 1.67–4.81, <i>P</i> = 0.001) overall. In subgroup analyses, elevated Lp(a) in patients with moderate-to-high HCY levels constituted a high-risk cohort for MACE and ACE occurrence (HR = 1.87, 95% CI = 1.01–3.46, <i>P</i> = 0.046;HR = 2.85, 95% CI = 1.32–6.18, <i>P</i> = 0.008). Among those with low HCY levels, elevated Lp(a) showed no association with either MACE or ACE (<i>P</i> &gt; 0.05).</p> Conclusion <p>When HCY is elevated, patients with increased Lp(a) experience amplified risk of recurrent cardiovascular events. This association shifts when HCY is at low levels. Future efforts should emphasize combined assessment of Lp(a) and HCY and explore targeted intervention strategies to reduce residual cardiovascular risk.</p>