Epidemiology
High Lp(a) plus high homocysteine triples MACE risk after premature myocardial infarction in a 1,741-patient cohort, validating a '50-15' dual threshold (Front Nutr 2026)
Original title: Prognostic impact of the combined effects of lipoprotein(a) and homocysteine in patients with premature myocardial infarction: a prospective cohort study
This prospective cohort study followed 1,741 patients with premature myocardial infarction (aged 55 or younger) at Tianjin Chest Hospital from January 2018 to June 2023. Over a median follow-up of 19.6 months, 224 patients (12.87%) had a major adverse cardiovascular event. High Lp(a), using the guideline-based 50 mg/dL cutoff, was independently associated with MACE (HR 2.266, 95% CI 1.685-3.046, P < 0.001), as was high homocysteine at a 15 micromol/L threshold (HR 1.597, 95% CI 1.204-2.117, P = 0.001), and patients with both elevated had a 3.566-fold higher risk than those with neither (95% CI 2.427-5.239, P < 0.001), with a significant additive interaction (RERI 1.630, 95% CI 0.314-2.945, P = 0.015). The authors propose this pragmatic '50-15' dual-threshold strategy for risk stratification and suggest B-vitamin or folate supplementation as a low-cost adjunct in dual-elevated patients, though that supplementation benefit itself was not tested here.
Original abstract
Background: Lipoprotein(a) [Lp(a)] is a causal driver of atherosclerosis, yet the interaction between Lp(a)-driven lipid accumulation and a prothrombotic state induced by hyperhomocysteinemia has not been systematically investigated in this high-risk population. From a clinical nutrition perspective, homocysteine (HCY) is a critical modifiable metabolite influenced by B vitamins and folate, making this interaction particularly relevant for dietary or supplementation strategies. This study aims to systematically evaluate the independent and combined prognostic significance of Lp(a) and homocysteine (HCY) in premature myocardial infarction (PMI).
Methods: This prospective cohort study enrolled 1741 PMI patients (aged ≤55 years) at Tianjin Chest Hospital (January 2018-June 2023). Restricted cubic spline (RCS) was used to explore nonlinearity between Lp(a)/HCY and major adverse cardiovascular events (MACE). HCY was analyzed both as a continuous variable and, for exploratory stratification, dichotomized at the clinically referenced threshold of 15 μmol/L. The cutoff for Lp(a) was pre-specified as 50 mg/dL based on clinical guidelines and further validated by maximally selected rank statistics (MSRS). Survival analyses assessed the effects of these factors on MACE. Net reclassification improvement (NRI) and integrated discrimination improvement (IDI) quantified incremental model value.
Results: During a median follow-up of 19.6 months, 224 (12.87%) patients experienced MACE. RCS revealed a nonlinear association between Lp(a) and MACE (p = 0.003), whereas HCY showed no significant nonlinear trend. High Lp(a; HR = 2.266, 95% CI: 1.685-3.046, p < 0.001) and high HCY (HR = 1.597, 95% CI: 1.204-2.117, p = 0.001) are independent MACE risk factors. Compared with the low Lp(a) + low HCY group, the high Lp(a) + high HCY group had a 3.566-fold greater MACE risk (95% CI, 2.427-5.239, p < 0.001). Additive interaction analysis revealed a statistically significant interaction: RERI = 1.630 (95% CI, 0.314-2.945, p = 0.015), AP = 0.456 (95% CI, 0.197-0.716, p < 0.001), SI = 1.840 (95% CI, 0.960-2.719, p = 0.061).
Conclusion: This study systematically characterizes the combined prognostic role of Lp(a) and HCY in PMI patients, validating a pragmatic "50-15" dual-threshold strategy for MACE risk stratification. The findings support a precision nutrition approach, suggesting that patients with dual elevation may benefit from targeted B-vitamin or folate supplementation as a low-cost adjunctive strategy.
Summary written by lp-a.org from the published abstract; figures as published. Page updated 17 August 2026. Methods.