Mechanisms
Elevated Lp(a) predicts mechanical prosthetic heart valve thrombosis, with a threshold above 19.6 mg/dL flagging risk (J Artif Organs 2025)
Original title: Lipoprotein (a) as a risk factor for prosthetic heart valve thrombosis
This cross-sectional study compared Lp(a) in 80 patients with mechanical prosthetic valve thrombosis (MPVT, median age 48.5 years, 47 male) against 75 age- and sex-matched controls with normally functioning mechanical valves. Lp(a) was significantly higher in the MPVT group than controls (22 [16.2-39.4] vs. 6.9 [2.9-24.6] mg/dL, P < 0.001). Elevated Lp(a), recent subtherapeutic anticoagulation, history of cerebrovascular accident, and a low admission INR were independent predictors of MPVT, and Lp(a) above 19.6 mg/dL predicted MPVT with 65% sensitivity and 71% specificity (AUC 0.767, 95% CI 0.687-0.847, P < 0.001); Lp(a) was also higher in MPVT patients with a prior cerebrovascular event (42.0 vs. 21.1 mg/dL, P = 0.012). The authors propose Lp(a), which competes with plasminogen and stimulates plasminogen activator inhibitor-1, as an additive marker for identifying prosthetic valve patients at risk of thrombosis and stroke.
Original abstract
Genetic and numerous epidemiologic studies have identified lipoprotein (a) [Lp(a)] as a risk factor for atherothrombotic diseases. The structure of Lp(a) is similar to plasminogen and tissue plasminogen activator and it competes with plasminogen for its binding site, leading to reduced fibrinolysis. Furthermore, since Lp(a) stimulates the secretion of plasminogen activator inhibitor-1, it may lead to thrombogenesis. In this cross-sectional study, we aimed to investigate Lp(a) levels in patients with mechanical prosthetic valve thrombosis (MPVT). Blood samples for Lp(a) determination were obtained from 80 MPVT patients (median age: 48.5 (39-59.75) years; 47 male) and 75 age and sex matched controls (median age: 52 (39-63) years; 44 male) with normally functioning mechanical prosthetic valves. The Lp(a) levels in the PVT group were significantly higher than in the controls [22(16.2-39.4) vs. 6.9(2.9-24.6) mg/dL, p < 0.001]. Elevated Lp(a) levels, recent history of subtherapeutic anticoagulation, history of cerebrovascular accidents (CVA) and a low value of international normalized ratio on admission were found to be the independent predictors of PVT. Lp(a) levels above 19.6 mg/dL predicted PVT with a sensitivity of 65% and a specificity of 71% (AUC:0.767; 95%CI: 0.687 to 0.847; p < 0.001). Lp(a) levels were significantly higher in PVT patients with a history of CVA [42.0 (23.6-53.6) vs. 21.1 (16.1- 36.2) mg/dL, p = 0.012]. Elevated Lp(a) levels may be associated with MPVT. The assessment of plasma Lp(a) levels in patients with prosthetic heart valves may provide additive information regarding the risk of PVT and CVA.
Summary written by lp-a.org from the published abstract; figures as published. Page updated 17 August 2026. Methods.