Circulating Lp-PLA2 is associated with high valvuloarterial impedance and low arterial compliance in patients with aortic valve bioprostheses

Background: We previously reported that plasma Lp-PLA2 was associated with aortic valve disease progression and degeneration of bioprostheses. Low systemic arterial compliance and high valvuloarterial impedance (Z_va) are predictors of poor survival in patients with aortic valve disease. However, the prevalence of high Z_va after AVR is largely unknown and whether Lp-PLA2 could predict Z_va has not been documented. We investigated the relationships between plasma lipoprotein-associated phospholipase A2 (Lp-PLA2) mass and activity and valvuloarterial impedance (Z_va), an index of global LV hemodynamic load, in patients that underwent aortic valve replacement (AVR). Methods: A total of 195 patients with aortic bioprostheses underwent echocardiographic assessment of the prosthetic aortic valve function 8 ± 3.4 years after AVR. Lp-PLA2 mass and activity were measured. Results: In this group of patients, the mean Z_va was elevated (5.73±1.21 mm Hg·ml^-1·m²). In univariate analyses, Lp-PLA2 mass (p=0.003) and Lp-PLA2 activity (p=0.046) were associated with Z_va. After adjustment for covariates including age, gender, clinical risk factors, anti-hypertensive medications, body mass index and prosthesis size, Lp-PLA2 mass was associated with high Z_va (≥4.5 mm Hg·ml^-1·m²) (OR: 1.29, 95%CI: 1.10-1.53; p=0.005) and was inversely related with the systemic arterial compliance (β=-0.01, SEM=0.003; p=0.003). Conclusions: An increased Z_va, an index of excessive hemodynamic load, was highly prevalent 8-year post-AVR and was independently related to circulating Lp-PLA2.