P282 - ASSOCIATION BETWEEN LIPOPROTEIN(A), OXIDIZED PHOSPHOLIPIDS AND BIOPROSTHETIC VALVE DYSFUNCTION FOLLOWING TRANSCATHETER AORTIC VALVE IMPLANTATION

Background: Lipoprotein(a) [Lp(a)] and oxidized phospholipids (OxPL) are involved in the initiation and progression of aortic stenosis (AS). Their association with Valve Academic Research Consortium-3 (VARC-3) criteria for bioprosthetic valve dysfunction (BVD) after transcatheter aortic valve implantation (TAVI) remains unclear. The objective of the present study was to investigate the association between Lp(a) and OxPL levels and the development of BVD following TAVI.

METHODS AND RESULTS: This analysis included 210 patients with severe AS treated with TAVI between January 2017 and 2020, enrolled in the TAVI-B study. Clinical and echocardiographic data were collected before the procedure and at one year. Lp(a), OxPL-apoB, OxPL-apo(a) were measured using chemiluminescent immunoassays, and their association with BVD was assessed using logistic regression. The mean age of the study population was 79.7±8.2 years and 120 (57.1%) were males. 25 (12%) patients developed BVD at 1 year following TAVI. Of these 25 patients, 9 (36%) had BVD stage 1 (morphological deterioration), 14 (56%) Stage 2 (moderate hemodynamic valve deterioration), and 2 (8%) stage 3 (severe hemodynamic valve deterioration). The etiology of BVD was SVD in 9/25 (36%), subclinical leaflet thrombosis (SLT) in 6/25 (24%) and undetermined in 10/25 (40%). Lp(a) (38.9 [8.5–123.6] nmol/L) and OxPL-apoB (9.0 [4.7–16.4] nmol/L) levels were significantly higher in patients with BVD. At 1 year post-TAVI, patients with Lp(a) ≥30 nmol/L had a higher incidence of: i) overall BVD (25 [18.5%] vs. 10 [7.8%], p=0.027; OR [95% CI]: 2.77 [1.08–7.08], p=0.033), ii) Stage 2 or 3 BVD (12 [8.6%] vs. 4 [2.3%], p=0.002); OR [95% CI]: 5.43 [1.58–17.48], p= 0.005, and iii) SLT (5 [6.2%] vs. 1 [0.8%], p=0.022). However, during a median follow-up of 2.6 years (IQR 2.2–3.6), neither Lp(a) ≥30 nmol/L nor BVD was associated with an increased risk of all-cause mortality (HR [95% CI]: 1.04 [0.54–2.00], p=0.89 and HR [95% CI]: 0.99 [0.35–2.82], p=0.99) respectively.

Conclusion: Elevated plasma levels of Lp(a) and OxPL-apoB were associated with an increased risk of BVD at 1-year follow-up. These findings emphasize the need for randomized clinical trials to determine whether Lp(a)-lowering therapies can reduce the risk of BVD and SVD, thereby improving valve durability and clinical outcomes after TAVI.