Association between lipoprotein (a) levels and cardiac allograft vasculopathy among heart transplant recipients: Insights from a single-center cohort.

BACKGROUND: Serum lipoprotein (a) [Lp(a)] is a causal risk factor for atherosclerotic cardiovascular disease in the general population, but its association with cardiac allograft vasculopathy (CAV) development has not been firmly established. OBJECTIVE: To assess the distribution of Lp(a) levels in heart transplant (HT) recipients and evaluate the correlation between Lp(a) levels and the presence and severity of CAV. METHODS: A retrospective observational cohort study encompassing 271 adult HT recipients on regular outpatient follow-up in a tertiary center. Lp(a) concentration was assessed during the last follow-up visit and compared between patients with and without clinically significant CAV, International Society for Heart and Lung Transplantation (grade 2-3 vs 0-1). RESULTS: Median serum Lp(a) concentration was 40 nmol/L; 62 patients (23%) had Lp(a) >125 nmol/L. Median Lp(a) levels did not significantly differ between patients with CAV 0-1 and patients with CAV 2-3 (median 37 vs 55 nmol/L, P = .408). High (>125 nmol/L) Lp(a) levels were not associated with CAV 2-3, neither on univariable nor on multivariable analysis (hazard ratio multivariate 1.02, 95% CI: 0.35-2.95, P = .977). Elevated Lp(a) concentrations (>75, >125, >200 nmol/L) did not show significant correlation with either CAV 2-3 nor with CAV 1-2-3. Older donor age was significantly related to CAV development (+1.018% increase of CAV for every year of increase of donor age, P value .009). CONCLUSION: Elevated serum Lp(a) levels were not associated with the presence and severity of CAV in patients with HT with long post-transplant follow-up. The relationship between Lp(a) and CAV warrants further investigation, given the small sample of the current study.