Elevated Lipoprotein A Levels and Development of Moderate or Severe Cardiac Allograft Vasculopathy in Patients with Heart Transplants.

Background: Cardiac allograft vasculopathy (CAV) is a high-incident complication of heart transplant (HT) and is the leading cause of death beyond the first post-HT year. Traditional risk factors have been related to CAV development. Elevated lipoprotein (a) (Lp[a]) is an independent, genetic, and causal risk factor for cardiovascular disease; nonetheless, its association with the development or worsening of CAV in HT has not been firmly established.

Methods: An observational nested case-control study including HT recipients under follow-up in a tertiary center. Lipoprotein (a) levels were determined at the time of inclusion. We considered elevated Lp(a) ≥30 mg/dL. We evaluated the association between Lp(a) levels and the presence and severity of CAV (The International Society For Heart And Lung Transplantation [ISHLT] Cardiac Allograft Vasculopathy Grading Scheme), dividing the sample between No or Mild CAV (0-1) and Moderate-Severe CAV (2-3). Routine coronary angiographies were performed the first year after the transplant and were subsequently symptom-driven.

Results: One hundred fifty patients with HTs were included, with a mean follow-up of 110 ± 77 months. Patients with CAV 2 to 3 presented higher median Lp(a) levels (17 vs 86 mg/dL, P = 0.001). Elevated Lp(a) level was an independent risk factor for developing CAV 2 to 3 (odds ratio 8.57 [95% CI 2.82-26.04]; P < .001). Patients with Lp(a) ≥30 mg also showed an earlier onset compared with those with Lp(a) <30 mg/dL.

Conclusions: Our study suggests that Lp(a) may play a role in the development of CAV. Lipoprotein (a) ≥30 mg/dL defines a subgroup of high-risk patients with HTs as portends to earlier onset and more severe CAV. Lipoprotein (a) determination should be a standard-of-care test in patients with HTs.