The PCSK9 inhibitor alirocumab, combined with a statin, appeared to reduce LDL cholesterol levels by more than 50% in patients after a heart transplant, findings of a clinical trial—CAVIAR—have shown.
William F Fearon (Stanford University School of Medicine, Stanford, USA) presented findings of the study in a late-breaking science presentation at the American Heart Association (AHA) 2025 scientific sessions (7–10 November, New Orleans, USA).
“Our study found treating patients who have had a heart transplant with a more aggressive cholesterol management regimen was safe and lowered their LDL-cholesterol levels significantly,” said Fearon. “These results support PCSK9 inhibitors for patients who have high LDL cholesterol levels in conjunction with statin therapy, however, we need more studies testing treatment with PCSK9 inhibitors with longer term follow-up with more participants to confirm if PCSK9s can reduce the development of cardiac allograft vasculopathy.”
In the trial researchers tested the safety and effectiveness of adding alirocumab to a statin regimen among patients soon after a heart transplant to prevent the development of cardiac allograft vasculopathy (CAV). CAV is common and the primary cause of death for many patients after a heart transplant.
The study, which included more than 100 adults after a heart transplant, also evaluated the change in coronary artery plaque volume soon after the heart transplant through one year later. Participants were assigned to take either alirocumab or a placebo, together with rosuvastatin, a commonly prescribed cholesterol-lowering medication.
The trial results showed that one-year post-transplant, alirocumab plus rosuvastatin was safe and effectively lowered LDL cholesterol. The cholesterol-lowering impact of taking both medications was beyond what was achieved with rosuvastatin alone. Coronary plaque reduction was not significant in either group though, and there was no statistically significant difference between the plaque progression in the groups.
After one year, the study found the average LDL cholesterol levels decreased by more than 50% among participants in the alirocumab group—from 72.7mg/dL at enrolment to 31.5mg/dL. The average LDL cholesterol levels among participants in the placebo group did not statistically change from the average 69mg/dL at enrolment.
Although the coronary artery plaque volume increased numerically in both groups from baseline to 12 months, there was no change in plaque volume between the alirocumab and placebo group. Plaque progression was minimal in both the alirocumab groups and the placebo group.
There were no significant side effects in either group.
The study had some limitations, with researchers noting that because there was less plaque progression than expected between both groups and because the LDL levels were low at baseline in the rosuvastatin alone (placebo) arm, the study power to detect a difference when adding alirocumab was reduced.
