byAmerican Heart Association

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The cholesterol medication alirocumab, a PCSK9 inhibitor, combined with a statin appeared to reduce LDL cholesterol levels by more than 50% among patients after a heart transplant, according to a late-breaking science presentation today at the American Heart Association'sScientific Sessions 2025. The meeting, held Nov. 7–10 in New Orleans, is a premier global exchange of the latest scientific advancements, research and evidence-based clinical practice updates in cardiovascular science. The research has been simultaneouslypublishedinCirculation.

"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 study author William F. Fearon, M.D., FAHA, a professor of medicine and chief of interventional cardiology at Stanford University School of Medicine in Stanford, California.

"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."

According to the American Heart Association, high LDL (low-density lipoprotein) cholesterol, known as "bad" cholesterol, has no symptoms, but it can increase risk for cardiovascular issues because it can cause plaque to build up in the arteries. This buildup may block blood flow or break loose and cause aheart attackor stroke.

In this clinical trial, called CAVIAR (Cardiac Allograft Vasculopathy Inhibition with AliRocumab), researchers tested the safety and effectiveness of adding the PCSK9 inhibitor 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 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. Based on various research studies, the American Heart Association recommends a "lower is better" approach for cholesterol, especially LDL-C, rather than a single ideal number for everyone. Forhealthy adults, an LDL-C level below 100 mg/dl is considered ideal. For those with pre-existing conditions like atherosclerotic cardiovascular disease or diabetes, target levels are more stringent and the guidelines focus on reducing LDL-C to 70 mg/dL or lower.

Study details, background and design:

CAV, which causes narrowing and blockage of vessels supplying blood to the heart, is a common complication after aheart transplantand a primary cause of death after a transplant. High LDL cholesterol is a contributing factor to CAV, and it is usually treated with statins. Treatment with statins alone, however, often falls short in achieving the target levels for low cholesterol.

More information: William F. Fearon et al, Cardiac Allograft Vasculopathy Inhibition with Alirocumab:The CAVIAR Trial, Circulation (2025). DOI: 10.1161/circulationaha.125.077603 Journal information: Circulation

Provided by American Heart Association