Dyslipidemia is common in patients after transplant. While statins are the mainstay of therapy, interactions with immunosuppressants such as calcineurin inhibitors (CNIs) can limit dose titration or lead to intolerance of this important drug class. Withdrawal of statin therapy can precipitate hyperlipidemia and potentially accelerate cardiovascular disease in transplant recipients, including coronary allograft vasculopathy (CAV) in heart transplant (HT) patients. Proprotein convertase subtilisin-kexin type 9 inhibitors (PCSK9i) may provide a safe, effective option for such patients. PCSK9i profoundly reduce low-density lipoprotein (LDL) and subsequently the risk of cardiovascular events in nontransplant patients. Further, these novel agents have no known interactions with CNIs. There is a paucity of data describing PSCK9i use post-transplant, with only a few small case series reported in HT recipients. Here, we summarize our experience along with available literature on this topic.
In this retrospective case series we investigated adult recipients of heart transplant who were treated with PCSK9 inhibitors from July 2015 to 2019 because of statin intolerance or refractory hyperlipidemia. We compared the data of patients at baseline and after various durations of therapy with the PSCK9i evolocumab and alirocumab using the median and interquartile range (IQR). Specifically, we evaluated PCSK9i efficacy, effect on immunosuppressant levels, cardiac function and adverse events.
Five patients (4 men; median age 54, IQR 52-60) underwent heart transplant an average of 7.4 years ago. Median treatment duration of evolocumab or alirocumab was 12 months (IQR 7-17). This led to a reduction of total cholesterol by 94 mg/dl (p=0.04) (47% decrease) and LDL cholesterol by 83 mg/dl (p=0.04) (69% decrease). No statistically significant difference in HDL cholesterol, triglycerides or liver function tests (LFTs) were observed. There were no episodes of rejection. Immunosuppressant levels remained at goal. One patient noted a few days of fatigue after alirocumab injections but otherwise no side effects were reported.
The PCSK9 inhibitors evolocumab and alirocumab are promising alternatives to statin therapy in transplant recipients with statin intolerance or refractory hyperlipidemia. Our study showed their potential to significantly reduce LDL cholesterol in heart transplant patients without altering IST levels. No episodes of transplant rejection were noted. Further long-term studies to establish the safety and efficacy of PSCK9 inhibitors post-transplant are needed.