Major cardiovascular events increase in long-term proprotein convertase subtilisin/kexin type 9 inhibitors therapy: the Tuscany cost-effective study

BACKGROUND

Proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) represent a breakthrough in the treatment of hypercholesterolemia. The aim of this study was to perform a multicentre prospective analysis on the effects of PCSK9i since their distribution in Italy.

METHODS

During the study period (July 2017 to February 2022) 246 patients (mean age 61 ± 11 years, male 73%) who were evolocumab (142/246) or alirocumab (104/246) new users were enrolled in the CERTI (Costo Efficacia Regione Toscana Inibitori PCSK9) study. Lipid value, adverse events (AEs), major cardiovascular events (MACEs) and intima-media thickness were analysed.

RESULTS

PCSK9i therapy allowed a significant improvement in patients' lipid profile [total cholesterol -35%, P < 0.001; triglycerides -9%, P < 0.05; low-density lipoprotein (LDL) cholesterol -51%, P < 0.001; Lp(a) levels -4%, P < 0.05], maintained during the follow-up. No significant variations in intima-media thickness were observed. In the subgroup of patients with more than 1 year of PCSK9i therapy (165/246 patients) we highlighted: a 66% reduction in MACEs compared with the year before recruitment; a progressive increase in MACEs during the follow-up (MACEs event/rate at first year 0.08 vs. MACEs event/rate at year 5: 0.47); a patients cluster with late MACEs older, with higher prevalence of hypertension, smoking habit and peripheral vascular disease. During the follow-up, we recorded AEs in 31% of patients, which mainly resulted in reduction/discontinuation of lipid-lowering therapy for 50 patients or in discontinuation/shift of PCSK9i (respectively 8 and 6 cases).

CONCLUSION

Our data agree with the large evidence on the effectiveness/tolerability of PCSK9i therapy; however, although PCSK9i represents a good cholesterol-lowering therapeutic option, our study shows a progressive increase in MACEs during the late follow-up that deserve further research.

Recent advances in the management and implementation of care for familial hypercholesterolaemia

Familial hypercholesterolaemia (FH) is a common autosomal semi-dominant and highly penetrant disorder of the low-density lipoprotein (LDL) receptor pathway, characterised by lifelong elevated levels of low-density lipoprotein cholesterol (LDL-C) and increased risk of atherosclerotic cardiovascular disease (ASCVD). However, many patients with FH are not diagnosed and do not attain recommended LDL-C goals despite maximally tolerated doses of potent statin and ezetimibe. Over the past decade, several cholesterol-lowering therapies such as those targeting proprotein convertase subtilisin/kexin type 9 (PCSK9) or angiopoietin-like 3 (ANGPTL3) with monoclonal antibody or ribonucleic acid (RNA) approaches have been developed that promise to close the treatment gap. The availability of new therapies with complementary modes of action of lipid metabolism has enabled many patients with FH to attain guideline-recommended LDL-C goals. Emerging therapies for FH include liver-directed gene transfer of the LDLR, vaccines targeting key proteins involved in cholesterol metabolism, and CRISPR-based gene editing of PCSK9 and ANGPTL3, but further clinical trials are required. In this review, current and emerging treatment strategies for lowering LDL-C, and ASCVD risk-stratification, as well as implementation strategies for the care of patients with FH are reviewed.

PCSK9 Antibody-based Treatment Strategies for Patients With Statin Intolerance

BACKGROUND

Statin intolerance refers to the inability of a patient to tolerate statin therapy, presenting muscle aches, pains, weakness and muscle inflammation. Thus, numerous patients are not treated with suitable statin-based therapy or take only very low doses. As a result, the desired decrease in low-density lipoprotein cholesterol (LDL-C) is not achieved, resulting in patients at a high risk for cardiovascular events, requiring an alternative lipid-lowering treatment. Common treatments manage to reduce the LDL-C level by up to 20%. Recently, new alternative treatment options have been proved to lower the LDL-C level by up to 70%. These treatment strategies are based on human monoclonal antibodies against protein convertase subtilisin/kexin 9 (PCSK9).

MATERIALS AND METHODS

Herein, we review the efficiency of anti-PCSK9 in treatment of hypercholesterolemic patients with statin intolerance. We focused on the use of PCSK9 inhibitors in statin-intolerant patients and we estimated the clinical results concerning the reduction of the mean LDL-C concentration and the side effects that were observed.

RESULTS

In the majority of cases, treatment strategy based on PCSK9 was successful and achieved the end-points.

CONCLUSION

PCSK9 inhibition can be considered as a treatment of option for lipid-lowering in statin-intolerant patients.

From lipoprotein apheresis to proprotein convertase subtilisin/kexin type 9 inhibitors: Impact on low-density lipoprotein cholesterol and C-reactive protein levels in cardiovascular disease patients

In this observational study, we compared the effect of lipoprotein apheresis and evolocumab or alirocumab on levels of lipoprotein cholesterol, triglycerides and inflammatory markers (C reactive protein and interleukin 6) in cardiovascular patients ( n = 9). Patients were monitored during the last year of lipoprotein apheresis followed by six months of treatment with proprotein convertase subtilisin/kexin type 9 inhibitors. The biochemical parameters were determined pre- and post- every apheresis procedure for 12 months and then after one, three and six months of treatment with evolocumab (140 mg every two weeks [Q2W]) or alirocumab (75 mg or 150 mg every two weeks [Q2W]). Lipoprotein apheresis significantly reduced low-density lipoprotein cholesterol levels from 138 ± 32 mg/dl to 46 ± 16 mg/dl ( p < 0.001), with an inter-apheresis level of 114 ± 26 mg/dl. Lipoprotein(a) was also reduced from a median of 42 mg/dl to 17 mg/dl ( p < 0.01). Upon anti-proprotein convertase subtilisin/kexin type 9 therapy, low-density lipoprotein cholesterol levels were similar to post-apheresis (59 ± 25, 41 ± 22 and 42 ± 21mg/dl at one, three and six months, respectively) as well as those of lipoprotein(a) (18 mg/dl). However, an opposite effect was observed on high-density lipoprotein cholesterol levels: –16.0% from pre- to post-apheresis and +34.0% between pre-apheresis and proprotein convertase subtilisin/kexin type 9 inhibitors. Apheresis significantly reduced high-sensitivity C-reactive protein levels (1.5 ± 1.2 mg/l pre-apheresis to 0.6 ± 0.6 mg/l post-apheresis), while no changes were found upon proprotein convertase subtilisin/kexin type 9 mAbs administration. In conclusion, our study demonstrated that, by switching from lipoprotein apheresis to anti-proprotein convertase subtilisin/kexin type 9 therapies, patients reached similar low-density lipoprotein cholesterol and lipoprotein(a) levels, increased those of high-density lipoprotein cholesterol, and showed no changes on high-sensitivity C-reactive protein.

Familial hypercholesterolaemia

Familial hypercholesterolaemia is a common inherited disorder characterized by abnormally elevated serum levels of low-density lipoprotein (LDL) cholesterol from birth, which in time can lead to cardiovascular disease (CVD). Most cases are caused by autosomal dominant mutations in LDLR, which encodes the LDL receptor, although mutations in other genes coding for proteins involved in cholesterol metabolism or LDLR function and processing, such as APOB and PCSK9, can also be causative, although less frequently. Several sets of diagnostic criteria for familial hypercholesterolaemia are available; common diagnostic features are an elevated LDL cholesterol level and a family history of hypercholesterolaemia or (premature) CVD. DNA-based methods to identify the underlying genetic defect are desirable but not essential for diagnosis. Cascade screening can contribute to early diagnosis of the disease in family members of an affected individual, which is crucial because familial hypercholesterolaemia can be asymptomatic for decades. Clinical severity depends on the nature of the gene that harbours the causative mutation, among other factors, and is further modulated by the type of mutation. Lifelong LDL cholesterol-lowering treatment substantially improves CVD-free survival and longevity. Statins are the first-line therapy, but additional drugs, such as ezetimibe, bile acid sequestrants, PCSK9 inhibitors and other emerging therapies, are often required.