Effects of Evolocumab Added to Moderate-Intensity Statin Therapy in Chinese Patients With Acute Coronary Syndrome: The EMSIACS Trial Study Protocol

PCSK9 Inhibitors "Fast Track" Use Versus "Stepwise" Lipid-Lowering Therapy in Patients with Acute Coronary Syndrome: A Retrospective Single-Center Study in a "Real-World" Population

Background: The "fast track" addition (within 48 h) of proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) to the optimized oral lipid-lowering therapy (LLT) during hospitalization for acute coronary syndrome (ACS) has been shown to rapidly achieve the low-density lipoprotein cholesterol (LDL-C) therapeutic targets. However, so far, its efficacy in real-world settings remains understudied. Methods: We retrospectively analyzed 128 ACS patients treated at our center, comparing "PCSK9i fast track" use within 48 h to standard "stepwise" LLT. Lipid levels and incidence of major adverse cardiovascular events (MACEs) were evaluated at 30 and 180 days. Results: The "PCSK9i fast track" group achieved significantly lower LDL-C levels at 30 days (41.5 ± 27.5 vs. 85.6 ± 35.9 mg/dL, p < 0.001) and 180 days (29.6 ± 21.0 vs. 59.0 ± 32.4 mg/dL, p < 0.001). Recommended LDL-C targets (<55 mg/dL) were met by 88.3% of the "PCSK9i fast track" group at 180 days, compared with 61.9% of controls (p < 0.001). No significant differences in MACEs were observed between groups. No adverse effects from PCSK9i use were noted. Conclusions: The "PCSK9i fast track" strategy was safe and effective in achieving LDL-C targets more rapidly than conventional approaches in real-world ACS patients.

Soluble PCSK9 Inhibition: Indications, Clinical Impact, New Molecular Insights and Practical Approach-Where Do We Stand?

Current research on cardiovascular prevention predominantly focuses on risk-stratification and management of patients with coronary artery disease (CAD) to optimize their prognosis. Several basic, translational and clinical research efforts aim to determine the etiological mechanisms underlying CAD pathogenesis and to identify lifestyle-dependent metabolic risk factors or genetic and epigenetic parameters responsible for CAD occurrence and/or progression. A log-linear association between the absolute exposure of LDL cholesterol (LDL-C) and the risk of atherosclerotic cardio-vascular disease (ASCVD) was well documented over the year. LDL-C was identified as the principal enemy to fight against, and soluble proprotein convertase subtilisin kexin type 9 (PCSK9) was attributed the role of a powerful regulator of blood LDL-C levels. The two currently available antibodies (alirocumab and evolocumab) against PCSK9 are fully human engineered IgG that bind to soluble PCSK9 and avoid its interaction with the LDLR. As documented by modern and dedicated "game-changer" trials, antibodies against soluble PCSK9 reduce LDL-C levels by at least 60 percent when used alone and up to 85 percent when used in combination with high-intensity statins and/or other hypolipidemic therapies, including ezetimibe. Their clinical indications are well established, but new areas of use are advocated. Several clues suggest that regulation of PCSK9 represents a cornerstone of cardiovascular prevention, partly because of some pleiotropic effects attributed to these newly developed drugs. New mechanisms of PCSK9 regulation are being explored, and further efforts need to be put in place to reach patients with these new therapies. The aim of this manuscript is to perform a narrative review of the literature on soluble PCSK9 inhibitor drugs, with a focus on their indications and clinical impact.

Impact of evolocumab on the pharmacodynamic profiles of clopidogrel in patients with atherosclerotic cardiovascular disease: a randomised, double-blind, placebo-controlled study

BACKGROUND

The impact of intense low-density lipoprotein cholesterol (LDL-C) reduction using a proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor on profiles of platelet reactivity has yet to be explored.

AIMS

Our aim was to investigate the effects of the PCSK9 inhibitor, evolocumab, on platelet reactivity in patients with atherosclerotic cardiovascular disease (ASCVD) on clopidogrel treatment.

METHODS

This was a prospective, randomised, double-blind, placebo-controlled pharmacodynamic study in patients with ASCVD on clopidogrel treatment and with LDL-C levels ≥70 mg/dL despite a maximally tolerated statin dose. Patients were stratified according to levels of platelet reactivity using VerifyNow P2Y12 reactivity units (PRU) into high platelet reactivity (HPR; PRU >208) or normal platelet reactivity (NPR; PRU >85 and ≤208). Each cohort was randomised to receive evolocumab 420 mg or placebo. The primary endpoint was the difference in PRU at 30 days.

RESULTS

A total of 84 patients (HPR, n=37 [19 evolocumab vs 18 placebo]; NPR, n=47 [22 evolocumab vs 25 placebo]) were included. Evolocumab significantly reduced LDL-C compared to placebo at 14 (p<0.001) and 30 (p=0.001) days. At 14 days, PRU levels were significantly lower with evolocumab compared to placebo in the HPR (218.2±29.7 vs 246.6±35.2; p=0.017), but not in the NPR cohort (141.2±42.8 vs 148.2±41.7; p=0.578). At 30 days, there were no significant differences in PRU in the HPR (219.3±38.3 vs 240.9±51.8; p=0.161) or NPR (141.5±54.3 vs 158.6±40.8; p=0.229) cohorts.

CONCLUSIONS

Compared to placebo, evolocumab in adjunct to statin therapy did not significantly reduce platelet reactivity at 30 days in ASCVD patients on clopidogrel treatment despite intense LDL-C reduction. ClinicalTrials.gov: NCT03096288.

Pharmacological rationale for the very early treatment of acute coronary syndrome with monoclonal antibodies anti-PCSK9

Immediate and aggressive lipid lowering therapies after acute coronary syndromes (ACS) and percutaneous coronary interventions (PCI) are supported by the ESC/EAS dyslipidemia guidelines, recommending the initiation of high-intensity statin therapy within the first 1-4 days of hospitalization. However, whether non statin lipid-lowering agents, added to statin treatment, could produce a further reduction in the risk of major adverse cardiovascular events (MACE) is still unknown. Thus, the efficacy of early treatment post-ACS with monoclonal antibodies (mAbs) anti PCSK9, evolocumab and alirocumab, is under investigation. The rationale to explore the rapid and aggressive pharmacological intervention with PCSK9 mAbs is supported by at least five confirmatory data in ACS: 1) circulating PCSK9 levels are raised during ACS 2) PCSK9 may stimulate platelet reactivity, this last being pivotal in the recurrence of ischemic events; 3) PCSK9 is associated with intraplaque inflammation, macrophage activation and endothelial dysfunction; 4) PCSK9 concentrations are associated with inflammation in the acute phase of ACS; and 5) statins raise PCSK9 levels promptly and, at times, dramatically. In this scenario, appropriate pharmacodynamic characteristics of anti PCSK9 therapies are a prerequisite for an effective response. Monoclonal antibodies act on circulating PCSK9 with a direct and rapid binding by blocking the interaction with the low-density lipoprotein receptor (LDLR). Evolocumab and alirocumab show a very rapid (within 4 h) and effective suppression of circulating unbound PCSK9 (- 95 % ÷ - 97 %). This inhibition results in a significant reduction of LDL-cholesterol (LDL-C) after 48 h (- 35 %) post injection with a full effect after 7-10 days (55-75 %). The complete and swift inhibitory action by evolocumab and alirocumab could have a potential clinical impact in ACS patients, also considering their potential inhibition of PCSK9 within the atherosclerotic plaque. Thus, administration of evolocumab or alirocumab is effective in lowering LDL-C levels in ACS, although the efficacy to prevent further cardiovascular (CV) events is still undetermined. The answer to this question will be provided by the ongoing clinical trials with evolocumab and alirocumab in ACS. In the present review we will discuss the pharmacological and biological rationale supporting the potential use of PCSK9 mAbs in ACS patients and the emerging evidence of evolocumab and alirocumab treatment in this clinical setting.