PCSK9 Inhibitors: From Nature's Lessons to Clinical Utility.

BACKGROUND: Proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors are a novel class of non-statin lipid lowering therapy that reduce LDL-cholesterol by 50 - 60%. PCSK9 inhibitors decrease LDL-cholesterol by preventing intracellular degradation of LDL receptors; subsequently, a greater number of LDL-receptors are available on the cell surface to extract circulating LDL. OBJECTIVE: To describe the origins of PCSK9 inhibitors and their current use in clinical practice. METHODS: We performed a narrative review of the PCSK9 inhibitor class of drugs. RESULTS: Current data indicate that PCSK9 inhibitors effectively reduce LDL-cholesterol and are well tolerated and safe. PCSK9 inhibitors have also been shown to reduce cardiovascular event rates in patients with stable atherosclerotic cardiovascular disease and in patients with a recent (up to one year) acute coronary syndrome. Given the costs, chronicity of the treatment and the potential budget impact, PCSK9 inhibitors are often limited to patients with the highest absolute risk for major adverse cardiovascular events despite optimal treatment with high-intensity statin and ezetimibe. CONCLUSION: PCSK9 inhibitors have a favorable safety, efficacy and tolerability profile. Postmarketing safety surveillance and real-world studies are needed to further support the long-term safety profile of this class of medicine.

Paraoxonase (PON)-1: a brief overview on genetics, structure, polymorphisms and clinical relevance.

Paraoxonase-1 (PON1) is a high-density lipoprotein-associated esterase and is speculated to play a role in several human diseases including diabetes mellitus and atherosclerosis. Low PON1 activity has been associated with increased risk of major cardiovascular events, therefore a variety of studies have been conducted to establish the cardioprotective properties and clinical relevance of PON1. The major aim of this review was to highlight the important studies and to subsequently assess if PON1 has clinical relevance. A review of the literature showed that there is currently insufficient data to suggest that PON1 has clinical relevance. It is our opinion that robust studies are required to clarify the clinical relevance of PON1.