Potential utility of the SAFEHEART risk equation for rationalising the use of PCSK9 monoclonal antibodies in adults with heterozygous familial hypercholesterolemia

How Can Implementation Science Improve the Care of Familial Hypercholesterolaemia?

PURPOSE OF REVIEW

Describe the application of implementation science to improve the detection and management of familial hypercholesterolaemia.

RECENT FINDINGS

Gaps between evidence and practice, such as underutilization of genetic testing, family cascade testing, failure to achieve LDL-cholesterol goals and low levels of knowledge and awareness, have been identified through clinical registry analyses and clinician surveys. Implementation science theories, models and frameworks have been applied to assess barriers and enablers in the literature specific to local contextual factors (e.g. stages of life). The effect of implementation strategies to overcome these factors has been evaluated; for example, automated identification of individuals with FH or training and education to improve statin adherence. Clinical registries were identified as a key infrastructure to monitor, evaluate and sustain improvements in care. The expansion in evidence supporting the care of familial hypercholesterolaemia requires a similar expansion of efforts to translate new knowledge into clinical practice.

Efficacy of PCSK9 inhibitors in the treatment of heterozygous familial hypercholesterolemia: A clinical practice experience

BACKGROUND

PCSK9 inhibitors are a treatment option for patients with familial hypercholesterolemia not on low-density lipoprotein cholesterol goals despite the use of maximally tolerated high intensity-statins dose.

OBJECTIVE

To evaluate the efficacy of alirocumab and evolocumab in LDL-C reduction and targets attainment in patients with heterozygous familial hypercholesterolemia in clinical practice setting.

METHODS

SAFEHEART is an open, long-term prospective study of a cohort of subjects with molecular diagnosis of familial hypercholesterolemia. This study analyze subjects ≥ 20 years of age on stable lipid-lowering therapy, who received PCSK9 inhibitors during the period 2016 to January 2020.

RESULTS

433 patients (mean age 55 years, 53% male, 39% with cardiovascular disease) were included and followed-up for a median of 2.5 years (IQR 1.6-3.0). Median LDL-C level prior to PCSK9 inhibitors was 145 mg/dL (IQR 125-173). The addition of PCSK9 inhibitors (211 alirocumab, 222 evolocumab) reduced LDL-C by 58% (IQR 41-70) p<0.001, in men and women, achieving a median LDL-C level of 62 mg/dL (IQR 44-87) without differences between both PCSK9 inhibitors. Out of them 67% with and 80% without cardiovascular disease reached 2016 ESC/EAS LDL-C targets, and 46% very high risk and 50% high risk patients achieved 2019 ESC/EAS LDL-C goals. Independent predictor factors for attainment of 2019 ESC/EAS LDL-C goals were to be male, smoking and the use of statins with ezetimibe. Both inhibitors were well tolerated.

CONCLUSIONS

PCSK9 inhibitors on top of maximum lipid-lowering treatment significantly reduced LDL-C levels in patients with familial hypercholesterolemia and improved the achievement of LDL-C targets.

Barriers to Early Diagnosis and Treatment of Familial Hypercholesterolemia: Current Perspectives on Improving Patient Care

Familial hypercholesterolemia (FH) is a frequent disorder associated with premature atherosclerotic cardiovascular disease. Different clinical diagnosis criteria are available, and cost of genetic testing has been reduced in the last years; however, most cases are not diagnosed worldwide. Patients with FH are at high cardiovascular risk and the risk can be reduced with lifelong lifestyle and pharmacological treatment. Statins and ezetimibe are available as generic drugs in most countries reducing the cost of treatment. However, the use of high-intensity statins combined with ezetimibe and PCSK9 inhibitors, if necessary, is low for different reasons that contribute to a high number of patients not reaching LDL-C targets according to guidelines. On the other hand, cardiovascular risk varies greatly in families with FH; therefore, risk stratification strategies including cardiovascular imaging is another element to consider for improving care and management of FH. There are numerous barriers depending on the awareness, knowledge, perception of risk, management and care of patients living with FH that impact in the diagnosis and treatment of the disorder. In this contemporary review, we analyze different barriers in the diagnosis and care of patients to improve patients’ care and prevention of atherosclerotic cardiovascular disease and describe recent advances and strategies to improve the gaps in the care of FH, including global collaboration and advocacy.

Inflammatory Biomarkers for Cardiovascular Risk Stratification in Familial Hypercholesterolemia

Familial hypercholesterolemia (FH) is a frequent autosomal genetic disease characterized by elevated concentrations of low-density lipoprotein cholesterol (LDL) from birth with increased risk of premature atherosclerotic complications. Accumulating evidence has shown enhanced inflammation in patients with FH. In vessels, the deposition of modified cholesterol lipoproteins triggers local inflammation. Then, inflammation facilitates fatty streak formation by activating the endothelium to produce chemokines and adhesion molecules. This process eventually results in the uptake of vascular oxidized LDL (OxLDL) by scavenger receptors in monocyte-derived macrophages and formation of foam cells. Further leukocyte recruitment into the sub-endothelial space leads to plaque progression and activation of smooth muscle cells proliferation. Several inflammatory biomarkers have been reported in this setting which can be directly synthetized by activated inflammatory/vascular cells or can be indirectly produced by organs other than vessels, e.g., liver. Of note, inflammation is boosted in FH patients. Inflammatory biomarkers might improve the risk stratification for coronary heart disease and predict atherosclerotic events in FH patients. This review aims at summarizing the current knowledge about the role of inflammation in FH and the potential application of inflammatory biomarkers for cardiovascular risk estimation in these patients.

Reducing cardiovascular risk in patients with familial hypercholesterolemia: Risk prediction and lipid management

Familial hypercholesterolemia (FH) is a frequent genetic disorder characterized by elevated low-density lipoprotein (LDL)-cholesterol (LDL-C) levels and early onset of atherosclerotic cardiovascular disease. FH is caused by mutations in genes that regulate LDL catabolism, mainly the LDL receptor (LDLR), apolipoprotein B (APOB) and gain of function of proprotein convertase subtilisin kexin type 9 (PCSK9). However, the phenotype may be encountered in individuals not carrying the latter monogenic defects, in approximately 20% of these effects of polygenes predominate, and in many individuals no molecular defects are encountered at all. These so-called FH phenocopy individuals have an elevated atherosclerotic cardiovascular disease risk in comparison with normolipidemic individuals but this risk is lower than in those with monogenic disease. Individuals with FH are exposed to elevated LDL-C levels since birth and this explains the high cardiovascular, mainly coronary heart disease, burden of these subjects. However, recent studies show that this risk is heterogenous and depends not only on high LDL-C levels but also on presence of previous cardiovascular disease, a monogenic cause, male sex, smoking, hypertension, diabetes, low HDL-cholesterol, obesity and elevated lipoprotein(a). This heterogeneity in risk can be captured by risk equations like one from the SAFEHEART cohort and by detection of subclinical coronary atherosclerosis. High dose high potency statins are the main stain for LDL-C lowering in FH, however, in most situations these medications are not powered enough to reduce cholesterol to adequate levels. Ezetimibe and PCSK9 inhibitors should also be used in order to better treat LDL-C in FH patients.