Non-response to (statin) therapy: the importance of distinguishing non-responders from non-adherers in pharmacogenetic studies

The potential benefit of statin prescription based on prediction of treatment responsiveness in older individuals: an application to the PROSPER randomized controlled trial

AIMS

Clinical guidelines often recommend treating individuals based on their cardiovascular risk. We revisit this paradigm and quantify the efficacy of three treatment strategies: (i) overall prescription, i.e. treatment to all individuals sharing the eligibility criteria of a trial; (ii) risk-stratified prescription, i.e. treatment only to those at an elevated outcome risk; and (iii) prescription based on predicted treatment responsiveness.

METHODS AND RESULTS

We reanalysed the PROSPER randomized controlled trial, which included individuals aged 70-82 years with a history of, or risk factors for, vascular diseases. We conducted the derivation and internal-external validation of a model predicting treatment responsiveness. We compared with placebo (n = 2913): (i) pravastatin (n = 2891); (ii) pravastatin in the presence of previous vascular diseases and placebo in the absence thereof (n = 2925); and (iii) pravastatin in the presence of a favourable prediction of treatment response and placebo in the absence thereof (n = 2890). We found an absolute difference in primary outcome events composed of coronary death, non-fatal myocardial infarction, and fatal or non-fatal stroke, per 10 000 person-years equal to: -78 events (95% CI, -144 to -12) when prescribing pravastatin to all participants; -66 events (95% CI, -114 to -18) when treating only individuals with an elevated vascular risk; and -103 events (95% CI, -162 to -44) when restricting pravastatin to individuals with a favourable prediction of treatment response.

CONCLUSION

Pravastatin prescription based on predicted responsiveness may have an encouraging potential for cardiovascular prevention. Further external validation of our results and clinical experiments are needed.

TRIAL REGISTRATION

ISRCTN40976937.

A virus-like particle-based bivalent PCSK9 vaccine lowers LDL-cholesterol levels in non-human primates

Elevated low-density lipoprotein cholesterol (LDL-C) is an important risk factor in the development of atherosclerotic cardiovascular disease (ASCVD). Inhibitors of proprotein convertase subtilisin/kexin type 9 (PCSK9), a negative regulator of LDL-C metabolism, have emerged as promising approaches for reducing elevated LDL-C levels. Here, we evaluated the cholesterol-lowering efficacy of virus-like particle (VLP) based vaccines that target epitopes found within the LDL receptor (LDL-R) binding domain of PCSK9. In both mice and non-human primates, a bivalent VLP vaccine targeting two distinct epitopes on PCSK9 elicited strong and durable antibody responses and lowered cholesterol levels. In macaques, a VLP vaccine targeting a single PCSK9 epitope was only effective at lowering LDL-C levels in combination with statins, whereas immunization with the bivalent vaccine lowered LDL-C without requiring statin co-administration. These data highlight the efficacy of an alternative, vaccine-based approach for lowering LDL-C.

Approach to the Patient With a Suboptimal Statin Response: Causes and Algorithm for Clinical Management

CONTEXT

Statins are the lipid-lowering therapy of choice for the prevention of atherosclerotic cardiovascular disease (ASCVD) but their effectiveness in lowering low-density lipoprotein cholesterol (LDL-C) can substantially differ between individuals. In this mini-review, we describe the different causes for a suboptimal statin response and an algorithm for the diagnosis and clinical management of these patients.

EVIDENCE ACQUISITION

A PubMed search using the terms "statin resistance," "statin sensitivity," "statin pharmacokinetics," "cardiovascular disease," and "lipid-lowering therapies" was performed. Published papers in the past 10 years that were relevant to the topic were examined to provide content for this mini-review.

EVIDENCE SYNTHESIS

Suboptimal lowering of LDL-C by statins is a major problem in the clinical management of patients and limits the value of this therapeutic approach. There are multiple causes of statin hyporesponsiveness with compliance being the most common explanation. Other causes, such as analytical issues with LDL-C measurement and the presence of common lipid disorders (familial hypercholesterolemia, elevated lipoprotein[a] and secondary dyslipidemias) should be excluded before considering primary statin resistance from rare genetic variants in lipoprotein-related or drug-metabolism genes. A wide variety of nonstatin lipid-lowering drugs are now available and can be added to statins to achieve more effective LDL-C lowering.

CONCLUSIONS

The evaluation of statin hyporesponsiveness is a multistep process that can lead to the optimization of lipid-lowering therapy for the prevention of ASCVD. It may also lead to the identification of distinct types of dyslipidemias that require specific therapies and/or the genetic screening of family members.

Vitamin D level regulates serum lipids discrepantly in adults with and without dyslipidemia

Vitamin D deficiency is associated with hyperlipidemia, but it remains unclear whether vitamin D supplementation reduces serum lipid levels. The aims of this study were to investigate the associations between increased serum 25-hydroxyvitamin D (25(OH)D) concentrations and lipid levels and identify the characteristics of people with or without lipid reduction associated with increased 25(OH)D levels. The medical records of 118 individuals (53 men; mean age, 54.4 ± 10.6 years) whose serum 25(OH)D levels increased between 2 consecutive measurements were retrospectively reviewed. People with increased 25(OH)D levels (from 22.7 (17.6-29.2) to 32.1 (25.6-36.8) mg/dL; P < 0.01) had a significant reduction in serum levels of triglycerides (TGs) (from 111.0 (80-164) to 104.5 (73-142) mg/dL; P < 0.01) and total cholesterol (TC) (from 187.5 (155-213) to 181.0 (150-210) mg/dL; P < 0.05). The individuals who responded to vitamin D (≥10% reduction in TG or TC levels) exhibited significantly higher baseline TG and TC levels than those who did not. Only patients with hyperlipidemia (not those without hyperlipidemia) at baseline exhibited significantly reduced TG and TC levels at follow-up. However, increasing serum 25(OH)D concentrations were significantly correlated with decreasing lipid levels in individuals with baseline 25(OH)D levels less than 30 ng/mL and in individuals aged 50-65 years (not in patients younger than 50 years or older than 65 years). In conclusion, increasing serum 25(OH)D concentrations may be potentially helpful for the treatment of hyperlipidemia in people with vitamin D deficiency.

Novel LDLR Variant in Familial Hypercholesterolemia: NGS-Based Identification, In Silico Characterization, and Pharmacogenetic Insights

BACKGROUND

Familial Hypercholesterolemia (FH) is a hereditary condition that causes a rise in blood cholesterol throughout a person's life. FH can result in myocardial infarction and even sudden death if not treated. FH is thought to be caused mainly by variants in the gene for the low-density lipoprotein receptor (LDLR). This study aimed to investigate the genetic variants in FH patients, verify their pathogenicity, and comprehend the relationships between genotype and phenotype. Also, review studies assessed the relationship between the LDLR null variants and the reaction to lipid-lowering therapy.

METHODS

The study utilised high-throughput next-generation sequencing for genetic screening of FH-associated genes and capillary sequencing for cascade screening. Furthermore, bioinformatic analysis was employed to describe the pathogenic effects of the revealed novel variant on the structural features of the corresponding RNA molecule.

RESULTS

We studied the clinical signs of hypercholesterolemia in a Saudi family with three generations of FH. We discovered a novel frameshift variant (c.666_670dup, p.(Asp224Alafs*43) in the LDLR and a known single nucleotide variant (c.9835A > G, p.(Ser3279Gly) in the APOB gene. It is thought that the LDLR variant causes a protein to be prematurely truncated, likely through nonsense-mediated protein decay. The LDLR variant is strongly predicted to be pathogenic in accordance with ACMG guidelines and co-segregated with the FH clinical characteristics of the family. This LDLR variant exhibited severe clinical FH phenotypes and was restricted to the LDLR protein's ligand-binding domain. According to computational functional characterization, this LDLR variant was predicted to change the free energy dynamics of the RNA molecule, thereby affecting its stability. This frameshift variant is thought to eliminate important functional domains in LDLR that are required for receptor recycling and LDL particle binding. We provide insight into how FH patients with a null variant in the LDLR gene respond to lipid-lowering therapy.

CONCLUSIONS

The findings expand the range of FH variants and assist coronary artery disease preventive efforts by improving diagnosis, understanding the genotype-phenotype relationship, prognosis, and personalised therapy for patients with FH.

What are the benefits and drawbacks of statins in carotid artery disease? A perspective review

INTRODUCTION

The prevalence of carotid artery stenosis in the general population is approximately 3%, but approximately 20% among people with acute ischemic stroke. Statins are recommended by multiple international guidelines as the drug of choice for lipid control in people with asymptomatic or symptomatic carotid artery stenosis due to their lipid-lowering and other pleiotropic effects.

AREAS COVERED

This review discusses the guidelines for statin usage as a cornerstone in the prevention and management of atherosclerotic carotid artery disease and the impact of statins on stroke incidence and mortality. Statin side effects, alternative therapy, and genetic polymorphisms are reviewed.

EXPERT OPINION

Statin therapy is associated with a decreased incidence of stroke and mortality as well as improved outcomes for patients treated with carotid revascularization. Statins are a safe and effective class of medications, but the initiation of therapy warrants close monitoring to avoid rare and potentially serious side effects. Lack of clinical efficacy or the presence of side effects suggests a need for treatment with an alternative therapy such as PCSK9 inhibitors. Understanding the interplay between the mechanisms of statins and PCSK9 inhibition therapies will allow optimal benefits while minimizing risks. Future research into genetic polymorphisms may improve patient selection for personalized therapy.

Uncovering Predictors of Lipid Goal Attainment in Type 2 Diabetes Outpatients Using Logic Learning Machine: Insights from the AMD Annals and AMD Artificial Intelligence Study Group

Identifying and treating lipid abnormalities is crucial for preventing cardiovascular disease in diabetic patients, yet only two-thirds of patients reach recommended cholesterol levels. Elucidating the factors associated with lipid goal attainment represents an unmet clinical need. To address this knowledge gap, we conducted a real-world analysis of the lipid profiles of 11.252 patients from the Annals of the Italian Association of Medical Diabetologists (AMD) database from 2005 to 2019. We used a Logic Learning Machine (LLM) to extract and classify the most relevant variables predicting the achievement of a low-density lipoprotein cholesterol (LDL-C) value lower than 100 mg/dL (2.60 mmol/L) within two years of the start of lipid-lowering therapy. Our analysis showed that 61.4% of the patients achieved the treatment goal. The LLM model demonstrated good predictive performance, with a precision of 0.78, accuracy of 0.69, recall of 0.70, F1 Score of 0.74, and ROC-AUC of 0.79. The most significant predictors of achieving the treatment goal were LDL-C values at the start of lipid-lowering therapy and their reduction after six months. Other predictors of a greater likelihood of reaching the target included high-density lipoprotein cholesterol, albuminuria, and body mass index at baseline, as well as younger age, male sex, more follow-up visits, no therapy discontinuation, higher Q-score, lower blood glucose and HbA1c levels, and the use of anti-hypertensive medication. At baseline, for each LDL-C range analysed, the LLM model also provided the minimum reduction that needs to be achieved by the next six-month visit to increase the likelihood of reaching the therapeutic goal within two years. These findings could serve as a useful tool to inform therapeutic decisions and to encourage further in-depth analysis and testing.

A Virus-like particle-based bivalent PCSK9 vaccine lowers LDL-cholesterol levels in Non-Human Primates

Elevated low-density lipoprotein cholesterol (LDL-C) is an important risk factor in the development of atherosclerotic cardiovascular disease (ASCVD). Inhibitors of proprotein convertase subtilisin/kexin type 9 (PCSK9), a negative regulator of LDL-C metabolism, have emerged as promising approaches for reducing elevated LDL-C levels. Here, we evaluated the cholesterol lowering efficacy of virus-like particle (VLP) based vaccines that target epitopes found within the LDL receptor (LDL-R) binding domain of PCSK9. In both mice and non-human primates, a bivalent VLP vaccine targeting two distinct epitopes on PCSK9 elicited strong and durable antibody responses and lowered cholesterol levels. In macaques, a VLP vaccine targeting a single PCSK9 epitope was only effective at lowering LDL-C levels in combination with statins, whereas immunization with the bivalent vaccine lowered LDL-C without requiring statin co-administration. These data highlight the efficacy of an alternative, vaccine-based approach for lowering LDL-C.

Bioaccumulation and biotransformation of simvastatin in probiotic bacteria: A step towards better understanding of drug-bile acids-microbiome interactions

Introduction: Although pharmacogenetics and pharmacogenomics have been at the forefront of research aimed at finding novel personalized therapies, the focus of research has recently extended to the potential of intestinal microbiota to affect drug efficacy. Complex interplay of gut microbiota with bile acids may have significant repercussions on drug pharmacokinetics. However, far too little attention has been paid to the potential implication of gut microbiota and bile acids in simvastatin response which is characterized by large interindividual variations. The Aim: In order to gain more insight into the underlying mechanism and its contribution in assessing the clinical outcome, the aim of our study was to examine simvastatin bioaccumulation and biotransformation in probiotic bacteria and the effect of bile acids on simvastatin bioaccumulation in in vitro conditions. Materials and methods: Samples with simvastatin, probiotic bacteria and three different bile acids were incubated at anaerobic conditions at 37°C for 24 h. Extracellular and intracellular medium samples were collected and prepared for the LC-MS analysis at predetermined time points (0 min, 15 min, 1 h, 2 h, 4 h, 6 h, 24 h). The concentrations of simvastatin were analyzed by LC-MS/MS. Potential biotransformation pathways were analyzed using a bioinformatics approach in correlation with experimental assay. Results: During the incubation, simvastatin was transported into bacteria cells leading to a drug bioaccumulation over the time, which was augmented upon addition of bile acids after 24 h. A decrease of total drug level during the incubation indicates that the drug is partly biotransformed by bacterial enzymes. According to the results of bioinformatics analysis, the lactone ring is the most susceptible to metabolic changes and the most likely reactions include ester hydrolysis followed by hydroxylation. Conclusion: Results of our study reveal that bioaccumulation and biotransformation of simvastatin by intestinal bacteria might be the underlying mechanisms of altered simvastatin bioavailability and therapeutic effect. Since this study is based only on selected bacterial strains in vitro, further more in-depth research is needed in order to elicit completely the contribution of complex drug-microbiota-bile acids interactions to overall clinical response of simvastatin which could ultimately lead to novel approaches for the personalized lipid-lowering therapy.

Factors Associated With Enhanced Low-Density Lipoprotein Cholesterol Lowering With Bempedoic Acid

Background

Bempedoic acid (BA) inhibits ATP‐citrate lyase in the cholesterol synthesis pathway and lowers low‐density lipoprotein cholesterol (LDL‐C). As with other lipid‐lowering therapies, interindividual variation in response to BA was observed in clinical trials. We characterized LDL‐C response to BA using guideline‐defined statin intensity categories and identified clinical factors associated with enhanced LDL‐C lowering with BA.

Methods and Results

This post hoc analysis used pooled data from 4 phase 3 studies. Patients were randomized 2:1 to once‐daily BA 180 mg (n=2321) or placebo (n=1167) for 12 to 52 weeks and grouped based on percent change in LDL‐C from baseline to week 12 according to guideline‐established statin intensity categories. Factors associated with ≥30% reduction in LDL‐C were identified using logistic regression analyses. From baseline to week 12, BA lowered LDL‐C levels comparable to a moderate‐ or high‐intensity statin (≥30%) in 28.9% of patients; this degree of LDL‐C lowering was observed in 50.9% of patients not receiving background statin therapy. In a multivariable analysis, the absence of statins, female sex, a history of diabetes, ezetimibe use, and higher high‐sensitivity C‐reactive protein level were associated with increased rates of achieving ≥30% LDL‐C reduction with BA (P<0.01 for each).

Conclusions

A large percentage of patients receiving BA achieved LDL‐C reductions comparable to a moderate‐ or high‐intensity statin. Factors including statin absence, female sex, diabetes history, ezetimibe use, and a higher high‐sensitivity C‐reactive protein level may be useful to identify patients who may have a greater LDL‐C reduction with BA.

Registration

URL: https://www.clinicaltrials.gov; Unique identifiers: NCT02666664, NCT02991118, NCT02988115, NCT03001076.

Artichoke and Bergamot Phytosome Alliance: A Randomized Double Blind Clinical Trial in Mild Hypercholesterolemia

Botanicals are natural alternatives to pharmacological therapies that aim at reducing hypercholesterolemia. In this context, despite bergamot being effective in modulating lipid profile, some subjects failed to achieve a satisfactory response to supplementation. The aim of this study was to evaluate whether the association of 600 mg of bergamot phytosome^® (from Citrus Bergamia Risso) and 100 mg of artichoke leaf standardized dry extract (from Cynara cardunculus L.) can be an alternative in patients with mild hypercholesterolemia who are poor responders to bergamot in a 2-month randomized placebo-controlled trial. Sixty overweight adults were randomized into two groups: 30 were supplemented and 30 received a placebo. The metabolic parameters and DXA body composition were evaluated at the start, after 30 and 60 days. Between the two groups, total and LDL cholesterol in the supplemented group (compared to placebo) showed significant decreases overtime. A significant reduction of waist circumference and visceral adipose tissue (VAT) was recorded in the supplemented group (compared to placebo), even in subjects who did not follow a low-calorie diet. In conclusion, the synergism between Citrus Bergamia polyphenols and Cynara cardunculus extracts may be an effective option and may potentially broaden the therapeutic role of botanicals in dyslipidemic patients.

Effectiveness and safety of PCSK9 inhibitors in real-world clinical practice. An observational multicentre study. The IRIS-PCSK9I study

Background and aims

The benefits of the PCSK9 inhibitors, alirocumab and evolocumab, in lowering LDL-cholesterol and preventing major adverse cardiac events (MACE) have been demonstrated in pivotal clinical trials. However, few studies of routine clinical practice have been conducted to analyse and compare the efficacy and safety of the two drugs.

Methods

Retrospective observational study of patients treated with a PCSK9 inhibitor in five hospitals in Andalusia (southern Spain). Baseline demographic and clinical data, LDL-cholesterol levels and the occurrence of MACEs during the follow-up period were recorded.

Results

A total of 141 patients were included in the study: 90 were treated with alirocumab and 51 with evolocumab. The patients' mean age (IQR) was 58 (11) years and 58 (41%) were women. The most frequent concomitant medications were statins, 94 (66.7%), followed by antiplatelet therapy (66%) and ezetimibe (65.2%). The median (IQR) follow-up period was 18 (18) months, with 18 (24) for alirocumab and 11 (18) for evolocumab. At the six-month follow-up visit, LDL-cholesterol values had decreased to pre-treatment levels and remained significantly decreased (p < 0.05) over time, for both drugs, and a greater reduction was achieved in patients with established cardiovascular disease and concomitant treatment with statins. With respect to adverse effects, there were nine MACEs (6.4%), of which seven were with alirocumab (7.8%) and two with evolocumab (3.9%) (p NS). Other adverse effects (9.2%) included local erythema (3.5%), muscle cramps (2.1%), respiratory symptoms (2.1%) and asthaenia (1.4%).

Conclusions

The efficacy and safety of alirocumab and evolocumab in routine clinical practice are consistent with the findings of the pivotal clinical trials.

GENetic characteristics and REsponse to lipid-lowering therapy in familial hypercholesterolemia: GENRE-FH study

Among the 146 patients enrolled in the Korean FH registry, 83 patients who had undergone appropriate LLT escalation and were followed-up for ≥ 6 months were analyzed for pathogenic variants (PVs). The achieved percentage of expected low-density lipoprotein-cholesterol (LDL-C) reduction (primary variable) and achievement rates of LDL-C < 70 mg/dL were assessed. The correlations between the treatment response and the characteristics of PVs, and the weighted 4 SNP-based score were evaluated. The primary variables were significantly lower in the PV-positive patients than in the PV-negative patients (p = 0.007). However, the type of PV did not significantly correlate with the primary variable. The achievement rates of LDL-C < 70 mg/dL was very low, regardless of the PV characteristics. Patients with a higher 4-SNP score showed a lower primary variable (R² = 0.045, p = 0.048). Among evolocumab users, PV-negative patients or those with only defective PVs revealed higher primary variable, whereas patients with at least one null PV showed lower primary variables. The adjusted response of patients with FH to LLT showed significant associations with PV positivity and 4-SNP score. These results may be helpful in managing FH patients with diverse genetic backgrounds.

Statins, LDL Cholesterol Control, Cardiovascular Disease Prevention, and Atherosclerosis Progression: A Clinical Perspective

Despite the longstanding and widespread use of statins, they are used quite inefficiently in everyday clinical practice. This might be because of a lack of robust evidence or the wide variety of different guidelines that are frequently changed. Using data from clinical trials and some simple mathematical modeling, we sought to expand upon the relation between low-density lipoprotein cholesterol (LDL-C) control and cardiovascular risk to offer a firm basis for independent decision making in everyday clinical practice. Analysis of the dose-response curves of different statins indicated that doubling the dose will provide a < 5% extra LDL-C gradient and that the relationship among different statin dose equipotencies is fourfold in the lower range and threefold in the higher range. Thus, the use of potent statins at very low doses might overcome patient statin reluctance. Moreover, whereas statins lower LDL-C percentwise, the prevention of atherosclerosis-related cardiovascular events (ARCVEs) depends on the absolute LDL-C gradient produced and the level of risk. Consequently, and counterintuitively, the lower the baseline LDL-C and/or ARCVE risk, the higher the statin therapy strength required, and approach that is also cost effective. We discuss the issue of threshold versus gradient in terms of clinical trials on plaque regression and speculate on the relationship between LDL-C and atherosclerosis.

Interindividual Variation in Low-Density Lipoprotein Cholesterol Level Reduction With Evolocumab: An Analysis of FOURIER Trial Data

Importance

Little is known about the heterogeneity in low-density lipoprotein cholesterol levels (LDL-C) lowering with proprotein convertase subtilisin kexin 9 (PCSK9) inhibitor medications.

Objective

To evaluate the interindividual variability in LDL-C reduction with the PCSK9 inhibitor drug evolocumab.

Design, Setting, and Participants

We examined the percentage change in LDL-C levels from baseline in the Further Cardiovascular Outcomes Research With PCSK9 Inhibition in Subjects With Elevated Risk (FOURIER) trial, a placebo-controlled randomized clinical trial of the PCSK9 inhibitor evolocumab in patients with stable atherosclerotic cardiovascular disease who were taking statin medications. Patients in either treatment arm who had high baseline LDL-C variability during screening and either did not receive the study drug, altered their background lipid-lowering therapy regimen, or had no LDL-C level sample in week 4 were excluded from the primary analysis. Analyses in the patients were stratified by treatment arm. Data was collected from 2013 to 2016, and data were analyzed from January 2018 to November 2018.

Main Outcomes and Measures

Interindividual variation in percent reduction in LDL-C with evolocumab.

Results

There were 27 564 individuals in the cohort; after exclusions for baseline variability (n = 3524) or alterations in background lipid therapy and other causes (n = 2272), 21 768 patients remained. At week 4, the median percent reduction in LDL-C levels from baseline was 66% (interquartile range, 54%-76%; median [interquartile range] baseline value, 90 [79-105] mg/dL; postchange value, 31 [21-44] mg/dL) with evolocumab. During the first year, a total of 10 325 of 10902 patients in the evolocumab group (94.7%) had a reduction 50% or greater in LDL-C levels, 10 669 of 10 902 (97.9%) had a reduction 30% or more, and 10 849 of 10 902 (99.5%) had any reduction in LDL-C levels. Fifty-three patients (0.5%) had no apparent reduction in LDL-C levels. In the placebo arm, the median LDL-C reduction was 4% (interquartile range, 6% increase to 13% reduction; baseline median [IQR] value, 90 [79-106] mg/dL; postchange value, 87 [74-103] mg/dL) at 4 weeks. Waterfall plots showed notable variability in the top and bottom 5% of patients for both evolocumab and placebo groups, with large changes in LDL-C levels in the placebo group (increases of ≥25%, 531 patients [4.9%]; decreases of ≥25%, 985 patients [9.1%]). At 4 weeks, the placebo-adjusted reductions in LDL-C levels with evolocumab were 50% or greater in 9839 of 10 866 patients (90.5%) and 30% or greater in 10 846 of 10 866 patients (99.8%). Results were consistent across clinically relevant subgroups.

Conclusions and Relevance

There appears to be a highly consistent robust reduction in LDL-C levels with evolocumab use.

Trial Registration

ClinicalTrials.gov identifier: NCT01764633.

Systematic review of the evidence on the cost-effectiveness of pharmacogenomics-guided treatment for cardiovascular diseases

PURPOSE

To examine the evidence on the cost-effectiveness of implementing pharmacogenomics (PGx) in cardiovascular disease (CVD) care.

METHODS

We conducted a systematic review using multiple databases from inception to 2018. The titles and abstracts of cost-effectiveness studies on PGx-guided treatment in CVD care were screened, and full texts were extracted.

RESULTS

We screened 909 studies and included 46 to synthesize. Acute coronary syndrome and atrial fibrillation were the predominantly studied conditions (59%). Most studies (78%) examined warfarin-CYP2C9/VKORC1 or clopidogrel-CYP2C19. A payer's perspective was commonly used (39%) for cost calculations, and most studies (46%) were US-based. The majority (67%) of the studies found PGx testing to be cost-effective in CVD care, but cost-effectiveness varied across drugs and conditions. Two studies examined PGx panel testing, of which one examined pre-emptive testing strategies.

CONCLUSION

We found mixed evidence on the cost-effectiveness of PGx in CVD care. Supportive evidence exists for clopidogrel-CYP2C19 and warfarin-CYP2C9/VKORC1, but evidence is limited in other drug-gene combinations. Gaps persist, including unclear explanation of perspective and cost inputs, underreporting of study design elements critical to economic evaluations, and limited examination of PGx panel and pre-emptive testing for their cost-effectiveness. This review identifies the need for further research on economic evaluations of PGx implementation.

A transcriptomic model to predict increase in fibrous cap thickness in response to high-dose statin treatment: Validation by serial intracoronary OCT imaging

Background

Fibrous cap thickness (FCT), best measured by intravascular optical coherence tomography (OCT), is the most important determinant of plaque rupture in the coronary arteries. Statin treatment increases FCT and thus reduces the likelihood of acute coronary events. However, substantial statin-related FCT increase occurs in only a subset of patients. Currently, there are no methods to predict which patients will benefit. We use transcriptomic data from a clinical trial of rosuvastatin to predict if a patient's FCT will increase in response to statin therapy.

Methods

FCT was measured using OCT in 69 patients at (1) baseline and (2) after 8–10 weeks of 40  mg rosuvastatin. Peripheral blood mononuclear cells were assayed via microarray. We constructed machine learning models with baseline gene expression data to predict change in FCT. Finally, we ascertained the biological functions of the most predictive transcriptomic markers.

Findings

Machine learning models were able to predict FCT responders using baseline gene expression with high fidelity (Classification AUC = 0.969 and 0.972). The first model (elastic net) using 73 genes had an accuracy of 92.8%, sensitivity of 94.1%, and specificity of 91.4%. The second model (KTSP) using 18 genes has an accuracy of 95.7%, sensitivity of 94.3%, and specificity of 97.1%. We found 58 enriched gene ontology terms, including many involved with immune cell function and cholesterol biometabolism.

Interpretation

In this pilot study, transcriptomic models could predict if FCT increased following 8–10 weeks of rosuvastatin. These findings may have significance for therapy selection and could supplement invasive imaging modalities.

Real-World Effectiveness of High- Versus Moderate-Intensity Statin Therapy in Thai Patients With Acute Coronary Syndrome and Who Had Undergone Primary Percutaneous Coronary Intervention

Although high-intensity statins are recommended for atherosclerotic cardiovascular disease, evidence has shown that Asians may need lower dose statins to achieve similar effect when compared to Caucasians. Moreover, awareness of adverse effects leads physicians to initiate moderate-intensity statins. Comparative of high versus moderate-intensive statins on LDL-C among patients who had undergone primary percutaneous coronary intervention (PPCI) for ST-segment elevation myocardial infarction (STEMI) are less established in Thailand. We conducted a retrospective cohort study to identify pattern of statins prescribing and explored the effectiveness on lipid profiles, including LDL-C goal achievement (<70 mg/dL) in STEMI patients underwent PPCI. A total of 983 patients with STEMI who had undergone PPCI were identified during 2005-2015. At 3-month follow-up, 31.9% patients were investigated for their lipid profile. There was 26.11% of patients who received high-intensity statins. When compared to baseline, we found more LDL-C reduction (38.22% ± 26.75% vs 22.36% ± 35.05%, P < .01) in the high-intensity group. Eighty-one patients achieved the target LDL-C, the high-intensity group were able to achieve the LDL-C goal than moderate-intensity group, but did not reach statistical significance (24.1% vs 30.5%, P = .26). This study confirmed that high-intensity statins have superior for LDL-C reduction and tend to achieve LDL-C goal more than moderate-intensity statins.

Assessment of the 1% of Patients with Consistent < 15% Reduction in Low-Density Lipoprotein Cholesterol: Pooled Analysis of 10 Phase 3 ODYSSEY Alirocumab Trials

PURPOSE

Clinical trials of statins and other lipid-lowering therapies (LLTs) often report large inter-individual variations in their effects on low-density lipoprotein cholesterol (LDL-C). We evaluated apparent hyporesponsiveness to the proprotein convertase subtilisin/kexin type 9 inhibitor alirocumab (defined as < 15% LDL-C reduction from baseline at all timepoints) using data from 10 Phase 3 trials (3120 hypercholesterolemic patients).

METHODS

This report assessed the LDL-C percent reduction from baseline at weeks 4-104 (depending on study), and alirocumab serum levels and antidrug antibodies, in patients with apparent hyporesponsiveness.

RESULTS

Among the 3120 patients evaluated, 98.9% responded to alirocumab, and 33 (1.1%) had < 15% LDL C reduction at all measured timepoints. Pharmacokinetics data indicated that 13/33 apparent hyporesponders had not received alirocumab; no pharmacokinetics data were available for 14/33, and 6/33 had detectable alirocumab. For the six patients with confirmed alirocumab receipt, the degree of adherence to pre-study concurrent LLTs could not be determined after study start; one of these patients had persistent antidrug antibodies.

CONCLUSIONS

Apparent hyporesponsiveness to alirocumab appeared to be due to lack of receipt of alirocumab determined by serum alirocumab levels, possible lack of adherence to concurrent LLTs, a theoretical and rare possibility of biological non-responsiveness due to persistent antidrug antibodies, or other causes, as yet unidentified.

A critical appraisal of pharmacogenetic inference

In essence, pharmacogenetic research is aimed at discovering variants of importance to gene-treatment interaction. However, epidemiological studies are rarely set up with this goal in mind. It is therefore of great importance that researchers clearly communicate which assumptions they have had to make, and which inherent limitations apply to the interpretation of their results. This review discusses considerations of, and the underlying assumptions for, utilizing different response phenotypes and study designs popular in pharmacogenetic research to infer gene-treatment interaction effects, with a special focus on those dealing with of clinical effects of drug treatment.

Efficacy of low- and moderate-intensity statins for achieving low- density lipoprotein cholesterol targets in Thai type 2 diabetic patients

Background

Low dose statins are commonly used among Asians, because plasma low-density lipoprotein cholesterol (LDL-C) reductions similar to those observed in Westerners are achieved at lower doses. We aimed to assess the efficacy of low- and moderate-intensity statins for achieving plasma lipid targets in Thai type2 diabetes (T2D) and to evaluate factors associated with greater LDL-C reduction by statins.

Methods

T2D patients who were treated with low- and moderate-intensity statins at the Siriraj Diabetes Clinic during the January 2013 to December 2014 study period were eligible for inclusion(n = 978), 400 patients were randomly recruited. Patients were classified into 1 of the following 2 groups according to their plasma LDL-C reductions by statins (N = 393); very favorable response (LDL-C reduction ≥50%) or less favorable response (LDL-C reduction <50%).

Results

Of the 400 patients, 41.3% were low-intensity statin users. Mean age was 64.4 ± 12.7 years, 64% were female. Median duration of diabetes was 13.3 years and mean HbA1C was 8.1 ± 1.9%. Plasma LDL-C goal of <100 mg/dl and <70 mg/dl was achieved in 84.3% and 38.0% respectively, with no significant difference between the low- and moderate-intensity statin users. LDL-C reductions ≥50% can be achieved in 38.4%. Factors associated with very favorable responses from statins were age, hypertension, patients with stable or reduced weight, and better glycemic control.

Conclusion

Low- and moderate-intensity statins achieved plasma LDL-C goal of <100 mg/dl and <70 mg/dl in 84.3%, and 38.4% of the patients respectively. Due to the improved response to lower doses observed in Asians, a titration dosage strategy should be considered.

Electronic supplementary material

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Applying metabolomics to cardiometabolic intervention studies and trials: past experiences and a roadmap for the future

Metabolomics and lipidomics are emerging methods for detailed phenotyping of small molecules in samples. It is hoped that such data will: (i) enhance baseline prediction of patient response to pharmacotherapies (beneficial or adverse); (ii) reveal changes in metabolites shortly after initiation of therapy that may predict patient response, including adverse effects, before routine biomarkers are altered; and( iii) give new insights into mechanisms of drug action, particularly where the results of a trial of a new agent were unexpected, and thus help future drug development. In these ways, metabolomics could enhance research findings from intervention studies. This narrative review provides an overview of metabolomics and lipidomics in early clinical intervention studies for investigation of mechanisms of drug action and prediction of drug response (both desired and undesired). We highlight early examples from drug intervention studies associated with cardiometabolic disease. Despite the strengths of such studies, particularly the use of state-of-the-art technologies and advanced statistical methods, currently published studies in the metabolomics arena are largely underpowered and should be considered as hypothesis-generating. In order for metabolomics to meaningfully improve stratified medicine approaches to patient treatment, there is a need for higher quality studies, with better exploitation of biobanks from randomized clinical trials i.e. with large sample size, adjudicated outcomes, standardized procedures, validation cohorts, comparison witth routine biochemistry and both active and control/placebo arms. On the basis of this review, and based on our research experience using clinically established biomarkers, we propose steps to more speedily advance this area of research towards potential clinical impact.

Managing the lipid profile of coronary heart disease patients

INTRODUCTION

Lipid profile management is even more critical in patients treated for secondary prevention, since patients with established coronary heart disease are at higher risk of developing events. Current guidelines encourage lifestyle modification and patient engagement in disease prevention. However, the American College of Cardiology/American Heart Association guidelines seem to differ considerably from their predecessors, having an impact on clinical practice of lipid management. Area covered: This review article discusses and provides a summary of the current recommendations for lipid profile management in patients with coronary heart disease, with a view to present lifestyle modification and novel treatment strategies, and to indicate areas of dispute among recent guidelines. Expert commentary: Existing controversies between current guidelines concerning treatment goals and therapeutic decisions may have potential implications on the clinical management of patients. In the meantime, we eagerly wait for the results of randomized controlled trials evaluating promising, potent, safe and prolonged drugs that are in progress.