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BCIS Fellow Editor: Lipid-Lowering Therapies in High-Risk Patients: Current Evidence and Emerging Agents

Ahmed M Salem
Cardiology ST8 – Oxford University Hospitals NHS Foundation Trust

 

Introduction

Atherosclerotic Cardiovascular Disease (ASCVD) remains a leading cause of mortality in Europe, accounting for over 4 million deaths annually.1 Prevention strategies should be tailored to an individual’s overall cardiovascular risk. This is especially pertinent in type 2 diabetes, where dyslipidaemia is a key contributor to the two- to threefold increase in cardiovascular risk compared with non-diabetic individuals. 2,3

Statins: Cornerstone and Controversies

In this high-risk populations, statins remain the cornerstone of both primary and secondary prevention of cardiovascular disease (CVD). Robust evidence supports their efficacy in reducing major adverse cardiovascular events (MACE).4,5

However, an unintended consequence of statin therapy is its association with a modestly increased risk of diabetes.6 This was first observed in 2008 with rosuvastatin, and has since been supported by meta-analyses of randomised trials showing around 10–12% increased incidence of diabetes with statin therapy compared to placebo.7,8 Though mechanisms are unclear—potentially involving altered insulin sensitivity and metabolic signaling—this diabetogenic effect remains outweighed by statins’ cardiovascular benefits.

Residual Risk and Statin Intolerance

Despite their efficacy, real-world data show that statin monotherapy often fails to achieve LDL-C targets in high-risk patients, even at maximal doses.9,10 Moreover, perceived or true statin intolerance continues to limit optimal lipid control. In these cases, adjunctive lipid-lowering therapies play a vital role in reducing residual risk.

Next-Line Agents: Ezetimibe and PCSK9 Inhibitors

Agents that inhibit cholesterol synthesis, such as ezetimibe, or block proprotein convertase subtilisin/kexin type 9 (PCSK9) activity, have proven effective. When used alone or in conjunction with statins, both drug classes significantly improve LDL-C levels and cardiovascular outcomes.11,12 However, cost-effectiveness remains debated. For instance, early economic analyses of evolocumab from the FOURIER trial suggested costs exceeded conventional thresholds.13

This concern is reflected in differences between guidelines. While the European Society of Cardiology (ESC) recommends PCSK9 inhibitors for patients with LDL-C levels >1.8 mmol/L (high-risk) or >1.4 mmol/L (very high-risk) despite lipid-lowering therapy14, NICE sets more conservative thresholds of >4.0 mmol/L and >3.5 mmol/L, respectively.15

Bempedoic Acid: A Cost-Effective Oral Alternative

Bempedoic acid (180 mg daily) is a novel oral lipid-lowering drug that inhibits ATP citrate lyase, enhancing LDL receptor activity. Because it is a prodrug activated only in the liver, muscle exposure is minimal—reducing risk of myotoxicity compared with statins.16

Phase III trials show a 21% LDL-C reduction with monotherapy and ~30% when combined with ezetimibe.17  The CLEAR —the first cardiovascular outcomes trial for bempedoic acid—trial demonstrated a significant reduction in MACE in statin-intolerant patients over 41 months.18 As such, NICE now recommends bempedoic acid with ezetimibe when statins are contraindicated or not tolerated.19

Beyond LDL-C: Addressing Triglyceride-Rich Lipoproteins

While LDL-C remains the main therapeutic target, elevated triglycerides and low HDL-C also contribute to residual risk.20

Pemafibrate, tested in the PROMINENT trial, achieved >25% triglyceride reduction in diabetic patients but did not lower cardiovascular events. However, its favourable hepatic profile suggests possible benefit in metabolic liver disease.21

Omega-3 Fatty Acids and Icosapent Ethyl

Omega-3 fatty acids (eicosapentaenoic acid [EPA] and/or docosahexaenoic acid [DHA]) have traditionally been employed for hypertriglyceridaemia management. However, multiple trials have reported mixed results regarding their impact on cardiovascular outcomes.22 These discrepancies likely stem from heterogeneity in patient populations, formulations, and dosages used.

In contrast, icosapent ethyl—a highly purified form of EPA—has emerged as a promising agent. In the REDUCE-IT trial, icosapent ethyl (2 g twice daily with food) reduced cardiovascular events by 25% and cardiovascular mortality by 20% over nearly five years in statin-treated patients with elevated triglyceride levels and established cardiovascular risk.23 Interestingly, the magnitude of benefit exceeded what would be expected based on triglyceride reduction alone, suggesting additional non-lipid mechanisms.

These may include anti-inflammatory effects (as suggested by reductions in high-sensitivity C-reactive protein), plaque stabilisation, and possible antithrombotic properties, as hinted by a (non-significant) increase in bleeding events compared to placebo (2.6% vs. 2.1%; P = 0.06).

Based on these results, NICE recommends icosapent ethyl for:

– Secondary prevention: CVD patients with triglycerides ≥1.7 mmol/L

– Primary prevention: Diabetic patients with additional risk factors and optimised LDL-C (statins ± ezetimibe) 24

ESC guidelines echo these recommendations.25

 

Summary of Practical Lipid-Lowering Approach

Clinical Scenario Therapy Recommendation
High LDL-C Start statin (maximally tolerated). If inadequate → add ezetimibe. If still above target → consider PCSK9 inhibitor (or bempedoic acid if cost or tolerance issues).
Statin intolerance Ezetimibe ± bempedoic acid. PCSK9i if LDL-C remains high.
Elevated triglycerides (≥1.7 mmol/L) Optimise LDL-C first (statin ± ezetimibe). Then add icosapent ethyl if established CVD or high-risk diabetes.
Mixed dyslipidaemia / Diabetes Comprehensive risk reduction with statins + lifestyle + triglyceride management. Consider pemafibrate or icosapent ethyl depending on profile.

Conclusion

Pharmacological lipid-lowering therapy remains central to CVD prevention, complementing lifestyle modification. As newer agents emerge, clinicians must understand their mechanisms, indications, and limitations. The evolution toward personalised, multi-target lipid management—addressing both LDL-C and triglyceride-rich lipoproteins—reflects modern precision medicine in cardiovascular prevention.

 

 

 

References:

  1. Cardiovascular disease in Europe–epidemiological update 2015. Eur – Google Search. https://www.google.com/search?client=safari&rls=en&q=Cardiovascular+disease+in+Europe–epidemiological+update+2015.+Eur&ie=UTF-8&oe=UTF-8.
  2. Brunzell, J. D. et al. Lipoprotein management in patients with cardiometabolic risk: consensus statement from the American Diabetes Association and the American College of Cardiology Foundation. Diabetes Care 31, 811–822 (2008).
  3. Sarwar, N. et al. Diabetes mellitus, fasting blood glucose concentration, and risk of vascular disease: A collaborative meta-analysis of 102 prospective studies. Lancet 375, 2215–2222 (2010).
  4. De Vries, F. M., Denig, P., Pouwels, K. B., Postma, M. J. & Hak, E. Primary prevention of major cardiovascular and cerebrovascular events with statins in diabetic patients: a meta-analysis. Drugs 72, 2365–2373 (2012).
  5. Cannon, C. P. et al. Intensive versus Moderate Lipid Lowering with Statins after Acute Coronary Syndromes. N. Engl. J. Med. 350, 1495–1504 (2004).
  6. Ridker, P. M. et al. Rosuvastatin to prevent vascular events in men and women with elevated C-reactive protein. N. Engl. J. Med. 359, 2195–2207 (2008).
  7. Sattar, N. et al. Statins and risk of incident diabetes: a collaborative meta-analysis of randomised statin trials. Lancet (London, England) 375, 735–742 (2010).
  8. Thakker, D., Nair, S., Pagada, A., Jamdade, V. & Malik, A. Statin use and the risk of developing diabetes: a network meta-analysis. Pharmacoepidemiol. Drug Saf. 25, 1131–1149 (2016).
  9. Salem, A. M. et al. Achievement of the ESC recommendations for secondary prevention of cardiovascular risk factors in high-risk patients with type 2 diabetes: A real-world national cohort analysis. Int. J. Cardiol. (2023) doi:10.1016/J.IJCARD.2023.02.004.
  10. Shin, D., Bohra, C. & Kongpakpaisarn, K. Abstract 181: Application of the 2018 Cholesterol Guideline for Secondary Prevention in Very High-risk Patients with Atherosclerotic Cardiovascular Disease in the United States. Circ. Cardiovasc. Qual. Outcomes 12, (2019).
  11. Cannon, C. P. et al. Ezetimibe Added to Statin Therapy after Acute Coronary Syndromes. N. Engl. J. Med. 372, 2387–2397 (2015).
  12. Sabatine, M. S. et al. Evolocumab and Clinical Outcomes in Patients with Cardiovascular Disease. N. Engl. J. Med. 376, 1713–1722 (2017).
  13. Fonarow, G. C. et al. Cost-effectiveness of Evolocumab Therapy for Reducing Cardiovascular Events in Patients With Atherosclerotic Cardiovascular Disease. JAMA Cardiol. 2, 1069–1078 (2017).
  14. Mach, F. et al. 2019 ESC/EAS Guidelines for the management of dyslipidaemias: Lipid modification to reduce cardiovascular risk. Eur. Heart J. 41, 111–188 (2020).
  15. 1 Recommendations | Evolocumab for treating primary hypercholesterolaemia and mixed dyslipidaemia | Guidance | NICE.
  16. Pinkosky, S. L. et al. Liver-specific ATP-citrate lyase inhibition by bempedoic acid decreases LDL-C and attenuates atherosclerosis. Nat. Commun. 2016 71 7, 1–13 (2016).
  17. Ballantyne, C. M. et al. Efficacy and safety of bempedoic acid added to ezetimibe in statin-intolerant patients with hypercholesterolemia: A randomized, placebo-controlled study. Atherosclerosis 277, 195–203 (2018).
  18. Nissen, S. E. et al. Bempedoic Acid and Cardiovascular Outcomes in Statin-Intolerant Patients. https://doi.org/10.1056/NEJMoa2215024 (2023) doi:10.1056/NEJMOA2215024.
  19. 1 Recommendations | Bempedoic acid with ezetimibe for treating primary hypercholesterolaemia or mixed dyslipidaemia | Guidance | NICE.
  20. Nordestgaard, B. G. & Varbo, A. Triglycerides and cardiovascular disease. Lancet 384, 626–635 (2014).
  21. Pradhan, A. Das et al. Triglyceride Lowering with Pemafibrate to Reduce Cardiovascular Risk. https://doi.org/10.1056/NEJMoa2210645 (2022) doi:10.1056/NEJMOA2210645.
  22. Nicholls, S. J. et al. Effect of High-Dose Omega-3 Fatty Acids vs Corn Oil on Major Adverse Cardiovascular Events in Patients at High Cardiovascular Risk: The STRENGTH Randomized Clinical Trial. JAMA 324, 2268–2280 (2020).
  23. Bhatt, D. L. et al. Cardiovascular Risk Reduction with Icosapent Ethyl for Hypertriglyceridemia. N. Engl. J. Med. 380, 11–22 (2019).
  24. 1 Recommendations | Icosapent ethyl with statin therapy for reducing the risk of cardiovascular events in people with raised triglycerides | Guidance | NICE.
  25. Mach, F. et al. 2019 ESC/EAS Guidelines for the management of dyslipidaemias: lipid modification to reduce cardiovascular riskThe Task Force for the management of dyslipidaemias of the European Society of Cardiology (ESC) and European Atherosclerosis Society (EAS). Eur. Heart J. 41, 111–188 (2020).