The benefit of adding ezetimibe to statin therapy in patients with prior coronary artery bypass graft surgery and acute coronary syndrome in the IMPROVE-IT trial

Saphenous Vein Graft Failure: Current Challenges and a Review of the Contemporary Percutaneous Options for Management

The use of saphenous vein grafts (SVGs) in the surgical management of obstructive coronary artery disease remains high despite a growing understanding of their limitations in longevity. In contemporary practice, approximately 95% of patients receive one SVG in addition to a left internal mammary artery (LIMA) graft. The precise patency rates for SVGs vary widely in the literature, with estimates of up to 61% failure rate at greater than 10 years of follow-up. SVGs are known to progressively degenerate over time and, even if they remain patent, demonstrate marked accelerated atherosclerosis. Multiple studies have demonstrated a marked acceleration of atherosclerosis in bypassed native coronary arteries compared to non-bypassed arteries, which predisposes to a high number of native chronic total occlusions (CTOs) and subsequent procedural challenges when managing graft failure. Patients with failing SVGs frequently require revascularisation to previously grafted territories, with estimates of 13% of CABG patients requiring an additional revascularisation procedure within 10 years. Redo CABG confers a significantly higher risk of in-hospital mortality and, as such, percutaneous coronary intervention (PCI) has become the favoured strategy for revascularisation in SVG failure. Percutaneous treatment of a degenerative SVG provides unique challenges secondary to a tendency for frequent superimposed thrombi on critical graft stenoses, friable lesions with marked potential for distal embolization and subsequent no-reflow phenomena, and high rates of peri-procedural myocardial infarction (MI). Furthermore, the rates of restenosis within SVG stents are disproportionately higher than native vessel PCI despite the advances in drug-eluting stent (DES) technology. The alternative to SVG PCI in failed grafts is PCI to the native vessel, 'replacing' the grafts and restoring patency within the previously grafted coronary artery, with or without occluding the donor graft. This strategy has additional challenges to de novo coronary artery PCI, however, due to the high burden of complex atherosclerotic lesion morphology, extensive coronary calcification, and the high incidence of CTO. Large patient cohort studies have reported worse short- and long-term outcomes with SVG PCI compared to native vessel PCI. The PROCTOR trial is a large and randomised control trial aimed at assessing the superiority of native vessel PCI versus vein graft PCI in patients with prior CABG awaiting results. This review article will explore the complexities of SVG failure and assess the contemporary evidence in guiding optimum percutaneous interventional strategy.

Medical care and biomarker-based assessment of mortality in two cohorts of patients with chronic coronary syndrome 10 years apart

BACKGROUND

This study aimed to describe the characteristics and mortality of two cohorts of patients with chronic coronary syndrome (CCS) recruited with identical study designs in the same rehabilitation clinics but approximately 10 years apart.

METHODS

The KAROLA cohorts included patients with CCS participating in an inpatient cardiac rehabilitation programme in Germany (KAROLA-I: years 1999/2000, KAROLA-II: 2009-2011). Blood samples and information on sociodemographic factors, lifestyle, and medical treatment were collected at baseline, at the end of rehabilitation, and after one year of follow-up. A biomarker-based risk model (ABC-CHD model) and Cox regression analysis were used to evaluate cardiovascular (CV) and non-CV mortality risk.

RESULTS

We included 1130 patients from KAROLA-I (mean age 58.7 years, 84.4% men) and 860 from KAROLA-II (mean age 60.4 years, 83.4% men). Patients in the KAROLA-I cohort had significantly higher concentrations of CV biomarkers and fewer patients were taking CV medications, except for statins. The biomarker-based ABC-CHD model provided a higher estimate of CV death risk for patients in the KAROLA-I cohort (median 3-year risk, 3.8%) than for patients in the KAROLA-II cohort (median 3-year risk, 2.7%, p-value for difference < 0.001). After 10 years of follow-up, 91 (8.1%) patients in KAROLA-I and 45 (5.2%) in KAROLA-II had died from a CV event.

CONCLUSIONS

Advances in disease management over the past 20 years may have led to modest improvements in pharmacological treatment during cardiac rehabilitation and long-term outpatient care for patients with CCS. However, modifiable risk factors such as obesity have increased in the more recent cohort and should be targeted to further improve the prognosis of these patients.

Pathophysiology and management of saphenous vein graft disease

INTRODUCTION

The saphenous vein graft (SVG) is the most used conduit in CABG. With standardization of its use as a conduit came an understanding of its accelerated atherosclerosis, known as saphenous vein graft disease (SVGD). Given its extensive use, a review of the pathophysiology and management of SVGD is important as we optimize its use.

AREAS COVERED

For this review, an extensive literature search was completed to identify and examine the evolution of SVG in CABG, mechanisms driving SVGD, and methods developed to prevent and manage it. This includes a review of relevant major papers and trials in this space.

EXPERT OPINION

Eras of evolution in SVG usage in CABG include an experimental era, era of SVG dominance in CABG, and the current era of mixed venous and arterial grafting. As SVGD was studied, the mechanisms behind it became more understood, and prevention and management methods were developed. As advances in surgical techniques and pharmacotherapy continue to reduce occurrence and severity of SVGD, long-term patency of SV grafts continues to improve and remain excellent in optimized settings. With continued innovation and improvement in operative techniques, the SVG conduit is and will remain an important player in the field of coronary bypass.

ANMCO position paper on the management of hypercholesterolaemia in patients with acute coronary syndrome

Patients suffering from acute coronary syndrome (ACS) present a high risk of recurrence and new adverse cardiovascular events after hospital discharge. Elevated plasma LDL-cholesterol (LDL-C) levels have been shown to be a causal factor for the development of coronary heart disease, and robust clinical evidence has documented that LDL-C levels decrease linearly correlates with a reduction in cardiovascular events. Recent studies have also demonstrated the safety and efficacy of an early and significant reduction in LDL-C levels in patients with ACS. In this position paper, Italian Association of Hospital Cardiologists proposes a decision algorithm on early adoption of lipid-lowering strategies at hospital discharge and short-term follow-up of patients with ACS, in the light of the multiple evidence generated in recent years on the treatment of hypercholesterolaemia and the available therapeutic options, considering current reimbursement criteria.

Benefit of Combination Ezetimibe/Simvastatin Among High-Risk Populations: Lessons from the IMPROVE-IT Trial

PURPOSE OF REVIEW

The Improved Reduction of Outcomes: Vytorin Efficacy International Trial (IMPROVE-IT) demonstrated the clinical benefit of the combination of ezetimibe-simvastatin compared to placebo-simvastatin following acute coronary syndrome (ACS). This review highlights key findings from this study with particular attention to the practice-changing impact on guidelines for low-density lipoprotein cholesterol (LDL-C) reduction after ACS, especially among high-risk populations.

RECENT FINDINGS

Consistent reductions in LDL-C have been reported with newer lipid-lowering therapies (proprotein convertase subtilisin/kexin type 9 inhibitors, cholesterol ester transfer proteins, bempedoic acid) in combination with statin in high-risk subgroups. Since high-risk subgroups remain a focus of guidelines, exploration of high-risk subgroups can help define the optimal use of new therapies. Ezetimibe reduced the LDL-C by 16.7 mg/dL compared to placebo at 1 year, resulting in a significant reduction in the primary composite endpoint (absolute risk difference 2.0%; relative risk difference 6.4%, hazard ratio, 0.936; 95% confidence interval, 0.89 to 0.99; P = 0.016). The benefits achieved with ezetimibe in both LDL-C reduction and the primary clinical composite across 10 pre-specified high-risk subgroups, including the elderly; women; patients with diabetes, prior coronary artery bypass graft, history of stroke, polyvascular disease, low baseline LDL-C, renal dysfunction, prior heart failure, and an elevated TIMI risk score for secondary prevention, were similar or greater than in the corresponding non-high-risk subgroups. Safety events were similar between ezetimibe and placebo across the high-risk subgroups. These data support the addition of ezetimibe to statin therapy in high-risk patients who require additional therapy to lower the LDL-C post-ACS.

[Therapeutic options to reduce LDL-cholesterol beyond statins]

Current dyslipidemia guidelines emphasize statins as the cornerstone of pharmacological lipid-lowering therapy. The cholesterol absorption inhibitor ezetimibe, PCSK9-antibodies, as well as bempedoic acid and inclisiran are newly available options to further reduce LDL-cholesterol. Since modern lipid-lowering therapy is characterized by an individual, "treat-to-target" approach the aim of this review is to provide a better understanding of cholesterol metabolism to guide decision-making and the rational for using early individualized combination therapies.

Approach to patients with elevated low-density lipoprotein cholesterol levels

Elevated low-density lipoprotein cholesterol (LDL-C) levels increase the risk of atherosclerotic cardiovascular disease (ASCVD) and lowering LDL-C levels reduces the risk of ASCVD. In patients with elevated LDL-C levels it is important to consider whether lifestyle, other medical conditions, medications, or genetic factors could be causing or contributing to the elevation. There are guidelines from various organizations outlining the approach to lowering LDL-C levels but while these guidelines agree on many issues there are numerous areas where recommendations are discordant. In this review, we outline several principles that will help in deciding who and how to treat patients with elevated LDL-C levels. Specifically, we discuss evidence indicating that the sooner one initiates therapy the better and the greater the reduction in LDL-C the better. Additionally, the higher the LDL-C level and the higher the risk of ASCVD, the greater the benefits of treatment. Using these principles will help in making decisions regarding the treatment of LDL-C levels.

Management and outcomes over time of acute coronary syndrome patients at particularly high cardiovascular risk : the ACSIS registry-based retrospective study

OBJECTIVE

Some patients following acute coronary syndrome (ACS) are at particularly increased risk for recurrent cardiovascular events. We aimed to examine temporal trends in the management and outcomes across the spectrum of these particularly high-risk patients.

DESIGN AND SETTING

A retrospective study based on the ACS Israeli survey (ACSIS) registry, a multicentre prospective national registry, taking place biennially in 25 cardiology departments in Israel. Temporal trends were examined in the early (2002-2008) and late (2010-2018) time periods.

PARTICIPANTS

Consecutive patients with ACS enrolled in the ACSIS registry were stratified according to the Thrombolysis in Myocardial Infarction Risk Score for secondary prevention (TRS2^°P) to high (TRS2^°p=3), very high (TRS2^°p=4) or extremely high risk (TRS2^°p=5-9). Patients with TRS2^°p<3 were excluded. From the initial 15 196 patients enrolled, 5359 patients were eventually included.Clinical outcome measures included 30-day major adverse cardiovascular events (MACE) and 1-year mortality.

RESULTS

Among 5359 patients (50% high risk, 30% very high risk and 20% extremely high risk), those with a higher risk were older, had more comorbidities, presented more with non-ST elevation myocardial infarction, and were treated less often with guideline-recommended pharmacotherapy and percutaneous coronary intervention. Over time, treatment has improved in all risk strata, and the rate of 30-day MACE has significantly decreased in all risk groups (from 21% to 10%, from 22% to 15%, and from 26% to 16%, in high, very high and extremely high-risk groups, respectively, p<0.001 for each). However, 1-year mortality decreased only among high and very high-risk patients, and not among extremely high-risk patients in whom 1-year mortality rates remained very high (28.7% vs 28.9%, p=1).

CONCLUSION

Within a particularly high-risk cohort of patients with ACS, treatment has significantly progressed over almost 2 decades. While short-term outcomes have improved in all risk groups, 1-year mortality has remained unchanged in extremely high-risk patients with ACS.

Effect of Perioperative Lipid Status on Clinical Outcomes after Cardiac Surgery

Patients undergoing cardiac surgery are at increased cardiovascular risk, which includes altered lipid status. However, data on the effect of cardiac surgery and cardiopulmonary bypass (CPB) on plasma levels of key lipids are scarce. We investigated potential effects of CPB on plasma lipid levels and associations with early postoperative clinical outcomes. This is a prospective bio-bank study of patients undergoing elective cardiac surgery at our center January to December 2019. The follow-up period was 1 year after surgery. Blood sampling was performed before induction of general anesthesia, upon weaning from cardiopulmonary bypass (CPB), and on the first day after surgery. Clinical end points included the incidence of postoperative stroke, myocardial infarction, and death of any cause at 30 days after surgery as well as 1-year all-cause mortality. A total of 192 cardiac surgery patients (75% male, median age 67.0 years (interquartile range 60.0-73.0), median BMI 26.1 kg/m² (23.7-30.4)) were included. A significant intraoperative decrease in plasma levels compared with preoperative levels (all p < 0.0001) was observed for total cholesterol (TC) (Cliff's delta d: 0.75 (0.68-0.82; 95% CI)), LDL-Cholesterol (LDL-C) (d: 0.66 (0.57-0.73)) and HDL-Cholesterol (HDL-C) (d: 0.72 (0.64-0.79)). At 24h after surgery, the plasma levels of LDL-C (d: 0.73 (0.650.79)) and TC (d: 0.77 (0.69-0.82)) continued to decrease compared to preoperative levels, while the plasma levels of HDL-C (d: 0.46 (0.36-0.55)) and TG (d: 0.40 (0.29-0.50)) rebounded, but all remained below the preoperative levels (p < 0.001). Mortality at 30 days was 1.0% (N = 2/192), and 1-year mortality was 3.8% (N = 7/186). Postoperative myocardial infarction occurred in 3.1% of patients (N = 6/192) and postoperative stroke in 5.8% (N = 11/190). Adjusting for age, sex, BMI, and statin therapy, we noted a protective effect of postoperative occurrence of stroke for pre-to-post-operative changes in TC (adjusted odds ratio (OR) 0.29 (0.07-0.90), p = 0.047), in LDL-C (aOR 0.19 (0.03-0.88), p = 0.045), and in HDL-C (aOR 0.01 (0.00-0.78), p = 0.039). No associations were observed between lipid levels and 1-year mortality. In conclusion, cardiac surgery induces a significant sudden drop in levels of key plasma lipids. This effect was pronounced during the operation, and levels remained significantly lowered at 24 h after surgery. The intraoperative drops in LDL-C, TC, and HDL-C were associated with a protective effect against occurrence of postoperative stroke in adjusted models. We demonstrate that the changes in key plasma lipid levels during surgery are strongly correlated, which makes attributing the impact of each lipid to the clinical end points, such as postoperative stroke, a challenging task. Large-scale analyses should investigate additional clinical outcome measures.

Intensive lipid-lowering therapy, time to think beyond low-density lipoprotein cholesterol

Statins have been shown to be effective in reducing cardiovascular events. Their magnitude of benefits has been proportionate to the reduction in low-density lipoprotein cholesterol (LDL-c). Intensive lipid-lowering therapies using ezetimibe and more recently proprotein convertase subtilisin kexin 9 inhibitors have further improved clinical outcomes. Unselective application of these treatments is undesirable and unaffordable and, therefore, has been guided by LDL-c level. Nonetheless, the residual risk in the post-statin era is markedly heterogeneous, including thrombosis and inflammation risks. Moreover, the lipo-protein related risk is increasingly recognised to be related to other non-LDL-c markers such as Lp(a). Emerging data show that intensive lipid-lowering therapy produce larger absolute risk reduction in patients with polyvascular disease, post coronary artery bypass graft and diabetes. Notably, these clinical entities share similar phenotype of large burden of atherosclerotic plaques. Novel plaque imaging may aid decision making by identifying patients with propensity to develop lipid rich plagues at multi-vascular sites. Those patients may be suitable candidates for intensive lipid lowering treatment.

Management and outcome across the spectrum of high-risk patients with myocardial infarction according to the thrmobolysis in myocardial infarction (TIMI) risk-score for secondary prevention

Background

Patients with myocardial infarction (MI) are at increased risk for recurrent cardiovascular events, yet some patients, such as the elderly and those with prior comorbidities, are particularly at the highest risk. Whether these patients benefit from contemporary management is not fully elucidated.

Methods

Included were consecutive patients with MI who underwent percutaneous coronary intervention (PCI) in a large tertiary medical center. Patients were stratified according to the thrombolysis in myocardial infarction (TIMI) risk score for secondary prevention (TRS2°P) to high (TRS2°P = 3), very high (TRS2°P = 4), or extremely high‐risk (TRS2°P = 5–9). Excluded were low and intermediate‐risk patients (TRS2°P < 3). Outcomes included 30‐day/1‐year major adverse cardiac events (MACE) and 1‐year mortality. Temporal trends were examined in the early (2004–2010) and late (2011–2016) time‐periods.

Results

Among 2053 patients, 50% were high‐risk, 30% very high‐risk and 20% extremely high‐risk. Extremely high‐risk patients were older (age 74 ± 10 year) and had significant comorbidities (chronic kidney disease 68%, prior CABG 40%, heart failure 78%, peripheral artery disease 29%). Drug‐eluting stents and potent antiplatelets were more commonly used over time in all risk‐strata. Over time, 30‐day MACE rates have decreased, mainly attributed to the very high (11.3% to 5.1%, p = .006) and extremely high‐risk groups (15.9% to 8.0%, p = .016), but not the high‐risk group, with similar quantitative results for 1‐year MACE. The rates of 1‐year mortality remained unchanged in either group.

Conclusion

Within a particularly high‐risk cohort of MI patients who underwent PCI, the implementation of guideline‐recommended therapies has improved over time, with the highest‐risk groups demonstrating the greatest benefit in outcomes.

Saphenous Vein Graft Failure: From Pathophysiology to Prevention and Treatment Strategies

Saphenous vein grafts (SVGs) remain the most frequently used conduits in coronary artery bypass graft surgery (CABG). Despite advances in surgical techniques and pharmacotherapy, SVG failure rates remain high, often leading to repeat coronary revascularization. The no-touch SVG harvesting technique (minimal graft manipulation with preservation of vasa vasorum and nerves) reduces the risk of SVG failure, whereas the effect of the off-pump technique on SVG patency remains unclear. Use of buffered storage solutions, intraoperative graft flow measurement, careful selection of the target vessels, and physiological assessment of the native coronary circulation before CABG may also reduce the incidence of SVG failure. Perioperative aspirin and high-intensity statin administration are the cornerstones of secondary prevention after CABG. Dual antiplatelet therapy is recommended for off-pump CABG and in patients with a recent acute coronary syndrome. Intermediate (30%-60%) SVG stenoses often progress rapidly. Stenting of intermediate SVG stenoses failed to improve outcomes; hence, treatment focuses on strict control of coronary artery disease risk factors. Redo CABG is associated with higher perioperative mortality compared with percutaneous coronary intervention (PCI); hence, the latter is preferred for most patients requiring repeat revascularization after CABG. SVG PCI is limited by high rates of no-reflow and a high incidence of restenosis during follow-up. Drug-eluting and bare metal stents provide similar long-term outcomes in SVG PCI. Embolic protection devices reduce no-reflow and should be used when feasible. PCI of the corresponding native coronary artery is associated with better short- and long-term outcomes and is preferred over SVG PCI, if technically feasible.

Thrombolysis In Myocardial Infarction (TIMI) Study Group: JACC Focus Seminar 2/8

In 1984, the National Heart, Lung, and Blood Institute (NHLBI) decided to study the efficacy and safety of the treatment of acute myocardial infarction with an emerging therapy, coronary thrombolysis, and thus the TIMI (Thrombolysis In Myocardial Infarction) Study Group was born. Following completion of 3 clinical trials of thrombolytic therapy supported by the NHLBI, TIMI became an academic research organization headquartered at Brigham and Women's Hospital and subsequently branched out to study a wide range of patients, including those with stable coronary, cerebrovascular, and peripheral arterial disease; dyslipidemia; heart failure; atrial fibrillation; diabetes; and obesity. TIMI also began to study a wide range of interventions including thrombolytic, antithrombotic, lipid-modifying, anti-inflammatory, heart failure, glucose-lowering, and weight loss agents. TIMI, now in its 37th year, has completed >70 trials. This review describes the origins of the TIMI Study Group, summarizes several of its completed trials and the major lessons learned from them, and discusses ongoing trials and future directions.

Influence of LDL-Cholesterol Lowering on Cardiovascular Outcomes in Patients With Diabetes Mellitus Undergoing Coronary Revascularization

BACKGROUND

Elevated low-density lipoprotein cholesterol (LDL-C) is associated with increased cardiovascular events, especially in high-risk populations.

OBJECTIVES

This study sought to evaluate the influence of LDL-C on the incidence of cardiovascular events either following a coronary revascularization procedure (percutaneous coronary intervention [PCI] or coronary artery bypass grafting [CABG]) or optimal medical therapy alone in patients with established coronary heart disease and type 2 diabetes (T2DM).

METHODS

Patient-level pooled analysis of 3 randomized clinical trials was undertaken. Patients with T2DM were categorized according to the levels of LDL-C at 1 year following randomization. The primary endpoint was major adverse cardiac or cerebrovascular events ([MACCE] the composite of all-cause mortality, nonfatal myocardial infarction, and nonfatal stroke).

RESULTS

A total of 4,050 patients were followed for a median of 3.9 years after the index 1-year assessment. Patients whose 1-year LDL-C remained ≥100 mg/dl experienced higher 4-year cumulative risk of MACCE (17.2% vs. 13.3% vs. 13.1% for LDL-C between 70 and <100 mg/dl and LDL-C <70 mg/dl, respectively; p = 0.016). When compared with optimal medical therapy alone, patients with PCI experienced a MACCE reduction only if 1-year LDL-C was <70 mg/dl (hazard ratio: 0.61; 95% confidence interval: 0.40 to 0.91; p = 0.016), whereas CABG was associated with improved outcomes across all 1-year LDL-C strata. In patients with 1-year LDL-C ≥70 mg/dl, patients undergoing CABG had significantly lower MACCE rates as compared with PCI.

CONCLUSIONS

In patients with coronary heart disease with T2DM, lower LDL-C at 1 year is associated with improved long-term MACCE outcome in those eligible for either PCI or CABG. When compared with optimal medical therapy alone, PCI was associated with MACCE reductions only in those who achieved an LDL-C <70 mg/dl.

[Management of dyslipidaemias: The New 2019 ESC/EAS-Guideline]

The updated guidelines for the management of dyslipidaemias 2019 sticks to the concept of individual risk-based intervention strategies, but intensifies LDL-C goals. Next to the established SCORE system non-invasive imaging techniques such as coronary CT or ultrasound of carotid or femoral arteries are now recommended for improved risk stratification. Screening for lipoprotein(a) identifies persons at higher cardiovascular risk. Non-statin trials with ezetimibe and PSCK9-inhibitors demonstrated further relative risk reduction for cardiovascular events. Cardiovascular risk reduction depends on the absolute lowering of LDL-C, duration of therapy and the individual cardiovascular risk. For patients at very high risk the new LDL-C goal is < 1.4 mmol/l (55 mg/dl) and reduction of ≥ 50 % from baseline. The overall aim is to reduce "cholesterol life years".

Outcome of patients with prior coronary bypass surgery admitted with an acute coronary syndrome

BACKGROUND

Patients with prior coronary artery bypass graft surgery (CABG) are at increased risk for recurrent cardiovascular ischaemic events. Advances in management have improved prognosis of patients with acute coronary syndrome (ACS), yet it is not known whether similar trends exist in patients with prior CABG.

AIM

Examine temporal trends in the prevalence, treatment and clinical outcomes of patients with prior CABG admitted with ACS.

METHODS

Time-dependent analysis of patients with or without prior CABG admitted with an ACS who enrolled in the ACS Israeli Surveys between 2000 and 2016. Surveys were divided into early (2000-2008) and late (2010-2016) time periods. Outcomes included 30 days major adverse cardiac events (30d MACE) (death, myocardial infarction, stroke, unstable angina, stent thrombosis, urgent revascularisation) and 1-year mortality.

RESULTS

Among 15 152 patients with ACS, 1506 (9.9%) had a prior CABG. Patients with prior CABG were older (69 vs 63 years), had more comorbidities and presented more with non-ST elevation-ACS (82% vs 51%). Between time periods, utilisation of antiplatelets, statins and percutaneous interventions significantly increased in both groups (p<0.001 for each). The rate of 30d MACE decreased in patients with (19.1%-12.4%, p=0.001) and without (17.4%-9.5%, p<0.001) prior CABG. However, 1-year mortality decreased only in patients without prior CABG (10.5% vs 7.4%, p<0.001) and remained unchanged in patients with prior CABG. Results were consistent after propensity matching.

CONCLUSIONS

Despite an improvement in the management and prognosis of patients with ACS in the last decade, the rate of 1-year mortality of patients with prior CABG admitted with an ACS remained unchanged.

Low-density lipoprotein cholesterol lowering therapy for the secondary prevention of atherosclerotic cardiovascular disease

Atherosclerotic cardiovascular disease (ASCVD) is highly prevalent and a major contributor to morbidity and mortality worldwide. Elevated blood cholesterol is a key driver of risk for atherosclerotic events, and patients with established ASCVD comprise a specific high-risk population in which low-density lipoprotein cholesterol (LDL-C) lowering therapy is strongly endorsed by multiple guidelines. An increasing number of medications across several pharmacologic classes are available today in clinical practice. Therefore, guidance on the appropriate use of these interventions is necessary for cost-effective solutions to managing residual atherothrombotic risk. In this review we summarize the key evidence supporting LDL-C lowering as described in the most recent 2018 multi-society Blood Cholesterol Guidelines, and provide a framework for optimizing LDL-C lowering therapy in secondary prevention populations.

Lipid Management in Patients Presenting With Acute Coronary Syndromes: A Review

Despite many improvements in its prevention and management, acute coronary syndrome (ACS) remains a major cause of morbidity and mortality in the developed world. Lipid management is an important part of secondary prevention after ACS, but many patients currently remain undertreated and do not attain guideline‐recommended levels of low‐density lipoprotein cholesterol reduction. This review details the current state of evidence on lipid management in patients presenting with ACS, provides directions for identification of patients who may benefit from early escalation of lipid‐lowering therapy, and discusses novel lipid‐lowering medication that is currently under investigation in clinical trials. Moreover, a treatment algorithm aimed at attaining guideline‐recommended low‐density lipoprotein cholesterol levels is proposed. Despite important advances in the initial treatment and secondary prevention of ACS, ≈20% of ACS survivors experience a subsequent ischemic cardiovascular event within 24 months, and 5‐year mortality ranges from 19% to 22%. Knowledge of the current state of evidence‐based lipid management after ACS is of paramount importance to improve outcomes after ACS.

Impact of lipid levels and high-intensity statins on vein graft patency after CABG: Midterm results of the ACTIVE trial

BACKGROUND

High-dose atorvastatin did not improve 1-year vein graft patency in the recent Aggressive Cholesterol Therapy to Inhibit Vein Graft Events trial. However, it remains unknown whether high-intensity statins may impact graft disease in the years that follow.

METHODS

In the trial, patients (N = 173) were randomized to receive atorvastatin 10 or 80 mg for 1 year after coronary bypass surgery (CABG). Beyond 1 year, the choice of statin was left to the patient's physician. In this study of participants who agreed to follow-up (N = 76), low-density lipoprotein (LDL) levels were measured and graft patency was assessed 3 years after surgery.

RESULTS

The rate of vein graft disease 3 years after surgery was not significantly reduced with atorvastatin 80 mg during the first postoperative year or the use of open-label high-intensity statin thereafter (p = NS). However, a trend was observed between higher LDL levels during the first postoperative year and a greater incidence of vein graft disease at 3 years (p = .12). Among patients who had LDL levels more than 90 mg/dl in the first year after CABG, 38.5% had vein graft disease at 3 years, compared to 19.0% for those with LDL levels less than 90 mg/dl (p = .15). Higher mean LDL levels during the first postoperative year were associated with a higher rate of vein disease 3 years after surgery both at the graft level (p = .03) and at the patient level (p = .03) in multivariate analysis.

CONCLUSIONS

Higher LDL levels during the first postoperative year were associated with significantly greater vein graft disease 3 years after CABG.

Effect of Ezetimibe + Pitavastatin on Cardiovascular Outcomes in Patients with ST-Segment Elevation Myocardial Infarction (from the HIJ-PROPER Study)

Lipid-lowering therapy is necessary to reduce cardiovascular event rates in patients with ST-segment elevation myocardial infarction (STEMI). This study aimed to evaluate the effect of intensive lipid-lowering therapy, which comprised pitavastatin and ezetimibe, on patients with STEMI. We therefore undertook a post hoc subanalysis of the HIJ-PROPER study's data that examined the clinical outcomes of the patients with dyslipidemia and STEMI (n = 880) who received pitavastatin and ezetimibe therapy (intensive lipid-lowering therapy group) or pitavastatin monotherapy (standard lipid-lowering therapy group), and we evaluated their cardiovascular events. The primary end point was a composite of all-cause death, nonfatal myocardial infarction, nonfatal stroke, unstable angina, and ischemia-driven revascularization. During the median 3.4-year follow-up period, the cumulative rates of the primary end point were 31.9% and 39.7% in the intensive lipid-lowering therapy and standard lipid-lowering therapy groups, respectively (hazard ratio [HR], 0.77; 95% confidence interval [CI], 0.62 to 0.97; p = 0.02). Compared with the standard lipid-lowering therapy group, the intensive lipid-lowering therapy group had significantly lower all-cause death (6.9% vs 3.2%; HR, 0.45; 95% CI, 0.23 to 1.84; p = 0.01) and nonfatal stroke (2.9% vs 1.6%; HR, 0.77; 95% CI, 0.62 to 0.97; p = 0.02) rates. Patients with pitavastatin and ezetimibe therapy, as compared with pitavastatin monotherapy, had a lower cardiovascular event in STEMI patients. In conclusion, adding ezetimibe to statin therapy may be beneficial for patients with dyslipidemia and STEMI.

Efficacy and safety of add on therapies in patients with hypercholesterolemia undergoing statin therapy

INTRODUCTION

Statins are the first-line treatment to reduce cardiovascular (CV) events, mainly by reducing low-density-lipoprotein cholesterol (LDL-C), but many patients need additional treatments to reach the current lipid goals.

AREAS COVERED

Herein, the authors review the published literature on the efficacy and safety of the therapies that are most often added to statins to achieve lipid targets.

EXPERT OPINION

Ezetimibe is usually the first additional treatment to achieve LDL-C targets. It reduces LDL-C by about a further 20% and has an excellent safety and tolerability profile. The monoclonal antibody proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, evolocumab, and alirocumab, can reduce LDL-C by ≥50% when added to statins and they also have a well-established safety and tolerability record. The recently approved bempedoic acid is well tolerated and appears to be free of skeletal muscle-related problems, but the CV outcome study with this drug has not been completed. Inclisiran, a small-interfering RNA targeting PCSK9 is at an advanced stage of development and the available data indicate a satisfactory safety profile and LDL-C lowering efficacy similar to the PCSK9 monoclonal antibodies with the advantage of less frequent administration.

Begründung für die neuen LDL-Cholesterin-Zielwerte

Die aktualisierte Dyslipidämie-Leitlinie von 2019 definiert noch tiefere Therapieziele in Abhängigkeit der individuellen Risikokategorie, sowohl für die Primär- als auch für die Sekundärprävention. LDL-Cholesterin bleibt das primäre Maß zur Risikoabschätzung und Haupt-Therapieziel. Daneben sollte Lp(a) einmal im Erwachsenenalter zur Identifikation von Risikopersonen bestimmt werden. Die letzten großen randomisierten Studien zu Ezetimib und PCSK9-Inhibitoren konnten eine weitere relative Risikoreduktion für kardiovaskuläre Ereignisse nachweisen. Dabei ist die Verringerung des kardiovaskulären Risikos proportional zur absoluten LDL-C-Senkung. Für Patienten mit sehr hohem Risiko ist das neue LDL-C-Ziel < 1,4 mmol/l (55 mg/dl) bzw. eine zusätzliche prozentuale Reduktion des LDL-C-Ausgangswerts um ≥ 50%. Eine ausreichende zelluläre Cholesterinversorgung besteht bei LDL-Spiegeln von nur 25 mg/dl (0,65 mmol/l), wie sie zur Geburt vorliegen.

Effect of Simvastatin-Ezetimibe Compared With Simvastatin Monotherapy After Acute Coronary Syndrome Among Patients 75 Years or Older: A Secondary Analysis of a Randomized Clinical Trial

Importance

Limited evidence is available regarding the benefit and hazard of higher-intensity treatment to lower lipid levels among patients 75 years or older. As a result, guideline recommendations differ for this age group compared with younger patients.

Objective

To determine the effect on outcomes and risks of combination ezetimibe and simvastatin compared with simvastatin monotherapy to lower lipid levels among patients 75 years or older with stabilized acute coronary syndrome (ACS).

Design, Setting, Participants

In this prespecified secondary analysis of the global, multicenter, prospective clinical randomized Improved Reduction of Outcomes: Vytorin Efficacy International Trial (IMPROVE-IT), outcomes and risks were compared by age among patients 50 years or older after a hospitalization for ACS. Data were collected from October 26, 2005, through July 8, 2010, with the database locked October 21, 2014. Data were analyzed May 29, 2015, through March 13, 2018, using Kaplan-Meier curves and Cox proportional hazards models.

Interventions

Double-blind randomized assignment to combined simvastatin and ezetimibe or simvastatin and placebo with follow-up for a median of 6 years (interquartile range, 4.3-7.1 years).

Main Outcomes and Measures

The primary composite end point consisted of death due to cardiovascular disease, myocardial infarction (MI), stroke, unstable angina requiring hospitalization, and coronary revascularization after 30 days. Individual adverse ischemic and safety end points and lipid variables were also analyzed.

Results

Of 18 144 patients enrolled (13 728 men [75.7%]; mean [SD] age, 64.1 [9.8] years), 5173 (28.5%) were 65 to 74 years old, and 2798 (15.4%) were 75 years or older at randomization. Treatment with simvastatin-ezetimibe resulted in lower rates of the primary end point than simvastatin-placebo, including 0.9% for patients younger than 65 years (HR, 0.97; 95% CI, 0.90-1.05) and 0.8% for patients 65 to 74 years of age (hazard ratio [HR], 0.96; 95% CI, 0.87-1.06), with the greatest absolute risk reduction of 8.7% for patients 75 years or older (HR, 0.80; 95% CI, 0.70-0.90) (P = .02 for interaction). The rate of adverse events did not increase with simvastatin-ezetimibe vs simvastatin-placebo among younger or older patients.

Conclusions and Relevance

In IMPROVE-IT, patients hospitalized for ACS derived benefit from higher-intensity therapy to lower lipid levels with simvastatin-ezetimibe compared with simvastatin monotherapy, with the greatest absolute risk reduction among patients 75 years or older. Addition of ezetimibe to simvastatin was not associated with any significant increase in safety issues among older patients. These results may have implications for guideline recommendations regarding lowering of lipid levels in the elderly.

Trial Registration

ClinicalTrials.gov identifier: NCT00202878.

Temporal Trends of the Management and Outcome of Patients With Myocardial Infarction According to the Risk for Recurrent Cardiovascular Events

BACKGROUND

Some patients are at higher risk for recurrent cardiovascular events following a myocardial infarction because of their clinical characteristics and comorbidities. Still, they are less often treated with guideline-recommended therapies. We examined trends for more than a decade in the treatment and outcome of patients with myocardial infarction according to the risk for recurrent cardiovascular events, using the Thrombolysis in Myocardial Infarction (TIMI) risk score for secondary prevention.

METHODS

This is a retrospective cohort study of patients after acute myocardial infarction who underwent percutaneous coronary intervention. Temporal trends were examined in the early (2004-2010) and late (2011-2016) time periods. Patients were stratified to low, intermediate, or high risk for recurrent cardiovascular events. Clinical outcomes included 30-day major adverse cardiovascular events (MACE), 1-year MACE, and 1-year mortality.

RESULTS

Among 4921 patients, 31% were low risk, 27% intermediate risk, and 42% high risk. Compared to lower-risk patients, high-risk patients were older, more commonly female, and had more comorbidities. They presented more often with non-ST elevation myocardial infarction and 3-vessel disease and were less likely to receive drug-eluting stents and potent antiplatelets, among other guideline-recommended therapies. In high-risk patients, 30-day MACE and 1-year mortality were higher. Comparing the early period to the late period, prescription rates increased for both statins and potent antiplatelets in all risk-groups. However, the rate of 30-day and 1-year MACE decreased principally in the high-risk group (from 9.9% to 5.5% and from 29.6% to 23.6%, respectively).

CONCLUSION

Despite greater application of guideline-recommended therapies, patients at high risk after myocardial infarction are still relatively undertreated, which may adversely affect their prognosis. Nevertheless, they demonstrated the most notable improvement in clinical outcomes over time.

Development of a risk score for early saphenous vein graft failure: An individual patient data meta-analysis

OBJECTIVES

Early saphenous vein graft (SVG) occlusion is typically attributed to technical factors. We aimed at exploring clinical, anatomical, and operative factors associated with the risk of early SVG occlusion (within 12 months postsurgery).

METHODS

Published literature in MEDLINE was searched for studies reporting the incidence of early SVG occlusion. Individual patient data (IPD) on early SVG occlusion were used from the SAFINOUS-CABG Consortium. A derivation (n = 1492 patients) and validation (n = 372 patients) cohort were used for model training (with 10-fold cross-validation) and external validation respectively.

RESULTS

In aggregate data meta-analysis (48 studies, 41,530 SVGs) the pooled estimate for early SVG occlusion was 11%. The developed IPD model for early SVG occlusion, which included clinical, anatomical, and operative characteristics (age, sex, dyslipidemia, diabetes mellitus, smoking, serum creatinine, endoscopic vein harvesting, use of complex grafts, grafted target vessel, and number of SVGs), had good performance in the derivation (c-index = 0.744; 95% confidence interval [CI], 0.701-0.774) and validation cohort (c-index = 0.734; 95% CI, 0.659-0.809). Based on this model. we constructed a simplified 12-variable risk score system (SAFINOUS score) with good performance for early SVG occlusion (c-index = 0.700, 95% CI, 0.684-0.716).

CONCLUSIONS

From a large international IPD collaboration, we developed a novel risk score to assess the individualized risk for early SVG occlusion. The SAFINOUS risk score could be used to identify patients that are more likely to benefit from aggressive treatment strategies.

Ezetimibe and Improving Cardiovascular Outcomes: Current Evidence and Perspectives

Low-density lipoprotein lowering with statins has convincingly and consistently proven to reduce cardiovascular events in both primary and secondary prevention. However, despite high-dose statin therapy, residual cardiovascular risk remains and many patients also do not tolerate statins. Ezetimibe was initially projected as a frontline alternative to statin. It is an intestinal cholesterol absorption inhibitor with modest LDL lowering effects. But, major studies failed to demonstrate any beneficial effect of CV outcomes, and the drug was relegated to oblivion. IMPROVE-IT, a contemporary, large, and well-designed trial, unequivocally demonstrated reduction in CV outcomes with ezetimibe when added to statin therapy. The benefits are seen in both sexes, elderly, CKD, diabetes mellitus, and in patients with prior CABG. It also reduces biomarkers and induces plaque regression like statins. The drug has now established itself as an add-on therapy to statin when monotherapy fails to achieve LDL goals and when it is not tolerated. The combination therapy has excellent safety and efficacy record. It has now been endorsed by major guidelines too in management of dyslipidemia. Yes, ezetimibe can indeed improve cardiovascular outcomes!

Effects of Alirocumab on Cardiovascular Events After Coronary Bypass Surgery

BACKGROUND

Patients with acute coronary syndrome (ACS) and history of coronary artery bypass grafting (CABG) are at high risk for recurrent cardiovascular events and death.

OBJECTIVES

This study sought to determine the clinical benefit of adding alirocumab to statins in ACS patients with prior CABG in a pre-specified analysis of ODYSSEY OUTCOMES (Evaluation of Cardiovascular Outcomes After an Acute Coronary Syndrome During Treatment With Alirocumab).

METHODS

Patients (n = 18,924) 1 to 12 months post-ACS with elevated atherogenic lipoprotein levels despite high-intensity statin therapy were randomized to alirocumab or placebo subcutaneously every 2 weeks. Median follow-up was 2.8 years. The primary composite endpoint of major adverse cardiovascular events (MACE) comprised coronary heart disease death, nonfatal myocardial infarction, ischemic stroke, or unstable angina requiring hospitalization. All-cause death was a secondary endpoint. Patients were categorized by CABG status: no CABG (n = 16,896); index CABG after qualifying ACS, but before randomization (n = 1,025); or CABG before the qualifying ACS (n = 1,003).

RESULTS

In each CABG category, hazard ratios (95% confidence intervals) for MACE (no CABG 0.86 [0.78 to 0.95], index CABG 0.85 [0.54 to 1.35], prior CABG 0.77 [0.61 to 0.98]) and death (0.88 [0.75 to 1.03], 0.85 [0.46 to 1.59], 0.67 [0.44 to 1.01], respectively) were consistent with the overall trial results (0.85 [0.78 to 0.93] and 0.85 [0.73 to 0.98], respectively). Absolute risk reductions (95% confidence intervals) differed across CABG categories for MACE (no CABG 1.3% [0.5% to 2.2%], index CABG 0.9% [-2.3% to 4.0%], prior CABG 6.4% [0.9% to 12.0%]) and for death (0.4% [-0.1% to 1.0%], 0.5% [-1.9% to 2.9%], and 3.6% [0.0% to 7.2%]).

CONCLUSIONS

Among patients with recent ACS and elevated atherogenic lipoproteins despite intensive statin therapy, alirocumab was associated with large absolute reductions in MACE and death in those with CABG preceding the ACS event. (ODYSSEY OUTCOMES: Evaluation of Cardiovascular Outcomes After an Acute Coronary Syndrome During Treatment With Alirocumab; NCT01663402).

Influence of lipoproteins and antiplatelet agents on vein graft patency 1 year after coronary artery bypass grafting

OBJECTIVE

It remains unclear whether aggressive low-density lipoprotein cholesterol (LDL-C) management (<1.8 mmol/L) can slow the process of vein graft stenosis. This study aimed to explore the impact of baseline LDL-C levels on vein graft patency in patients on ticagrelor with or without aspirin 1 year after coronary artery bypass grafting (CABG).

METHODS

This was a post hoc analysis of the DACAB (Different Antiplatelet Therapy Strategy After Coronary Artery Bypass Graft Surgery) trial (NCT02201771), a randomized controlled trial (ticagrelor + aspirin or ticagrelor vs aspirin) of patients undergoing CABG in China. The study subjects were stratified as LDL-low (baseline LDL-C <1.8 mmol/L, 148 patients with 430 vein grafts) versus LDL-high (baseline LDL-C ≥1.8 mmol/L, 352 patients with 1030 vein grafts). The primary outcome was the 1-year vein graft patency (Fitzgibbon grade A) assessed by coronary computed tomographic angiography or coronary angiography.

RESULTS

Baseline/1-year LDL-C were 1.4/1.6 and 2.6/2.4 mmol/L in the LDL-low and LDL-high subgroups, respectively. Regardless of antiplatelet regimen, no significant inter-subgroup difference was observed for 1-year graft patency (LDL-low: 83.8% [359/430 grafts]; LDL-high: 82.3% [848/1030 grafts]; adjusted OR for non-patency [OR_adj], 0.96; 95% confidence interval [CI], 0.62-1.50, P = .857). For both subgroups, the 1-year graft patency rates were greater with ticagrelor + aspirin versus aspirin (LDL-low: OR_adj, 0.41; 95% CI, 0.17-0.97; LDL-high: OR_adj, 0.38; 95% CI, 0.20-0.71; inter P = .679).

CONCLUSIONS

In general, baseline LDL-C is not associated with 1-year vein graft patency after CABG. Regardless of the baseline LDL-C levels, ticagrelor + aspirin was superior to aspirin alone in maintaining vein graft patency. The primary factor causing early vein graft disease might not be atherosclerosis but thrombosis.

Effects of intensive lipid-lowering therapy on mortality after coronary bypass surgery: A meta-analysis of 7 randomised trials

BACKGROUND AND AIMS

The recent reported analysis from the ODYSSEY OUTCOMES trial showed that patients with previous coronary bypass graft surgery (CABG) had enhanced clinical benefits in response to intensive low-density lipoprotein-cholesterol (LDL-c). Nonetheless, the impact on cardiovascular and all-cause mortality was difficult to ascertain given the relatively small number.

METHODS

We conducted a meta-analysis investigating the role of more versus less intensive lipid-lowering treatment, taking into consideration the difference in studies duration when reporting treatment effect.

RESULTS

A significant 14% reduction in deaths from any cause [RR 0.86 (95% CI, 0.74 to 0.99)] and 25% reduction in cardiovascular mortality [RR 0.75, (95% CI, 0.65 to 0.86)] were associated with intensive LDL-c reduction in patients post CABG. Importantly, this reduction was apparent in patients who were stable or developed an acute coronary syndrome following CABG.

CONCLUSIONS

Patients with previous CABG incurred reduction in all-cause mortality and particularly cardiovascular mortality in response to intensive LDL-c reduction. Patient's clinical presentation following CABG did not modulate the associated benefits with intensive LDL-c reduction. Characterising atherosclerotic disease may help identify other high-risk groups who may benefit maximally from additional lipid-lowering therapies.

Lowering Targeted Atherogenic Lipoprotein Cholesterol Goals for Patients at "Extreme" ASCVD Risk

PURPOSE OF REVIEW

To review randomized interventional clinical and imaging trials that support lower targeted atherogenic lipoprotein cholesterol goals in "extreme" and "very high" atherosclerotic cardiovascular disease (ASCVD) risk settings. Major atherosclerotic cardiovascular event (MACE) prevention among the highest risk patients with ASCVD requires aggressive management of global risks, including lowering of the fundamental atherogenic apolipoprotein B-associated lipoprotein cholesterol particles [i.e., triglyceride-rich lipoprotein remnant cholesterol, low-density lipoprotein cholesterol (LDL-C), and lipoprotein(a)]. LDL-C has been the long-time focus of imaging studies and randomized clinical trials (RCTs). The 2004 adult treatment panel (ATP-III) update recognized that the long-standing targeted LDL-C goal of < 100 mg/dL potentially fostered substantial undertreatment of the very highest coronary heart disease (CHD) risk individuals and was lowered to < 70 mg/dL as an "optional" goal for "very high" 10-year CHD [CHD death + myocardial infarction (MI)] risk exceeding 20%. This evidence-based guideline change was supported by the observed benefits demonstrated in the high-risk primary and secondary prevention populations in the Heart Protection Study (HPS), the acute coronary syndrome (ACS) population in the Pravastatin or Atorvastatin Evaluation and Infection Therapy-Thrombolysis in Myocardial Infarction 22 trial (PROVE-IT), and the secondary prevention population in the Reversal of Atherosclerosis with Aggressive Lipid Lowering (REVERSAL) intravascular ultrasound (IVUS) study. Subsequent national and international guidelines maintained a targeted LDL-C goal < 70 mg/dL, or a threshold for management of > 70 mg/dL for patients with CHD, CHD risk equivalency, or ASCVD.

RECENT FINDINGS

Subgroup or meta-analyses of several RCTs, IVUS imaging studies, and the ACS population in IMProved Reduction of Outcomes: Vytorin Efficacy International Trial (IMPROVE-IT) supported the evidence-based 2017 American Association Clinical Endocrinologist (AACE) guideline change establishing a targeted LDL-C goal < 55 mg/dL, non-HDL-C < 80 mg/dl, and apolipoprotein B (apo B) < 70 mg/dL for patients at "Extreme" ASCVD risk, i.e., 10-year 3-point-MACE-composite (CV death, non-fatal MI, or ischemic stroke) risk exceeding 30%. Moreover, with no recognized lower-limit-associated intolerance or safety issues, even more intensive lowering of atherogenic cholesterol levels is supported by the following evidence base: (1) analysis of eight high-intensity statin-based prospective secondary prevention IVUS atheroma volume regression trials; (2) a distribution analysis of on-treatment, ezetimibe and background-statin, of the very low LDL-C levels reached and CVD event risk in the IMPROVE-IT ACS population; (3) the secondary prevention Global Assessment of Pl\aque Regression With a PCSK9 Antibody as Measured by Intravascular Ultrasound (GLAGOV) on background-statin; and (4) the secondary prevention population of Further Cardiovascular Outcomes Research with PCSK9 Inhibition in Subjects with Elevated Risk (FOURIER). By example, in FOURIER, the population on background-statin at a baseline median 92 mg/dL achieved median LDL-C level of 30 mg/dL and non-HDL-C to < 65 mg/dl, and apo B to < 50 mg/dL, and subgroup and post hoc analyses all demonstrated additional ASCVD event reduction benefits as LDL-C was further reduced. The level of ASCVD risk determines the degree, urgency, and persistence in global risk management, including fundamental atherogenic lipoprotein cholesterol particle lowering. "Extreme" risk patients may require extremely low targeted LDL-C, non-HDL-C and apo B goals; such efforts, implied by more recent interventional trials and analyses, are aimed at maximal atheroma plaque regression, stabilization, and MACE event reduction with the aspiration of improved quality lifespan.

Maximizing the benefits of cholesterol-lowering drugs

PURPOSE OF REVIEW

Drugs to lower LDL-C levels are very widely used. In this brief review, I will use selected recent studies to delineate several important principles that provide a rationale for how to maximize the benefits of using LDL-C lowering drugs to reduce cardiovascular disease. The focus will be on using statins, ezetimibe, and PCSK9 monoclonal antibodies as recent studies have predominantly utilized these agents.

RECENT FINDINGS

The key principles to consider when using LDL-C-lowering drugs to reduce cardiovascular disease are: the lower the LDL-C the better; the sooner and the longer one lowers LDL-C the better; the higher the risk of cardiovascular disease the greater the absolute benefit; the higher the baseline LDL-C the greater the absolute benefit; and compared with the benefits of cholesterol-lowering drugs on reducing cardiovascular disease the risk of side effects is very modest.

SUMMARY

Understanding and employing these key concepts in caring for patients will allow one to use cholesterol-lowering drugs wisely to maximize the reduction of cardiovascular events.

Risk Categorization Using New American College of Cardiology/American Heart Association Guidelines for Cholesterol Management and Its Relation to Alirocumab Treatment Following Acute Coronary Syndromes

Supplemental Digital Content is available in the text.

The 2018 US cholesterol management guidelines recommend additional lipid-lowering therapies for secondary prevention in patients with low-density lipoprotein cholesterol ≥70 mg/dL or non−high-density lipoprotein cholesterol ≥100 mg/dL despite maximum tolerated statin therapy. Such patients are considered at very high risk (VHR) based on a history of >1 major atherosclerotic cardiovascular disease (ASCVD) event or a single ASCVD event and multiple high-risk conditions. We investigated the association of US guideline-defined risk categories with the occurrence of ischemic events after acute coronary syndrome and reduction of those events by alirocumab, a PCSK9 (proprotein convertase subtilisin/kexin type 9) inhibitor.

Pharmacological lipid-modification therapies for prevention of ischaemic heart disease: current and future options

Atherosclerosis and its clinical manifestation as ischaemic heart disease remains a considerable health burden. Given that many factors contribute to ischaemic heart disease, a multifactorial approach to prevention is recommended, starting with lifestyle advice, smoking cessation, and control of known cardiovascular risk factors, such as blood pressure and lipids. Within the lipid profile, the principal target is lowering LDL cholesterol, firstly with lifestyle interventions and subsequently with pharmacological therapy. Statins are the recommended first-line pharmacological treatment. Some individuals might require further lowering of LDL cholesterol or be unable to tolerate statins. Additional therapies targeting different pathways in cholesterol metabolism are now available, ranging from small molecules taken orally, to injectable therapies. Examples include ezetimibe, which targets Niemann-Pick C1-like protein, and monoclonal antibodies that target PCSK9. Phase 3 trials have also been completed for bempedoic acid (targeting ATP-citrate lyase) and inclisiran (an interference RNA-based therapeutic targeting hepatic PCSK9 synthesis). In addition to LDL cholesterol, mendelian randomisation studies support a causal role for lipoprotein(a) and triglycerides in ischaemic heart disease. In this Series paper, we appraise currently available and emerging therapies for lowering LDL cholesterol, lipoprotein(a), and triglycerides for prevention of ischaemic heart disease.

Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) Inhibitors, Reality or Dream in Managing Patients with Cardiovascular Disease

BACKGROUND

Statins have been a major keystone in the management of patients with atherosclerotic cardiovascular disease. The benefits of inhibiting HMG CoA reductase, via statins, were translated into reduction in LDL-c with proportionate decrease in cardiovascular events in response to the magnitude of LDL-c reduction. Despite major advances in pharmacological treatments, including the use of high-dose statins, there are urgent need to further reduce future cardiovascular risk. This is in particularly important since 1 out of 5 high-risk atherosclerotic patients who achieve low LDL-c return with a second cardiovascular event within five years. Although this residual risk post-statin is largely heterogeneous, lowering LDL-c beyond 'normal' or guidelines-recommended level using novel therapies has resulted in further reduction in cardiovascular events.

OBJECTIVE

The current review will discuss the use of PCSK9 inhibitors in patients with atherosclerotic disease. PCSK9 inhibitors are a new class of lipid-lowering drugs that are either fully human monoclonal antibodies (evolocumab and alirocumab) or humanised monoclonal antibodies (bococizumab) that effectively reduce LDL-c to unprecedented level. By blocking circulating PCSK9, these drugs would preserve LDL receptors and prevent them from cellular degradation. This process promotes recycling of LDL receptors back to hepatocytes surface, leading into further reduction of LDL-c. Combining PCSK9 inhibitors with statin have led into lower LDL-c, reduction in plaque volume and more importantly reduction in future cardiovascular events.

CONCLUSION

These drugs are very promising, nonetheless, the unselective approach of applying these monoclonal antibodies may not prove to be cost-effective and potentially exposing some patients to unnecessary side effects.

Mechanistic Insights to Target Atherosclerosis Residual Risk

Current pharmacological and mechanical therapies have reduced future cardiovascular risk. Nonetheless, a significant proportion of patients remained at high risk of recurrent events despite achieving guideline-directed therapeutic targets. This residual risk poses challenges despite tackling 'traditional' risk factors. Targeting the residual risk has been the focus of numerous pharmacotherapies which were associated with variable success. Incomplete understanding of the mechanistic nature combined with the lack of tools to precisely quantify the residual risk contributed to the relatively high residual risk after 'optimal' medical therapy. The development of atherosclerotic plaque is derived from lipid retention within arterial intima that triggers an inflammatory cascade accelerating atherosclerosis progression and rendering plaque more prone to rupture. The exposed subendothelial space with activated platelets causes arterial occlusion leading to potential fatality. Therefore, a distinctive approach to characterize these features may offer the opportunity to tailor novel antiatherosclerotic to reduce the residual risk. The traditional approach of measuring risk factors is beneficial at population-level but maybe less informative upon quantifying risk at an individual-basis. This review will discuss lipid accumulation, thrombosis, and inflammation as therapeutic targets of atherosclerosis. Additionally, we will summarize previous challenges of antiatherosclerosis therapies and the future role to tackle the residual risk.

An updated review of lipid-modifying therapy

Statin drugs reduce low-density lipoprotein (LDL)-cholesterol (LDL-C) and cardiovascular risk. Ezetimibe may be used to supplement statin therapy, or used alone in cases of statin intolerance. Statin-associated side effects do occur, especially muscle symptoms and new onset diabetes, but they do not detract from the benefits of statin therapy. Inhibitors of proprotein convertase subtilisin/kexin type 9 (PCSK9) reduce LDL-C and cardiovascular risk. Evolocumab is subsidised in Australia for patients with familial hypercholesterolaemia when LDL-C is not adequately controlled with maximum doses of statin or ezetimibe or when statin therapy is contraindicated. Fenofibrate reduces triglycerides and cardiovascular risk in patients with type 2 diabetes when triglycerides are elevated and high-density lipoprotein (HDL) is low. A role for dietary omega-3 fatty acids and esters in reducing cardiovascular risk remains controversial. All cases of secondary cardiovascular disease prevention merit intensive lipid therapy, unless a contraindication exists. Lipid therapy is justified in cases of primary prevention when absolute risk is high, especially when lipids are highly elevated or when multiple risk factors are present. Clinical management requires a focus on the predominant lipid disorder present, namely hypercholesterolaemia, hypertriglyceridaemia or combined hyperlipidaemia. There is an ongoing problem of poor long term persistence on lipid therapy, as well as reduced awareness by practitioners of poor risk factor control.

The emerging concept of "individualized cholesterol-lowering therapy": A change in paradigm

High LDL-cholesterol concentrations constitute a risk for atherosclerotic cardiovascular disease. By consensus, cholesterol-lowering therapy is initiated with a statin that reduces endogenous cholesterol synthesis, upregulates hepatic LDL receptor activity, increases LDL clearance and lowers LDL-cholesterol concentrations in the bloodstream. The efficacy of statin treatment is dose dependent and achieves a risk reduction of up to 50%. However, a substantial body of evidence suggests that a quarter of statin-treated patients do not respond adequately as a result of low endogenous cholesterol synthesis. In humans fractional cholesterol absorption varies from 20% to 80%. High cholesterol absorbers, which are characterized by a low-to-normal cholesterol synthesis, exhibit poor responsiveness to statin treatment. On the other hand, the cholesterol absorption inhibitor ezetimibe effectively reduces serum cholesterol levels in these patients. On this background, we suggest to "get personal" and individualize cholesterol-lowering therapies, according to the individual's status of cholesterol synthesis and absorption.

Polyvascular disease, type 2 diabetes, and long-term vascular risk: a secondary analysis of the IMPROVE-IT trial

BACKGROUND

Polyvascular disease and type 2 diabetes are each associated with increased cardiovascular risk, but whether these risks are additive is unknown. In this exploratory analysis of a randomised trial, we explored the long-term cardiovascular risk associated with polyvascular disease, type 2 diabetes, and their combination in patients with acute coronary syndrome, and assessed the effect of ezetimibe given on top of statin therapy in patients with these concomitant conditions.

METHODS

IMPROVE-IT was a multicentre, double-blind, randomised, placebo-controlled trial assessing the effect of ezetimibe added to statin therapy after acute coronary syndrome. Recruitment was from Oct 26, 2005, to July 8, 2010, and the trial was done at 1158 sites in 39 countries. 18 144 patients aged 50 years and older who had been stabilised after an acute coronary syndrome were randomly assigned to 40 mg per day simvastatin plus either 10 mg per day ezetimibe or matched placebo, for a median duration of 6 years. In this post-hoc exploratory analysis, we assessed the prespecified endpoints of the trial, including the primary composite endpoint (cardiovascular death, a major coronary event [non-fatal myocardial infarction, documented unstable angina requiring hospital admission, or coronary revascularisation occurring at least 30 days after randomisation], or stroke [ischaemic or haemorrhagic]) by concomitant polyvascular disease at baseline (peripheral artery disease or previous stroke or transient ischaemic attack) and stratified by concomitant type 2 diabetes. Efficacy analyses were done according to intention to treat and event rates. IMPROVE-IT is registered with ClinicalTrials.gov, number NCT00202878.

FINDINGS

1005 patients (6%) had peripheral artery disease and 1071 (6%) had stroke or transient ischaemic attack at baseline. Of these, 388 (39%) and 409 (38%) also had concomitant type 2 diabetes, respectively. At 7 years, patients with either polyvascular disease or type 2 diabetes had similar rates of the primary endpoint (39·8% and 39·9%, respectively), which were higher than patients without polyvascular disease or diabetes (29·6%). Polyvascular disease with concomitant type 2 diabetes was associated with further heightened risk (60·0% 7-year Kaplan-Meier rate, adjusted hazard ratio versus those with polyvascular disease 1·60, 95% CI 1·38-1·85; p<0·0001). Ezetimibe reduced cardiovascular risk consistently across groups with greater numerical absolute risk reductions in the highest-risk subgroups.

INTERPRETATION

In patients with coronary artery disease, concomitant polyvascular disease or type 2 diabetes are associated with increased long-term cardiovascular risk. The combination of polyvascular disease and diabetes is additive, resulting in very high risk. The benefit of ezetimibe is consistent in patients with and without polyvascular disease and type 2 diabetes; however, by nature of their higher risk patients with one, or especially both, of these diseases might derive the greatest absolute benefits.

FUNDING

Merck.

Lipids: a personal view of the past decade

The past decade has witnessed considerable progress in the field of lipids. New drugs have been "rapidly" developed and some of these drugs have already been evaluated in event-based large trials. This evidence has led to the guidelines recommending new, more aggressive treatment goals for low-density lipoprotein cholesterol (LDL-C) levels. Although LDL-C remains the principal goal for cardiovascular disease (CVD) risk reduction, there has also been considerable interest in other lipid variables, such as high-density lipoprotein cholesterol, triglycerides, and lipoprotein(a). Statin intolerance is now considered a very important topic in daily clinical practice. This has resulted in more attention focusing on non-statin drugs [e.g., ezetimibe and proprotein convertase subtilisin/kexin 9 (PCSK9) inhibitors] and statin-related side effects. The latter mainly involve muscles, but there is also a need to consider other adverse effects associated with statin use (e.g., new onset diabetes). New specific areas of statin use have attracted interest. For example, statin-loading before procedures (e.g., coronary stenting), the prevention of stroke, and the treatment of non-alcoholic fatty liver disease (NAFLD). Statins will remain the most widely used drugs to treat dyslipidaemia and decrease CVD risk. However, we also need to briefly consider some other lipid-lowering drugs, including those that may become available in the future.