Effects of probucol and pravastatin on common carotid atherosclerosis in patients with asymptomatic hypercholesterolemia. Fukuoka Atherosclerosis Trial (FAST)

Multipathway Regulation for Targeted Atherosclerosis Therapy Using Anti-miR-33-Loaded DNA Origami

Given the multifactorial pathogenesis of atherosclerosis (AS), a chronic inflammatory disease, combination therapy arises as a compelling approach to effectively address the complex interplay of pathogenic mechanisms for a more desired treatment outcome. Here, we present cRGD/ASOtDON, a nanoformulation based on a self-assembled DNA origami nanostructure for the targeted combination therapy of AS. cRGD/ASOtDON targets αvβ3 integrin receptors overexpressed on pro-inflammatory macrophages and activated endothelial cells in atherosclerotic lesions, alleviates the oxidative stress induced by extracellular and endogenous reactive oxygen species, facilitates the polarization of pro-inflammatory macrophages toward the anti-inflammatory M2 phenotype, and inhibits foam cell formation by promoting cholesterol efflux from macrophages by downregulating miR-33. The antiatherosclerotic efficacy and safety profile of cRGD/ASOtDON, as well as its mechanism of action, were validated in an AS mouse model. cRGD/ASOtDON treatment reversed AS progression and restored normal morphology and tissue homeostasis of the diseased artery. Compared to probucol, a clinical antiatherosclerotic drug with a similar mechanism of action, cRGD/ASOtDON enabled the desired therapeutic outcome at a notably lower dosage. This study demonstrates the benefits of targeted combination therapy in AS management and the potential of self-assembled DNA nanoformulations in addressing multifactorial inflammatory conditions.

Pharmacological interventions for asymptomatic carotid stenosis

BACKGROUND

Carotid artery stenosis is narrowing of the carotid arteries. Asymptomatic carotid stenosis is when this narrowing occurs in people without a history or symptoms of this disease. It is caused by atherosclerosis; that is, the build-up of fats, cholesterol, and other substances in and on the artery walls. Atherosclerosis is more likely to occur in people with several risk factors, such as diabetes, hypertension, hyperlipidaemia, and smoking. As this damage can develop without symptoms, the first symptom can be a fatal or disabling stroke, known as ischaemic stroke. Carotid stenosis leading to ischaemic stroke is most common in men older than 70 years. Ischaemic stroke is a worldwide public health problem.

OBJECTIVES

To assess the effects of pharmacological interventions for the treatment of asymptomatic carotid stenosis in preventing neurological impairment, ipsilateral major or disabling stroke, death, major bleeding, and other outcomes.

SEARCH METHODS

We searched the Cochrane Stroke Group trials register, CENTRAL, MEDLINE, Embase, two other databases, and three trials registers from their inception to 9 August 2022. We also checked the reference lists of any relevant systematic reviews identified and contacted specialists in the field for additional references to trials.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs), irrespective of publication status and language, comparing a pharmacological intervention to placebo, no treatment, or another pharmacological intervention for asymptomatic carotid stenosis.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. Two review authors independently extracted the data and assessed the risk of bias of the trials. A third author resolved disagreements when necessary. We assessed the evidence certainty for key outcomes using GRADE.

MAIN RESULTS

We included 34 RCTs with 11,571 participants. Data for meta-analysis were available from only 22 studies with 6887 participants. The mean follow-up period was 2.5 years. None of the 34 included studies assessed neurological impairment and quality of life. Antiplatelet agent (acetylsalicylic acid) versus placebo Acetylsalicylic acid (1 study, 372 participants) may result in little to no difference in ipsilateral major or disabling stroke (risk ratio (RR) 1.08, 95% confidence interval (CI) 0.47 to 2.47), stroke-related mortality (RR 1.40, 95% CI 0.54 to 3.59), progression of carotid stenosis (RR 1.16, 95% CI 0.79 to 1.71), and adverse events (RR 0.81, 95% CI 0.41 to 1.59), compared to placebo (all low-certainty evidence). The effect of acetylsalicylic acid on major bleeding is very uncertain (RR 0.98, 95% CI 0.06 to 15.53; very low-certainty evidence). The study did not measure neurological impairment or quality of life. Antihypertensive agents (metoprolol and chlorthalidone) versus placebo The antihypertensive agent, metoprolol, may result in no difference in ipsilateral major or disabling stroke (RR 0.14, 95% CI 0.02 to1.16; 1 study, 793 participants) and stroke-related mortality (RR 0.57, 95% CI 0.17 to 1.94; 1 study, 793 participants) compared to placebo (both low-certainty evidence). However, chlorthalidone may slow the progression of carotid stenosis (RR 0.45, 95% CI 0.23 to 0.91; 1 study, 129 participants; low-certainty evidence) compared to placebo. Neither study measured neurological impairment, major bleeding, adverse events, or quality of life. Anticoagulant agent (warfarin) versus placebo The evidence is very uncertain about the effects of warfarin (1 study, 919 participants) on major bleeding (RR 1.19, 95% CI 0.97 to 1.46; very low-certainty evidence), but it may reduce adverse events (RR 0.89, 95% CI 0.81 to 0.99; low-certainty evidence) compared to placebo. The study did not measure neurological impairment, ipsilateral major or disabling stroke, stroke-related mortality, progression of carotid stenosis, or quality of life. Lipid-lowering agents (atorvastatin, fluvastatin, lovastatin, pravastatin, probucol, and rosuvastatin) versus placebo or no treatment Lipid-lowering agents may result in little to no difference in ipsilateral major or disabling stroke (atorvastatin, lovastatin, pravastatin, and rosuvastatin; RR 0.36, 95% CI 0.09 to 1.53; 5 studies, 2235 participants) stroke-related mortality (lovastatin and pravastatin; RR 0.25, 95% CI 0.03 to 2.29; 2 studies, 1366 participants), and adverse events (fluvastatin, lovastatin, pravastatin, probucol, and rosuvastatin; RR 0.76, 95% CI 0.53 to1.10; 7 studies, 3726 participants) compared to placebo or no treatment (all low-certainty evidence). The studies did not measure neurological impairment, major bleeding, progression of carotid stenosis, or quality of life.

AUTHORS' CONCLUSIONS

Although there is no high-certainty evidence to support pharmacological intervention, this does not mean that pharmacological treatments are ineffective in preventing ischaemic cerebral events, morbidity, and mortality. High-quality RCTs are needed to better inform the best medical treatment that may reduce the burden of carotid stenosis. In the interim, clinicians will have to use other sources of information.

Safety and efficacy of low-dose rt-PA with tirofiban to treat acute non-cardiogenic stroke: a single-center randomized controlled study

BACKGROUND AND PURPOSE

The recanalization rate after intravenous thrombolysis (IVT) is not enough and there is still the possibility of re-occlusion. We aim to investigate the effectiveness and safety of infusing tirofiban after IVT.

METHODS

We performed a prospective controlled study of 60 patients with acute non-cardiogenic ischemic stroke who were hospitalized in Yantai Yuhuangding Hospital from January 2018 to December 2019. The patients were divided into 2 groups: those who received tirofiban for 24 h after IVT (rt-PA + T group) and those who did not receive postprocedural intravenous tirofiban (rt-PA group). The rt-PA + T group received low-dose rt-PA (0.6 mg/kg). The rt-PA group received standard dose rt-PA (0.9 mg/kg). The main outcome measure were safety, included the symptomatic intracranial hemorrhage (sICH), any ICH, severe systemic bleeding, and mortality. The secondary outcome measure is curative efficacy which were evaluated by the 7d-NIHSS score and functional outcomes at 90 days. During hospitalization, the deterioration of neurological function was recorded.

RESULTS

All patients completed the follow-up with complete data, there were 30 patients in each of groups. The general characteristics between the two group patients had no statistically significant differences. Compared with the rt-PA + T group and the rt-PA group, in terms of safety, the rates of the sICH, severe systemic bleeding, and mortality in both groups were 0, and there was no statistically significant difference in the rates of any ICH between the two groups (10.0% vs. 3.3%, P = 0.306). In terms of efficacy, the rate of the early neurological deterioration events (END) was no statistical significance (0 vs. 6.6%, P = 0.246). There was no significant difference in the NIHSS score between the two groups before the IVT, and also at 24 h, however, the 7d-NIHSS score was lower in the rt-PA + T group compared with the rt-PA group (2.33 ± 1.85 vs. 4.80 ± 4.02, P = 0.004). At 90 days, 83.3% of patients in the rt-PA + T group had favorable functional outcomes compared with 60.0% of patients in the rt-PA group (P = 0.045).

CONCLUSIONS

Low-dose rt-PA combined with tirofiban in acute non-cardiogenic ischemic stroke did not increase the risk of ICH, and mortality, and it was associated with neurological improvement.

TRIAL REGISTRATION

The trial has been registered at the ChiCTR and identified as ChiCTR1800014666 (28/01/2018).

Can an ultrathin strut stent design and a polymer free, proendothelializing probucol matrix coating improve early strut healing? The FRIENDLY-OCT trial. An intra-patient randomized study with OCT, evaluating early strut coverage of a novel probucol coated polymer-free and ultra-thin strut sirolimus-eluting stent compared to a biodegradable polymer sirolimus-eluting stent

BACKGROUND

incomplete strut coverage determines the risk of stent thrombosis in the first months after stent implantation.

AIMS

To evaluate the potential better early healing of a novel probucol coated polymer free ultra-thin strut sirolimus eluting stent (PF-SES). [Clinical trial unique identifier: NCT02785237].

METHODS

Patients with two (angiographically similar) lesions with clinical indication for PCI were enrolled. The investigated stent was compared to a thin strut, bioresorbable polymer, sirolimus eluting stent (BP-SES). Every patient received both stents, one in each lesion, assigned in a randomized sequence. OCT was systematically performed at 3 months. Primary end point was the difference in the proportion of covered struts at 3 months (defined as ≥20 μm of tissue coverage). Secondary end points included differences in percentage of uncovered struts (0 μm coverage), mean strut coverage thickness, and malapposed struts' coverage proportion. Major adverse cardiac events (cardiac death, myocardial infarction, target lesion revascularization, and definite or probable stent thrombosis) at 12 months were also evaluated.

RESULTS

70 patients were included. At 3 months, a consistent and significantly higher strut coverage rate (≥20 μm) was observed in PF-SES as compared to BP-SES, both for well apposed (87.3% versus 79.1%, p < 0.001) and malapposed struts (50.4% vs 37.8%, p 0.00). Uncoverage rate (0 μm) was also significantly lower for the PF-SES (3.1% vs 5.3%, p < 0.001). There were no differences in clinical endpoints.

CONCLUSION

The probucol coated non-polymeric ultra-thin strut sirolimus eluting stent showed a significantly better early strut coverage at 3 months.

Non-Transferrin-Bound Iron in the Spotlight: Novel Mechanistic Insights into the Vasculotoxic and Atherosclerotic Effect of Iron

Significance: While atherosclerosis is an almost inevitable consequence of aging, food preferences, lack of exercise, and other aspects of the lifestyle in many countries, the identification of new risk factors is of increasing importance to tackle a disease, which has become a major health burden for billions of people. Iron has long been suspected to promote the development of atherosclerosis, but data have been conflicting, and the contribution of iron is still debated controversially. Recent Advances: Several experimental and clinical studies have been recently published about this longstanding controversial problem, highlighting the critical need to unravel the complexity behind this topic. Critical Issues: The aim of the current review is to provide an overview of the current knowledge about the proatherosclerotic impact of iron, and discuss the emerging role of non-transferrin-bound iron (NTBI) as driver of vasculotoxicity and atherosclerosis. Finally, I will provide detailed mechanistic insights on the cellular processes and molecular pathways underlying iron-exacerbated atherosclerosis. Overall, this review highlights a complex framework where NTBI acts at multiple levels in atherosclerosis by altering the serum and vascular microenvironment in a proatherogenic and proinflammatory manner, affecting the functionality and survival of vascular cells, promoting foam cell formation and inducing angiogenesis, calcification, and plaque destabilization. Future Directions: The use of additional iron markers (e.g., NTBI) may help adequately predict predisposition to cardiovascular disease. Clinical studies are needed in the aging population to address the atherogenic role of iron fluctuations within physiological limits and the therapeutic value of iron restriction approaches. Antioxid. Redox Signal. 35, 387-414.

Natural products: The role and mechanism in low-density lipoprotein oxidation and atherosclerosis

Atherosclerosis is a chronic inflammatory, metabolic, and epigenetic disease, which leads to the life-threatening coronary artery disease. Emerging studies from bench to bedside have demonstrated the pivotal role of low-density lipoprotein (LDL) oxidation in the initiation and progression of atherosclerosis. This article hereby reviews oxidation mechanism of LDL, and the pro-atherogenic and biomarker role of oxidized LDL in atherosclerosis. We also review the pharmacological effects of several representative natural products (vitamin E, resveratrol, quercetin, probucol, tanshinone IIA, epigallocatechin gallate, and Lycopene) in protecting against LDL oxidation and atherosclerosis. Clinical and basic research supports the beneficial effects of these natural products in inhibiting LDL oxidation and preventing atherosclerosis, but the data are still controversial. This may be related to factors such as the population and the dosage and time of taking natural products involved in different studies. Understanding the mechanism of LDL oxidation and effect of oxidized LDL help researchers to find novel therapies against atherosclerosis.

All-Cause Mortality and Cardiovascular Death between Statins and Omega-3 Supplementation: A Meta-Analysis and Network Meta-Analysis from 55 Randomized Controlled Trials

Statins and omega-3 supplementation have shown potential benefits in preventing cardiovascular disease (CVD), but their comparative effects on mortality outcomes, in addition to primary and secondary prevention and mixed population, have not been investigated. This study aimed to examine the effect of statins and omega-3 supplementation and indirectly compare the effects of statin use and omega-3 fatty acids on all-cause mortality and CVD death. We included randomized controlled trials (RCTs) from meta-analyses published until December 2019. Pooled relative risks (RRs) and 95% confidence intervals (CIs) were calculated to indirectly compare the effect of statin use versus omega-3 supplementation in a frequentist network meta-analysis. In total, 55 RCTs were included in the final analysis. Compared with placebo, statins were significantly associated with a decreased the risk of all-cause mortality (RR = 0.90, 95% CI = 0.86–0.94) and CVD death (RR = 0.86, 95% CI = 0.80–0.92), while omega-3 supplementation showed a borderline effect on all-cause mortality (RR = 0.97, 95% CI = 0.94–1.01) but were significantly associated with a reduced risk of CVD death (RR = 0.92, 95% CI = 0.87–0.98) in the meta-analysis. The network meta-analysis found that all-cause mortality was significantly different between statin use and omega-3 supplementation for overall population (RR = 0.91, 95% CI = 0.85–0.98), but borderline for primary prevention and mixed population and nonsignificant for secondary prevention. Furthermore, there were borderline differences between statin use and omega-3 supplementation in CVD death in the total population (RR = 0.92, 95% CI = 0.82–1.04) and primary prevention (RR = 0.85, 95% CI = 0.68–1.05), but nonsignificant differences in secondary prevention (RR = 0.97, 95% CI = 0.66–1.43) and mixed population (RR = 0.92, 95% CI = 0.75–1.14). To summarize, statin use might be associated with a lower risk of all-cause mortality than omega-3 supplementation. Future direct comparisons between statin use and omega-3 supplementation are required to confirm the findings.

Comparative Effect of Statins and Omega-3 Supplementation on Cardiovascular Events: Meta-Analysis and Network Meta-Analysis of 63 Randomized Controlled Trials Including 264,516 Participants

Statins and omega-3 supplementation have been recommended for cardiovascular disease prevention, but comparative effects have not been investigated. This study aimed to summarize current evidence of the effect of statins and omega-3 supplementation on cardiovascular events. A meta-analysis and a network meta-analysis of 63 randomized controlled trials were used to calculate pooled relative risks (RRs) and 95% confidence intervals (CIs) for the effects of specific statins and omega-3 supplementation compared with controls. Overall, the statin group showed significant risk reductions in total cardiovascular disease, coronary heart disease, myocardial infarction, and stroke; however, omega-3 supplementation significantly decreased the risks of coronary heart disease and myocardial infarction only, in the comparison with the control group. In comparison with omega-3 supplementation, pravastatin significantly reduced the risks of total cardiovascular disease (RR = 0.81, 95% CI = 0.72–0.91), coronary heart disease (RR = 0.75, 95% CI = 0.60–0.94), and myocardial infarction (RR = 0.71, 95% CI = 0.55–0.94). Risks of total cardiovascular disease, coronary heart disease, myocardial infarction, and stroke in the atorvastatin group were statistically lower than those in the omega-3 group, with RRs (95% CIs) of 0.80 (0.73–0.88), 0.64 (0.50–0.82), 0.75 (0.60–0.93), and 0.81 (0.66–0.99), respectively. The findings of this study suggest that pravastatin and atorvastatin may be more beneficial than omega-3 supplementation in reducing the risk of total cardiovascular disease, coronary heart disease, and myocardial infarction.

Applications of inorganic nanoparticles in the diagnosis and therapy of atherosclerosis

Atherosclerosis is a chronic progressive disease, which may result in serious clinical outcomes, such as acute heart events or stroke with high mortality. At present, the clinical problems of atherosclerosis mainly consist of the difficulty in confirming the plaques or identifying the stability of the plaques in the early phase and the shortage of valid treatments. Fortunately, with the development of nanotechnology, various inorganic nanoparticles with imaging enhancement and noninvasive therapy functions have been studied in the imaging and treatment of atherosclerosis, which has brought new hope to patients. This review focuses on the recent progress in the use of inorganic nanoparticles in the diagnosis and therapy of atherosclerosis, including the key processes in the development of atherosclerosis and the mainly involved cells, inorganic nanoparticle-based dual-mode imaging methods classified by the types of targeting cells, and inorganic nanoparticle-based therapeutic approaches, such as photothermal therapy (PTT), photodynamic therapy (PDT), sonodynamic therapy (SDT), drug delivery, gene therapy and imaging-guided therapy for atherosclerosis. Finally, this review discusses the challenges and directions of inorganic nanoparticles in potential clinical translation of anti-atherosclerosis in future. We believe this review will enable readers to systematically understand the progress of the inorganic nanoparticle-based imaging and therapy of atherosclerosis and therefore promote the further development of anti-atherosclerosis.

Probucol Trial for Secondary Prevention of Atherosclerotic Events in Patients with Coronary Heart Disease (PROSPECTIVE)

AIMS

Although intensive statin therapy reduced cardiovascular risks, cardiovascular events have not been completely prevented. Probucol is a potent antioxidant and reduces tendon xanthomas in familial hypercholesterolemia patients despite reduction of high-density lipoprotein (HDL)-cholesterol (HDL-C). We investigated whether probucol can reduce cardiovascular events on top of conventional lipid-lowering therapy in patients with coronary heart disease (CHD).

METHODS

PROSPECTIVE is a multicenter, randomized, prospective study that recruited 876 Japanese patients with CHD and dyslipidemia with a low-density lipoprotein (LDL)-cholesterol (LDL-C) level of ≥ 140 mg/dL without medication or those treated with lipid-lowering drugs. Lipid-lowering agents were administered during the study period in the control group (n=438), and probucol 500 mg/day was added to lipid-lowering therapy in the probucol group (n=438). Patients were randomly assigned to two treatment groups by adjusting the LDL-C level and presence of diabetes and hypertension and followed up for more than 3 years. The primary end point was a composite of cerebrovascular and cardiovascular events (cardiovascular disease death including sudden death, nonfatal myocardial infarction, nonfatal stroke, hospitalization for unstable angina, hospitalization for heart failure, or coronary revascularization). The secondary end point was carotid intima-media thickness in a subset of patients.

RESULTS

The incidence of the primary end point showed a trend to be lower in the probucol group compared with that in the control group despite reduced HDL-C without serious adverse events. Anti-atherogenic effects of probucol may be attributed to its potent antioxidative function and enhancement of reverse cholesterol transport.

CONCLUSION

Since there was no statistical significance between the probucol and control groups despite a marked reduction of HDL-C, further studies on the clinical outcomes of probucol on top of conventional therapy may be necessary in the future (UMIN000003307).

Effect of Probucol and/or Cilostazol on Carotid Intima Media Thickness in Patients with Coronary Heart Disease: A Randomized, Multicenter, Multinational Study

Aim: In a prospective randomized multinational open blinded endpoint study, the long-term effects of probucol or probucol and cilostazol with statin on carotid mean intima media thickness (IMT) were evaluated for the first time.

Methods: Hypercholesterolemic patients with coronary artery disease were randomized to three groups and received study drugs for 3 years: the control with statin alone; the probucol group with statin and probucol; and the combo group with statin, probucol, and cilostazol. Primary efficacy endpoint was changes of mean carotid IMT at 3 years. Biomarkers, major adverse cerebro-cardiovascular events (MACCEs) and safety were secondary endpoints.

Results: Two hundred eighty-one patients were randomized into three groups. All three groups showed significant regression of carotid IMT at 3 years compared with baseline. Decrease in mean carotid IMT was significantly greater in the combo group than in the control group at 1 year. However, there were no significant differences in changes of mean carotid IMT between groups at 3 years (control; −0.12 ± 0.36 mm vs. probucol; −0.11 ± 0.32 mm vs. combo; −0.16 ± 0.38 mm). MACCEs were frequent in the control group, but the difference was not significant (control; 10.8% vs. probucol; 4.4% vs. combo; 6.9%, p = 0.35). Probucol and cilostazol were well tolerated in long-term treatment without serious drug-related adverse reactions.

Conclusion: Probucol or probucol and cilostazol with statin did not reduce carotid IMT in comparison with statin alone in this study. However, the clinical outcome of probucol-based treatment with current standard statin treatment may need further studies.

D-Allulose enhances uptake of HDL-cholesterol into rat's primary hepatocyte via SR-B1

D-Allulose, a C-3 epimer of D-fructose, is a rare sugar and a non-caloric sweetener. D-Allulose is reported to have several health benefits, such as suppressing a rise in postprandial glucose levels and preventing fat accumulation in rodents and humans. Additionally, low HDL-cholesterol levels post-D-allulose feeding were observed in humans but it is unclear how D-allulose decreased HDL-cholesterol levels. It is necessary to research the mechanism of HDL-cholesterol reduction by D-allulose ingestion because low HDL-cholesterol levels are known to associate with increased atherosclerosis risk. We therefore investigated the mechanism by which D-allulose lowers HDL-cholesterol using rat's primary hepatocytes. Sprague Dawley rats were fed an AIN-93G based diet containing 3% D-allulose for 2 weeks. Thereafter, primary hepatocytes were isolated by perfusion of collagenase. We measured the ability of HDL-cholesterol uptake in hepatocytes and the protein levels of scavenger receptor class B type 1 (SR-B1) as a HDL-cholesterol receptor. D-Allulose enhanced hepatocyte uptake of HDL-cholesterol, with a concurrent increase in hepatic SR-B1 protein levels. The results suggest that D-allulose enhances HDL-cholesterol uptake into the liver by increasing SR-B1 expression. It is estimated that HDL-cholesterol levels decreased accordingly. Since SR-B1 overexpression would decrease HDL-cholesterol levels, reportedly preventing atherosclerosis development, D-allulose could be a useful sweetener for atherosclerosis prevention.

Changes in High-Density Lipoprotein Cholesterol and Risks of Cardiovascular Events: A Post Hoc Analysis from the PICASSO Trial

BACKGROUND AND PURPOSE

Whether pharmacologically altered high-density lipoprotein cholesterol (HDL-C) affects the risk of cardiovascular events is unknown. Recently, we have reported the Prevention of Cardiovascular Events in Asian Patients with Ischaemic Stroke at High Risk of Cerebral Haemorrhage (PICASSO) trial that demonstrated the non-inferiority of cilostazol to aspirin and superiority of probucol to non-probucol for cardiovascular prevention in ischemic stroke patients (clinicaltrials.gov: NCT01013532). We aimed to determine whether on-treatment HDL-C changes by cilostazol and probucol influence the treatment effect of each study medication during the PICASSO study.

METHODS

Of the 1,534 randomized patients, 1,373 (89.5%) with baseline cholesterol parameters were analyzed. Efficacy endpoint was the composite of stroke, myocardial infarction, and cardiovascular death. Cox proportional hazards regression analysis examined an interaction between the treatment effect and changes in HDL-C levels from randomization to 1 month for each study arm.

RESULTS

One-month post-randomization mean HDL-C level was significantly higher in the cilostazol group than in the aspirin group (1.08 mmol/L vs. 1.00 mmol/L, P<0.001). The mean HDL-C level was significantly lower in the probucol group than in the non-probucol group (0.86 mmol/L vs. 1.22 mmol/L, P<0.001). These trends persisted throughout the study. In both study arms, no significant interaction was observed between HDL-C changes and the assigned treatment regarding the risk of the efficacy endpoint.

CONCLUSIONS

Despite significant HDL-C changes, the effects of cilostazol and probucol treatment on the risk of cardiovascular events were insignificant. Pharmacologically altered HDL-C levels may not be reliable prognostic markers for cardiovascular risk.

Cholesterol Lowering and Stroke: No Longer Room for Pleiotropic Effects of Statins - Confirmation from PCSK9 Inhibitor Studies

BACKGROUND

The relationship between cholesterol levels and stroke has been much less clear than the relationship between cholesterol levels and coronary heart disease. This is likely mostly due to the inadequate power of older studies and the low intensity of cholesterol-lowering interventions available at the time. Because a reduction in stroke has been, conversely, clearly observed in trials with statins, for long "pleiotropic" effects of such drugs, unrelated to cholesterol lowering, have been invoked. In a previous analysis of all randomized trials of cholesterol-lowering treatments reporting on stroke we had, however, reached the conclusion that any cholesterol lowering is related to a significant reduction of stroke, in a relationship that appeared to exist for both statin and nonstatin cholesterol-lowering interventions. Outcome results of the FOURIER trial with evolocumab, SPIRE-1 and -2 with bococizumab, and ODYSSEY OUTCOMES trial with alirocumab now offer the opportunity of clearly confirming or confuting this concept.

METHODS

We here report on an updated meta-regression of the relationship of total cholesterol changes that occur with various drugs or treatments and changes in the risk of stroke compared with control.

RESULTS

Relative risk (RR) figure found in FOURIER, SPIRE-1/2, and ODYSSEY OUTCOMES (0.79, 0.60, and 0.79) are extremely close to the RRs of 0.79, 0.79, and 0.84, respectively, predicted by our new meta-regression.

CONCLUSIONS

These findings offer definitive proof that the pure total (and low-density lipoprotein) cholesterol lowering, with any available lipid-lowering intervention, reduces stroke risk proportional to the extent of cholesterol reduction, without the need of invoking "pleiotropic" effects of any such treatment.

Recent advances in synthetic pharmacotherapies for dyslipidaemias

Despite the demonstrated benefits of statins and injectable biologics, there is a need for new and safe oral agents for addressing classical lipid targets, low-density lipoprotein cholesterol (LDL-C), triglycerides and high-density lipoprotein cholesterol (HDL-C). LDL-C is unquestionably causal in the development of atherogenesis and atherosclerotic cardiovascular disease, but new options are required to address triglyceride-rich lipoproteins and lipoprotein(a). For hypercholesterolaemia, pitavastatin provides a very low dose and potent statin that does not adversely affect glucose metabolism; bempedoic acid acts at a biochemical step preceding hydroxymethylglutaryl-CoA reductase and is not associated with muscular side effects. For hypertriglyceridaemia, pemafibrate displays a unique and selective agonist activity on peroxisomal proliferator activated receptor-α that does not elevate homocysteine or creatinine. Although omega-3 fatty acids supplementation is not effective in secondary prevention, high dose eicosapentaenoic ethyl ester can lead to a remarkable fall in first and recurrent events in high risk patients with hypertriglyceridaemia/low HDL-C. Gemcabene, a dicarboxylic acid regulating apolipoprotein B-100, is effective in reducing both cholesterol and triglycerides. Among cholesteryl ester transfer protein antagonists that elevate HDL-C, only anacetrapib reduces cardiovascular events. Probucol stimulates reverse cholesteryl ester transport, lowers LDL-C stabilizing plaques and may lower incidence of cardiovascular events. These agents, which act through novel mechanisms, afford good and potentially safe treatment choices that may increase adherence and the attainment of therapeutic targets.

The role of APOE4 in Alzheimer's disease: strategies for future therapeutic interventions

Alzheimer’s disease (AD) is the leading cause of dementia affecting almost 50 million people worldwide. The ε4 allele of Apolipoprotein E (APOE) is the strongest known genetic risk factor for late-onset AD cases, with homozygous APOE4 carriers being approximately 15-times more likely to develop the disease. With 25% of the population being APOE4 carriers, understanding the role of this allele in AD pathogenesis and pathophysiology is crucial. Though the exact mechanism by which ε4 allele increases the risk for AD is unknown, the processes mediated by APOE, including cholesterol transport, synapse formation, modulation of neurite outgrowth, synaptic plasticity, destabilization of microtubules, and β-amyloid clearance, suggest potential therapeutic targets. This review will summarize the impact of APOE on neurons and neuronal signaling, the interactions between APOE and AD pathology, and the association with memory decline. We will then describe current treatments targeting APOE4, complications associated with the current therapies, and suggestions for future areas of research and treatment.

Comparative effects of lipid lowering, hypoglycemic, antihypertensive and antiplatelet medications on carotid artery intima-media thickness progression: a network meta-analysis

Background

Carotid artery intima-media thickness (cIMT) progression is a surrogate marker of atherosclerosis with a high predictive value for future CVD risk. This study evaluates the comparative efficacies of lipid lowering, hypoglycemic, antihypertensive and antiplatelet medications on cIMT progression.

Methods

We conducted a network meta-analysis (NMA) to evaluate the relative efficacies of several drug classes in modifying cIMT progression. After a literature search in several electronic databases, studies were selected by following predetermined eligibility criteria. An inverse variance-heterogeneity model was used for NMA. Sensitivity analyses were performed to check the reliability of the overall NMA, and transitivity analyses were performed to examine the effects of modifiers on the NMA outcomes.

Results

Data were taken from 47 studies (15,721 patients; age: 60.2 years [95% confidence interval (CI) 58.8, 61.6]; BMI: 27.2 kg/m² [95% CI 26.4, 28.0]; and gender: 58.3% males [95% CI 48.3, 68.3]). Treatment duration was 25.8 months [95% CI 22.9, 28.7]. Of the 13 drug classes in the network, treatment with phosphodiesterase III inhibitors was the most effective in retarding annual mean cIMT against network placebo (weighted mean difference (WMD) − 0.059 mm [95% CI − 0.099, − 0.020) followed by the calcium channel blockers (WMD − 0.055 mm [95% CI − 0.099, 0.001]) and platelet adenosine diphosphate inhibitors (WMD − 0.033 mm [95% CI − 0.058, 0.008]). These 3 drug classes also attained the same positions when the NMA was conducted by using first-year changes in mean cIMT. In transitivity analyses, longer treatment duration, higher body mass index (BMI), and a higher baseline cIMT were found to be independently associated with a lesser reduction in annual mean cIMT. However, in a multivariate analysis with these 3 modifiers, none of these factors was significantly associated with annual change in mean cIMT. In the placebo group, age was inversely associated with annual change in mean cIMT independently.

Conclusion

Phosphodiesterase III inhibitors and calcium channel blockers are found more effective than other drug classes in retarding cIMT progression. Age, BMI, and baseline cIMT may have some impact on these outcomes.

Electronic supplementary material

The online version of this article (10.1186/s12933-019-0817-1) contains supplementary material, which is available to authorized users.

Antioxidants in the Fight Against Atherosclerosis: Is This a Dead End?

PURPOSE OF REVIEW

The purpose of this review is to focus on the outcome of recent antioxidant interventions using synthetic and naturally occurring molecules established as adjuvant strategies to lipid-lowering or anti-inflammatory therapies designed to reduce the risk of cardiovascular disease.

RECENT FINDINGS

To date, accumulated evidence regarding oxidation as a pro-atherogenic factor indicates that redox biochemical events involved in atherogenesis are indeed a very attractive target for the management of cardiovascular disease in the clinic. Nevertheless, although evidence indicates that redox reactions are important in the initiation and progression of atherosclerosis, oxidation with a pro-atherogenic context does not eliminate the fact that oxidation participates in many cases as an essential messenger of important cellular signaling pathways. Therefore, disease management and therapeutic goals require not only high-precision and high-sensitivity methods to detect in plasma very low amounts of reducing and oxidizing molecules but also a much better understanding of the normal processes and metabolic pathways influenced and/or controlled by oxidative stress. As several methodologies have been specifically described for the quantification of the total antioxidant capacity and the oxidation state of diverse biological systems, a successful way to carefully study how redox reactions influence atherosclerosis can be achieved. Since there is still a lack of standardization with many of these methods, clinical trials studying antioxidant capacity have been difficult to compare and therefore difficult to use in order to reach a conclusion. We believe a comprehensive analysis of new knowledge and its relationship with the presence of plasma antioxidants and their reducing capacity will undoubtedly open new ways to understand and develop new therapeutic pathways in the fight not only against atherosclerosis but also against other degenerative diseases.

Long-Term Effect of Pravastatin on Carotid Intima-Media Complex Thickness: The J-STARS Echo Study (Japan Statin Treatment Against Recurrent Stroke)

BACKGROUND AND PURPOSE

The effect of statins on progression of carotid intima-media complex thickness (IMT) has been shown exclusively in nonstroke Western patients. This study aimed to determine the effect of low-dose pravastatin on carotid IMT in Japanese patients with noncardioembolic ischemic stroke.

METHODS

This is a substudy of the J-STARS trial (Japan Statin Treatment Against Recurrent Stroke), a multicenter, randomized, open-label, parallel-group trial to examine whether pravastatin reduces stroke recurrence. Patients were randomized to receive pravastatin (10 mg daily, usual dose in Japan; pravastatin group) or not to receive any statins (control group). The primary outcome was IMT change of the common carotid artery for a 5-year observation period. IMT change was compared using mixed-effects models for repeated measures.

RESULTS

Of 864 patients registered in this substudy, 71 without baseline ultrasonography were excluded, and 388 were randomly assigned to the pravastatin group and 405 to the control group. Baseline characteristics were not significantly different, except National Institutes of Health Stroke Scale scores (median, 0 [interquartile range, 0-2] versus 1 [interquartile range, 0-2]; P=0.019) between the 2 groups. Baseline IMT (mean±SD) was 0.887±0.155 mm in the pravastatin group and 0.887±0.152 mm in the control group (P=0.99). The annual change in the IMT at 5-year visit was significantly reduced in the pravastatin group as compared with that in the control group (0.021±0.116 versus 0.040±0.118 mm; P=0.010).

CONCLUSIONS

The usual Japanese dose of pravastatin significantly reduced the progression of carotid IMT at 5 years in patients with noncardioembolic stroke.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00361530.

Factors Associated with Intima-Media Complex Thickness of the Common Carotid Artery in Japanese Noncardioembolic Stroke Patients with Hyperlipidemia: The J-STARS Echo Study

Aims: There may be ethnic differences in carotid atherosclerosis and its contributing factors between Asian and other populations. The purpose of this study was to examine intima-media complex thickness (IMT) of the carotid artery and associated clinical factors in Japanese stroke patients with hyperlipidemia from a cohort of the Japan Statin Treatment Against Recurrent Stroke Echo Study.

Methods: Patients with hyperlipidemia, not on statins, who developed noncardioembolic ischemic stroke were included in this study. Mean IMT and maximum IMT of the distal wall of the common carotid artery were centrally measured using carotid ultrasonography. Significant factors related to mean IMT and maximum IMT were examined using multivariable analysis.

Results: In 793 studied patients, mean IMT was 0.89 ± 0.15 mm and maximum IMT was 1.19 ± 0.32 mm. Age (per 10 years, parameter estimate = 0.044, p < 0.001), smoking (0.022, p = 0.004), category of blood pressure (0.022, p = 0.006), HDL cholesterol (per 10 mg/dl, −0.009, p = 0.008), and diabetes mellitus (0.033, p = 0.010) were independently associated with mean IMT. Age (per 10 years, 0.076, p < 0.001), smoking (0.053, p = 0.001), HDL cholesterol (−0.016, p = 0.036), and diabetes mellitus (0.084, p = 0.002) were independently associated with maximum IMT.

Conclusion: Baseline mean and maximum values of carotid IMT in Japanese noncardioembolic stroke patients with hyperlipidemia were 0.89 ± 0.15 mm and 1.19 ± 0.32 mm, respectively, which were similar to those previously reported from Western countries. Age, smoking, hypertension, HDL cholesterol, and diabetes mellitus were associated with mean IMT, and those, except for hypertension, were associated with maximum IMT.

Design and Rationale of the Intima-Medial Thickness Sub-Study of the PreventIon of CArdiovascular Events in iSchemic Stroke Patients with High Risk of Cerebral hemOrrhage (PICASSO-IMT) Study

BACKGROUND

Atherosclerosis is one of the main mechanisms of stroke and cardiovascular diseases and is associated with increased risk of recurrent stroke and cardiovascular events. Intima-medial thickness (IMT) is a well-known surrogate marker of atherosclerosis and has been used to predict stroke and cardiovascular events. However, the clinical significance of IMT and IMT change in stroke has not been investigated in well-designed studies. The PreventIon of CArdiovascular events in iSchemic Stroke patients with high risk of cerebral hemOrrhage-Intima-Media Thickness (PICASSO-IMT) sub-study is designed to investigate the effects of cilostazol, probucol, or both on IMT in patients with stroke.

METHODS

PICASSO-IMT is a prospective sub-study of the PICASSO study designed to measure IMT and plaque score at 1, 13, 25, 37, and 49 months after randomization.

RESULTS

The primary outcome is the change in mean carotid IMT, which is defined as the mean of the far-wall IMTs of the right and left common carotid arteries, between baseline and 13 months after randomization.

CONCLUSION

PICASSO-IMT will provide the largest IMT data set in a stroke population and will provide valuable information about the clinical significance of IMT in patients with ischemic stroke.

The Japan Statin Treatment Against Recurrent Stroke (J-STARS) Echo Study: Rationale and Trial Protocol

OBJECTIVE

The preventive effect of 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (statins) on progression of carotid intima-media complex thickness (IMT) has been shown exclusively in nonstroke Western patients. The Japan Statin Treatment Against Recurrent Stroke (J-STARS) Echo Study aims to determine the effect of pravastatin on carotid IMT in Japanese patients with hyperlipidemia who developed noncardioembolic ischemic stroke.

DESIGN

This is a substudy of the J-STARS, a multicenter, randomized, open-label, blinded-end point, parallel-group trial to examine whether pravastatin reduces stroke recurrence in patients with noncardioembolic stroke. The patients are randomized to receive pravastatin (10 mg daily) or not to receive any statins. Carotid ultrasonography is performed by well-trained certified examiners in each participating institute, and the recorded data are measured centrally. The primary outcome is change in the IMT of the distal wall in a consecutive 2-cm section on the central side of the common carotid artery bifurcation over 5 years of observation.

CONCLUSION

The trial may help determine if the usual dose of pravastatin for daily clinical practice in Japan can affect carotid IMT in Japanese patients with noncardioembolic stroke.

Dyslipidemia Part 2: Review of Dyslipidemia Treatment in Patients With Noncoronary Vascular Disease

Dyslipidemia is one of the major modifiable risk factors associated with atherosclerotic cardiovascular disease. Appropriate modification of lipid profiles reduces the progression of atherosclerosis in vessel walls across all vascular beds. The management of dyslipidemia has evolved over the last several decades, especially since the discovery of 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors, also known as statins. Statin use in atherosclerotic heart disease is well described in observational and prospective placebo-controlled studies, citing both lipid-lowering and pleiotropic effects. However, the effect of statins and other lipid-lowering agents on noncoronary arterial beds (the aorta, arteries to the extremities, renal, and carotid arteries) is less understood. This article is part 2 of a 2-part review, with part 1 having focused on lipid metabolism and the downstream effects of lipids on the development of atherosclerosis. The current review (part 2) will discuss trials, retrospective reviews, and observational cohort studies regarding the use of statins and/or other lipid-lowering drugs for primary and secondary prevention of peripheral noncoronary atherosclerotic disease.

Re-evaluation of cholesteryl ester transfer protein function in atherosclerosis based upon genetics and pharmacological manipulation

PURPOSE OF REVIEW

To re-evaluate the functions of plasma cholesteryl ester transfer protein (CETP) in atherosclerosis based upon recent findings from human genetics and pharmacological CETP manipulation.

RECENT FINDINGS

CETP is involved in the transfer of cholesteryl ester from HDL to apolipoprotein B-containing lipoproteins, a key step of reverse cholesterol transport (RCT). CETP inhibitors have been developed to raise serum HDL-cholesterol (HDL-C) levels and reduce cardiovascular events. However, outcome studies of three CETP inhibitors (torcetrapib, dalcetrapib and evacetrapib) were prematurely terminated because of increased mortality or futility despite marked increases in HDL-cholesterol and decreases in LDL-cholesterol except for dalcetrapib. Patients with CETP deficiency show remarkable changes in HDL and LDL and are sometimes accompanied by atherosclerotic cardiovascular diseases. Recent prospective epidemiological studies demonstrated atheroprotective roles of CETP. CETP inhibition induces formation of small dense LDL and possibly dysfunctional HDL and downregulates hepatic scavenger receptor class B type I (SR-BI). Therefore, CETP inhibitors may interrupt LDL receptor and SR-BI-mediated cholesterol delivery back to the liver.

SUMMARY

For future drug development, the opposite strategy, namely enhancers of RCT via CETP and SR-BI activation as well as the inducers of apolipoprotein A-I or HDL production might be a better approach rather than delaying HDL metabolism by inhibiting a main stream of RCT in vivo.

Heme Oxygenases in Cardiovascular Health and Disease

Heme oxygenases are composed of two isozymes, Hmox1 and Hmox2, that catalyze the degradation of heme to carbon monoxide (CO), ferrous iron, and biliverdin, the latter of which is subsequently converted to bilirubin. While initially considered to be waste products, CO and biliverdin/bilirubin have been shown over the last 20 years to modulate key cellular processes, such as inflammation, cell proliferation, and apoptosis, as well as antioxidant defense. This shift in paradigm has led to the importance of heme oxygenases and their products in cell physiology now being well accepted. The identification of the two human cases thus far of heme oxygenase deficiency and the generation of mice deficient in Hmox1 or Hmox2 have reiterated a role for these enzymes in both normal cell function and disease pathogenesis, especially in the context of cardiovascular disease. This review covers the current knowledge on the function of both Hmox1 and Hmox2 at both a cellular and tissue level in the cardiovascular system. Initially, the roles of heme oxygenases in vascular health and the regulation of processes central to vascular diseases are outlined, followed by an evaluation of the role(s) of Hmox1 and Hmox2 in various diseases such as atherosclerosis, intimal hyperplasia, myocardial infarction, and angiogenesis. Finally, the therapeutic potential of heme oxygenases and their products are examined in a cardiovascular disease context, with a focus on how the knowledge we have gained on these enzymes may be capitalized in future clinical studies.

Rationale and Design of the PROSPECTIVE Trial: Probucol Trial for Secondary Prevention of Atherosclerotic Events in Patients with Prior Coronary Heart Disease

BACKGROUND

Reduction of serum LDL-cholesterol by statins was shown to improve clinical outcomes in patients with coronary heart disease (CHD). Although intensive statin therapy significantly reduced cardiovascular risks, atherosclerotic cardiovascular events have not been completely prevented. Therefore, effective pharmacologic therapy is necessary to improve "residual risks" in combination with statins. Probucol has a potent antioxidative effect, inhibits the oxidation of LDL, and reduces xanthomas. Probucol Trial for Secondary Prevention of Atherosclerotic Events in Patients with Prior Coronary Heart Disease (PROSPECTIVE) is a multicenter, randomized, prospective study designed to test the hypothesis that the addition of probucol to other lipid-lowering drugs will prevent cerebro- and cardiovascular events in patients with prior coronary events and high LDL cholesterol levels.

STUDY DESIGN

The study will recruit approximately 860 patients with a prior CHD and dyslipidemia with LDL-C level ≥140 mg/dl without any medication and those treated with any lipid-lowering drugs with LDL-C level ≥100 mg/dl. Lipid-lowering agents are continuously administered during the study period in control group, and probucol (500 mg/day, 250 mg twice daily) is added to lipid-lowering therapy in the test group. The efficacy and safety of probucol with regard to the prevention of cerebro- and cardiovascular events and the intima-media thickness of carotid arteries as a surrogate marker will be evaluated.

SUMMARY

PROSPECTIVE will determine whether the addition of probucol to other lipid-lowering drugs improves cerebro- and cardiovascular outcomes in patients with prior coronary heart disease. Furthermore, the safety of a long-term treatment with probucol will be clarified.

All cholesterol-lowering interventions are expected to reduce stroke: Confirmatory data from IMPROVE-IT

The relationship of cholesterol with stroke is much less clear than its relationship with myocardial infarction, thus confounding the interpretation of results with cholesterol-lowering trials (Di Napoli et al., 2002) [1], (De Caterina et al., 2010) [2]). IMPROVE-IT data ((Cannon et al. 2015) [3]), showing a 13.3% reduction in total cholesterol at one year in association with a hazard ratio (HR) of 0.i86 for total stroke during the trial, are very closely aligned with the relative risk of 0.90 predicted based on the totality of lipid lowering interventions ((De Caterina et al., 2016) [4]). We here provide the data from the original trials used to construct this meta-analysis, with the now added additional data from IMPROVE-IT, well-fitting the previously found meta-regression line. These data are important to predict stroke outcomes in currently ongoing trials now testing PCSK9 or cholesterol ester transfer protein inhibitors.

Pharmacological modulation of dietary lipid-induced cerebral capillary dysfunction: Considerations for reducing risk for Alzheimer's disease

An increasing body of evidence suggests that cerebrovascular dysfunction and microvessel disease precede the evolution of hallmark pathological features that characterise Alzheimer's disease (AD), consistent with a causal association for onset or progression. Recent studies, principally in genetically unmanipulated animal models, suggest that chronic ingestion of diets enriched in saturated fats and cholesterol may compromise blood-brain barrier (BBB) integrity resulting in inappropriate blood-to-brain extravasation of plasma proteins, including lipid macromolecules that may be enriched in amyloid-β (Aβ). Brain parenchymal retention of blood proteins and lipoprotein bound Aβ is associated with heightened neurovascular inflammation, altered redox homeostasis and nitric oxide (NO) metabolism. Therefore, it is a reasonable proposition that lipid-lowering agents may positively modulate BBB integrity and by extension attenuate risk or progression of AD. In addition to their robust lipid lowering properties, reported beneficial effects of lipid-lowering agents were attributed to their pleiotropic properties via modulation of inflammation, oxidative stress, NO and Aβ metabolism. The review is a contemporary consideration of a complex body of literature intended to synthesise focussed consideration of mechanisms central to regulation of BBB function and integrity. Emphasis is given to dietary fat driven significant epidemiological evidence consistent with heightened risk amongst populations consuming greater amounts of saturated fats and cholesterol. In addition, potential neurovascular benefits associated with the use of hypolipidemic statins, probucol and fenofibrate are also presented in the context of lipid-lowering and pleiotropic properties.

Did we abandon probucol too soon?

PURPOSE OF REVIEW

Probucol is a potent antioxidative drug that has been used for prevention and treatment of atherosclerotic cardiovascular diseases and xanthoma. Probucol has been used as a lipid-lowering drug for a long time especially in Japan, although Western countries quitted its use because of the reduction in serum HDL-cholesterol (HDL-C). This review highlights both basic and clinical studies that provide new insights into the pleiotropic effects of probucol.

RECENT FINDINGS

Recently, the mechanisms for the pharmacologic actions of probucol have been elucidated at the molecular level with a special focus on HDL metabolism and its functions. Probucol enhances plasma cholesteryl ester transfer protein activity and hepatic scavenger receptor class B type I, causing a decrease in HDL-C. It also accelerates the antioxidative function of HDL via increase in paraoxonase 1 activity. Recent retrospective analyses of probucol-treated patients with heterozygous familial hypercholesterolemia and those after coronary revascularization demonstrated a strong beneficial effect of probucol on secondary prevention of cardiovascular events and mortality.

SUMMARY

Probucol has pleiotropic and beneficial therapeutic effects on cardiovascular system. Although statins are effective for lowering LDL-cholesterol (LDL-C) and reducing coronary heart disease risk, probucol should be considered as an option in case statins are not effective.

Rationale and design of the PreventIon of CArdiovascular events in iSchemic Stroke patients with high risk of cerebral hemOrrhage (PICASSO) study: A randomized controlled trial

RATIONALE

Prior intracerebral haemorrhage and cerebral microbleeds may increase the risk of haemorrhagic stroke. However, the optimal long-term antiplatelet therapy and lipid management in these patients remain unclear.

AIM

PreventIon of CArdiovascular events in iSchemic Stroke patients with high risk of cerebral hemOrrhage was designed to compare cilostazol and aspirin and to assess the effect of adding probucol, a lipid-lowering and anti-oxidative agent, in patients at high risk of haemorrhagic stroke.

SAMPLE SIZE ESTIMATE

The projected sample size is 1600 patients with at least 12 months of follow-up.

METHODS AND DESIGN

PreventIon of CArdiovascular events in iSchemic Stroke patients with high risk of cerebral hemOrrhage is a randomized trial involving 67 institutes from 3 countries. Patients with non-cardioembolic ischemic stroke or transient ischemic attack within 180 days and with prior intracerebral haemorrhage or multiple cerebral microbleeds on gradient echo imaging are eligible. Enrolled patients are simultaneously randomized in a 2 × 2 factorial design: double-blind for cilostazol 200 mg/day vs. aspirin 100 mg/day, and an open-label, blind end-point evaluation for probucol 500 mg/day vs. non-probucol.

STUDY OUTCOMES

The co-primary end-points are the safety end-point of haemorrhagic stroke and the efficacy end-point of a composite of stroke, myocardial infarction, or vascular death. Time-to-event will be analyzed separately for each intervention: superiority testing for the safety of cilostazol over aspirin as well as the efficacy of probucol over non-probucol, and non-inferiority testing for the efficacy of cilostazol to aspirin.

DISCUSSION

PreventIon of CArdiovascular events in iSchemic Stroke patients with high risk of cerebral hemOrrhage is the largest secondary stroke prevention trial for informing antiplatelet therapy and lipid management in patients at high risk of haemorrhagic stroke.

Antioxidant and lipid-regulating effects of probucol combined with atorvastatin in patients with acute coronary syndrome

OBJECTIVE

To investigate the effects of probucol combined with atorvastatin on the serum oxidation index and lipid levels in patients diagnosed with acute coronary syndrome (ACS).

METHODS

We randomly assigned 126 ACS patients (77 males and 49 females) to the control group (atorvastatin 20 mg/day, n=62) or the treatment group (atorvastatin 20 mg/day and probucol 750 mg/day, n=64). All the patients were followed up for 12 weeks. As oxidization indices, we measured the serum levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), oxidized LDL (ox-LDL), and paraoxonase-1 (PON1) before and after treatment. We also monitored the adverse effects of the drugs during the treatment.

RESULTS

At baseline, there were no obvious differences (P>0.05) between the two groups (including age, gender, etc.). After 12 weeks of treatment, the ox-LDL levels in the treatment group were significantly lower while PON1 levels were significantly higher than those in the control group. There were no statistically significant difference between the two groups with respect to the side effects (P<0.05).

CONCLUSIONS

The combined use of atorvastatin and probucol in ACS patients could reduce ox-LDL expression and increase PON1 expression more effectively than use atorvastatin alone.

Effects of probucol on restenosis after percutaneous coronary intervention: a systematic review and meta-analysis

BACKGROUND

Restenosis after percutaneous coronary intervention (PCI) is a remained clinical problem which limits long-term success of PCI. Although there was recognition that probucol in treating restenosis after percutaneous transluminal coronary angioplasty, the efficacy of probucol on restenosis after stent-implantation is controversial. So this meta-analysis was conducted to investigate the association between probucol and late restenosis.

METHODS

Articles were assessed by four trained investigators, with divergences resolved by consensus. PubMed, EMBASE, ScienceDirect and the Cochrane Central Register of clinical trials were searched for pertinent studies. Inclusion criteria were random allocated to treatment and a comparison of probucol-treated patients and control patients (not treated with lipid-lowering drug) undergoing PCI.

RESULTS

Fifteen studies with 859 subjects were analyzed. Major outcome, binary angiographic restenosis defined as >50% stenosis upon follow-up angiography, was significantly decreased with probucol treatment (RR = 0.59 [0.43, 0.80] among vessels, P = 0.0007; and RR = 0.52 [0.40, 0.68] among patients, P<0.00001). Probucol also increased the minimal luminal diameter (SMD = 0.45 [0.30, 0.61], P<0.00001) and decreased late loss upon follow-up after 6 months (SMD = -0.41 [-0.60, -0.22], P<0.0001). Moreover, there was a significantly lower incidence of major adverse cardiac events (MACE) in the probucol group than control group (RR = 0.69 [0.51, 0.93], P = 0.01).

CONCLUSION

Probucol is more than a lipid-lowering drug. It is also effective in reducing the risk of restenosis and incidence of MACE after PCI.

Oral absorption enhancement of probucol by PEGylated G5 PAMAM dendrimer modified nanoliposomes

Probucol (PB), an antioxidant drug, is commonly used as a lipid concentration lowering drug to reduce blood plasma cholesterol levels in the clinic. However, the therapeutic effects of this drug are negatively impacted by its poor water solubility and low oral absorption efficiency. In this study, a PEGylated G5 PAMAM dendrimer (G5-PEG) modified nanoliposome was employed to increase water solubility, transepithelial transport, and oral absorption of PB. The uptake mechanism was explored in vitro in Caco-2 cells with the results suggesting that the absorption improvement of G5-PEG modified PB-liposome (PB-liposome/G5-PEG) was related to P-glycoprotein (P-gp) efflux pump but was independent of caveolae endocytosis pathways. Additionally, plasma lipid concentration lowering effects of PB-liposome/G5-PEG were evaluated in vivo in a LDLR-/- hyperlipidemia mouse model. Compared with saline treated group, treatment with PB-liposome/G5-PEG significantly inhibited the increase of plasma total cholesterol (TC) and triglyceride (TG) of mice induced by a high fat diet. Moreover, its lipid concentration lowering effects and plasma drug concentration were greater than PB alone or commercial PB tablets. Our results demonstrated that PB-liposome/G5-PEG significantly increased the oral absorption of PB and therefore significantly improved its pharmacodynamic effects.

Probucol suppresses human glioma cell proliferation in vitro via ROS production and LKB1-AMPK activation

AIM

Probucol, an anti-hyperlipidemic drug, has been reported to exert antitumor activities at various stages of tumor initiation, promotion and progression. In this study we examined whether the drug affected glioma cell growth in vitro and the underlying mechanisms.

METHODS

Human glioma U87 and glioblastoma SF295 cell lines were used. Cell proliferation was accessed using the cell proliferation assay and BrdU incorporation. The phosphorylation of AMPK, liver kinase B1 (LKB1) and p27(Kip1) was detected by Western blot. The activity of 26S proteasome was assessed with an in situ fluorescent substrate. siRNAs were used to suppress the expression of the relevant signaling proteins.

RESULTS

Treatment of U87 glioma cells with probucol (10-100 μmol/L) suppressed the cell proliferation in dose- and time dependent manners. Meanwhile, probucol markedly increased the ROS production, phosphorylation of AMPK at Thr172 and LKB1 at Ser428 in the cells. Furthermore, probucol significantly decreased 26S proteasome activity and increased p27(Kip1) protein level in the cells in an AMPK-dependent manner. Probucol-induced suppression of U87 cell proliferation could be reversed by pretreatment with tempol (a superoxide dismutase mimetic), MG132 (proteasome inhibitor) or compound C (AMPK inhibitor), or by gene silencing of LKB1, AMPK or p27(Kip1). Similar results were observed in probucol-treated SF295 cells.

CONCLUSION

Probucol suppresses human glioma cell proliferation in vitro via ROS production and LKB1-AMPK activation, which reduces 26S proteasome-dependent degradation of p27(Kip1).

Carotid atherosclerotic plaque stenosis: the stabilizing role of statins

BACKGROUND

Both pathophysiology and treatments of carotid atherosclerotic plaque stenosis represent two interesting fields of strong scientific investigation. Among different drugs, safety and efficacy of statin treatment have been widely investigated and proved.

MATERIALS AND METHODS

This narrative review is based on the material searched for and obtained via MEDLINE and PubMed up to March 2014. The search terms we used were: 'carotid plaque, intima-media thickness, plaque burden, stroke' in combination with 'statins, pleiotropic effects, HMG-CoA reductase inhibitors, lipid-lowering drugs'.

RESULTS

Carotid stenosis represents both a useful parameter to evaluate the atherosclerotic burden and a target for therapeutic (medical or surgical) decisions. Statins do not only improve the lipid profile, but also induce some 'pleiotropic' anti-inflammatory activities that contribute to carotid plaque stabilization. Statin-mediated protective activities are under active investigation at subclinical levels with the potential benefit of advanced imaging techniques. However, considering that some new techniques (excepted B-mode ultrasound) remain quite expensive, they can have for the moment an important role in research, but not in the clinical field.

CONCLUSIONS

Emerging evidence suggests that statin treatment improves carotid atherosclerosis, inducing a partial regression of plaque inflammation and size. Innovative imaging techniques might also ameliorate the identification of patients at high risk of cerebrovascular and coronary events, for which preventive statin treatments might be essential.

Probucol inhibited Nox2 expression and attenuated podocyte injury in type 2 diabetic nephropathy of db/db mice

The present study was conducted to investigate the effects of probucol on the progression of diabetic nephropathy and the underlying mechanism in type 2 diabetic db/db mice. Eight weeks db/db mice were treated with regular diet or probucol-containing diet (1%) for 12 weeks. Non-diabetic db/m mice were used as controls. We examined body weight, blood glucose, and urinary albumin. At 20 weeks, experimental mice were sacrificed and their blood and kidneys were extracted for the analysis of blood chemistry, kidney histology, oxidative stress marker, and podocyte marker. As a result, 24 h urinary albumin excretions were reduced after probucol treatment. There were improvements of extracellular matrix accumulation and fibronectin and collagen IV deposition in glomeruli in the probucol-treated db/db mice. The reduction of nephrin and the loss of podocytes were effectively prevented by probucol in db/db mice. Furthermore, probucol significantly decreased the production of thiobarbituric acid-reactive substances (TBARS), an index of reactive oxygen species (ROS) generation and down-regulated the expression of Nox2. Taken together, our findings support that probucol may have the potential to protect against type 2 diabetic nephropathy via amelioration of podocyte injury and reduction of oxidative stress.

Non-invasive vulnerable plaque imaging: how do we know that treatment works?

Atherosclerosis is an inflammatory disorder that can evolve into an acute clinical event by plaque development, rupture, and thrombosis. Plaque vulnerability represents the susceptibility of a plaque to rupture and to result in an acute cardiovascular event. Nevertheless, plaque vulnerability is not an established medical diagnosis, but rather an evolving concept that has gained attention to improve risk prediction. The availability of high-resolution imaging modalities has significantly facilitated the possibility of performing in vivo regression studies and documenting serial changes in plaque stability. This review summarizes the currently available non-invasive methods to identify vulnerable plaques and to evaluate the effects of the current cardiovascular treatments on plaque evolution.

Add-on effect of probucol in atherosclerotic, cholesterol-fed rabbits treated with atorvastatin

Objective

Lowering the blood concentration of low-density lipoprotein (LDL) cholesterol is the primary strategy employed in treating atherosclerotic disorders; however, most commonly prescribed statins prevent cardiovascular events in just 30% to 40% of treated patients. Therefore, additional treatment is required for patients in whom statins have been ineffective. In this study of atherosclerosis in rabbits, we examined the effect of probucol, a lipid-lowering drug with potent antioxidative effects, added to treatment with atorvastatin.

Methods and Results

Atherosclerosis was induced by feeding rabbits chow containing 0.5% cholesterol for 8 weeks. Probucol 0.1%, atorvastatin 0.001%, and atorvastatin 0.003% were administered solely or in combination for 6 weeks, beginning 2 weeks after the start of atherosclerosis induction. Atorvastatin decreased the plasma concentration of non-high-density lipoprotein cholesterol (non-HDLC) dose-dependently; atorvastatin 0.003% decreased the plasma concentration of non-HDLC by 25% and the area of atherosclerotic lesions by 21%. Probucol decreased the plasma concentration of non-HDLC to the same extent as atorvastatin (i.e., by 22%) and the area of atherosclerotic lesions by 41%. Probucol with 0.003% atorvastatin decreased the plasma concentration of non-HDLC by 38% and the area of atherosclerotic lesions by 61%. Co-administration of probucol with atorvastatin did not affect the antioxidative effects of probucol, which were not evident on treatment with atorvastatin alone, such as prevention of in vitro LDL-oxidation, increase in paraoxonase-1 activity of HDL, and decreases in plasma and plaque levels of oxidized-LDL in vivo.

Conclusions

Probucol has significant add-on anti-atherosclerotic effects when combined with atorvastatin treatment; suggesting that this combination might be beneficial for treatment of atherosclerosis.

New insights into intracellular locations and functions of heme oxygenase-1

SIGNIFICANCE

Heme oxygenase-1 (HMOX1) plays a critical role in the protection of cells, and the inducible enzyme is implicated in a spectrum of human diseases. The increasing prevalence of cardiovascular and metabolic morbidities, for which current treatment approaches are not optimal, emphasizes the necessity to better understand key players such as HMOX1 that may be therapeutic targets.

RECENT ADVANCES

HMOX1 is a dynamic protein that can undergo post-translational and structural modifications which modulate HMOX1 function. Moreover, trafficking from the endoplasmic reticulum to other cellular compartments, including the nucleus, highlights that HMOX1 may play roles other than the catabolism of heme.

CRITICAL ISSUES

The ability of HMOX1 to be induced by a variety of stressors, in an equally wide variety of tissues and cell types, represents an obstacle for the therapeutic exploitation of the enzyme. Any capacity to modulate HMOX1 in cardiovascular and metabolic diseases should be tempered with an appreciation that HMOX1 may have an impact on cancer. Moreover, the potential for heme catabolism end products, such as carbon monoxide, to amplify the HMOX1 stress response should be considered.

FUTURE DIRECTIONS

A more complete understanding of HMOX1 modifications and the properties that they impart is necessary. Delineating these parameters will provide a clearer picture of the opportunities to modulate HMOX1 in human disease.

Vascular protectants for the treatment of atherosclerosis

AGI-1067, the monosuccinic acid ester of probucol, is a phenolic antioxidant member of a novel class of agents termed vascular protectants. It has strong antioxidant properties, equipotent to those of probucol, and anti-inflammatory properties. It inhibits gene expression of vascular cell adhesion molecule-1 and monocyte chemotactic protein-1 and has been effective at preventing atherosclerosis in all tested animal models. It also improved luminal dimensions of reference segments in the percutaneous coronary intervention (PCI) vessels in the CART-1 clinical trial, which suggests a direct anti-atherosclerosis effect. Two important trials that test the antioxidant/anti-inflammatory hypothesis are ongoing with AGI-1067: the Canadian Atherosclerosis and Restenosis Trial, which assesses its value for the reduction of both atherosclerosis progression in non-PCI vessels and post-PCI restenosis, and the Aggressive Reduction of Inflammation Stops Events trial, which is evaluating the effects of AGI-1067 on hard cardiovascular outcomes.

AGI-1067, a novel vascular protectant, anti-inflammatory drug and mild antiplatelet agent for treatment of atherosclerosis

Oxidation-sensitive signals play an important role in platelet activation. AGI-1067 is a novel, phenolic, intra- and extracellular antioxidant that inhibits the expression of a number of proinflammatory genes involved in atherosclerosis. AGI-1067 is the metabolically stable monosuccinic acid ester of probucol, and a potent phenolic antioxidant representing a novel class of orally bioavailable compounds termed vascular protectants. AGI-1067 exhibits antioxidant activity equipotent to probucol. In addition, animal studies have demonstrated dual pharmacological activities of AGI-1067: the ability to block the expression of oxidation-sensitive inflammatory genes including genes that code for vascular cell adhesion molecule-1 and monocyte chemotactic protein-1. Importantly, AGI-1067 also exhibits mild antiplatelet properties inhibiting surface expression of various key platelet receptors, the formation of platelet monocyte microparticles and PAR-1 thrombin receptors. AGI-1067 is currently being tested in the late trials, and if proven to improve clinical outcomes (ARISE trial), the drug will ultimately be used in patients with different manifestations of atherosclerosis and atherothrombosis.