Pravastatin reduces restenosis two years after percutaneous transluminal coronary angioplasty (REGRESS trial)

Effectiveness of lipid-lowering therapy on mortality and major adverse cardiovascular event outcomes in patients undergoing percutaneous coronary intervention: a network meta-analysis of randomised controlled trials

BACKGROUND

Emergency percutaneous coronary intervention (PCI) can quickly restore myocardial perfusion after acute coronary syndrome. Whether and which lipid-lowering regimens are effective in reducing major adverse cardiovascular events (MACEs) and mortality risk after PCI remain unclear.

OBJECTIVE

This study assessed the benefits of different lipid-lowering regimens on the risk of MACEs and mortality in the post-PCI population by network meta-analysis.

METHODS

Public databases, including PubMed, Embase and the Cochrane Library, were searched from inception to August 2022. Randomised controlled trials (RCTs) on lipid-lowering regimens in post-PCI populations were included and analysed. The outcomes were the incidence of all-cause mortality and MACEs, whether reported as dichotomous variables or as HRs.

RESULTS

Thirty-nine RCTs were included. For MACEs, alirocumab plus rosuvastatin (OR: 0.18; 95% CI: 0.07 to 0.44), evolocumab plus ezetimibe and statins (OR: 0.19; 95% CI: 0.06 to 0.59), eicosapentaenoic acid (EPA) plus pitavastatin (HR: 0.67; 95% CI: 0.49 to 0.96) and icosapent ethyl plus statins (HR: 0.73; 95% CI: 0.62 to 0.86) had significant advantages and relatively high rankings. For mortality, rosuvastatin (OR: 0.30; 95% CI: 0.11 to 0.84), ezetimibe plus statins (OR: 0.55; 95% CI: 0.43 to 0.89) and icosapent ethyl plus statins (OR: 0.66; 95% CI: 0.45 to 0.96) had significant advantages compared with the control.

CONCLUSION

EPA, especially icosapent ethyl, plus statins had a beneficial effect on reducing the risk of MACEs and mortality in post-PCI patients. Proprotein convertase subtilisin/kexin type-9 inhibitors plus statins were able to reduce the risk of MACEs, but the risk of mortality remained unclear.

PROSPERO REGISTRATION NUMBER

CRD42018099600.

Pravastatin for lowering lipids

BACKGROUND

A detailed summary and meta-analysis of the dose-related effect of pravastatin on lipids is not available.

OBJECTIVES

Primary objective To assess the pharmacology of pravastatin by characterizing the dose-related effect and variability of the effect of pravastatin on the surrogate marker: low-density lipoprotein (LDL cholesterol). The effect of pravastatin on morbidity and mortality is not the objective of this systematic review. Secondary objectives • To assess the dose-related effect and variability of effect of pravastatin on the following surrogate markers: total cholesterol; high-density lipoprotein (HDL cholesterol); and triglycerides. • To assess the effect of pravastatin on withdrawals due to adverse effects.

SEARCH METHODS

The Cochrane Hypertension Information Specialist searched the following databases for randomized controlled trials (RCTs) up to September 2021: CENTRAL (2021, Issue 8), Ovid MEDLINE, Ovid Embase, Bireme LILACS, the WHO International Clinical Trials Registry Platform, and ClinicalTrials.gov. We also contacted authors of relevant papers regarding further published and unpublished work. The searches had no language restrictions.

SELECTION CRITERIA

Randomized placebo-controlled trials evaluating the dose response of different fixed doses of pravastatin on blood lipids over a duration of three to 12 weeks in participants of any age with and without evidence of cardiovascular disease.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility criteria for studies to be included, and extracted data. We entered lipid data from placebo-controlled trials into Review Manager 5 as continuous data and withdrawal due to adverse effects (WDAEs) data as dichotomous data. We searched for WDAEs information from all trials. We assessed all trials using Cochrane's risk of bias tool under the categories of sequence generation, allocation concealment, blinding, incomplete outcome data, selective reporting, and other potential biases.

MAIN RESULTS

Sixty-four RCTs evaluated the dose-related efficacy of pravastatin in 9771 participants. The participants were of any age, with and without evidence of cardiovascular disease, and pravastatin effects were studied within a treatment period of three to 12 weeks. Log dose-response data over the doses of 5 mg to 160 mg revealed strong linear dose-related effects on blood total cholesterol and LDL cholesterol, and a weak linear dose-related effect on blood triglycerides. There was no dose-related effect of pravastatin on blood HDL cholesterol. Pravastatin 10 mg/day to 80 mg/day reduced LDL cholesterol by 21.7% to 31.9%, total cholesterol by 16.1% to 23.3%,and triglycerides by 5.8% to 20.0%. The certainty of evidence for these effects was judged to be moderate to high. For every two-fold dose increase there was a 3.4% (95% confidence interval (CI) 2.2 to 4.6) decrease in blood LDL cholesterol. This represented a dose-response slope that was less than the other studied statins: atorvastatin, rosuvastatin, fluvastatin, pitavastatin and cerivastatin. From other systematic reviews we conducted on statins for its effect to reduce LDL cholesterol, pravastatin is similar to fluvastatin, but has a decreased effect compared to atorvastatin, rosuvastatin, pitavastatin and cerivastatin. The effect of pravastatin compared to placebo on WADES has a risk ratio (RR) of 0.81 (95% CI 0.63 to 1.03). The certainty of evidence was judged to be very low.

AUTHORS' CONCLUSIONS

Pravastatin lowers blood total cholesterol, LDL cholesterol and triglyceride in a dose-dependent linear fashion. This review did not provide a good estimate of the incidence of harms associated with pravastatin because of the lack of reporting of adverse effects in 48.4% of the randomized placebo-controlled trials.

Atherosclerosis: Making a U Turn

The development of potent cholesterol-reducing medications in the last decade of the twentieth century has altered the approach to prevention and treatment of cardiovascular disease (CVD). Initial experience with statins, and more recently with the addition of PCSK9 inhibitors, has proven that human CVD, like that in animal models, can be halted and regressed. Available clinical data show that the lower the achieved level of low-density lipoprotein cholesterol, the greater the regression of disease. Investigative studies are now aimed to understand those factors that both accelerate and impede this healing process. Some of these are likely to be modifiable, and the future of atherosclerotic CVD treatment is likely to be early screening, use of measures to repair atherosclerotic arteries, and prevention of most CVD events.

Different Statin Effects of ST-elevation Versus Non-ST-Elevation Acute Myocardial Infarction After Stent Implantation

BACKGROUND

Intensive statin therapy reduces cardiovascular events in acute coronary syndrome. The data concerning the long-term clinical impacts of statin therapy between ST-segment elevation myocardial infarction (STEMI) and non-STEMI (NSTEMI) after drug-eluting stent implantation are limited. We compared the 2-year clinical outcomes between these 2 groups after statin therapy.

MATERIALS AND METHODS

A total of 30,616 Korean patients with acute myocardial infarction (AMI) were enrolled. Among them, 13,686 patients were classified as group A (STEMI statin user), 3,824 patients were as group B (STEMI statin nonuser), 10,398 patients were as group C (NSTEMI statin user), and 2,708 patients were as group D (NSTEMI statin nonuser). The major clinical endpoint was the occurrence of major adverse cardiac events (MACE) defined as all-cause death, recurrent myocardial infarction (re-MI), and any repeat revascularization during a 2-year follow-up period.

RESULTS

After adjustment, the cumulative risks of MACE (adjusted hazard ratio [aHR] = 1.112 [1.002-1.235]; P = 0.047), all-cause death (aHR = 1.271 [1.054-1.532]; P = 0.012), and target vessel revascularization (TVR, aHR = 1.262 [1.049-1.518]; P = 0.014) in group C were significantly higher than group A. The cumulative risks of MACE, all-cause death, and cardiac death of the statin nonuser group (groups B and D) were significantly higher compared with statin user group (groups A and C).

CONCLUSIONS

Statin therapy was more effective in reducing the cumulative risks of MACE, all-cause death, and TVR in the STEMI group than NSTEMI group in Korean patients with AMI after successful drug-eluting stent implantation.

Monocyte-mediated drug delivery systems for the treatment of cardiovascular diseases

Major advances have been achieved in understanding the mechanisms and risk factors leading to cardiovascular disorders and consequently developing new therapies. A strong inflammatory response occurs with a substantial recruitment of innate immunity cells in atherosclerosis, myocardial infarction, and restenosis. Monocytes and macrophages are key players in the healing process that ensues following injury. In the inflamed arterial wall, monocytes, and monocyte-derived macrophages have specific functions in the initiation and resolution of inflammation, principally through phagocytosis, and the release of inflammatory cytokines and reactive oxygen species. In this review, we will focus on delivery systems, mainly nanoparticles, for modulating circulating monocytes/monocyte-derived macrophages. We review the different strategies of depletion or modulation of circulating monocytes and monocyte subtypes, using polymeric nanoparticles and liposomes for the therapy of myocardial infarction and restenosis. We will further discuss the strategies of exploiting circulating monocytes for biological targeting of nanocarrier-based drug delivery systems for therapeutic and diagnostic applications.

Effects of Low-Dose Atorvastatin on Vascular Responses in Patients Undergoing Percutaneous Coronary Intervention With Stenting

Background: The primary endpoint of this study was to evaluate the effects of low-dose atorvastatin on carotid intima-media thickness (IMT) and endothelial function, and the secondary endpoint comprised restenosis and target lesion revascularization (TLR) in patients undergoing percutaneous coronary intervention (PCI) with stenting for the treatment of coronary artery disease.

Methods: Two hundred five consecutive patients (mean age, 60 years) undergoing PCI were prospectively randomized to usual therapy (control group, n = 100) or to 10 mg of atorvastatin daily plus usual therapy (statin group, n = 105). Carotid IMT, endothelial function (flow-mediated dilatation [FMD] of the brachial artery), and coronary angiograms were taken before the study and 6 months after randomization. The 6-month follow-up measurements of the above factors were obtained in 83 patients (83%) of the control group and in 97 patients (92%) of the statin group.

Results: No significant differences were noted in the baseline clinical and angiographic findings in either group. FMD was significantly improved during the 6 months in the statin group (4.38% ± 1.7% vs 4.85% ± 1.6%, P = .003), but did not change in the control group. Carotid IMT did not show any significant changes at 6 months in either group. There was a trend in favor of statin in terms of restenosis rate (26.8% vs 36.1%, P = .177) and TLR rate (18.6% vs 25.3%, P = .274). The changes of FMD were significantly correlated with the changes of total cholesterol and the changes of low-density lipoprotein, respectively ( r= -0.336, P = .009, and r = -0.310, P = .046).

Conclusion: Low-dose atorvastatin reduces endothelial dysfunction as measured by FMD, which coincides with the beneficial effects on lipid profiles, and can decrease restenosis and TLR rate in patients undergoing PCI with stenting.

Stents and statins: history, clinical outcomes and mechanisms

The 1980s witnessed the inception of both stents and 3-hydroxy-3-methyl-glutaryl-CoA reductase inhibitors (statins). While they evolved separately, it was soon realized that they each offered a unique and powerful mechanism for targeting the major offender in cardiovascular disease, namely atherosclerosis. Coincidentally, the first statin was approved by the US FDA in 1987, the same year that the coronary stent was conceived. Since that time, stents and statins have revolutionized the field of cardiovascular medicine and their paths have been intertwined. Several pivotal randomized clinical trials have established statins as an effective therapy for improving clinical outcomes after percutaneous coronary intervention (PCI) among patients presenting with stable coronary artery disease and acute coronary syndromes. In addition, chronic statin therapy and acute loading of statins prior to PCI has consistently been shown to limit periprocedural myocardial necrosis. The mechanism for improved clinical outcomes with statins has clearly been associated with statin-induced reductions in LDL. In addition, statins may also exert 'pleiotropic' effects, independent of LDL lowering, that might counteract the inflammatory and prothrombotic mileu created with PCI. This article provides a brief historical perspective of the evolution of the use of statins and stents in patients with coronary artery disease, an evaluation of the available clinical data supporting the use of statins in patients undergoing PCI across a wide spectrum of clinical scenarios, and a discussion of the potential mechanisms of the benefit of statins in these patients.

Preventing restenosis in early drug-eluting stent era: recent developments and future perspectives

Restenosis is the major limitation of the successful therapy of percutaneous coronary intervention (PCI) for patients with coronary artery disease. The problem was appreciated in the late 1970s to early 1980s. Only in recent years, anti-restenotic therapy has achieved a breakthrough with the development of drug-eluting stents. Here, we provide an overview about pathological mechanisms of restenosis after PCI. Present therapeutic approaches to overcome restenosis and recent clinical results are revisited, and some major concerns in the post-drug-eluting stent era are discussed.

Liposomal simvastatin attenuates neointimal hyperplasia in rats

Monocytes, macrophages, and inflammation play a key role in the process of neointimal proliferation and restenosis. The present study evaluated whether systemic and transient depletion of monocytes could be obtained by a single intravenous (IV) injection of simvastatin liposomes, for the inhibition of neointima formation. Balloon-injured carotid artery rats (n = 30) were randomly assigned to treatment groups of free simvastatin, simvastatin in liposomes (3 mg/kg), and saline (control). Stenosis and neointima to media ratio (N/M) were determined 14 days following single IV injection at the time of injury by morphometric analysis. Depletion of circulating monocytes was determined by flow cytometry analyzes of blood specimens. Inhibition of RAW264.7, J774, and THP-1 proliferation by simvastatin-loaded liposomes and free simvastatin was determined by the 3-(4, 5-dimethylthiazolyl-2)-2, 5- diphenyltetrazolium bromide assay. Simvastatin liposomes were successfully formulated and were found to be 1.5-2 times more potent than the free drug in suppressing the proliferation of monocytes/macrophages in cell cultures of RAW 264.7, J774, and THP-1. IV injection of liposomal simvastatin to carotid-injured rats (3 mg/kg, n = 4) resulted in a transient depletion of circulating monocytes, significantly more prolonged than that observed following treatment with free simvastatin. Administration to balloon-injured rats suppressed neointimal growth. N/M at 14 days was 1.56 +/- 0.16 and 0.90 +/- 0.12, control and simvastatin liposomes, respectively. One single systemic administration of liposomal simvastatin at the time of injury significantly suppresses neointimal formation in the rat model of restenosis, mediated via a partial and transient depletion of circulating monocytes.

Statins in prevention of repeat revascularization after percutaneous coronary intervention--a meta-analysis of randomized clinical trials

Recent prospective cohort studies have shown that patients discharged on statins after percutaneous coronary intervention (PCI) are at lower risks of repeat revascularization and mortality when compared to those not on statins after discharge. However, few randomized clinical trials among post-PCI patients confirmed these beneficial effects. It is needed to evaluate the effects of post-procedural statin therapy on individual clinical outcomes to facilitate the further investigation on identifying the underlying mechanism(s). A meta-analysis of randomized clinical trials was conducted to examine the effects of statin therapy initiated after coronary angioplasty on repeat revascularization, all-cause mortality and myocardial infarction (MI). From relevant reports on Medline (from inception to October 2009), six randomized clinical trials comprising 2979 patients were included. Relative risks were evaluated for pooled data via random effect models. Compared with controls, post-PCI statin therapy was associated with a significantly decreased risk of repeat revascularization (risk ratio (RR)=0.73, 95% confidence interval (CI), 0.55-0.98, p=0.04), nonsignificantly decreased risks of all-cause mortality (RR=0.88, 95% CI, 0.35-2.21, p=0.79), MI (RR=0.76, 95% CI, 0.49-1.18, p=0.23), and target lesion or target vessel revascularization (RR=0.58, 95% CI, 0.24-1.39, p=0.22). In conclusion, statin therapy after PCI can reduce the risk of repeat revascularization. Further investigation is needed to identify the underlying mechanism(s).

Beneficial effects of statins after percutaneous coronary intervention

BACKGROUND

Evidence about the efficacy of statin treatment among patients after percutaneous coronary intervention (PCI) is very limited. The rapid advancement in PCI technology and near universal use of adjunctive cardioprotective medications make it necessary to formally assess the effect of statin therapy on cardiac events after PCI.

DESIGN

This was a multicenter prospective cohort study.

METHODS

Patients who received stent implantation and survived to hospital discharge from the National Heart, Lung, and Blood Institute Dynamic Registry from 2004 to 2006 formed the study cohort. Patients with cardiogenic shock, in-hospital adverse events [including myocardial infarction and coronary artery bypass graft surgery (CABG)], liver disease, renal disease, alcoholism, or drug abuse were excluded. The occurrences of death, CABG, and repeat PCI, and repeat revascularization were collected over 1-year follow-up.

RESULTS

Of the 3227 patients evaluated, 2737 (85%) were prescribed a statin at discharge. By 1-year follow-up, incident events were 98 deaths, 44 CABG, 290 repeat PCI procedures, and 328 repeat revascularizations. After propensity score adjustment, postdischarge statin therapy was associated with lower risks of death [hazard ratio (HR): 0.58, 95% confidence interval (CI): 0.36-0.93, P = 0.02], CABG (HR: 0.49, 95% CI: 0.24-1.00, P = 0.05), and repeat revascularization (HR: 0.74, 95% CI: 0.56-1.00, P = 0.05).

CONCLUSION

These results support the routine use of statin therapy after PCI.

The pleiotropic effects of statins on endothelial function, vascular inflammation, immunomodulation and thrombogenesis

Statins have been demonstrated to significantly affect the prognosis and outcome of patients with risk factors to atherosclerosis (in primary and secondary prevention trials). Several clinical and recently basic studies have suggested an extra-beneficial effect of the statins in the prevention of atherosclerosis and coronary artery disease. These studies showed that statins may affect the cardiovascular system beyond their effect on the lipid profile, and it was suggested that they affect the immunological system and vascular inflammation. Many of the beneficial pleiotropic effects of statins occur as a result of modulated endothelial function and reduced inflammatory processes. Attempting to understand these properties of statins is an exciting field of research that will also improve our understanding of vascular biology in health and disease, and thus enable the better use of this drug class in clinical practice.

Comparison of the efficacies of five different statins on inhibition of human saphenous vein smooth muscle cell proliferation and invasion

Statins (HMG-CoA reductase inhibitors) exhibit beneficial effects on the vasculature independently of their cholesterol-lowering properties. These pleiotropic effects underlie the ability of statins to reduce intimal hyperplasia in saphenous vein (SV) bypass grafts by attenuating smooth muscle cell (SMC) invasion and proliferation. Although all statins can effectively lower cholesterol, the pleiotropic effects of individual statins may well differ. We therefore compared the concentration-dependent effects of 4 lipophilic statins (simvastatin, atorvastatin, fluvastatin, and lovastatin) and 1 hydrophilic statin (pravastatin) on the proliferation and invasion of SMC cultured from SV of 9 different patients undergoing coronary artery bypass grafting (CABG). The lipophilic statins inhibited SV-SMC proliferation over a 4-day period with an order of potency of fluvastatin > atorvastatin > simvastatin > lovastatin (IC50 range = 0.07 to 1.77 microM). Similarly, these statins also inhibited SV-SMC invasion through an artificial basement membrane barrier (fluvastatin > atorvastatin > simvastatin >> lovastatin; IC50 range = 0.92 to 26.9 microM). In contrast, the hydrophilic pravastatin had no significant effect on SV-SMC proliferation at concentrations up to 10 microM, nor did it attenuate SV-SMC invasion (up to 30 microM). Our data provide strong evidence that individual statins possess differential pleiotropic effects on SV-SMC function. This may be of clinical relevance in the selection of individual statins for the treatment of CABG patients.

Temporal gene expression analysis of human coronary artery endothelial cells treated with Simvastatin

Increasing evidence indicates that the beneficial "pleiotropic" effects of statins on clinical events involve nonlipid mechanisms including the modification of blood vessel endothelial cell function. However, the involved molecular events and pathways are not completely understood. In the present study, Affymetrix microarrays were used to monitor the temporal gene expression of human coronary artery endothelial cells (HCAEC) treated with simvastatin (Sim) to gain insight into statins' direct effects on the endothelial function. We isolated and labeled mRNA from HCAEC treated with Sim for 0, 3, 6, 12, 24, and 48 h and hybridized these samples to Affymetrix GeneChip HG-U95Av2 to analyze the temporal gene expression profile. Out of 12,625 genes present on the HG-U95Av2 GeneChip, expression of 5,432 genes was detected. There were 1,475 of 5,432 genes that displayed the differential expression compared to baseline (0 h). Fifty-four genes were upregulated (< or = twofold) while 61 genes were downregulated ( > or = twofold) at 24-48 h after the Sim treatment. Many new target genes and pathways modulated by Sim were uncovered. This study indicates that many aspects of the pleiotropic effect of Sim on the endothelial cell function can be mediated by transcriptional control. Physiological function of 22% of 115 differentially expressed genes in Sim-treated HCAEC are currently unknown. These newly identified genes could be useful for new mechanistic study and new therapeutic modalities. Expressions of 13 out of 18 genes (> 70%) in the cell cycle/proliferation control process were significantly inhibited by the Sim treatment. CDC25B and ITGB4 gene expressions were validated by RT-PCR and Western blotting. Sim's inhibitory effect of on HCAEC growth was confirmed by the measurement of [3H]thymidine incorporation into the DNA synthesis. Further in-depth analysis of this effect may shed light on molecular mechanisms of Sim's beneficial inhibition of neointima formation in the atherosclerotic artery stenosis.

Analysis of Clinical Factors that Influence Re-stenosis after Percutaneous Coronary Stenting

Evidence has recently been accumulating that a sirolimus-eluting stent (DES) is superior to a bare-metal stent (BMS) in preventing restenosis after percutaneous coronary intervention (PCI), and an increasing number of Japanese hospitals have been adopting DES. We conducted a retrospective study to identify clinical factors that influence the risk of restenosis after PCI, including stent types, by analyzing the data of 49 continuous patients who received PCI and follow-up coronary angiography in Hiratsuka City Hospital between March, 2004 and March, 2005. Age, sex, body mass index, smoking, complications, clinical diagnosis before PCI, the site and number of stenoses, implanted stent type (BMS or DES), the number of stents used, maximum inflating pressure and withdrawal of ticlopidine due to its adverse drug reactions were chosen as potential factors that may influence the risk of restenosis, and the correlation between these factors and restenosis was tested by Student's t-test or chi-square test. Coronary restenosis developed in 10 out of 49 patients, and factors having significant correlation with restenosis were age (73+/-7 in the restenosis group (R) and 64+/-12 in the non-restenosis group (N) (p<0.05)) and the type of stent (DES used in only one of 10 cases in R whereas in 24 of 39 in N (p<0.001)). Multivariate analysis showed older age (odds ratio (OR): 1.200 (95% CI: 1.038-2.823)) and the use of DES are independent predictors for restenosis (OR: 0.015 (95%CI: 0.001-0.249)). Our study further supports the efficacy of DES in PCI, but its long-term outcome is yet to be confirmed.

Atorvastatin Reduces Remnant Lipoproteins and Small, Dense Low‐Density Lipoproteins Regardless of the Baseline Lipid Pattern

Elevated plasma levels of remnant lipoproteins and small, dense low-density lipoprotein (LDL) particles increase the risk of atherosclerosis. This prospective, placebo-controlled, crossover trial evaluated the effect of atorvastatin on various lipid parameters including remnant lipoproteins and small, dense-LDL cholesterol levels. Forty-five subjects were enrolled in the study. These subjects fell into three distinct lipid patterns: atherogenic dyslipidemia, isolated hypercholesterolemia, and mixed dyslipidemia. Regardless of the baseline lipid profile, atorvastatin (10 mg q x d) reduced levels of remnant lipoproteins by 25%, LDL-cholesterol by 27%, and the three LDL subfractions by 23%-28% (p<0.0001 for all). Combining all patients, atorvastatin did not significantly alter the overall LDL subfraction pattern; however, in the isolated hypercholesterolemia group, the proportion of LDL present as the small, dense fraction increased by 23% (p=0.01) with treatment, whereas it did not change significantly in the other two groups. Overall, atorvastatin reduced triglycerides by 18% and apolipoprotein-B100 by 23% and increased high-density lipoproteins by 6.2% (p<0.001 all). Since atorvastatin is known to reduce the risk for coronary heart disease events and these data suggest that it does not appear to alter the LDL subfraction pattern, it is unclear whether or not the latter is an important risk predictor independent of LDL-cholesterol concentrations. Increased attention should be paid to absolute concentrations of LDL subfraction cholesterol, which may be a more sensitive indicator of coronary heart disease risk than total LDL or an LDL pattern.

Statin therapy in South-Asian patients: clinical implications beyond lipid lowering?

Whether used as primary or secondary prevention, 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (statins) can lead to a significant reduction in mortality and morbidity from cardiovascular disease. Given the benefit in halting atherosclerotic disease progression in patients with stable and acute coronary syndrome, the potential for use in South-Asians remains largely unreported. As this ethnic group has a high rate of coronary events at a younger age, with more extensive and diffuse atheroma, the authors review the impact of statins in relation to observed lipid profiles, as well as novel markers of vascular disease.

Short-term atorvastatin treatment does not modify neointimal morphology but reduces MMP-2 expression in normocholesterolemic rabbit stented arteries

The aim of our study was to explore some potential pleïotropic effects of atorvastatin, after stenting in the iliac arteries of normocholesterolemic rabbits. On day 0, 27 rabbits underwent stent implantation and were randomized into either the control group (standard chow, CTRL, n = 15) or the atorvastatin group (10 mg/kg/d per os, Ator, n = 12). On day 30, the stented arteries were harvested for histomorphometry and neointimal analysis [macrophages, matrix metalloproteinases (MMP-2), tissue inhibitor of metalloproteinase-2, vascular smooth muscle cells, and collagen]. Atorvastatin did not induce significant histomorphometric and inflammatory modifications but reduced neointimal expression of MMP-2 with no modification of tissue inhibitor of metalloproteinase-2, and also induced higher neointimal collagen content (Ator vs. CTRL: MMP-2: 0.05 +/- 0.03 vs. 0.70 +/- 0.20, P < 0.01; collagen: 17.0+/-0.7%/mm vs. 12.0 +/- 1.2%/mm(2) P < 0.01). Atorvastatin treatment also induced a significant decrease in neointimal vascular smooth muscle cells and cellular density (respectively: 2.0 +/- 0.2 vs. 1.4 +/- 0.2, P < 0.05; 5406 +/- 241 nuclei/mm(2) vs. 4402 +/- 163 nuclei/mm(2), P < 0.001). Our study provides new insights into the field of MMP response to stenting and the effects of statin therapy, which could have important implications in the field of in-stent restenosis.

Endothelial dysfunction: a multifaceted disorder (The Wiggers Award Lecture)

Endothelial cells synthesize and release various factors that regulate angiogenesis, inflammatory responses, hemostasis, as well as vascular tone and permeability. Endothelial dysfunction has been associated with a number of pathophysiological processes. Oxidative stress appears to be a common denominator underlying endothelial dysfunction in cardiovascular diseases. However, depending on the pathology, the vascular bed studied, the stimulant, and additional factors such as age, sex, salt intake, cholesterolemia, glycemia, and hyperhomocysteinemia, the mechanisms underlying the endothelial dysfunction can be markedly different. A reduced bioavailability of nitric oxide (NO), an alteration in the production of prostanoids, including prostacyclin, thromboxane A2, and/or isoprostanes, an impairment of endothelium-dependent hyperpolarization, as well as an increased release of endothelin-1, can individually or in association contribute to endothelial dysfunction. Therapeutic interventions do not necessarily restore a proper endothelial function and, when they do, may improve only part of these variables.

Elevated preprocedural high-sensitivity C-reactive protein levels are associated with neointimal hyperplasia and restenosis development after successful coronary artery stenting

BACKGROUND

Recent data indicate that an elevated serum level of high-sensitivity C-reactive protein (hs-CRP) predicts the risk of recurrent coronary events, and that statin therapy decreases the risk of coronary events. This study assessed the relationship between the pre-procedural hs-CRP level and in-stent neointimal hyperplasia (NIH) after stenting and the effects of statins on the relationship between restenosis after stenting and the serum hs-CRP levels of patients with coronary artery disease.

METHODS AND RESULTS

This study included 100 patients who underwent stent implantation for angiographically significant stenosis. Patients were divided into a normal C-reactive protein (CRP) group (<0.5 mg/dl, n=59) and elevated CRP group (>or=0.5 mg/dl, n=41). All patients underwent angiographic and intravascular ultrasound follow-up at 6 months. The baseline CRP level was 0.29+/-0.08 mg/dl in the normal CRP group and 2.90+/-2.31 mg/dl in the elevated CRP group. The NIH cross-sectional area (CSA) in the minimal lumen CSA at follow-up was significantly larger in the elevated CRP group compared with the normal CRP group (1.9+/-1.3 mm2 vs 3.0+/-1.5 mm2, p=0.001). A significant positive correlation was found between pre-interventional CRP level and NIH area (r=0.52, p<0.001). In patients with normal CRP, an association between statin therapy and restenosis was not observed. However, when the analysis was confined to patients with elevated CRP, statin therapy significantly reduced the restenosis rate (20% vs 37.5%, p=0.031). In the normal CRP group, the intra-stent neointimal area at 6 months was not different between the non-statin and statin groups (2.2+/-1.4 mm2 vs 1.8+/-1.1 mm2). However, in the elevated CRP group, statin therapy significantly decreased the neointimal area at 6-month follow-up (3.6+/-1.7 mm2 vs 2.4+/-1.3 mm2, p<0.001).

CONCLUSION

Measuring the pre-interventional hs-CRP level may help predict the development of restenosis after stenting and statin therapy will significantly reduce the restenosis rate in patients with an elevated hs-CRP.

Effect of statin on restenosis after radius stent implantation in patients with acute coronary syndrome

Despite reports that statin treatment reduces the rate of coronary restenosis with a balloon expandable stent, there is no evidence that statins affect the incidence of restenosis with a self-expanding Radius stent. Ninety-five patients with acute coronary syndrome who had been implanted with a Radius stent were classified into two groups: those with hyperlipidemia and initial statin treatment (statin group, n = 38) and those without statin treatment (comparative group, n = 57). At six months after stent implantation, the rate of coronary restenosis was significantly lower in the statin group (10.5%) than control group (28.1%) (p = 0.033), while there were no differences in morphology, maximal inflation pressure or stent size between the two groups. Interestingly, there was no difference in the serum lipid profile between the two groups at the 6-month follow-up, although the statin group had a significantly lower rate of restenosis. In conclusion, initial statin therapy reduced the rate of coronary restenosis even when a Radius stent was implanted.

Coronary stenting and inflammation

Restenosis after stent implantation is mainly caused by neointimal proliferation through the stent struts. Experimental studies performed in the last decade indicate that inflammatory mechanisms play a key role in the process of neointimal proliferation and restenosis. Coronary stenting is a strong inflammatory stimulus, and the acute local and systemic inflammatory responses to local inflammation produced by coronary stenting are highly individual and predictive of restenosis and event-free survival. The benefit of anti-inflammatory periprocedural therapy, such as with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) and steroids, and long-term follow-up is dependent on the individual's inflammatory status. Measurement of acute-phase reactants, such as C-reactive protein plasma concentration, appears to be important for the identification of subjects at high risk and the development of specific treatment tailored to individual patients.

Percutaneous coronary interventions for coronary artery disease: the long and short of optimizing medical therapy

Atherosclerosis is a dynamic process and timely introduction of pharmacological treatment can have a significant bearing on the patient's health and outcome. In addition to treating the culprit lesion mechanically, admission for percutaneous coronary interventions (PCI) for coronary artery disease (CAD) gives an opportunity for the interventional cardiologist to optimize medical therapy. The aim of this review is to provide an overview of the current medical literature pertaining to cardiovascular (CV) risk reduction and vascular event prevention in the setting of PCI, with emphasis on antiplatelet therapies, beta-blockers, HMG-Co A reductase inhibitors (statins) and angiotensin-converting enzyme inhibitors, with regard to therapy optimization during PCI and for chronic CAD. We discuss the effects of these oral therapies in reducing ischaemic events, thus augmenting the benefits of PCI, as well as preventing recurrent CV events after the procedure.

G protein mediated signaling pathways in lysophospholipid induced cell proliferation and survival

Agonist activation of a subset of G protein coupled receptors (GPCRs) stimulates cell proliferation, mimicking the better known effects of tyrosine kinase growth factors. Cell survival or apoptosis is also regulated via pathways initiated by stimulation of these same GPCRs. This review focuses on aspects of signaling by the lysophospholipid mediators, lysophosphatidic acid (LPA), and sphingosine 1 phosphate (S1P), which make these agonists uniquely capable of modulating cell growth and survival. The general features of GPCR coupling to specific G proteins, downstream effectors and signaling cascades are first reviewed. GPCR coupling to G(i) and Ras/MAPK or to G(q) and phospholipase generated second messengers are insufficient to regulate cell proliferation while G(12/13)/Rho engagement provides additional complementary signals required for cell proliferation. Survival is best predicted by coupling to G(i) pathways that regulate PI3K and Akt, but other signals generated through different G protein pathways are also implicated. The unique ability of LPA and S1P to concomitantly stimulate G(i), G(q), and G(12/13) pathways, given the proper complement of expressed LPA or S1P receptors, allows these receptors to support cell survival and proliferation. In pathophysiological situations, e.g., vascular disease, cancer, brain injury, and inflammation, components of the signaling cascade downstream of lysophospholipid receptors, in particular those involving Ras or Rho, may be altered. In addition, up or downregulation of LPA or S1P receptor subtypes, altering their ratio, and increased availability of the lysophospholipid ligands at sites of injury or inflammation, likely contribute to disease and may be important targets for therapeutic intervention.

Prognostic significance of simvastatin therapy in patients with ischemic heart failure who underwent percutaneous coronary intervention for acute myocardial infarction

We prospectively followed 202 patients with ischemic heart failure who underwent percutaneous coronary intervention (PCI) for acute myocardial infarction (left ventricular [LV] ejection fraction <40%). Patients were divided into 2 groups: groups I (simvastatin group, n = 106, aged 60.8 +/- 10.3 years, men 71.7%) and II (non-simvastatin group, n = 96, aged 60.9 +/- 10.4 years, men 78.1%). During 1-year clinical follow-up, simvastatin therapy was associated with a significant reduction in mortality (1.9% vs 7.5%, p = 0.048), restenosis rate (25.7% vs 43.1%, p = 0.033), and repeat PCI rate (25.7% vs 43.1%, p = 0.033), and with significant improvement in LV ejection fraction (31% to 42% vs 32% to 39%, p = 0.042). The event-free survival rate was higher in group I than in group II (79.8% vs 57.0%, p = 0.001). In conclusion, simvastatin therapy improves LV systolic function and decreases mortality, restenosis, and repeat PCI rate in patients with ischemic heart failure who underwent PCI for acute myocardial infarction.

Effects of statins on vascular structure and function: a systematic review

PURPOSE

Statins reduce cardiovascular events by more than can be explained by their effects on lipids. We conducted a systematic review of how statins affect vascular structure and function, differences among statins, and correlations between the effects of statins on vascular outcomes and either lipid levels or cardiovascular outcomes.

METHODS

We primarily searched MEDLINE (1980 to March 2004) to identify all studies with at least 10 subjects that reported the effects of currently available statins on coronary artery stenosis, carotid intima-media thickness, and endothelial function (excluding studies of drug combinations and subjects with organ transplants). Meta-analyses were performed when feasible.

RESULTS

Statins decrease the progression and increase the regression of coronary artery lesions and luminal narrowing. Compared with placebo, statins decrease the likelihood of coronary artery restenosis (summary risk ratio = 0.85; 95% confidence interval: 0.77 to 0.95). Statins appear to slow the progression of carotid artery intima-media thickness. Although the effect of statins on coronary endothelial function is uncertain, statins appear to improve peripheral endothelial function. There is no conclusive evidence to suggest that individual statins differ in their effects on these outcomes. Studies generally found weak or no correlation between the effects of statins on vascular outcomes and lipid levels. No study showed a correlation between vascular effect and clinical outcome.

CONCLUSION

Statins slow the progression of, and may reverse, atherosclerosis. The magnitude of these effects, however, is small compared with the effects of statins on cardiovascular events. Statins also improve measures of vascular function, which may contribute to their clinical benefits. There is insufficient evidence to suggest that individual statins differ in their vascular effects.

Preprocedural C-Reactive Protein Is Not Associated with Angiographic Restenosis or Target Lesion Revascularization after Coronary Artery Stent Placement

Background: We assessed the predictive value of preprocedural plasma C-reactive protein (CRP) concentrations and statin therapy on 6 months angiographic and 1-year clinical outcome after nonurgent coronary stent placement.

Methods and Results: Baseline plasma high-sensitivity CRP concentrations were prospectively measured in 345 patients undergoing elective stent placement in a native coronary artery. The binary angiographic in-stent restenosis (ISR; stenosis ≥50% of vessel diameter) rate was 19% in patients with CRP values within the reference interval (≤3 mg/L) and 22% in patients with CRP &gt;3 mg/L [odds ratio (OR) = 1.2; 95% confidence interval (CI), 0.73–2.09]. Statin therapy in a univariate analysis significantly reduced both angiographic and clinical ISR rates. Multivariate logistic regression analysis identified unstable angina, smoking, and stent length, but neither CRP concentration nor statin therapy as independent predictors for angiographic ISR. Patients with an abnormal CRP value showed a trend toward a higher risk of nonfatal myocardial infarction (3.8% vs 0.5%; OR = 7.43; 95% CI, 0.87–61.65). Target lesion revascularization rates did not differ between the two groups (9.6% vs 10.6%; OR = 1.13; 95% CI, 0.56–2.28). In multivariate analysis, male sex (OR = 0.44, 95% CI, 0.19–0.97) and statin therapy (OR = 0.26; 95% CI, 0.09–0.68) were independent predictors for the occurrence of target lesion revascularization.

Conclusions: This study demonstrated a lack of association between preprocedural plasma CRP concentrations and angiographic coronary ISR or clinically driven target lesion revascularization. Patients with an abnormal CRP concentration showed a trend toward higher risk of nonfatal myocardial infarction during 1 year of follow-up. Statin therapy was independently associated with decreased clinically driven target lesion revascularization, underlining the beneficial effects of statins on clinical outcome.

Therapeutic Potential of Oral Antiproliferative Agents in the Prevention of Coronary Restenosis

The treatment of coronary artery disease has reached many milestones - from balloon angioplasty to drug-eluting stents. The last decade witnessed the revolution of bare metal stents with new designs, alloys and strut thicknesses. Yet restenosis, the aphorismic 'Achilles heel', remains to be conquered. The restenosis rates with balloon angioplasty alone are 30-40% and are reduced to 20-30% with stents. Although intravascular brachytherapy proved to be a durable and safely used technique to treat in-stent restenosis, clinical event rates were not reduced to single digits.Drug-eluting stents are showing positive results in this direction, but it is too early to predict their efficacy in various subsets of lesions. With the increased usage of these stents, there are reports of problems such as late stent malapposition, subacute and late thromboses, and aneurysm formations due to the vessel toxicity associated with this method of treatment. Furthermore, when multivessel stenting is considered, the cost of drug-eluting stents is a significant problem given the fact that these are no longer 'zero restenosis' devices. There is a definite need for a simple, safe and durable solution to restenosis. Oral agents are an alternative delivery strategy that can target multiple coronary lesions, which are targets for catheter-based revascularisation with any approved metal stent and with potentially lower cost. Although oral agents have been an interesting option to treat restenosis and several agents have been tested in trials since the 1980s, the results were disappointing. The development of devices such as intravascular ultrasound has led to a greater understanding of restenosis mechanisms, and the focus on pathophysiological mechanisms, which centred mainly on platelets, growth factors and lipids, has changed to inflammation, endothelium and smooth muscle cell proliferation.Accordingly, the targets of pharmaceutical agents have shifted from platelets to cell cycle inhibition, smooth muscle cell proliferation and migration, synthesis of extra cellular matrix, and inflammatory mediators. Initial encouraging results with oral drugs such as cilostazol, sirolimus (rapamycin) and thiazolidinediones indicate a definite place for this strategy to reduce restenosis. A desirable oral agent would be anti-inflammatory, inhibit smooth muscle cell migration and proliferation, promote endothelial growth, and be well tolerated and free from significant adverse effects. It may be useful to start with a high loading dose before stent implantation and then follow with a short-term lower maintenance dose. Future trials should be aimed at finding an ideal agent, effective loading dose, maintenance dose and optimum duration of therapy.

The neointimal response to endovascular injury is increased in obese Zucker rats

BACKGROUND

Restenosis after revascularization procedures is accelerated in persons with type 2 diabetes.

AIM

The current study tested the hypothesis that the neointimal response to endovascular injury is enhanced in female obese Zucker (OZ) rats, a model of type 2 diabetes.

METHODS

Animals were randomized to receive either a standard diet (SD) or a diabetogenic diet (DD) for 6 weeks. Four weeks later, balloon injury of the right common carotid artery was induced. All rats were euthanized 2 weeks after injury. Lean Zucker (LZ) rats served as controls.

RESULTS

At the time of death, plasma glucose was elevated in OZ rats fed a SD (208 +/- 13 mg/dl) and a DD (288 +/- 21 mg/dl) compared to corresponding LZ rats (SD: 153 +/- 8; DD: 132 +/- 7 mg/dl). The ratio of high-density lipoprotein cholesterol (HDLc) to total cholesterol (Totc), an index of atherogenicity, was reduced in OZ rats on both diets (SD: 0.77 +/- 0.06; DD: 0.80 +/- 0.09) compared to LZ controls (SD: 1.11 +/- 0.02; DD: 1.20 +/- 0.05). Histomorphometric analysis of injured arteries showed that the intima to media (I : M) ratio was significantly increased in OZ (1.37 +/- 0.07) compared to LZ (0.79 +/- 0.08) rats. Elevations in plasma glucose and triglycerides (Tg) correlated positively and decreases in HDLc negatively with an increased I : M ratio. Administration of the DD did not further enhance the I : M ratio in LZ (0.87 +/- 0.06) or OZ (1.29 +/- 0.09) rats.

CONCLUSIONS

These results suggest that neointima formation following endoluminal injury of the carotid artery is enhanced at an early stage in the development of diabetes mellitus.

Early revascularisation and 1-year survival in 14-day survivors of acute myocardial infarction: a prospective cohort study

BACKGROUND

Randomised trials of early revascularisation in acute coronary syndromes have yielded conflicting results with respect to effects on survival. We assessed the association between revascularisation within 14 days after the index event and 1-year mortality in individuals who survived for at least 14 days after an acute myocardial infarction.

METHODS

We studied a prospective cohort of patients admitted to the coronary care units of 61 Swedish hospitals between 1995 and 1998. We obtained 1-year mortality data from the Swedish National Cause of Death Register. We assessed 21,912 individuals with first registry-recorded acute myocardial infarction, who were younger than age 80 years, and alive at day 14. Relative risk of 1-year mortality in patients who had revascularisation (n=2554) or those who did not (n=19,358) within 14 days was calculated by Cox regression analysis, adjusting for multiple covariates that affect mortality and with a propensity score that adjusted for covariates that affected the likelihood of early revascularisation.

FINDINGS

At 1 year, unadjusted mortality was 9.0% (1751 deaths) in the conservative group and 3.3% (84 deaths) in the early revascularisation group. In the Cox regression analysis early revascularisation was associated with a reduction in 1-year mortality (relative risk 0.47; 95% CI 0.37-0.60; p<0.001). This relative reduction of mortality was similar in all subgroups irrespective of age, sex, baseline characteristics, previous disease manifestations, or treatment.

INTERPRETATION

Early revascularisation in individuals with acute myocardial infarction is associated with substantial reduction in 1-year mortality. Our findings lend support to the use of an invasive approach early after an acute myocardial infarction.

The Lescol(R) Intervention Prevention Study (LIPS): a double-blind, placebo-controlled, randomized trial of the long-term effects of fluvastatin after successful transcatheter therapy in patients with coronary heart disease

BACKGROUND: The 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) inhibit atherosclerosis and reduce both morbidity and mortality in patients with coronary heart disease. No randomised prospective study, however, has investigated the long-term effect of statins on clinical outcomes in patients who have undergone first successful transcatheter therapy. METHODS: The Lescol((R)) Intervention Prevention Study (LIPS) is a double-blind randomized trial designed to compare the effect of fluvastatin (Lescol) with that of placebo on the time which patients with serum cholesterol >/= 3.5 mmol/l and < 7.0 mmol/l (135-270 mg/dl) remain free of major adverse cardiac events (MACE) after successful first transcatheter therapy (TCT). Patients, aged 18-80 years inclusive, will be randomized in a 1 : 1 ratio to receive fluvastatin, 40 mg, or placebo, twice daily for three to five years. The primary endpoint is the survival time during which patients remain MACE free after first TCT. Secondary endpoints are the incidence of MACE, noncardiac death, hospitalization for other atherosclerotic diseases, changes in serum lipid concentrations and anginal status. SUMMARY: LIPS is unique because it is the first study that will investigate whether MACE can be prevented or reduced by fluvastatin in patients who have undergone successful first transcatheter therapy for coronary heart disease.

Pravastatin and endothelium dependent vasomotion after coronary angioplasty: the PREFACE trial

OBJECTIVE

To test the hypothesis that the 3-hydroxy-3-methylglutaryl coenzyme-A reductase inhibitor pravastatin ameliorates endothelium mediated responses of dilated coronary segments: the PREFACE (pravastatin related effects following angioplasty on coronary endothelium) trial.

DESIGN

A double blind, randomised, placebo controlled, multicentre study.

SETTING

Four hospitals in the Netherlands.

PATIENTS

63 non-smoking, non-hypercholesterolaemic patients scheduled for elective balloon angioplasty (pravastatin 34, placebo 29).

INTERVENTIONS

The effects of three months of pravastatin treatment (40 mg daily) on endothelium dependent vasomotor function were studied. Balloon angioplasty was undertaken one month after randomisation, and coronary vasomotor function tests using acetylcholine were performed two months after balloon angioplasty. The angiograms were analysed quantitatively.

MAIN OUTCOME MEASURES

The efficacy measure was the acetylcholine induced change in mean arterial diameter, determined in the dilated segment and in an angiographically normal segment of an adjacent non-manipulated coronary artery.

RESULTS

Increasing acetylcholine doses produced vasoconstriction in the dilated segments (p = 0.004) but not in the normal segments. Pravastatin did not affect the vascular response to acetylcholine in either the dilated segments (p = 0.09) or the non-dilated sites. Endothelium dependent vasomotion in normal segments was correlated with that in dilated segments (r = 0.47, p < 0.001). There were fewer procedure related events in the pravastatin group than in the placebo group (p < 0.05).

CONCLUSIONS

Endothelium dependent vasomotion in normal segments is correlated with that in dilated segments. A significant beneficial effect of pravastatin on endothelial function could not be shown, but in the dilated segments there was a trend towards a beneficial treatment effect in the pravastatin group.

Potential influence of timing of low-density lipoprotein cholesterol evaluation in patients with acute coronary syndrome

OBJECTIVE

To determine the significance of timing of low-density lipoprotein (LDL) cholesterol evaluation in patients with chest pain as it relates to subsequent National Cholesterol Education Program (NCEP) treatment decisions.

DESIGN

Prospective, observational study.

SETTING

A university-affiliated tertiary care hospital.

PATIENTS

Sixty-two patients with coronary heart disease who were not receiving lipid-lowering therapy and whose LDL levels were obtained 25-48 hours after onset of chest pain.

INTERVENTION

We evaluated laboratory test results of patients with chest pain admitted to the cardiac care unit to determine risk to patients when LDL levels obtained inappropriately are used to make decisions regarding antihyperlipidemic therapy.

MEASUREMENTS AND MAIN RESULTS

Inpatient and outpatient LDL levels were compared, and changes in NCEP treatment decisions analyzed. Differences between inpatient and outpatient LDL levels were significant (p<0.05), which frequently resulted in changes in therapy using the NCEP guidelines. The LDL levels of most inpatients were consistent with NCEP goals for patients with coronary heart disease, whereas the outpatient levels showed a need for drug therapy.

CONCLUSION

Lipid values obtained 25-48 hours after hospital admission in patients with acute coronary syndromes do not represent baseline values and may significantly alter the treatment approach; thus, they should not be used to direct drug therapy.