Rationale and design of the Myocardial Ischemia Reduction with Aggressive Cholesterol Lowering (MIRACL) study that evaluates atorvastatin in unstable angina pectoris and in non-Q-wave acute myocardial infarction

A Prognostic Merit of Statins in Patients with Chronic Hemodialysis after Percutaneous Coronary Intervention-A 10-Year Follow-Up Study

BACKGROUND

Patients with end-stage renal disease (ESRD) on chronic hemodialysis who are complicated by coronary artery disease (CAD) are at very high risk of cardiovascular (CV) events and mortality. However, the prognostic benefit of statins, which is firmly established in the general population, is still under debate in this particular population.

METHODS

As a part of a prospective single-center percutaneous coronary intervention (PCI) registry database, this study included consecutive patients on chronic hemodialysis who underwent PCI for the first time between 2000 and 2016 (n = 201). Participants were divided into 2 groups by following 2 factors, such as (1) with or without statin, and (2) with or without high LDL-C (> and ≤LDL-C = 93 mg/dL, median) at the time of PCI. The primary endpoint was defined as CV death, and the secondary endpoints included all-cause and non-CV death, and 3 point major cardiovascular adverse events (3P-MACE) which is the composite of CV death, non-fatal myocardial infarction and stroke. The median and range of the follow-up period were 2.8, 0-15.2 years, respectively.

RESULTS

Kaplan-Meier analyses showed significantly lower cumulative incidences of primary and secondary endpoints other than non-CV deaths in patients receiving statins. Conversely, no difference was observed when patients were divided by the median LDL-C at the time of PCI (p = 0.11). Multivariate Cox proportional hazard analysis identified statins as an independent predictor of reduced risk of CV death (Hazard ratio of statin use: 0.43, 95% confidence interval 0.18-0.88, p = 0.02), all-cause death (HR: 0.50, 95%CI 0.29-0.84, p = 0.007) and 3P-MACE (HR: 0.50, 95%CI 0.25-0.93, p = 0.03).

CONCLUSIONS

Statins were associated with reduced risk of adverse outcomes in patients with ESRD following PCI.

A Phase III, Multicenter, Randomized, Double-blind, Active Comparator Clinical Trial to Compare the Efficacy and Safety of Combination Therapy With Ezetimibe and Rosuvastatin Versus Rosuvastatin Monotherapy in Patients With Hypercholesterolemia: I-ROSETTE (Ildong Rosuvastatin & Ezetimibe for Hypercholesterolemia) Randomized Controlled Trial

PURPOSE

Combination therapy with ezetimibe and statins is recommended in cases of statin intolerance or insufficiency. The objective of this study was to compare the efficacy and safety of combination therapy with ezetimibe and rosuvastatin versus those of rosuvastatin monotherapy in patients with hypercholesterolemia.

METHODS

I-ROSETTE (Ildong ROSuvastatin & ezETimibe for hypercholesTElolemia) was an 8-week, double-blind, multicenter, Phase III randomized controlled trial conducted at 20 hospitals in the Republic of Korea. Patients with hypercholesterolemia who required medical treatment according to National Cholesterol Education Program Adult Treatment Panel III guidelines were eligible for participation in the study. Patients were randomly assigned to receive ezetimibe 10 mg/rosuvastatin 20 mg, ezetimibe 10 mg/rosuvastatin 10 mg, ezetimibe 10 mg/rosuvastatin 5 mg, rosuvastatin 20 mg, rosuvastatin 10 mg, or rosuvastatin 5 mg in a 1:1:1:1:1:1 ratio. The primary end point was the difference in the mean percent change from baseline in LDL-C level after 8 weeks of treatment between the ezetimibe/rosuvastatin and rosuvastatin treatment groups. All patients were assessed for adverse events (AEs), clinical laboratory data, and vital signs.

FINDINGS

Of 396 patients, 389 with efficacy data were analyzed. Baseline characteristics among 6 groups were similar. After 8 weeks of double-blind treatment, the percent changes in adjusted mean LDL-C levels at week 8 compared with baseline values were -57.0% (2.1%) and -44.4% (2.1%) in the total ezetimibe/rosuvastatin and total rosuvastatin groups, respectively (P < 0.001). The LDL-C-lowering efficacy of each of the ezetimibe/rosuvastatin combinations was superior to that of each of the respective doses of rosuvastatin. The mean percent change in LDL-C level in all ezetimibe/rosuvastatin combination groups was >50%. The number of patients who achieved target LDL-C levels at week 8 was significantly greater in the ezetimibe/rosuvastatin group (180 [92.3%] of 195 patients) than in the rosuvastatin monotherapy group (155 [79.9%] of 194 patients) (P < 0.001). There were no significant differences in the incidence of overall AEs, adverse drug reactions, and serious AEs; laboratory findings, including liver function test results and creatinine kinase levels, were comparable between groups.

IMPLICATIONS

Fixed-dose combinations of ezetimibe/rosuvastatin significantly improved lipid profiles in patients with hypercholesterolemia compared with rosuvastatin monotherapy. All groups treated with rosuvastatin and ezetimibe reported a decrease in mean LDL-C level >50%. The safety and tolerability of ezetimibe/rosuvastatin therapy were comparable with those of rosuvastatin monotherapy. ClinicalTrials.gov identifier: NCT02749994.

Carotid Stenting without Angioplasty

Background:

Carotid angioplasty and stenting is gaining popularity as an alternative to carotid endarterectomy for the treatment of carotid bifurcation stenosis. The major concern with the procedure is the risk of embolic stroke which may be initiated by balloon angioplasty of friable atherosclerotic plaque. Elimination of angioplasty may result in a lower incidence of embolic complications.

Method:

We describe a case in which a self-expanding stent alone, without balloon angioplasty, was used to successfully dilate an atherosclerotic stenosis of the carotid bifurcation.

Results:

A moderate increase in vessel diameter, from 75% to 50%, was immediately observed after stent placement alone. No embolic complications were observed and follow-up plain film and ultrasound examinations showed progressive stent enlargement with excellent anatomic and hemodynamic results.

Conclusions:

In this case of severe carotid stenosis, the use of a self-expanding stent alone, without balloon angioplasty, resulted in excellent anatomic and hemodynamic improvement.

High-dose atorvastatin versus moderate dose on early vascular protection after ST-elevation myocardial infarction

Background and aim

Clinical benefits of early high-dose statin therapy after acute coronary syndromes are widely known; however, there is poor evidence on the specific setting of ST-elevation myocardial infarction (STEMI) and dose-dependent effects of this therapy on endothelial function and inflammatory biomarkers in the most vulnerable phase after acute coronary syndromes: the postdischarge period. In our study, we compared the short-term effects of high (80 mg) vs moderate doses of atorvastatin (20 mg) in patients with STEMI undergoing primary percutaneous coronary intervention on endothelial function and vascular inflammation. The aim of our study was the evaluation of dose-dependent short-term effects.

Subjects and methods

We enrolled 52 patients within 48 hours of a STEMI to atorvastatin 80 mg (n=26) or 20 mg (n=26). Every patient underwent endothelial function evaluation by the reactive hyperemia–peripheral arterial tonometry (RH-PAT) index on the first day and 1 month after the STEMI. At the same time, we measured lipid profile and serum levels of high-sensitivity CRP, IL6, TNFα, and oxidized LDL.

Results

After 1 month of therapy, we observed differences in high-sensitivity CRP levels (0.04±0.02 mg/dL vs 0.36±0.3 mg/dL, P=0.001), IL6 (1.12±0.93 pg/mL vs 3.13±2.84 pg/mL, P=0.03), and improvement in RH-PAT index (1.96±0.16 vs 1.72±0.19, P=0.002) in the group treated with high-dose vs moderate-dose atorvastatin. There was no significant difference in levels of TNFα or oxidized LDL with atorvastatin 20 mg, while there was a reduction in these variables in the group treated with atorvastatin 80 mg. We observed a correlation between high-sensitivity polymerase chain reaction and RH-PAT index on the 30th day after STEMI (r=0.5, P=0.001).

Conclusion

Higher dose statin therapy in patients with STEMI undergoing primary percutaneous coronary intervention showed early greater vascular protective effects that moderate dose.

Plant sterols and stanols as dietary factors reducing hypercholesterolemia by inhibiting intestinal cholesterol absorption

The review is focussed on the mechanisms of action, lipid-lowering activity, structural characteristics, and safety of plant sterins and stanols. Phytosterins and phytostanols inhibit intestinal cholesterol (CH) absorption, therefore decreasing plasma CH levels. The emphasis is put on prospective epidemiological studies of representative samples, which demonstrated that plasma concentrations of phytosterins and phytostanols in patients with coronary heart disease (CHD) are substantially lower than in CHD-free participants. A two-fold increase in serum sytosterin concentration was associated with a reduction in relative risk of CHD by 22 %. Plant sterin and sterol esters could be regarded as effective and safe dietary ingredients decreasing blood levels of CH — one of the major cardiovascular disease risk factors.

Updated evidence on early statin therapy for acute coronary syndromes: meta-analysis of 18 randomized trials involving over 14,000 patients

BACKGROUND

The short-term effects of early statin therapy in acute coronary syndromes (ACS) on clinical outcomes remain unclear. Our objective was to update the evidence on patient relevant outcomes from all randomized trials comparing early statin therapy with placebo or usual care at 1 and 4 months following ACS.

METHODS

We performed a systematic review and meta-analysis of randomized trials that compared statins to control, initiated within 14 days after onset of ACS and with minimal follow-up of 30 days. Data were extracted in duplicate and analyzed by a random effects model. Investigators from individual trials contributed additional data where needed.

RESULTS

A total of 18 trials involving 14,303 patients with ACS were included in the meta-analysis. We found no evidence for further trials on the topic. Risk ratios for the combined endpoint of death, myocardial infarction, and stroke of early statin therapy compared to control were 0.93 (95% confidence interval [CI], 0.80-1.08; P=0.34) at 1 month and 0.93 (95% CI, 0.81-1.06; P=0.27) at 4 months following ACS. There were favorable trends related to statin use for all individual secondary endpoints but there was no statistically significant risk reduction except for unstable angina with a risk ratio of 0.76 (95% CI, 0.59-0.96; P=0.02) at 4 months following ACS.

CONCLUSIONS

Initiation of statin therapy within 14 days following ACS results in directionally favorable but non-significant reduction in death, myocardial infarction, or stroke up to 4 months, and significant reduction in the occurrence of unstable angina at 4 months following ACS.

Benefits of statin therapy in patients with special risks: coronary bypass surgery, stable coronary disease, and acute coronary syndromes

Several major clinical studies have examined the impact of lipid lowering in patients with and without coronary heart disease and have demonstrated that lowering lipid levels can successfully and significantly delay the onset of cardiovascular events. Although epidemiologic studies and small clinical trials have suggested that more aggressive and sustained lowering of low-density lipoprotein cholesterol (LDL-C) to < 100 mg/dl (2.6 mmol/l) can result in reductions in cardiovascular events in these populations, reducing LDL-C to these concentrations has only recently been shown in larger clinical trials. However, few clinical trials have been conducted in patients with certain special high risks, such as those who have had a recent revascularization procedure or have experienced an acute coronary event. Three trials examined the short- and long-term clinical benefits of aggressive lipid lowering in patients who underwent coronary artery bypass surgery (Post-CABG), were candidates for angioplasty (AVERT), or were hospitalized for acute coronary syndromes (MIRACL).

Effects of high-dose atorvastatin in patients > or =65 years of age with acute coronary syndrome (from the myocardial ischemia reduction with aggressive cholesterol lowering [MIRACL] study)

After acute coronary syndromes (ACSs), older patients are particularly susceptible to early complications, including death and recurrent ACS. Lipid management guidelines do not differentiate elderly from younger patients, and lack of evidence for statin benefits in older patients has led to underutilization of statins in the elderly. The MIRACL study randomized 3,086 patients to 16 weeks of 80 mg/day of atorvastatin or placebo 24 to 96 hours after ACS and demonstrated significant decreases in the combined primary end point (nonfatal acute myocardial infarction, resuscitated cardiac arrest, recurrent symptomatic myocardial ischemia). This post hoc analysis compared benefits of 80 mg of atorvastatin in older (> or =65 years) versus younger (<65 years) patients. Event rates were approximately two- to threefold higher in older than in younger patients. Treatment-by-age heterogeneity testing indicated no difference in treatment effect by age for any of the primary or secondary end points, and relative risk decreases in the primary end point with atorvastatin versus placebo were similar in younger and older patients (22% vs 14%, respectively). The safety profile of atorvastatin was similar between the 2 age groups. In conclusion, these results and a greater immediate cardiovascular risk in older patients argue for early, intensive atorvastatin therapy as routine practice after ACS.

Progressive coronary calcification despite intensive lipid-lowering treatment: a randomised controlled trial

OBJECTIVES

To evaluate the effect of intensive lipid-lowering treatment on coronary artery calcification in a substudy of a trial recruiting patients with calcific aortic stenosis.

METHODS

In a double blind randomised controlled trial, 102 patients with calcific aortic stenosis and coronary artery calcification were randomly assigned by the minimisation technique to atorvastatin 80 mg daily or matched placebo. Coronary artery calcification was assessed annually by helical computed tomography.

RESULTS

48 patients were randomly assigned to atorvastatin and 54 to placebo with a median follow up of 24 months (interquartile range 24-30). Baseline characteristics and coronary artery calcium scores were similar in both groups. Atorvastatin reduced serum low density lipoprotein cholesterol (-53%, p < 0.001) and C reactive protein (-49%, p < 0.001) concentrations whereas there was no change with placebo (-7% and 17%, p > 0.95 for both). The rate of change in coronary artery calcification was 26%/year (0.234 (SE 0.037) log arbitrary units (AU)/year; n = 39) in the atorvastatin group and 18%/year (0.167 (SE 0.034) log AU/year; n = 49) in the placebo group, with a geometric mean difference of 7%/year (95% confidence interval -3% to 18%, p = 0.18). Serum low density lipoprotein concentrations were not correlated with the rate of progression of coronary calcification (r = 0.05, p = 0.62).

CONCLUSION

In contrast to previous observational studies, this randomised controlled trial has shown that, despite reducing systemic inflammation and halving serum low density lipoprotein cholesterol concentrations, statin treatment does not have a major effect on the rate of progression of coronary artery calcification.

In-hospital initiation of statin therapy in acute coronary syndromes: maximizing the early and long-term benefits

Patients with acute coronary syndrome (ACS) are at high risk for recurrent coronary events, sudden death, and all-cause mortality. Conventional revascularization therapies reduce the risk of further ischemia but do not affect the underlying atherosclerotic disease. Statins have a proven record in the secondary prevention of coronary heart disease. Furthermore, statins have been shown to exert varying degrees of pleiotropic effects, which may stabilize vulnerable atherosclerotic plaques. A compelling body of evidence from randomized controlled trials demonstrates that high-dose, potent statin therapy initiated immediately after an acute coronary event can significantly reduce early as well as longer-term morbidity and mortality. Furthermore, high-dose, potent statin therapy displays a reasonable safety profile. National guidelines now recommend that in patients with ACS, statin therapy should be initiated in hospital prior to discharge, irrespective of baseline low-density lipoprotein cholesterol levels, to improve clinical outcomes. Every effort should be made to ensure all eligible patients with ACS are initiated and maintained on statin therapy.

Tissue Inhibitor of Metalloproteinase 1 Adenoviral Gene Therapy Alone Is Equally Effective in Reducing Restenosis as Combination Gene Therapy in a Rabbit Restenosis Model

Neointimal formation is a common feature after angioplasty, bypass grafting and stenting. Angioplasty damages endothelium, causing pathological changes in arteries which lead to smooth muscle cell proliferation, synthesis of extracellular matrix components and eventually restenosis formation. Adenoviruses offer an efficient transgene expression in the vascular system. In this study, we compared the effects of different gene combinations. We wanted to find out whether adenoviral catheter-mediated delivery of an additive combination of the vascular endothelial growth factor (VEGF)-A with VEGF-C is more effective than the combination of tissue inhibitor of metalloproteinase 1 (TIMP-1) alone or with VEGF-C in a rabbit balloon denudation model. Additionally, we wanted to clarify whether the combination therapy prolongs the treatment effect. It was found that TIMP-1 alone prevents restenosis and that the combination of VEGF-A and VEGF-C has a similar effect at the 2-week time point. However, the combination of VEGF-A and VEGF-C lost the treatment effect at the 4-week time point due to the catch-up growth of neointima. On the other hand, TIMP-1 and the combination of TIMP-1 with VEGF-C still had an extended treatment effect at the 4-week time point. When considering the gene combination used in this study, it is concluded that gene therapy with adenoviral TIMP-1 alone is sufficient in reducing restenosis and that combination gene therapy does not bring any significant advantages.

Atrial Natriuretic Peptide Preserves Endothelial Function during Intimal Hyperplasia

BACKGROUND

Atrial and C-type natriuretic peptides (ANP and CNP), acting through different receptors, have antiproliferative effects in vitro. Beneficial effects of CNP in vivo on early atherosclerosis have been described, but it is not known if ANP is antiproliferative in vivo. In the present study, the effects of chronic in vivo ANP were tested and compared with CNP on endothelial dysfunction and intimal thickening caused by peri-arterial collars.

METHODS

Non-occlusive collars were placed bilaterally around the common carotid arteries of rabbits. One collar was filled with saline vehicle. The contralateral collar was filled with ANP or CNP (1 or 10 microM, n = 5-7) with slow replacement of peptide via mini-pump (1 or 10 fmol/h).

RESULTS

After 7 days, endothelium-dependent vasorelaxation in saline-collared arteries was 33 +/- 3% of maximum [averaged over 0.03-1 muM acetylcholine (ACh)] compared to 64 +/- 2% in normal (uncollared) arteries (p < 0.05, n = 23). In vivo ANP restored the ACh relaxation to normal (e.g., 57 +/- 6%, 1 microM ANP), similar to effects seen with CNP in vivo. Endothelium-independent vasorelaxation of collared-vessels was not altered by either peptide. Intimal hyperplasia induced by the collars was not prevented by peri-arterial natriuretic peptides. In additional rabbits (n = 6), CNP (100 pmol/h) given directly into the lumen of collared carotid arteries for 7 days reduced neointima formation by 16 +/- 5% (p < 0.05), whereas ANP given intraluminally (100 pmol/h; n = 6) did not.

CONCLUSIONS

The more potent actions of CNP on vascular smooth muscle cell migration and proliferation (established in vitro) may explain differences between the peptides on intimal hyperplasia in vivo. The major hallmark of atherosclerosis and restenosis, endothelial dysfunction, was prevented by chronic, peri-arterial administration of ANP or CNP.

High-density lipoprotein, but not low-density lipoprotein cholesterol levels influence short-term prognosis after acute coronary syndrome: results from the MIRACL trial

AIMS

Patients with acute coronary syndrome (ACS) in the Myocardial Ischaemia Reduction with Aggressive Cholesterol Lowering (MIRACL) study had diminished cardiovascular events after 16 weeks of treatment of atorvastatin 80 mg daily. We determined whether plasma lipoproteins at baseline and then at 6 weeks after randomization predicted clinical outcome.

METHODS AND RESULTS

Cox proportional hazards models were constructed to determine relations between lipoproteins and clinical endpoint events. Baseline LDL cholesterol (LDL-C) did not predict outcome. In contrast, baseline HDL-C predicted outcome with a hazard ratio of 0.986 per mg/dL increment in HDL-C, P<0.001, indicating 1.4% reduction in risk for each 1 mg/dL increase in HDL-C. Atorvastatin treatment profoundly lowered LDL-C, but had minimal effect on HDL-C. Neither Week 6 LDL-C nor absolute change of LDL-C from baseline by Week 6 had any significant impact on clinical endpoints occurring between Week 6 and Week 16 after randomization.

CONCLUSION

Plasma HDL-C, but not LDL-C, measured in the initial stage of ACS predicts the risk of recurrent cardiovascular events over the ensuing 16 weeks. LDL-C reduction does not account for the clinical risk reduction with atorvastatin treatment after ACS. This finding may suggest that the clinical benefit of atorvastatin after ACS is mediated by qualitative changes in the LDL particle and/or by non-lipid (pleiotropic) effects of the drug.

New and emerging data from clinical trials of statins

Recent clinical trials of statins have clearly demonstrated the benefit of statin therapy in preventing both coronary and cerebral vascular events. These benefits have been demonstrated to be present without reference to older age, sex, or comorbid conditions, including hypertension and diabetes. Future trials will test the value of more aggressive low-density lipoprotein cholesterol lowering, the value of immediate statin intervention during acute coronary syndromes, the role of cholesterol lowering with or without angioplasty, and the role of cholesterol lowering in stroke prevention.

Reduction in cardiovascular events after vascular surgery with atorvastatin: a randomized trial

OBJECTIVES

This prospective, randomized, placebo-controlled, double-blind clinical trial was performed to analyze the effect of atorvastatin compared with placebo on the occurrence of a 6-month composite of cardiovascular events after vascular surgery. Cardiovascular complications are the most important cause of perioperative morbidity and mortality among patients undergoing vascular surgery. Statin therapy may reduce perioperative cardiac events through stabilization of coronary plaques.

METHODS

One hundred patients were randomly assigned to receive 20 mg atorvastatin or placebo once a day for 45 days, irrespective of their serum cholesterol concentration. Vascular surgery was performed on average 30 days after randomization, and patients were prospectively followed up over 6 months. The cardiovascular events studied were death from cardiac cause, nonfatal myocardial infarction, unstable angina, and stroke.

RESULTS

Fifty patients received atorvastatin, and 50 received placebo. During the 6-month follow-up primary end points occurred in 17 patients, 4 in the atorvastatin group and 13 in the placebo group. The incidence of cardiac events was more than three times higher with placebo (26.0%) compared with atorvastatin (8.0%; P =.031). The risk for an event was compared between the groups with the Kaplan-Meier method, as event-free survival after vascular surgery. Patients given atorvastatin exhibited a significant decrease in the rate of cardiac events, compared with the placebo group, within 6 months after vascular surgery (P =.018).

CONCLUSION

Short-term treatment with atorvastatin significantly reduces the incidence of major adverse cardiovascular events after vascular surgery.

Characterization of the Response of Bone Marrow-Derived Progenitor Cells to Cyclic Strain: Implications for Vascular Tissue-Engineering Applications

One of the major failings in vascular tissue engineering is the limited capacity of autologous differentiated cells to reconstitute tissues. A logical solution is to use multipotent progenitor cells, which in vascular treatments have been underutilized. Although biochemical stimulation has been explored to differentiate bone marrow-derived progenitor cells (BMPCs) to smooth muscle cells (SMCs), the use of biomechanical forces in differentiation remains unexplored. The purpose of this work was to explore the effects of cyclic strain alone on BMPC morphology, proliferation, and differentiation. BMPCs were isolated from rat bone marrow and, after 7 days in culture, the cells grew in distinct multilayered colonies. BMPCs were stimulated with 10% strain at 1 Hz for 7 days. Observations showed that cyclic strain inhibited proliferation (p < 0.05) and caused alignment of the cells (p < 0.05) and of the F-actin cytoskeleton perpendicular to the direction of strain. In addition, cyclic strain resulted in expression by the cells of vascular smooth muscle alpha-actin and h1-calponin. This work demonstrates the potential of physiologic biomechanical stimulation in the differentiation of BMPCs to SMCs, and this could have important implications for vascular tissue engineering and other therapies in which cell sourcing is a major concern.

Eccentric Dosing of Nitrates Does Not Increase Cardiac Events in Patients with Healed Myocardial Infarction

This study was performed to investigate the risk of cardiac events by eccentric or continuous dosing of nitrates in patients with healed myocardial infarction. A total of 573 patients with healed myocardial infarction were assigned to one of two groups: a nitrate-treatment (n =239) and a nontreatment (n =334) group. The nitrate-treatment group was further subdivided into a group receiving eccentric dosing of nitrates (n =153) and a group receiving continuous dosing of nitrates (n =86). The mean observation period was 11.2+/-8.2 months. The cardiac events investigated were nonfatal and fatal recurrent myocardial infarction, death from congestive heart failure, sudden death, worsening angina and rebound angina. Baseline characteristics were also compared among the three groups to determine any effects on outcome. Among the patients receiving eccentric or continuous dosing of nitrates, the rates of cardiac events were 12.7/1,000 person.year and 67.4/1,000 person.year, respectively, whereas the rate was 19.7/1,000 person.year in the nontreated patients. The incidence of cardiac events was significantly greater in patients receiving continuous dosing of nitrates than in the nontreated patients (p <0.05). Continuous dosing of nitrates thus increases cardiac events, and while eccentric dosing of nitrates does not increase them, it is also not effective at preventing them in patients with healed myocardial infarction.

Undertreatment of dyslipidemia in peripheral arterial disease and other high-risk populations: an opportunity for cardiovascular disease reduction

Atherosclerosis is a form of arterial disease that manifests in the coronary circulation as coronary artery disease (CAD), in the carotid arteries as cerebrovascular disease, and in the aorta and lower extremity arteries as peripheral arterial disease (PAD). The systemic nature of the disease is reflected in the fact that individuals with PAD or carotid artery disease are more likely to have CAD than those without. Since individuals with PAD are at markedly increased risk of cardiovascular ischemic events, early identification of this population and more aggressive medical interventions could substantially improve both morbidity and survival. The incidence of PAD in the general population is high, and currently affects 8-10 million Americans. The risk of developing PAD is predicted by both age and common atherosclerosis risk factors (e.g., smoking and diabetes). Efficient office-based PAD detection depends on the application of objective techniques to establish this diagnosis. Objective noninvasive tests, such as measurement of the ankle-brachial index (ABI), are known to be more sensitive than traditional clinical assessments. Since the major threat to patients with PAD is from secondary cardiovascular ischemic events, a primary therapeutic goal is to modify atherosclerotic risk factors. While national recommendations mandate aggressive lowering of serum low-density lipoprotein cholesterol (LDL-C) levels as a primary treatment goal in all patients with overt atherosclerosis, as 'coronary heart disease risk equivalent' syndromes, individuals with PAD are less intensively treated than those with CAD. Statins are the most effective of current treatments in lowering LDL-C, and have proven efficacy in secondary prevention among patients with established CAD. The use of statin medications in high-risk groups such as PAD patients could prove particularly beneficial in reducing cardiovascular morbidity and mortality and therefore merits prospective clinical investigation.

Aggressive lipid management for cardiovascular prevention: evidence from clinical trials

Epidemiologic evidence shows that elevated serum cholesterol, specifically low-density lipoprotein cholesterol (LDL-C), increases the risk of coronary heart disease (CHD). Moreover, large-scale intervention trials demonstrate that treatment with HMG-CoA reductase inhibitors (statins), the most effective drug class for lowering LDL-C, significantly reduces the risk of CHD events. Unfortunately, only a moderate percentage of hypercholesterolemic patients are achieving LDL-C targets specified by the National Cholesterol Education Program (NCEP), in part because clinicians are not effectively titrating medications as needed to achieve LDL-C goals. Recent evidence suggests that more aggressive LDL-C lowering may provide greater clinical benefit, even in individuals with moderately elevated serum cholesterol levels. Furthermore, recent studies suggest that statins have cardioprotective effects in many high-risk individuals, including those with baseline LDL-C <100 mg/dl. High-density lipoprotein cholesterol (HDL-C) was recognized by the NCEP-Adult Treatment Panel II (ATP II) as a negative risk factor for CHD. The NCEP-ATP III guidelines have also reaffirmed the importance of HDL-C by increasing the low HDL-C designation from <35 to <40 mg/dl as a major risk factor for CHD. Similarly, triglyceride control will play a larger role in dyslipidemia management. As more clinicians effectively treat adverse lipid and lipoprotein cardiovascular risk factors, patients will likely benefit from reductions in cardiovascular events.

Pretreatment with statins enhances myocardial protection during coronary revascularization

OBJECTIVE

This experimental study was undertaken to determine whether pretreatment with statins would enhance myocardial protection and minimize ischemic injury during revascularization of acutely ischemic myocardium.

METHODS

In 20 pigs the second and third diagonal arteries were occluded for 90 minutes, followed by 45 minutes of blood cardioplegic arrest and 180 minutes of reperfusion. Ten pigs received atorvastatin (40 mg orally every day) for 21 days before surgical intervention; 10 others received no statins. Ischemic damage was assessed on the basis of the need for cardioversions for ventricular arrhythmias, regional wall-motion scores (4 = normal to -1 = dyskinesia) were determined by means of 2-dimensional echocardiography, endothelial function was assessed on the basis of bradykinin-induced coronary artery relaxation, and infarct size was calculated by determining the area of necrosis to the area of risk by means of histochemical staining. Results are given as means +/- SE.

RESULTS

Statin-treated animals required fewer cardioversions (0.11 +/- 0.01 vs 2.87 +/- 0.20, P =.0001), had improved wall-motion scores (2.81 +/- 0.10 vs 1.52 +/- 0.08, P =.01), had lower infarct size (21% +/- 2% vs 41% +/- 2%, P =.0001), and had more complete coronary artery relaxation (34% +/- 5% vs 8% +/- 4%, P =.01). Total serum cholesterol levels were similar between the groups (62 +/- 5 mg/dL for statin-treated animals vs 68 +/- 5 mg/dL for non-statin-treated animals, P =.30).

CONCLUSIONS

Pretreatment with statins enhances myocardial protection during revascularization by means of mechanisms that are independent of their cholesterol-lowering properties.

Prevention of sudden death in patients with coronary artery disease: do lipid-lowering drugs play a role?

Ventricular arrhythmias are the most common cause of sudden cardiac death in patients with coronary artery disease. Since treatment of hypercholesterolemia in patients with coronary artery disease reduces the risk of major coronary events by about 30%, one could speculate that this treatment could also result in a reduction of arrhythmic episodes in high-risk patients. In this review, the importance of myocardial ischemia as a trigger for ventricular arrhythmias, as well as the available data that suggest a possible effect of anti-ischemic treatments, including lipid-lowering drugs, on these arrhythmias are presented. Also, possible mechanisms and future research to test the hypothesis that lipid-lowering drugs can reduce life-threatening ventricular arrhythmias are discussed.

Early statin therapy for acute coronary syndromes

OBJECTIVE

To review the clinical benefit of statins in the early management of acute coronary syndromes (ACSs) and their possible mechanisms of benefit.

DATA SOURCES

A MEDLINE search (1966-September 2001) was conducted using the following terms: pravastatin, lovastatin, simvastatin, atorvastatin, cerivastatin, fluvastatin, statins, hydroxymethylglutaryl coenzyme A reductase inhibitor, acute coronary syndromes, unstable angina, and myocardial infarction. Pertinent articles referenced in these publications were also reviewed.

STUDY SELECTION AND DATA EXTRACTION

French- and English-language human and animal studies were selected and analyzed.

DATA SYNTHESIS

In addition to their lipid-lowering properties, statins produce several nonlipid-related properties. These pleiotropic properties include improved endothelial function, reduction of inflammation at the site of the atherosclerotic plaque, inhibition of platelet aggregation, and anticoagulant effects, all of which may result in clinical benefit during ACSs. Preliminary studies and retrospective analyses of large clinical trials support the hypothesis that statins may be of benefit in ACSs. A recently published randomized, double-blind, multicenter trial evaluated the clinical impact of high-dose atorvastatin in patients with ACSs. Use of atorvastatin resulted in a decrease in a combined endpoint of cardiovascular events. Furthermore, initiation of statin therapy during hospitalization improves long-term compliance and may significantly improve clinical outcome.

CONCLUSIONS

Early use of statins in ACSs appears to decrease cardiovascular events. We believe statin therapy should be initiated early (at the latest before hospital discharge) in all patients who have been hospitalized for ACSs. Ongoing studies will clarify the benefit of these agents in ACSs, the importance of their nonlipid-lowering properties, and the optimal cholesterol-target concentrations.

High doses of atorvastatin do not affect activity of prothrombinase in patients with acute coronary syndromes

Membrane-dependent coagulation processes play a key role in acute coronary syndromes (ACS), where the generation of thrombin depends on the complex of activated factors X and V (prothrombinase complex) assembled on activated platelets. The aim of the present study was to evaluate prothrombinase activity in patients with ACS and to examine the effect of treatment with 80 mg/day atorvastatin on prothrombinase activity. Blood samples were obtained at admission from 22 patients with ACS, and then again at 2 weeks and at 16 weeks after double-blind randomization to either placebo or atorvastatin. Prothrombinase activity was evaluated by measuring the generation of thrombin by in vitro reconstructed thrombi, and also by measuring plasma levels of prothrombin fragment F1 + 2. Twenty age-matched subjects with stable angina and 11 without coronary disease were used as controls. At admission, prothrombinase activity and F1 + 2 were significantly higher in ACS patients than in controls. Prothrombinase activity was still high at 2 weeks while it returned to normal levels at 16 weeks. F1 + 2 remained high both at 2 and at 16 weeks. Our data indicate that prothrombinase activity is high in patients with ACS, and that it is not affected by high-dose atorvastatin.

Renin-angiotensin system antagonism and lipid-lowering therapy in cardiovascular risk management

The renin-angiotensin system (RAS) and dyslipidaemia have been shown to be involved in the genesis and progression of atherosclerosis. Manipulation of the RAS has been effective in modifying human coronary artery disease progression. Similarly, the 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase inhibitors or statins have been shown to reduce cholesterol and lower cardiovascular events in primary and secondary prevention trials in coronary artery disease. In addition to their primary mode of action, statins and blockers of the RAS possess common additional properties that include restoration of endothelial activity and inhibition of cellular proliferation. This article reviews the current data on the common properties of these classes of drugs in which the beneficial effects extend beyond their antihypertensive and lipid-lowering properties.

The Myocardial Ischemia Reduction with Acute Cholesterol Lowering trial: MIRACuLous or not, it's time to change current practice

The Myocardial Ischemia Reduction with Aggressive Cholesterol Lowering (MIRACL) study was the first trial to assess whether statins might be of clinical benefit in those with recently unstable coronary disease. MIRACL found that high-dose atorvastatin was safe and reduced the incidence of the composite endpoint, death, non-fatal myocardial infarction, resuscitated sudden cardiac death or emergent rehospitalization for recurrent ischemia at 16 weeks when compared with placebo. Despite a number of important study limitations, MIRACL's findings and the prior observation that inpatient initiation of lipid-lowering therapy is associated with higher rates of subsequent utilization, suggest that it is prudent to begin statin therapy when patients present with an acute coronary syndrome.

Effect of an aggressive lipid-lowering strategy on progression of atherosclerosis in the left main coronary artery from patients in the post coronary artery bypass graft trial

BACKGROUND

The Post Coronary Artery Bypass Graft Trial, designed to compare the effects of two lipid-lowering regimens and low-dose anticoagulation versus placebo on progression of atherosclerosis in saphenous vein grafts of patients who had had CABG surgery, demonstrated that aggressive lowering of LDL cholesterol levels to a mean yearly cholesterol level from 93 to 97 mg/dL compared with a moderate reduction to a level of 132 to 136 mg/dL decreased the progression of atherosclerosis in saphenous vein grafts. Low-dose anticoagulation did not affect progression. This secondary analysis tested the hypothesis that a similar decrease in progression of atherosclerosis would also be present in native coronary arteries as measured in the left main coronary artery (LMCA).

METHODS AND RESULTS

A sample of 402 patients was randomly selected from 1102 patients who had baseline and follow-up views of the LMCA suitable for analysis. Patients treated with the aggressive lipid-lowering strategy had less progression of atherosclerosis in the LMCA as measured by changes in minimum (P=0.0003) lumen diameter or the maximum percent stenosis (P=0.001), or the presence of substantial progression (P=0.008), or vascular occlusion (P=0.005) when compared with the moderate strategy.

CONCLUSIONS

A strategy of aggressive lipid lowering results in significantly less atherosclerosis progression than a moderate approach in LMCAs.

Going from immutable to mutable atherosclerotic plaques

Atherosclerotic coronary disease develops over several decades and was once thought to be an inevitable, irreversible consequence of aging. Atherogenesis is an inflammatory response that occurs after injury to the endothelium. Thrombosis, because of either endothelial erosion or plaque disruption, precipitates acute coronary events. Effective lipid lowering with statins has consistently and significantly decreased the risk that acute ischemic events will occur. The beneficial effects of statins likely result not only from their lipid-lowering effects but also from mechanisms that influence plaque behavior. Atherosclerotic plaques are not immutable; rather, their structure and composition can be altered by therapeutic modification. Ample evidence from clinical trials supports statin treatment in patients with stable coronary disease. Results of recent clinical trials support early treatment of high-risk patients with unstable coronary disease; early and aggressive statin treatment resulted in fewer recurrent ischemic events in patients with an acute coronary syndrome. Additional studies are needed to confirm the benefit of early statin treatment in patients with unstable coronary disease and to elucidate the reasons for the occurrence of events in treated patients. Research is also necessary to clarify the role of other lipids, as well as nonlipid risk factors, in the occurrence of acute ischemic events.

Making practical sense of clinical trial data in decreasing cardiovascular risk

Clinical studies now affirm what epidemiologic evidence has long suggested-that a broad range of patients can benefit from lipid reduction, including those without overt coronary artery disease and only moderate lipid elevations. Together, these studies suggest that current goals for cholesterol reduction may not be sufficiently stringent to slow the epidemic of heart disease in this country and that aggressive lipid lowering may be just what the doctor should order.

Are we aggressive enough in lowering cholesterol?

To date, 5 major randomized, placebo-controlled statin trials--the Scandinavian Simvastatin Survival Study, West of Scotland Coronary Prevention Study, Cholesterol and Recurrent Events trial, Long-term Intervention with Pravastatin in Ischaemic Disease, and Air Force/Texas Coronary Atherosclerosis Prevention Study--have convincingly shown that total mortality and major coronary events can be significantly reduced by lowering levels of low-density lipoprotein cholesterol (LDL-C) with statin therapy. These results were achieved in a broad range of patients including those with and without a history of coronary artery disease and with elevated or average LDL-C levels. The results also support the large body of epidemiologic evidence demonstrating that the lower the cholesterol level, the lower the cardiovascular risk. Evidence now substantially supports the urgency of physicians to aggressively target the lowering of LDL-C levels for the primary and secondary prevention of coronary disease.

Stable angina and acute coronary syndromes are associated with nitric oxide resistance in platelets

OBJECTIVES

The study examined possible clinical determinants of platelet resistance to nitric oxide (NO) donors in patients with stable angina pectoris (SAP) and acute coronary syndromes (ACS), relative to nonischemic patients and normal subjects.

BACKGROUND

We have shown previously that platelets from patients with SAP are resistant to the antiaggregating effects of nitroglycerin (NTG) and sodium nitroprusside (SNP).

METHODS

Extent of adenosine diphosphate (1 micromol/liter)-induced platelet aggregation (impedance aggregometry in whole blood) and inhibition of aggregation by NTG (100 micromol/liter) and SNP (10 micromol/liter) were compared in normal subjects (n = 43), nonischemic patients (those with chest pain but no fixed coronary disease, (n = 35) and patients with SAP (n = 82) or ACS (n = 153). Association of NO resistance with coronary risk factors, coronary artery disease (CAD), intensity of angina and current medication was examined by univariate and multivariate analyses.

RESULTS

In patients with SAP and ACS as distinct from nonischemic patients and normal subjects, platelet aggregability was increased (both p < 0.01), and inhibition of aggregation by NTG and SNP was decreased (both p < 0.01). Multivariate analysis revealed that NO resistance occurred significantly more frequently with ACS than with SAP (odds ratio [OR] 2.3:1), and was less common among patients treated with perhexiline (OR 0.3:1) or statins (OR 0.45:1). Therapy with other antianginal drugs, extent of CAD, intensity of angina and coronary risk factors were not associated with variability in platelet responsiveness to NO donor.

CONCLUSIONS

Patients with symptomatic ischemic heart disease, especially ACS, exhibit increased platelet aggregability and decreased platelet responsiveness to the antiaggregatory effects of NO donors. The extent of NO resistance in platelets is not correlated with coronary risk factors. Pharmacotherapy with perhexiline and/or statins may improve platelet responsiveness to NO.

Effect of lipid-lowering therapy on early mortality after acute coronary syndromes: an observational study

BACKGROUND

Lipid-lowering agents are known to reduce long-term mortality in patients with stable coronary disease or significant risk factors. However, the effect of lipid-lowering therapy on short-term mortality immediately after an acute coronary syndrome has not been determined. We did an observational study using data from two randomised trials to investigate this issue.

METHODS

We used data from the GUSTO IIb and PURSUIT trials to compare all-cause mortality among patients with acute coronary syndromes who were discharged on lipid-lowering agents (n=3653) with those who were not (n=17,156). A propensity analysis was done to adjust for presumed selection biases in the prescription of lipid-lowering agents.

FINDINGS

Lipid-lowering therapy was associated with a smaller proportion of deaths at 30 days (17 [0.5%] vs 179 [1.0%], hazard ratio 0.44 [95% CI 0.27-0.73], p=0.001) and at 6 months (63 [1.7%] vs 605 [3.5%], 0.48 [0.37-0.63], p<0.0001). After adjustment for the propensity to be prescribed lipid-lowering agents and other potential confounders, prescription of a lipid-lowering agent at discharge remained associated with a reduced risk of death at 6 months (0.67 [0.48-0.95], p=0.023).

INTERPRETATION

Prescription of a lipid-lowering drug at hospital discharge was independently associated with reduced short-term mortality among patients after an acute coronary syndrome.

Usefulness of in-hospital prescription of statin agents after angiographic diagnosis of coronary artery disease in improving continued compliance and reduced mortality

Despite well-documented clinical benefit of the use of statins in patients with coronary artery disease (CAD) and even mild lipid elevations, studies have documented the presence of a significant "treatment gap" between those patients in whom treatment is indicated and those patients who actually receive it. It has been proposed that a prescription for statin therapy given to indicated patients at the time of initial angiographic diagnosis of CAD has the potential to improve long-term medication compliance, but this requires further evaluation. We prospectively followed 600 patients with angiographically demonstrated CAD (diameter stenosis > or = 70%) who met the National Cholesterol Education Project (NCEP) guidelines for statin therapy for an average of 3.0 years (range 2.0 to 4.6). Patients were an average of 65 years of age, 78% were men, 77% presented initially with acute ischemic syndrome, and 64 (10.7%) died during follow-up. Overall, 105 patients (18%) were discharged from the initial hospitalization with a statin prescription. At long-term follow-up, the number of patients taking statins had increased to 47%. However, long-term statin compliance was significantly higher among patients initially discharged with a statin prescription than those who were not (77% vs 40%; p < 0.0001). Additionally, those patients discharged with a statin prescription had significantly reduced mortality rate at long-term follow-up (5.7% vs 11.7%; p = 0.05). Cox hazard regression analysis, controlling for all known clinical baseline variables, confirmed the absence of a prehospital discharge statin prescription to be an independent predictor of increased mortality (hazard ratio 2.4) with a statistical trend (p = 0.06). Thus, this study demonstrates that after angiographic diagnosis of CAD, prescription of appropriate statin therapy at the time of hospital discharge improves long-term statin compliance and may significantly enhance survival.

Clinical relevance of statins: instituting treatment early in acute coronary syndrome patients

The efficacy of statins in lowering the total and low-density lipoprotein cholesterol and reducing the risk of cardiac events is now well established. The secondary prevention studies started treatment several months after the acute event. However, the greatest risk of recurrence is shortly after the index event. Recent evidence from small-scale clinical trials shows that standard doses of statins can be both safe and effective when given early after an acute coronary event, including early after thrombolytic therapy for myocardial infarction. Angiographic studies have shown beneficial effects of pravastatin on coronary stenosis when initiated after a coronary event. While none of these studies have been powered to demonstrate an effect on outcome, each has shown a reduction in major cardiovascular events. Two large observational studies have shown a reduction in 6- and 12-month risk-adjusted mortality among post-MI patients treated early with statins. Large-scale trials of all statins are now in progress to evaluate further the efficacy of early initiation of statin therapy in acute coronary syndromes. The largest of these is the Australian Pravastatin Acute Coronary Treatment (PACT) study, which will compare early outcomes in patients treated with pravastatin versus placebo prescribed within the first 24 h of an acute coronary event.

The Myocardial Ischemia Reduction with Acute Cholesterol Lowering (MIRACL) trial: a new frontier for statins?

The Myocardial Ischemia Reduction with Acute Cholesterol Lowering (MIRACL) Trial tested the hypothesis that intensive lowering of cholesterol with atorvastatin (80 mg/day) initiated 24-96 h after an acute coronary syndrome would, over 4 months, reduce the incidence of the composite endpoint of death, nonfatal infarction, resuscitated cardiac arrest, and recurrent symptomatic myocardial ischemia with new objective symptoms requiring emergency rehospitalization. This primary composite endpoint was reduced from 17.4% to 14.8% (P = 0.048) among the 3086 patients enrolled. The results of MIRACL suggest that patients with acute coronary syndromes should begin to receive this treatment before leaving hospital, irrespective of baseline levels of low-density lipoprotein-cholesterol.

Debate: "How low should LDL cholesterol be lowered for optimum prevention of vascular disease?" Viewpoint: "Below 100 mg/dl"

Arteriosclerotic vascular disease manifests as heart disease, stroke, aortic aneurysms, and peripheral vascular disease, and is a growing problem world-wide. The preventive efforts made so far have demonstrated that lowering LDL-C is one action that individuals and populations can do with significant success in delaying the onset of clinical events. Epidemiological studies and small clinical trials suggest that more aggressive and sustained lowering to LDL-C below 100 mg/dl could result in 50 to 70% reductions in vascular death. The full benefit of reducing LDL-C is only now being tested in adequate clinical trials.

Calming the plaque to delay intervention for 24 hours in acute coronary syndromes

One approach to management of patients with acute coronary syndromes involves use of pharmacologic therapy to passivate plaque for at least 24 hours before interventional procedures are undertaken. This approach is supported by the view that whatever subsequent treatment the patient receives will less likely be complicated. An important factor in revolutionizing treatment for acute coronary syndromes in recent years has been the introduction of potent new antithrombotic and antiplatelet pharmacologic therapies such as low-molecular-weight heparins and glycoprotein IIb/IIIa inhibitors. Incorporation of these newer agents into clinical practice, along with a better understanding of the pathophysiology underlying acute coronary syndromes, has contributed greatly to improved outcomes in these patients. Although the optimal methods for integrating the newer therapies remains to be determined, thus far, they have been shown to lower the risk of acute complications, as well as improve long-term results.

Beneficial effects of pravastatin (+/-colestyramine/niacin) initiated immediately after a coronary event (the randomized Lipid-Coronary Artery Disease [L-CAD] Study)

Secondary prevention of coronary heart disease by antilipidemic therapy beginning at > or =3 months after an acute coronary syndrome is well documented. The impact, however, of immediate initiation of antilipidemic therapy on coronary stenoses and clinical outcome in patients with acute coronary syndrome is unknown. In our study, patients were randomized, on average, 6 days after an acute myocardial infarction and/or percutaneous transluminal coronary angioplasty secondary to unstable angina, to pravastatin (combined, when necessary, with cholestyramine and/or nicotinic acid) to achieve low-density lipoprotein cholesterol levels of < or =130 mg/dl (group A, n = 70). In controls (group B, n = 56), antilipidemic therapy was determined by family physicians. Quantitative coronary angiography was performed at inclusion, and at 6- and 24-month follow-up. The combined clinical end points were total mortality, cardiovascular death, nonfatal myocardial infarction, need for coronary intervention, stroke, and new onset of peripheral vascular disease. Minimal lumen diameter in group A increased by 0.05 +/- 0.20 mm after 6 months and 0.13 +/- 0.29 mm after 24 months, whereas it decreased by 0.08 +/- 0.20 mm and 0.18 +/- 0.27 mm, respectively, in group B (p = 0.004 at 6 months and p <0.001 at 24 months). After 2 years, 29 patients of 56 patients in group B, but only 16 of 70 patients in group A, experienced a clinical end point (p = 0.005; odds ratio 0.28, confidence intervals 0.13 to 0.6). We conclude that pravastatin-based therapy initiated immediately after an acute coronary syndrome is well tolerated and safe, lessens coronary atherosclerosis, and has a pronounced clinical benefit.

Effects of pravastatin in 3260 patients with unstable angina: results from the LIPID study

BACKGROUND

The LIPID study is a major trial of secondary prevention of coronary-heart-disease events that includes hospital admission with unstable angina (as well as myocardial infarction) as a qualifying event. In this substudy of LIPID, we compared subsequent cardiovascular risks and the effects of pravastatin in patients with previous unstable angina or previous myocardial infarction.

METHODS

3260 patients diagnosed with unstable angina and 5754 with acute myocardial infarction 3-36 months previously were randomly assigned 40 mg pravastatin daily or placebo over a mean of 6.0 years. The risk reduction of a range of cardiovascular events was estimated by means of the hazard ratio in Cox's proportional hazards model.

FINDINGS

Among patients assigned placebo, survival in the two diagnosis groups was similar. The relative risk reduction for mortality with pravastatin was 20.6% in the myocardial infarction group and 26.3% in the unstable angina group (p=0.55). Pravastatin significantly reduced the rates of all prespecified coronary endpoints in the myocardial infarction group. In patients with previous unstable angina, coronary heart disease mortality, total mortality, myocardial infarction, a need for coronary revascularisation, the number of admissions to hospital, and the number of days in hospital were significantly lower with pravastatin. Overall, hospital admission for unstable angina was the most common endpoint (24.6% of the placebo group; 22.3% of the pravastatin group).

INTERPRETATION

Patients who have survived acute myocardial infarction or unstable angina have a similar long-term prognosis, a high occurrence of subsequent unstable angina, and benefit similarly from therapy with pravastatin.

Exploring new strategies for the management of acute coronary syndromes

Patients who present today with an acute coronary syndrome face a substantially lower risk of death, recurrent myocardial infarction, or severe ischemia than patients did a decade ago. Researchers are pursuing new strategies to further improve the outcomes of patients with acute coronary syndromes. These strategies may be grouped into 3 paradigms: (1) restoration and maintenance of coronary flow at the site of culprit lesion; (2) reduction of infarct size, reperfusion injury, and postischemic dysfunction; (3) stabilization of the coronary arterial wall and its interaction with the bloodstream to reduce recurrent ischemic events. The last approach encompasses strategies to alter the underlying vascular pathophysiology that leads to plaque instability and coronary thrombosis. Investigation into each of these paradigms may yield new strategies that will be incorporated into standard clinical management of acute coronary syndromes in coming years. With so many mechanistically different approaches to the management of acute coronary syndromes, clinicians have reason for optimism that continued progress will further reduce the morbidity and mortality associated with acute coronary syndromes and the likelihood of their recurrence.

Should intensive cholesterol lowering play a role in the management of acute coronary syndromes?

Although several large, well-controlled trials with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) demonstrate the benefits of cholesterol lowering on cardiovascular morbidity and mortality, these trials excluded patients with recent unstable angina or myocardial infarction. Thus, the potentially beneficial effects that may accrue from early statin therapy have not been apparent. Mechanistic and experimental studies show that benefits from statin therapy may include improved endothelial function, a decrease in platelet thrombus deposition, and a reduction in inflammation at the site of the lesion. Large-scale clinical trials are now under way to determine the effect of aggressive cholesterol lowering in patients with acute coronary syndromes. If the findings of the smaller studies are confirmed, statin therapy should be considered early after infarction or unstable angina.

Inflammation and infection in acute coronary syndrome

Basic science research has revealed that monocytes and macrophages are important factors in atherogenesis. Immune system activation occurs at all stages of plaque formation, from the fatty streak to an advanced, complicated lesion. The inflammatory response not only stimulates changes in coronary artery endothelial cells causing endothelial injury and dysfunction, but also plays a role in plaque instability and rupture. New perspectives of atherosclerosis and acute coronary syndromes will be discussed in relation to inflammation. In addition, discussion will focus on bacterial and viral infectious microorganisms as a potential factor that may induce and promote inflammation and lead to acute coronary events. Clinical studies in humans have provided insight relating inflammation and infectious agents to atherosclerosis and plaque vulnerability. Other studies focus on specific interventions that may aid in diagnosis and treatment.

Lipid lowering drugs and recurrences of life-threatening ventricular arrhythmias in high-risk patients

OBJECTIVES

To evaluate a possible effect of lipid lowering drugs on recurrences of ventricular arrhythmias (VA) after implantable cardioverter defibrillator (ICD) implantation.

BACKGROUND

In patients with coronary artery disease (CAD), lipid lowering drugs reduce total and sudden cardiac death. Because the mechanism is not completely understood, we studied whether these drugs have a favorable influence on the occurrence of life-threatening VA in patients with CAD and ICD implants.

METHODS

We conducted an observational study in 78 patients with CAD and life-threatening VA, treated with an ICD. After ICD implantation, 27 patients were on treatment with lipid lowering drugs (group I) and 51 were not (group II). Patients were studied for the following end points: recurrences of VA requiring ICD intervention, cardiac death and hospitalization.

RESULTS

After a mean follow-up of 490 +/- 319 days, 35 patients (45%) had recurrences of VA requiring ICD intervention. In multivariate analysis, the use of lipid lowering drugs (chi-square 6.33, p = 0.012) and poorly tolerated sustained monomorphic ventricular tachycardia as initial presentation (chi-square 4.84, p = 0.028) remained as independent predictors of recurrences of VA. Patients in groups I and II had similar baseline clinical characteristics, but patients in group I had a lower incidence of recurrences of VA (6/27 or 22% vs. 29/51 or 57%, p = 0.004) and of the combined end points of cardiac death and hospitalization (4/27 or 15% vs. 23/51 or 45%, p = 0.015) compared with patients in group II.

CONCLUSIONS

This is the first observation that the use of lipid lowering drugs is associated with a reduction of recurrences of VA in patients with CAD and ICD implants. These data require confirmation in a prospective randomized trial.

Cholesterol lowering in atherosclerosis

Lipid-lowering with statins reduces disease progression, prevents myocardial infarction and other hard end points, and prolongs survival. Data from large-scale trials with these agents further show that lowering low-density lipoprotein (LDL) cholesterol in patients with coronary artery disease reduces the incidence of cardiovascular events and that the lower the LDL cholesterol achieved, the lower the event rate. Currently available evidence supports the National Cholesterol Education Program (NCEP) recommendations for reduction of LDL-cholesterol levels to at least 100 mg/dL in patients with coronary artery disease. The Treating to New Targets study, which will evaluate the effects of LDL-cholesterol lowering to < or = 75 mg/dL with atorvastatin, may help clarify if additional benefit accrues with further reductions. However, up to 82% of patients with proven coronary disease are not even at the current NCEP lipid goal. Up to 55% need a > 30-mg/dL reduction in LDL cholesterol to reach that goal. These data suggest that many patients are not receiving a statin or are receiving an inadequate dose. Aggressive lipid lowering, although a desirable goal, does not yet appear to be standard practice.

Guidelines for the diagnosis and management of unstable angina and non-Q-wave myocardial infarction: proposed revisions. International Cardiology Forum

BACKGROUND

In 1994, the United States Agency for Health Care Policy and Research issued clinical practice guidelines for the diagnosis and management of unstable angina and non-Q-wave myocardial infarction. In the past 5 years, rapid progress has been made in the management of patients with unstable coronary syndromes, yet current guidelines do not necessarily reflect these advances.

METHODS AND RESULTS

An international forum of cardiology investigators reviewed existing guidelines and discussed areas in which the diagnosis and treatment of unstable angina and non-Q-wave myocardial infarction should be modified. It was agreed that there is sufficient evidence to recommend the following changes: (1) use of serum cardiac markers should be expanded to include troponin I and T levels as diagnostic and prognostic tools; (2) low-molecular-weight heparins should replace unfractionated heparin as antithrombotic agents; (3) new classes of antiplatelet agents are recommended in addition to aspirin; and (4) the use of cholesterol-lowering drugs is appropriate in the long-term management of these patients.

CONCLUSIONS

Evidence from clinical trials within the last 5 years requires that significant changes be made to existing guidelines for the diagnosis and management of unstable angina and non-Q-wave myocardial infarction. The recommendations detailed should be considered in the creation and implementation of updated guidelines.