Long-Term Intervention with Pravastatin in Ischaemic Disease (LIPID) Study Group. Prevention of cardiovascular events and death with pravastatin in patients with coronary heart disease and a broad range of initial cholesterol levels

After 4S, CARE and LIPID--is evidence-based medicine being practised?

Between 1994 and 1997, three major trials - 4S, CARE and LIPID - showed that simvastatin and pravastatin reduced the risk of a recurrent coronary event in patients with established coronary heart disease (CHD) [Scandinavian Simvastatin Survival Study (4S) Group. Lancet 1994;344:1383-89; Sacks FM et al. New Engl. J. Med. 1996;335: 1001-9; Long-term Intervention with Pravastatin in Ischaemic Disease (LIPID) Study Group. New Engl. J. Med. 1998;339:1349-57]. The results of CARE and LIPID, with pravastatin, also showed that the benefits of improved survival extended to the majority of patients with CHD whose cholesterol levels were in the 'normal' range. Despite this compelling evidence, recent CHD prevention surveys between 1994 and 1998 have unveiled a wide therapeutic gap between scientific evidence and practice in the secondary prevention of CHD. These recent surveys revealed a high prevalence of hypercholesterolaemia in patients discharged from hospital and after 6 months following a coronary event, but low levels of statin prescribing in these patients. Of the minority of patients prescribed a statin by a consultant on discharge from hospital, nearly all were still receiving this treatment in primary care 6 months later. These findings therefore clearly highlight the need for an integrated approach involving hospital specialists, primary-care physicians and the patient, to overcome the wide treatment gap in lowering even 'normal' cholesterol levels in high-risk patients in line with evidence-based medicine.

Study of Cardiovascular Risk Intervention by Pharmacists (SCRIP): a randomized trial design of the effect of a community pharmacist intervention program on serum cholesterol risk

OBJECTIVE

To determine the efficacy of a program of intervention by pharmacists on lipid risk management in patients at high risk for cardiovascular events.

METHODS

Randomized, multicenter (44 sites in Alberta and Saskatchewan) study of community pharmacist intervention versus usual care in 1000 patients. Patients are those at high risk of vascular events (existing atherosclerotic vascular disease, or diabetes with > or = 1 other risk factor). After obtaining consent, the pharmacist calls the Project Office to randomize. Patients allocated to intervention receive a brochure and education about cardiovascular risk factors. Pharmacists also complete a physician contact form, which lists the patient's risk factors, medications, and any recommendations. A point-of-care cholesterol test is performed, the result is discussed with the patient, and it is entered on the contact form. If appropriate, the patient is asked to see his or her primary care physician for further assessment and/or treatment, and the form is faxed to the physician. Patients are followed up at two, four, eight, 12, and 16 weeks. During follow-up visits, pharmacists provide educational reinforcement and check for primary end point occurrence. Patients allocated to usual care receive the brochure only, with minimal follow-up. The primary end point is a composite of measurement of a complete lipid panel by the physician, or addition or modification of lipid-lowering drug therapy. Substudies will evaluate economics (third-party payer and pharmacy manager perspective), patient satisfaction, and quality of life.

CONCLUSIONS

SCRIP (Study of Cardiovascular Risk Intervention by Pharmacists) is a unique ongoing trial that is evaluating a community pharmacist intervention designed to optimize cholesterol risk management in patients at high risk for cardiovascular events.

Effect of lipid-lowering therapy on vasomotion and endothelial function

The recent clinical trials of lipid lowering have established the benefit of this therapy in men and women with, or at high risk for, cardiovascular disease. It is now thought that most of the reduction in the risk of clinical events is due to functional rather than anatomic changes in atherosclerotic arteries. Cholesterol-lowering drugs improve endothelial vasomotor function and vascular nitric oxide in patients with coronary artery disease over several months. These changes in vasomotor function may reflect other beneficial changes that are regulated by nitric oxide such as the reduced recruitment and activation of inflammatory cells and a shift in the coagulation balance to favor thrombolysis. These mechanisms may contribute to the reduction in myocardial ischemia and clinical events observed with lipid lowering in patients with vascular disease. Lipid-lowering therapy decreases cardiovascular events and is an important adjunct to coronary revascularization most likely because an improvement in endothelial function prevents the development and destabilization of new atherosclerotic lesions and subsequent ischemic events.

Preventive cardiology

Over the past year, significant new advances have been made in preventive cardiology. New trials of lipid lowering, estrogen therapy, and hypertension control have added to our understanding of the pathophysiology and prevention of coronary atherosclerosis. This review highlights these new trials and provides insight into their applications in the practice of cardiology.

Pharmacotherapy of dyslipidemia in postmenopausal women: weighing the evidence

In the United States, coronary heart disease (CHD) is the leading cause of death in women. The incidence of CHD rises dramatically in women following menopause, which can be partially attributed to a more atherogenic lipoprotein profile. For years, observational and epidemiological data have suggested that estrogen and progesterone therapy reduced CHD end points. However, the first prospective trial that evaluated hormone replacement therapy (HRT) for secondary CHD prevention demonstrated no positive cardiovascular benefit of HRT compared with placebo. In interventional studies, the 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA)reductase inhibitors significantly reduced CHD outcomes in postmenopausal women, and these agents have emerged as the drugs of choice for primary and secondary CHD prevention. The selective estrogen receptor modulators (SERMs) may have a role in CHD prevention, but long-term clinical trials evaluating end points are needed. An evidence-based approach is necessary when deciding the appropriate pharmacotherapy of dyslipidemia in postmenopausal women.

Lipid management in patients at moderate risk for coronary heart disease: insights from the Air Force/Texas Coronary Atherosclerosis Prevention Study (AFCAPS/TexCAPS)

The results of AFCAPS/TexCAPS provide strong evidence for the benefits of primary prevention through lipid-regulating treatment across the spectrum of clinical coronary events that are often the first manifestations of atherosclerotic disease. These results reinforce current NCEP guidelines and demonstrate the need for the inclusion of HDL-C in clinical evaluations. The clear benefit observed in AFCAPS/TexCAPS reinforces the need to implement treatment in all individuals with average LDL-C and low HDL-C who may be at risk for CHD. According to estimates based on phase-2 NHANES III data (1991-1994), only 1.4 million (6.6%) of 21.1 million American adults eligible for cholesterol-lowering drug therapy by NCEP guidelines were receiving such therapy, including 14% of those eligible in secondary prevention and 4% of those eligible in primary prevention. Of diet- or drug-eligible adults, 65% received no therapy of any kind. Undertreatment of dyslipidemia continues to be a problem today. These statistics suggest that physicians must improve their efforts to reverse the toll of atherosclerotic disease through risk factor management.

Gemfibrozil for the secondary prevention of coronary heart disease in men with low levels of high-density lipoprotein cholesterol. Veterans Affairs High-Density Lipoprotein Cholesterol Intervention Trial Study Group

BACKGROUND

Although it is generally accepted that lowering elevated serum levels of low-density lipoprotein (LDL) cholesterol in patients with coronary heart disease is beneficial, there are few data to guide decisions about therapy for patients whose primary lipid abnormality is a low level of high-density lipoprotein (HDL) cholesterol.

METHODS

We conducted a double-blind trial comparing gemfibrozil (1200 mg per day) with placebo in 2531 men with coronary heart disease, an HDL cholesterol level of 40 mg per deciliter (1.0 mmol per liter) or less, and an LDL cholesterol level of 140 mg per deciliter (3.6 mmol per liter) or less. The primary study outcome was nonfatal myocardial infarction or death from coronary causes.

RESULTS

The median follow-up was 5.1 years. At one year, the mean HDL cholesterol level was 6 percent higher, the mean triglyceride level was 31 percent lower, and the mean total cholesterol level was 4 percent lower in the gemfibrozil group than in the placebo group. LDL cholesterol levels did not differ significantly between the groups. A primary event occurred in 275 of the 1267 patients assigned to placebo (21.7 percent) and in 219 of the 1264 patients assigned to gemfibrozil (17.3 percent). The overall reduction in the risk of an event was 4.4 percentage points, and the reduction in relative risk was 22 percent (95 percent confidence interval, 7 to 35 percent; P=0.006). We observed a 24 percent reduction in the combined outcome of death from coronary heart disease, nonfatal myocardial infarction, and stroke (P< 0.001). There were no significant differences in the rates of coronary revascularization, hospitalization for unstable angina, death from any cause, and cancer.

CONCLUSIONS

Gemfibrozil therapy resulted in a significant reduction in the risk of major cardiovascular events in patients with coronary disease whose primary lipid abnormality was a low HDL cholesterol level. The findings suggest that the rate of coronary events is reduced by raising HDL cholesterol levels and lowering levels of triglycerides without lowering LDL cholesterol levels.

Laboratory-based calculation of coronary heart disease risk in a hospital diabetic clinic

AIMS

To develop an estimation of risk of coronary heart disease (CHD) based on the Framingham equation for use in a diabetes clinic, given concerns about the accuracy of the Sheffield risk tables in this setting.

METHODS

A computer program using the Framingham equation based on patients' age, sex, systolic blood pressure, smoking history, presence of diabetes and left ventricular hypertrophy was applied to requests for lipid screening of patients attending the diabetes clinics of Birmingham Heartlands Hospital. The calculated risks for the population were compared with those estimated from the Sheffield tables.

RESULTS

Of 1060 patients with diabetes mellitus, 215 (20%) had an annual CHD risk > or =3%, which is considered to be the threshold at which lipid-lowering drugs are cost-effective. Only 24 of these 215 patients (11%) were correctly identified by the Sheffield tables, which we conclude have an unacceptably low sensitivity in diabetes mellitus.

CONCLUSIONS

A laboratory-based CHD risk calculation system is a practical alternative to the Sheffield system and may have a greater sensitivity in the diabetic clinic.

[Drug therapy for prognostic improvement after acute myocardial infarct]

This review article summarizes the long-term standard therapy for patients with myocardial infarction. The chronic therapy is able to significantly improve quality of life and survival of affected patients. Previous studies showed that in most western countries, the established standard therapy is not given to all patients who would benefit from chronic treatment. The essential parts of today's myocardial infarction treatment consists of effective beta-blockade, inhibition of the angiotensin-conversion enzyme, inhibition of platelet aggregation and lipid lowering agents. This article reviews the clinical benefits which may be expected from each of these therapeutic approaches. Newer, but not yet proven strategies, like blockade of the angiotensin receptor subtype 1 and treatment with antioxidative agents will be discussed.

Optimal treatment of patients with acute coronary syndromes and non-ST-elevation myocardial infarction

Non-ST-elevation myocardial infarction is usually indistinguishable from unstable angina at the initial presentation. The diagnosis is made subsequently when cardiac enzymes are found to be elevated either at admission or within 18 hours. Our understanding of the pathophysiology of acute coronary syndromes has advanced dramatically, and coupled with this understanding has been the introduction of new antiplatelet and antithrombotic treatments. The best way to integrate these treatments into percutaneous revascularization procedures has not yet been defined. In general, patients with non-ST-elevation myocardial infarction should be treated in the same way as those with unstable angina. Patients should be risk profiled at admission and subsequently according to clinical features, electrocardiographic findings, results of laboratory tests including measurement of troponins, and response to therapy. They should also be monitored carefully for signs of ischemia. Patients at low risk with a normal electrocardiogram and normal troponin T or I levels should be assessed for early discharge and outpatient assessment with exercise or pharmacological testing for inducible ischemia. Patients at intermediate risk should be treated with aspirin, unfractionated or low-molecular-weight heparin and, if unfractionated heparin is chosen, an adjunctive IIb/IIIa receptor antagonist. Patients at high risk should be treated with the same therapies and considered for expeditious angiography and revascularization as appropriate. A long-term secondary prevention strategy should be implemented.

Statin trials and goals of cholesterol-lowering therapy after AMI

Several randomized clinical trials using statins in the prevention of coronary heart disease (CHD) have demonstrated benefit, both in terms of retardation of the progression of signs of coronary atherosclerosis and in reduced morbidity and mortality rates. Three of these trials have examined the long-term effect of statins in patients with previous myocardial infarction. The Scandinavian Simvastatin Survival Study (4S) showed that a mean reduction of low-density-lipoprotein (LDL) cholesterol by 35% reduced coronary mortality rates by 42% and total mortality rates by 30%. In the Cholesterol and Recurrent Events trial, a 28% reduction in LDL-cholesterol was associated with a reduction in major coronary events of 24%. In the Long Term Intervention with Pravastatin in Ischemic Disease study, the 25% LDL-cholesterol reduction produced a 24% reduction in coronary disease mortality rates and 22% reduction in death from all causes. All event reductions were highly statistically significant. Other trials using statins in patients without signs of CHD have yielded similar risk reductions. Post hoc analysis of the results of the trials have produced diverging indications as to what is the optimal goal of cholesterol lowering. Analysis of the 4S indicates that aggressive treatment aiming at LDL-cholesterol levels lower than the current recommendations of expert panels in the United States and in Europe may yield additional benefit. This strategy finds some support in epidemiological studies and in a study with angiographic end points. Analysis of two trials using pravastatin contradict this and conclude that there is little or no additional benefit of reducing LDL-cholesterol below 125 mg/dL (3.2 mmol/L). Future studies need to address this question prospectively.

High risk strategies for atherosclerosis

Calculating a person's chances of developing coronary heart disease (CHD) is not simple, as many risk factors interact in a complex fashion. Thus many markers, though significant in univariate comparisons, are no longer so when multivariate analysis is performed. Those factors contributing independently to risk can be identified only in prospective investigations such as the Münster Heart (PROCAM) or the Framingham studies. In the Münster Heart study, follow-up of middle-aged men for eight years identified the following nine independent risk variables: age, smoking history, personal history of angina pectoris, family history of myocardial infarction, systolic blood pressure, raised plasma low density lipoprotein cholesterol (LDL-C), low plasma high density lipoprotein cholesterol, raised fasting plasma triglyceride and presence of diabetes mellitus. These have been used to generate an algorithm for prediction of first coronary events which is available in interactive fashion on the internet'. Large trials have shown that lowering LDL-C reduces the risk of CHD, and diminishes CHD morbidity and mortality in persons without prior evidence of coronary atherosclerosis (primary prevention). This is even more the case in patients with such evidence (secondary prevention). It appears that lowering of LDL-C also reduces all-cause mortality in secondary prevention.

Long-term effects of pravastatin on plasma concentration of C-reactive protein. The Cholesterol and Recurrent Events (CARE) Investigators

BACKGROUND

Elevated plasma concentrations of C-reactive protein (CRP) are associated with increased cardiovascular risk. We evaluated whether long-term therapy with pravastatin, an agent that reduces cardiovascular risk, might alter levels of this inflammatory parameter.

METHODS AND RESULTS

CRP levels were measured at baseline and at 5 years in 472 randomly selected participants in the Cholesterol and Recurrent Events (CARE) trial who remained free of recurrent coronary events during follow-up. Overall, CRP levels at baseline and at 5 years were highly correlated (r=0.60, P<0.001). However, among those allocated to placebo, median CRP levels and the mean change in CRP tended to increase over time (median change, +4. 2%; P=0.2 and mean change, +0.07 mg/dL; P=0.04). By contrast, median CRP levels and the mean change in CRP decreased over time among those allocated to pravastatin (median change, -17.4%; P=0.004 and mean change, -0.07 mg/dL; P=0.002). Thus, statistically significant differences were observed at 5 years between the pravastatin and placebo groups in terms of median CRP levels (difference, -21.6%; P=0.007), mean CRP levels (difference, -37.8%; P=0.002), and absolute mean change in CRP (difference, -0.137 mg/dL; P=0.003). These effects persisted in analyses stratified by age, body mass index, smoking status, blood pressure, and baseline lipid levels. Attempts to relate the magnitude of change in CRP to the magnitude of change in lipids in both the pravastatin and placebo groups did not reveal any obvious relationships.

CONCLUSIONS

Among survivors of myocardial infarction on standard therapy plus placebo, CRP levels tended to increase over 5 years of follow-up. In contrast, randomization to pravastatin resulted in significant reductions in this inflammatory marker that were not related to the magnitude of lipid alterations observed. Thus, these data further support the potential for nonlipid effects of this agent.

Postmarketing studies: benefits and risks

OBJECTIVE

To consider the benefits and risks of large postmarketing outcomes studies, as demonstrated by studies of the statin drugs.

METHODS

Literature review.

RESULTS

The risks were that the statin studies had a strong coat-tail effect. Each new study was beneficial to all statins as well as the one studied. Economic analyses based on the results of the postmarketing studies concluded that the drugs were not cost-effective. Long-term postmarketing studies were slow to be put into perspective and did not immediately influence other researchers or clinicians. During that time, the sponsoring companies shouldered opportunity costs as well as the actual costs of the studies. The risk that one drug company would use another company's results instead of investing in their own research did not materialize. The benefits were that the studies definitively showed that the drugs and the lowering of lipids were safe and efficacious. The studies also expanded the indications for the drugs, generated goodwill in the medical and research communities for the sponsors, allowed sponsors to include specific claims in their advertisements, generated follow-up studies, spawned economic analyses that sparked interest in the medical and lay press, and had a major impact on clinicians' use of the drug.

CONCLUSION

The risks and benefits of postmarketing studies may depend on the company's time perspective. In the short term, the risks may outweigh the benefits. Only companies that have a longer perspective may find it beneficial to undertake large postmarketing studies.

Diabetes and myocardial infarction

Myocardial infarction (MI) is a common cause of mortality in people with diabetes. The case fatality from MI is high and may be reduced by thrombolysis and treatment with aspirin, beta-blockers and angiotensin-converting enzyme inhibitors. Poor metabolic control is common among diabetic patients with MI, but the importance of controlling blood glucose during and following an MI is debatable. Treatment with statins reduces cardiovascular end-points in diabetic patients with previous MI (secondary prevention). Large studies in diabetic patients without existing heart disease have shown statistically insignificant reductions in heart disease and MI with improved glycaemic control of the diabetes (primary prevention). The treatment of hypertension in people with diabetes prevents cardiovascular end-points, and studies on whether the treatment of hyperlipidaemia reduces heart disease and MI are proceeding.

Frequency of lipid-lowering therapy after a coronary event in Helsinki, Finland

The results from a survey in Finland suggest an important treatment gap of lipid-lowering medications. Patients whose coronary artery disease was diagnosed before 1995 were less likely to be on lipid therapy than patients with a more recent diagnosis.

Management of the older person with ventricular arrhythmias

OBJECTIVE

To review the prognosis and management of ventricular arrhythmias (VA) in persons with and without heart disease, with emphasis on older adults.

DATA SOURCES

A computer-assisted search of the English language literature (MEDLINE database) followed by a manual search of the bibliographies of pertinent articles.

STUDY SELECTION

Studies on the prognosis and management of VA in persons with and without heart disease were screened for review. Studies in older persons and recent studies were emphasized.

DATA EXTRACTION

Pertinent data were extracted from the reviewed articles. Emphasis was placed on studies involving older persons. Relevant articles were reviewed in depth.

DATA SYNTHESIS

Available data on the prognosis and management of VA in persons with and without heart disease, with emphasis on studies in older persons, were summarized.

CONCLUSIONS

Ventricular arrhythmias in older persons without heart disease should not be treated with antiarrhythmic drugs, nor should Class I antiarrhythmic drugs be used to treat VA in older persons with heart disease. Beta-blockers should be used to treat complex VA in older persons with ischemic or nonischemic heart disease without contraindications to beta-blockers. Amiodarone should be reserved for life-threatening ventricular tachyarrhythmias in older persons who cannot tolerate or who do not respond to beta-blockers. Angiotensin-converting enzyme inhibitors should be used to treat older persons with heart failure, an anterior myocardial infarction, or a left ventricular ejection fraction < or = 40%. If older persons have life-threatening recurrent ventricular tachycardia (VT) or ventricular fibrillation (VF) resistant to antiarrhythmic drugs, invasive intervention should be performed. The automatic implantable cardioverter-defibrillator is recommended in older persons who have medically refractory sustained VT or VF.

Evaluation and management of lipid disorders

Plasma lipids play a key role in the development of atherosclerosis. Recent trial data support early identification of asymptomatic adults with high-risk lipid profiles for primary prevention of coronary heart disease. 3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitors have been shown to reduce coronary events in both asymptomatic adults and those with known coronary heart disease. The optimal plasma low-density lipoprotein cholesterol for secondary coronary prevention remains controversial. The Second Report of the Expert Panel on Detection, Evaluation and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel II), published in 1993 by the National Cholesterol Education Program, recommends guidelines for evaluation and diagnosis of lipids. Subsequently, several clinical trials have identified populations benefiting from pharmacologic intervention and new approaches to the management of lipid disorders. Consequently, these guidelines should be applied with the interval evidence in mind.

Evidence supporting secondary prevention strategies

Currently 14 million individuals in the United States have coronary disease. Within the next 2 decades, this number is expected to increase to 21 million persons. To minimize the excessive risk of recurrent cardiac events in these people, evidence-based, cost-effective prevention strategies must be developed. This review highlights the evidence supporting commonly used means of secondary prevention and is divided into two major sections: lifestyle modifications and pharmacologic interventions. Lifestyle changes discussed include smoking cessation, especially newer pharmacologic adjuncts; the efficacy of dietary interventions; and current inroads into the treatment of depression in recurrent events. Pharmacologic innovations include reexamination of a role for warfarin; continued advances in the treatment of hyper- and dyslipidemias, new roles for beta-blockade in congestive heart failure, and finally a view of future measures, risk and targets of risk intervention.

The treatment and prevention of coronary heart disease in Canada: do older patients receive efficacious therapies? The Clinical Quality Improvement Network (CQIN) Investigators

OBJECTIVES

To review the evidence for clinical efficacy and cost-effectiveness of proven medications in the treatment and prevention of myocardial infarction (MI) in older patients; to summarize Canadian data on treatment patterns and clinical outcomes for younger and older patients with coronary heart disease; to explore the reasons for gaps between best care, based on the evidence of efficacy from trials, and usual care, based on the population effectiveness audits; and to explore potential approaches to closing the care gaps.

DESIGN

Review of the recent clinical trial literature on the management of MI, highlighting results in older patients. Review of medication utilization and outcomes data from a series of large, consecutively enrolled patient cohorts with acute MI (N = 7070) in a variety of cardiac care settings (10 centers in five Canadian provinces, including university-based teaching hospitals, community hospitals, cardiologist and family physician out-patient clinics) from 1987 to 1996.

RESULTS

There is no qualitative interaction of cardiac therapies: thrombolytics, beta-blockers, acetylsalicylic acid (ASA), and statins are efficacious in all clinically relevant patient subgroups, including older people. However, there are consistent gaps between usual care and best care, particularly among older patients (in whom there is also a concomitantly higher mortality risk). Repeated multivariate analyses confirm older age to be an independent contributor to increased risk. Use of efficacious medications is, in contrast, consistently associated with increased survival. Analysis of temporal trends suggests beneficial changes in practice patterns and outcomes are possible to achieve. However, "best care" has not been rapidly or completely achieved. Review of strategies to close these care gaps suggests that audit and feedback, critical pathways, and multifactorial interventions involving patients and other members of the healthcare team as well as physicians may be the most efficacious strategies for change.

CONCLUSIONS

Despite equal or enhanced efficacy, there is consistently less prescription of proven drugs among older cardiac patients. These care patterns may contribute to their enhanced risk. The causes underlying these practice patterns are complex, and their population impact may be undervalued by clinicians and managers. Improvement of these patterns is difficult, but ultimately it would be beneficial for this presently disadvantaged, readily identified, high risk patient population.

Diabetic dyslipidaemia

The risk of coronary heart disease and atherosclerosis is increased in both Type 2 and Type I diabetes mellitus. The dyslipidaemia of Type 2 diabetes consists of hypertriglyceridaemia and low levels of high-density lipoprotein (HDL) cholesterol. In Type I diabetes, hypertriglyceridaemia is also present, but when glycaemic control is good, HDL cholesterol levels may be normal or even increased. In both types of diabetes, nephropathy is associated with an exacerbation of hypertriglyceridaemia, a decline in HDL cholesterol level and an increase in serum cholesterol. In the absence of nephropathy, serum cholesterol levels are typically similar to those of the background non-diabetic population. The risk of coronary heart disease (CHD) associated with serum cholesterol is, however, considerably higher in diabetics than in non-diabetic people, and is much less in diabetic populations living in countries where the average cholesterol level is low, even when hypertension is present. Currently, the strongest evidence that lipid-lowering drug therapy will decrease the risk of CHD, particularly in secondary prevention, comes from trials of statins that lower cholesterol. There is growing experimental and observational evidence that hypertriglyceridaemia, because of its effects on cholesteryl ester transfer, leading to the formation of a small low-density lipoprotein susceptible to oxidation, compounds the risk of serum cholesterol in diabetes. Both fibrates and statins can decrease this cholesteryl ester transfer. Further studies of fibrates with clinical end-points should clarify their role in the prevention of CHD. In the meantime, statins should be part of routine diabetic clinical practice, fibrates having a more limited role when hypertriglyceridaemia is extreme.

Prevention of cardiovascular events in elderly hypercholesterolemic patients

The management of hyperlipidemia in the elderly patient is a major problem, given the frequency of dyslipidemias and cardiovascular disorders in this age group. Therapy must take current uncertainties into account and, in the absence of therapeutic studies carried out in the elderly, is typically based upon a case-by-case approach. Raised cholesterol levels remain a significant risk factor for coronary heart disease (CHD) in the elderly. Although the relative risk of CHD tends to diminish with increasing age, this reduction is accompanied by an increase in absolute risk (ie, the number of events) as the frequency of the illness increases markedly with age. The results of major outcome studies with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins), when analyzed according to patient age, indicate that the benefits of these agents are not merely confined to younger individuals. However, the elderly form a unique patient population--the proportion of women is greater and the profile of cardiovascular illnesses is characterized, among others, by a greater incidence of cerebrovascular accidents. Problems relating to poor tolerability and comorbidity (which may give rise to drug-drug interactions) also occur more frequently in this age group. Moreover, the potential widespread treatment of hyperlipidemia in the elderly has profound economic implications. Under these circumstances, the clinical practice recommendations depend upon a reasonable extrapolation of epidemiologic and therapeutic data obtained from middle-aged men. At present, treatment is therefore aimed at patients with the most severe forms of hyperlipidemia, generally in the secondary prevention setting, taking into account the patient's life expectancy. The results of ongoing studies will determine the benefits of lipid-lowering therapy for primary prevention of CHD in the elderly.

Triglyceride-rich lipoproteins: are links with atherosclerosis mediated by a procoagulant and proinflammatory phenotype?

Specific treatment that primarily reduces low density lipoprotein cholesterol (LDLc) levels improves survival of patients with pre-existing vascular disease by 20-30%. Failure to produce a more marked improvement in outcome is most likely explained by: (1) the observation from angiographic studies that established atherosclerotic vascular disease (AVD) is largely irreversible with current therapy and (2) other important factors cause AVD besides LDLc. One such risk factor predicting development of AVD is the atherogenic lipoprotein phenotype (ALP), comprising abnormalities of triglyceride enriched lipoproteins, high density lipoprotein cholesterol (HDLc) and small dense LDL particles. Despite strong links between the ALP and AVD, the mechanism(s) linking these relatively subtle lipoprotein abnormalities to vascular disease is poorly understood. Recent evidence suggests that a procoagulant and proinflammatory state develops within the vasculature, perhaps mediating a link between the ALP and AVD. The purpose of this review is to discuss mechanisms by which the ALP, and specifically, certain triglyceride-rich lipoproteins, may cause AVD by adverse affects on platelet function, coagulation and vascular inflammation. All rights reserved.

New developments in the treatment of low high-density lipoprotein cholesterol

Reduced levels of high-density lipoprotein (HDL) cholesterol represent an important risk factor for the development and progression of coronary artery disease. In recent years, clinical outcome studies have verified that statin therapy may reduce the risk of initial or recurrent cardiovascular events in subjects with elevated or "normal" cholesterol levels. Subgroup analysis has also revealed that patients with low HDL benefit from this therapy. Two recently presented outcome trials using fibrate therapy also demonstrated a potential role for these medications in subjects with low HDL. The use of various HDL raising agents, singly or in combination on arteriographic progression and their potential mechanisms of action are reviewed. The latter may be an important consideration in the treatment of high-risk patients with low HDL.

Combination drug therapy for dyslipidemia

Effective treatment of dyslipidemia improves prognosis. Statin therapy has been documented to decrease the cardiovascular event rate in the setting of elevated low-density lipoprotein (LDL) cholesterol levels and coronary heart disease, but most patients are not treated to the target (LDL <or=100 mg/dL) set by the National Cholesterol Education Program. The triglyceride level is also being increasingly recognized as an important mediator in the process of progressive atherosclerosis and cardiovascular events. Studies suggest the target level for triglycerides should be the same as for LDL cholesterol levels-- no more than 100 mg/dL. In order to achieve these LDL and triglyceride levels, combination therapy is required frequently. Probably the most effective combination for mixed dyslipidemia is a statin with niacin. The use of adjunctive omega-3 supplementation also should be considered especially for patients with elevated triglyceride levels. Other adjunctive agents including sitostanol ester (in the form of a margarine) and a well-tolerated second generation bile acid sequestrant that will lower LDL cholesterol an additional 10% to 18% and will be available soon.

Effects of lovastatin therapy on susceptibility of LDL to oxidation during alpha-tocopherol supplementation

A randomized, double-masked, crossover clinical trial was carried out to evaluate whether lovastatin therapy (60 mg daily) affects the initiation of oxidation of low density lipoprotein (LDL) in cardiac patients on alpha-tocopherol supplementation therapy (450 IU daily). Twenty-eight men with verified coronary heart disease and hypercholesterolemia received alpha-tocopherol with lovastatin or with dummy tablets in random order. The two 6-week, active-treatment periods were preceded by a washout period of at least 8 weeks. The oxidizability of LDL was determined by 2 methods ex vivo. The depletion times for LDL ubiquinol and LDL alpha-tocopherol were determined in timed samples taken during oxidation induced by 2, 2-azobis(2,4-dimethylvaleronitrile). Copper-mediated oxidation of LDL isolated by rapid density-gradient ultracentrifugation was used to measure the lag time to the propagation phase of conjugated-diene formation. alpha-Tocopherol supplementation led to a 1.9-fold concentration of reduced alpha-tocopherol in LDL (P<0.0001) and to a 2.0-fold longer depletion time (P<0.0001) of alpha-tocopherol compared with determinations after the washout period. A 43% prolongation (P<0.0001) was seen in the lag time of conjugated-diene formation. Lovastatin decreased the depletion time of reduced alpha-tocopherol in metal ion-independent oxidation by 44% and shortened the lag time of conjugated-diene formation in metal ion-dependent oxidation by 7%. In conclusion, alpha-tocopherol supplementation significantly increased the antioxidative capacity of LDL when measured ex vivo, which was partially abolished by concomitant lovastatin therapy.

Diabetes, hyperlipidemia, and coronary artery disease

Type 2 diabetes is associated with a marked increase in the risk of coronary artery disease. Dyslipidemia is believed to be a major source of this increased risk. Several studies in diabetic patients have demonstrated a decreased incidence of coronary artery disease with the use of drugs that lower the level of low-density lipoprotein in diabetic patients, but other forms of dyslipidemia, such as hypertriglyceridemia, are believed to play a role in the etiology of coronary artery disease in diabetes. Drugs, such as fenofibrate, which improve these other forms of dyslipidemia, are being investigated in diabetic patients to determine if they decrease mortality and morbidity from coronary artery disease.

Hypertriglyceridemia: changes in the plasma lipoproteins associated with an increased risk of cardiovascular disease

There is a growing body of evidence from epidemiologic, clinical, and laboratory data that indicates that elevated triglyceride levels are an independent risk factor for cardiovascular disease. Identification and quantification of atherogenic lipoproteins in patients with hypertriglyceridemia are important steps in the prevention of cardiovascular disease. Increased levels of apoC-III, apoC-I, or apoA-II on the apoB-containing lipoproteins may alter lipoprotein metabolism and result in the accumulation of atherogenic remnants. Hypertriglyceridemic patients at risk for cardiovascular disease often develop a lipoprotein profile characterized by elevated triglyceride, dense LDL, and low HDL cholesterol. Understanding that each of these factors contributes separately to the patient's risk of cardiovascular disease can help physicians provide patients with more effective risk-reduction programs for cardiovascular disease.

Glycemic control and cardiovascular disease in type 2 diabetes: a review

Cardiovascular disease is the major cause of morbidity and mortality in people with Type 2 diabetes, and risk of atherosclerotic disease is markedly increased in people with diabetes compared to people with normal glucose tolerance. The excess risk can not be completely explained by increased prevalence of other cardiovascular disease risk factors such as hypertension and hyperlipidaemia in people with diabetes. This review examines the role of hyperglycemia and glycemic control in cardiovascular disease in people with Type 2 diabetes. The results of prospective observational studies and randomized controlled trials are summarized. We conclude that control of hypertension and hyperlipidemia are important to reduce risk of cardiovascular disease in people with diabetes and may be more easily achieved than tight glycemic control.

Best practice--ongoing polemics

Current treatment strategies and disease management programs for hyperlipidemia employ a range of lipid-lowering drugs. Results from early lipid-lowering trials using diet, fibrates, niacin and other classes of drug showed that lowering plasma cholesterol can significantly reduce the risk of developing ischemic cardiovascular events. The landmark statin trials have clearly demonstrated the benefits of lipid-lowering therapy in coronary heart disease (CHD) prevention and unlike early lipid-lowering studies, a reduction in mortality may become evident with statin therapy during the first year of treatment. The number of successful lipid-intervention trials continues to increase and evidence is accumulating that lipid modification can also reduce the risk of cardiovascular events among individuals with only modest degrees of blood-lipid abnormalities. With increasingly powerful drugs to modify blood lipids, the potential levels at which to initiate treatment and the appropriate target levels are rapidly changing and debate surrounds the question of where the line to initiate treatment should be drawn. The relative lack of major adverse events with statin therapy means that the level of CHD risk at which clinical benefit occurs cannot be determined by the degree of risk at which benefit exceeds adverse events. Therefore, patients with only moderately raised cholesterol levels can be treated because statin treatment is well tolerated. One of the most important aspects of the statin trials is the finding that clinical events, such as death and disability due to coronary artery disease, may be preventable or limited in a significant number of patients if they receive aggressive therapy. Current goals for cholesterol levels in patients with established CHD are rarely achieved with non-aggressive treatment; however, with aggressive lipid lowering statins can achieve these goals in a safe and effective manner.

Achieving National Cholesterol Education Program goals for low-density lipoprotein cholesterol in cardiac patients: importance of diet, exercise, weight control, and drug therapy

OBJECTIVE

To determine how frequently the National Cholesterol Education Program (NCEP) goal of a low-density lipoprotein (LDL) cholesterol level of 100 mg/dL or less is achieved in clinical practice in patients with coronary artery disease and what fraction of patients can achieve this goal without drug therapy.

DESIGN

We examined the results of lipid management in 152 consecutive patients who had completed cardiac rehabilitation after an acute coronary event. Patients were randomized to follow-up by specially trained nurses or by preventive cardiologists, and they were not receiving lipid-lowering drugs at the start of the study.

MATERIAL AND METHODS

Patients were given aggressive diet and exercise recommendations and lipid-lowering drugs in accordance with NCEP guidelines. Follow-up was continued for a mean of 526 days after the first lipid assessment subsequent to the coronary event. Multiple logistic regression analysis was used to identify independent predictors of a final LDL cholesterol level of 100 mg/dL or less.

RESULTS

Of the study group, 39% achieved the NCEP goal LDL cholesterol level of 100 mg/dL or less. Characteristics of the patients with LDL cholesterol levels of 100 mg/dL or less in comparison with those with LDL cholesterol levels of more than 100 mg/dL included a greater frequency of drug therapy (65% versus 38%), more rigorous dietary compliance, longer follow-up (586 +/- 317 days versus 493 +/- 264 days), more favorable weight change (-0.3 +/- 4.9 kg versus +1.7 +/- 5.0 kg), and more extensive weekly exercise (183 +/- 118 minutes versus 127 +/- 107 minutes).

CONCLUSION

The registered nurses managed the lipids of these patients as effectively as did the preventive cardiologists. Appropriate drug therapy was the most important factor in achieving an LDL cholesterol level of 100 mg/dL or less, but 35% of patients attaining this NCEP goal were not receiving drug therapy. Exercise, dietary compliance, and weight loss were also important factors.