Effects of an angiotensin-converting-enzyme inhibitor, ramipril, on cardiovascular events in high-risk patients

Update in pharmacologic treatment of hypertension

Initial pharmacologic therapy for hypertension is low-dose thiazide diuretics, beta-blockers, and ACE inhibitors. Increasing data have confirmed that ACE inhibitors have specific benefit in patients with diabetes, atherosclerosis, left ventricular dysfunction, and renal insufficiency. CCBs are alternative agents for ISH in the elderly and appear to decrease stroke with perhaps less protection against progression of renal insufficiency and proteinuria, CAD mortality and new onset heart failure versus other initial agents, especially ACE inhibitors. ARBs are well tolerated and effective blood pressure lowering agents but have not been confirmed as effective as ACE inhibitors for reducing renal progression, clinical events, or mortality from heart failure. Effective pharmacologic antihypertensive therapy may avoid disabling and undetected cerebrovascular disease, cognitive dysfunction, and disturbing symptoms of elevated blood pressure. Vasopeptidase inhibitor, such as omapatrilat, and endothelin-1 antagonist, such as bosentan, may become future agents approved for the reduction of morbidity and mortality with hypertension. The ALLHAT trial continues to examine the potential benefits and harms of amlodipine versus chlorthalidone and lisinopril in a diverse high-risk population. Based on ALLHAT data, however, doxazosin is no longer an acceptable initial pharmacological agent. Intensive pharmacologic treatment with blood pressure lowering to less than 130/85 mm Hg is recommended with diabetes, renal insufficiency, and heart failure with additional goal of less than 125/75 mm Hg with renal failure and proteinuria greater than 1 g/24 h, based on multiple outcome studies.

Cardiac mechanotransduction: from sensing to disease and treatment

In heart muscle a mechanical stimulus is sensed and transformed into adaptive changes in cardiac function by a process called mechanotransduction. Adaptation of heart muscle to mechanical load consists of neurohumoral activation and growth, both of which decrease the initial load. Under prolonged overload this process becomes maladaptive, leading to the development of left ventricular hypertrophy and ultimately to heart failure. Widespread synergism and crosstalk among a variety of molecules and signals involved in hypertrophic signaling pathways make the prevention or treatment of left ventricular hypertrophy and heart failure a challenging task. Therapeutic strategies should include either a complete and continuous reduction of load or normalization of left ventricular mass by interventions aimed at specific targets involved in mechanotransduction.

How important is atheromatous renal artery stenosis as a cause of end-stage renal disease?

In recent years atheromatous renal artery stenosis has been proposed as a common and potentially preventable cause of end-stage renal disease (ESRD). Occlusive renal artery disease causes renal failure that can be reversed following successful revascularization, but this scenario is relatively rare. Nonocclusive renal artery stenosis is commonly found in association with varying degrees of renal impairment. However, recent evidence and clinical observation suggest that a cause and effect relationship is unlikely. Experimentally, split renal function studies in cases of unilateral stenosis find similar degrees of renal impairment in both kidneys. Clinically, severe renal impairment is often found in the presence of unilateral stenoses. Another nephropathic process must be going on, probably a combination of hypertensive and atheroembolic damage. It is not surprising that the two pathologies often coexist, in view of their shared causes (principally hypertension and tobacco smoking). Previous studies of the importance of renal artery stenosis in causing ESRD probably included many cases of hypertensive and atheroembolic nephropathy. Unfortunately the potential for renal revascularization to prevent ESRD has been exaggerated.

Reduction of ACE activity is insufficient to decrease microalbuminuria in normotensive patients with type 1 diabetes

OBJECTIVE

To study whether administration of 1.25 and 5.0 mg ramipril daily, compared with placebo treatment, reduces the urinary albumin excretion rate (UAER) in normotensive patients with type 1 diabetes.

RESEARCH DESIGN AND METHODS

Ramipril was administered double blind at two different doses (1.25 [n = 19] and 5.0 mg [n = 18]), and compared with placebo (n = 18) after a single-blind placebo period of 1-4 weeks. The patients (total, n = 55; women, n = 14) were followed for 2 years. To document an effect on the renin-angiotensin system, ACE activity and plasma-renin activity (PRA) were measured. In addition, 24-h ambulatory blood pressure (BP) was recorded at baseline and repeated after 1 and 2 years using a Spacelab 90207 ambulatory BP recording device (Spacelab, Redmont, CA).

RESULTS

Both doses of ramipril were sufficient to reduce ACE activity and to increase PRA significantly as compared with placebo (P < 0.05 for both). On the other hand, neither ambulatory nor clinic BP was affected by either dose of ramipril compared with the placebo group. There was no progression of UAER in the placebo group during the 2 years of the study. Analysis of covariance showed no differences in UAER between the three treatment groups at year 1 (P = 0.94) or year 2 (P = 0.97), after adjusting for baseline. Furthermore, there were no statistically significant changes from baseline UAER within any of the three treatment groups.

CONCLUSIONS

Treatment with ramipril did not affect microalbuminuria or clinic or ambulatory BP in this study. On the basis of the present study, we question the clinical use of ACE inhibitors in stably normotensive patients with type 1 diabetes and microalbuminuria in whom a concomitant reduction in BP is not demonstrated.

A critique of hypertension treatment trials and of their evaluation

Progressive improvements in antihypertensive drug therapy over the past four decades have provided clear benefits in limiting cardiovascular complications. Unfortunately, and largely inexplicably, the inclusion in meta-analyses of defective trials plus the employment of inappropriate diagnostic criteria for adverse coronary events have led to spurious, exaggerated claims for the advantages of such treatment. The consequence has been a devaluation of the very real worth of prophylactic drug therapy for hypertension.

Cost effectiveness of ramipril treatment for cardiovascular risk reduction

OBJECTIVE

To assess the cost effectiveness of ramipril treatment in patients at low, medium, and high risk of cardiovascular death.

DESIGN

Population based cost effectiveness analysis from the perspective of the health care provider in the UK. Effectiveness was modelled using data from the HOPE (heart outcome prevention evaluation) trial. The life table method was used to predict mortality in a medium risk cohort, as in the HOPE trial (2.44% annual mortality), and in low and high risk groups (1% and 4.5% annual mortality, respectively).

SETTING

UK population using 1998 government actuary department data.

MAIN OUTCOME MEASURE

Cost per life year gained at five years and lifetime treatment with ramipril.

RESULTS

Cost effectiveness was £36 600, £13 600, and £4000 per life year gained at five years and £5300, £1900, and £100 per life year gained at 20 years (lifetime treatment) in low, medium, and high risk groups, respectively. Cost effectiveness at 20 years remained well below that of haemodialysis (£25 000 per life year gained) over a range of potential drug costs and savings. Treatment of the HOPE population would cost the UK National Health Service (NHS) an additional £360 million but would prevent 12 000 deaths per annum.

CONCLUSIONS

Ramipril is cost effective treatment for cardiovascular risk reduction in patients at medium, high, and low pretreatment risk, with a cost effectiveness comparable with the use of statins. Implementation of ramipril treatment in a medium risk population would result in a major reduction in cardiovascular deaths but would increase annual NHS spending by £360 million.

Effect of ACE inhibitors on angiographic restenosis after coronary stenting (PARIS): a randomised, double-blind, placebo-controlled trial

BACKGROUND

The DD genotype for the angiotensin-I converting enzyme (ACE I) deletion allele (D) polymorphism is a possible genetic risk factor for restenosis after coronary stent implantation. We aimed to establish whether or not blockade of ACE with high doses of ACE inhibitors could reduce this risk of angiographic restenosis.

METHODS

We characterised the ACE I/D polymorphism in 345 consecutive patients who were undergoing coronary stenting. 115 had the DD genotype. We assigned 91 of these 115 patients to quinapril 40 mg daily (n=46) or placebo (n=45). Treatment was started within 48 h after stent implantation and continued for 6 months. 79 patients complied with the protocol and underwent follow-up angiography after 6 months.

FINDINGS

Our primary endpoint of late loss in minimum lumen diameter (a quantitative index of restenosis) was significantly higher in the quinapril group than in the controls (mean 1.11 mm [SD 0.70] vs 0.76 mm [0.60]; p=0.018). Secondary endpoints also showed consistent trends towards increased angiographic restenosis in the treatment group.

INTERPRETATION

Contrary to our expectations, ACE inhibitor treatment did not reduce restenosis after coronary stent implantation in patients with DD genotype, but was associated with an exaggerated restenotic process when compared with administration of placebo.

Angiotensin II and atherosclerosis

Numerous clinical and laboratory data are now available supporting the hypothesis that the renin-angiotensin system is mechanistically relevant in the pathogenesis of atherosclerosis. The traditional role of the renin-angiotensin system in the context of blood pressure regulation has been modified to incorporate the concept that angiotensin II (Ang II) is a potent proinflammatory agent. In vascular cells, Ang II is a potent stimulus for the generation of reactive oxygen species. As a result, Ang II upregulates the expression of many redox-sensitive cytokines, chemokines, and growth factors that have been implicated in the pathogenesis of atherosclerosis. Extensive data now confirm that inhibition of the renin-angiotensin system inhibits atherosclerosis in animal models as well as in humans. These studies provide mechanistic insights into the precise role of Ang II in atherosclerosis and suggest that pharmacologic interventions involving the renin-angiotensin system may be of fundamental importance in the treatment and prevention of atherosclerosis.

Formulating clinical strategies for angiotensin antagonism: a review of preclinical and clinical studies

Extensive animal studies and a growing number of human clinical trials have now definitively demonstrated the central role of the renin-angiotensin-aldosterone system in the expression and modulation of cardiovascular disease. In contrast to the original hypothesis, the benefits of angiotensin antagonism do not emanate from the antihypertensive effect alone. Subsequent extensive investigations of angiotensin blockade suggest that the benefits of this approach may also result from the pharmacologic alteration of endothelial cell function and the ensuing changes in the biology of the vasculature. The more recent availability of direct antagonists of the AT(1) angiotensin receptor has introduced an element of doubt into this realm of clinical decision making. The receptor antagonists and the more widely studied converting-enzyme inhibitors share many endpoint attributes. Nevertheless, the partially overlapping mechanisms of action for the two classes of angiotensin antagonists confer distinct pharmacologic properties, including side effect profiles, mechanisms of action, and theoretic salutary effects upon the expression of cardiovascular disease. The current review will attempt to contrast the biology of angiotensin converting-enzyme inhibition with angiotensin II receptor antagonism. A discussion of the differential effects of these drug classes on endothelial cell function and on the modulation of vascular disease will be utilized to provide a theoretic framework for clinical decision making and therapeutics.

Vascular protective effects of angiotensin converting enzyme inhibitors and their relation to clinical events

Endothelial cells are a rich source of a variety of vasoactive substances, which either cause vasodilation or vasoconstriction. Important endothelium-derived vasodilators are prostacyclin, bradykinin, nitric oxide and endothelium-derived hyperpolarizing factor. In particular, nitric oxide inhibits cellular growth and migration. In concert with prostacyclin. nitric oxide exerts potent anti-atherogenic and thromboresistant properties by preventing platelet aggregation and cell adhesion. Endothelium-derived contracting factors include the 21 amino acid peptide endothelin (ET). vasoconstrictor prostanoids such as thromboxane A2 and prostaglandin H2, as well as free radicals and components of the renin angiotensin system. In hypertension, elevated blood pressure transmits into cardiovascular disease by causing endothelial dysfunction. Hence, modem therapeutic strategies in human hypertension focus on preserving or restoring endothelial integrity. Angiotensin converting enzyme (ACE) inhibitors are a primary candidate for that concept as they inhibit the circulating and local renin angiotensin system. Angiotensin converting enzyme is an endothelial enzyme which converts angiotensin-I (A-I) into angiotensin-II (A-II). This effect of the ACE inhibitor prevents direct effects of angiotensin-II such as vasoconstriction and proliferation in the vessel wall but also prevents activation of the ET system and of plasminogen activator inhibitor. Furthermore, inhibition of ACE prolongs the half-life of bradykinin and stabilizes bradykinin receptors linked to the formation of nitric oxide and prostacyclin. In isolated arteries ACE inhibitors prevent the contractions induced by angiotensin II and enhance relaxation induced by bradykinin. Chronic treatment of experimental hypertension with ACE inhibitors normalizes endothelium-dependent relaxation to acetylcholine and other agonists. In addition, the dilator effects of exogenous nitric oxide donors are enhanced, at least in certain models of hypertension. In humans with essential hypertension ACE inhibitors augment endothelium-dependent relaxation to bradykinin, while those to acetylcholine remain unaffected, at least in the time frame of the published studies, i.e. 3-6 months. In patients with coronary artery disease, however, paradoxical vasoconstriction to acetylcholine is markedly reduced after 6 months of ACE inhibition. After myocardial infarction ACE inhibitors reduce the development of overt heart failure, the occurrence of reinfarction and cardiovascular death in hypertensive patients. These effects have also been demonstrated in a subgroup analysis of the SOLVD (Studies of Left Ventricular Dysfunction) trial. Thus, in summary, ACE inhibitors are an important class of drugs providing cardiovascular protection in patients with increased cardiovascular risk.

Beneficial effects of ramipril on left ventricular end-diastolic and end-systolic volume indexes after uncomplicated invasive revascularization are associated with a reduction in cardiac events in patients with moderately impaired left ventricular function and no clinical heart failure

OBJECTIVES We sought to assess the effect of ramipril on left ventricular (LV) volumes, and the clinical significance thereof, in patients with moderate LV dysfunction and no clinical heart failure undergoing invasive revascularization for chronic stable angina.

BACKGROUND

It is unsettled whether treatment with an angiotensin-converting enzyme inhibitor has an impact on LV volumes in this patient group, and, if so, whether this is associated with the clinical outcome.

METHODS

A total of 133 patients with a left ventricular ejection fraction (LVEF) between 0.30 and 0.50 and no clinical heart failure undergoing invasive revascularization for chronic stable angina were randomized to receive ramipril 10 mg once daily or placebo and were followed for a median of 33 months with echocardiography at baseline and 3, 12 and 24 months postoperatively.

RESULTS

Repeated measures analysis of all time points showed that ramipril significantly reduced the end-diastolic volume index (EDVI) (p = 0.032) and end-systolic volume index (ESVI) (p = 0.006) as compared with placebo. Ramipril also reduced the incidence of the triple composite end point of cardiac death, acute myocardial infarction or development of heart failure (p = 0.046). Cox regression analysis, controlling for baseline LVEF and assignment to ramipril, revealed: 1) that increases in EDVI and ESVI up to three months predicted an increasing risk of a future adverse clinical outcome; and 2) that the benefit with ramipril on clinical outcome was partly dependent on a reduction in LV volumes.

CONCLUSIONS

Even in this patient group, LV dilation may supervene and lead to an adverse clinical outcome. Ramipril reduces the postoperative increase in LV volumes and may thereby improve clinical outcome.

Choice of drug treatment for obesity-related hypertension: where is the evidence?

Hypertension and obesity are common medical conditions independently associated with increased cardiovascular risk. Many large epidemiological studies have demonstrated associations between body mass index and blood pressure, and there is evidence to suggest that obesity is a causal factor in the development of hypertension in obese individuals. Consequently, all hypertension management guidelines consider weight reduction as a first step in the management of increased blood pressure in obese individuals. Weight reduction may be achieved by behaviour modification, diet and exercise, or by the use of anti-obesity medications. However, the long-term outcomes of weight management programmes for obesity are generally poor, and most hypertensive patients will require antihypertensive drug treatment. Some classes of antihypertensive agents may have potentially unwanted effects on some of the metabolic and haemodynamic abnormalities that link obesity and hypertension, yet most hypertension guidelines fail to provide specific advice on the pharmacological management of obese patients. This may be because there are currently no studies examining the efficacy of specific antihypertensive agents in reducing mortality in obese hypertensive patients. This paper reviews the theoretical reasons for the differential use of the major classes of antihypertensive agents in the pharmacological management of obesity-related hypertension and also considers the potential role of anti-obesity agents.

Theodore Cooper Lecture: Tissue angiotensin and pathobiology of vascular disease: a unifying hypothesis

There is increasing evidence that direct pathobiological events in the vessel wall play an important role in vascular disease. An important mechanism involves the perturbation of the homeostatic balance between NO and reactive oxygen species. Increased reactive oxygen species can inactivate NO and produce peroxynitrite. Angiotensin II is a potent mediator of oxidative stress and stimulates the release of cytokines and the expression of leukocyte adhesion molecules that mediate vessel wall inflammation. Inflammatory cells release enzymes (including ACE) that generate angiotensin II. Thus, a local positive-feedback mechanism could be established in the vessel wall for oxidative stress, inflammation, and endothelial dysfunction. Angiotensin II also acts as a direct growth factor for vascular smooth muscle cells and can stimulate the local production of metalloproteinases and plasminogen activator inhibitor. Taken together, angiotensin II can promote vasoconstriction, inflammation, thrombosis, and vascular remodeling. In this article, we propose a model that unifies the interrelationship among cardiovascular risk factors, angiotensin II, and the pathobiological mechanisms contributing to cardiovascular disease. This model may also explain the beneficial effects of ACE inhibitors on cardiovascular events beyond blood pressure reduction.

Baseline characteristics of the diabetic participants in the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT)

OBJECTIVE

Hypertension (HTN) is a major risk factor for cardiovascular disease (CVD) in the setting of diabetes. There is no consensus on how best to treat hypertension among those with diabetes. Here we describe the characteristics of a cohort of hypertensive adults with diabetes who are part of a large prospective blood pressure study. This study will help clarify the treatment of HTN in the setting of diabetes.

RESEARCH DESIGN AND METHODS

The Antihypertensive and Lipid-Lowering high-risk hypertensive participants, ages > or = 55 years, designed to determine whether the incidence of fatal and nonfatal coronary heart disease (CHD) and combined cardiovascular events (fatal and nonfatal CHD, revascularization surgery, angina pectoris, congestive heart failure, and stroke) differs between diuretic (chlorthalidone) treatment and three alternative antihypertensive therapies: a calcium channel blocker (amlodipine), an ACE inhibitor (lisinopril), and an alpha-adrenergic blocker (doxazosin). The planned follow-up is an average of 6 years, to be completed March 2002.

RESULTS

There are 15,297 diabetic individuals in the ALLHAT study (36.0% of the entire cohort). Of these individuals, 50.2% are male, 39.4% are African-American, and 17.7% are Hispanic. Demographic and laboratory characteristics of the cohort are similar to those of other studies of the U.S. elderly population with HTN. The sample size has 42 and 93% confidence, treatments for the two study outcomes.

CONCLUSIONS

The diabetic cohort in ALLHAT wil be able to provide valuable information about the treatment of hypertension in older diabetic patients at risk for incident CVD.

Comparative effects of ACE inhibitors and an angiotensin receptor blocker on atherosclerosis and vascular function

BACKGROUND

Both angiotensin-converting enzyme inhibitors (ACE-I(s)) and angiotensin receptor blockers (ARB(s)) provide vascular protection. This study was designed to compare ACE-I(s) with widely differing tissue affinity (captopril and quinapril) and an ARB (losartan) on vascular protection against the adverse effects of high cholesterol.

METHODS AND RESULTS

Forty-two New Zealand rabbits on a 0.5% cholesterol diet were randomized into control, captopril (10 mg/kg/d), quinapril (0.3 mg/kg/d), and losartan (8 mg/kg/d) groups for 14 weeks. Captopril, quinapril, and losartan significantly attenuated aortic lipid lesions (P=0.001). Captopril and quinapril were more effective than losartan in preserving vascular relaxation.

CONCLUSIONS

Captopril, quinapril, and losartan had similar protective effects against atherogenesis. Captopril and quinapril were more effective than losartan in preserving vascular function. Increased bradykinin by ACE inhibition may be responsible for this improved vascular endothelial function.

Nitric oxide and atherosclerosis

Endothelial dysfunction has been shown in a wide range of vascular disorders including atherosclerosis and related diseases. Here, we examine and address the complex relationship among nitric oxide (NO)-mediated pathways and atherogenesis. In view of the numerous pathophysiological actions of NO, abnormalities could potentially occur at many sites: (a) impairment of membrane receptors in the arterial wall that interact with agonists or physiological stimuli capable of generating NO; (b) reduced concentrations or impaired utilization of l-arginine; (c) reduction in concentration or activity both of inducible and endothelial NO synthase; (d) impaired release of NO from the atherosclerotic damaged endothelium; (e) impaired NO diffusion from endothelium to vascular smooth muscle cells followed by decreased sensitivity to its vasodilator action; (f) local enhanced degradation of NO by increased generation of free radicals and/or oxidation-sensitive mechanisms; and (g) impaired interaction of NO with guanylate cyclase and consequent limitation of cyclic GMP production. Therefore, one target for new drugs should be the preservation or restoration of NO-mediated signaling pathways in arteries. Such novel therapeutic strategies may include administration of l-arginine/antioxidants and gene-transfer approaches.

Renoprotection: one or many therapies?

BACKGROUND

Renal disease that progresses to end-stage renal disease (ESRD) imposes a great burden on the affected individual and on society, which mainly bears the cost of ESRD (currently more than $10 billion to treat about 333,000 patients annually in the U.S.). Thus, there is a great need to identify therapies that arrest the progression mechanisms common to all forms of renal disease. Progress is being made. Perhaps the most visible advance is the randomized controlled trials (RCT) demonstrating the renoprotective effects of angiotensin-converting enzyme (ACE) inhibitors. There are also numerous other promising renoprotective therapies. Unfortunately, testing each therapy in RCT is not feasible. Thus the nephrologist has two choices: restrict renoprotective therapy to those shown to be effective in RCT, or expand the use of renoprotective therapies to include those that, although unproven, are plausibly effective and prudent to use. The goal of this work is to provide the documentation needed for the nephrologist to choose between these strategies.

METHODS

This work first describes the mechanisms believed to be involved in the progression of renal disease. Based largely on this information, 18 separate interventions that slow the progression are described. Each intervention is assigned a level of recommendation (Level 1 is the highest and Level 3 the lowest) according to the strength of evidence supporting its renoprotective efficacy.

RESULTS

The number of interventions at each level of recommendation are: Level 1, N = 4; Level 2, N = 4; Level 3, N = 10. Our own experience with the multiple-risk-factor intervention is that most patients can achieve the majority of the Level 1 and 2 interventions, and many of the Level 3 interventions. We recommend the expanded renoprotection strategy.

CONCLUSION

This work advances the hypothesis that, until better information becomes available, a broad-based, multiple-risk-factor intervention intended to slow the progression of renal disease can be justified in those with progressive nephropathies. This work is intended primarily for clinical nephrologists and thus each recommended intervention is described in substantial practical detail.

Methods for monitoring oxidative stress, lipid peroxidation and oxidation resistance of lipoproteins

After a brief discussion of lipid peroxidation mechanism and the action of antioxidants and their potential to exhibit prooxidant effects, we give an overview on the clinical relevance of oxidative stress parameters. Many diseases are associated with oxidative stress e.g. by radical damage, among them atherosclerosis, diabetes mellitus, chronic renal failure, rheumatoid arthritis, and neurodegenerative diseases, and in many cases the investigation of parameters of oxidative stress has brought substantial insights into their pathogenesis. We then briefly review methods for the continuous monitoring of lipid peroxidation processes in vitro, which has helped in elucidating their mechanism and in some more detail cover such methods which have been proposed more recently to assess oxidative status and antioxidant activity in biological samples.

Adjunctive therapies in the treatment of acute coronary syndromes

Survival after myocardial infarction has been improving steadily in recent decades, in part because of more effective adjunctive medical therapies. However, the issue of underutilization of effective medical therapies remains. Adjunctive therapy for acute myocardial infarction should include aspirin, beta-adrenergic blocking agents, angiotensin-converting enzyme inhibitors, and lipid-lowering agents, all of which improve survival in the treatment and secondary prevention of myocardial infarction. This review presents the current knowledge supporting the use of specific adjunctive pharmacologic agents and also discusses the current status of other agents that are emerging or controversial.

Reducing cardiovascular risk in diabetes. Which factors to modify first?

Up to 80% of diabetic patients die of macrovascular complications, including CAD, stroke, and peripheral vascular disease. Because of the growing numbers of diabetic patients and the increased mortality after their first cardiovascular event, it is critical to identify and treat risk factors early and aggressively in these patients. Numerous studies in patients with type 2 diabetes have shown the benefits of aggressive treatment of blood pressure and lipids to levels that 10 years ago would have seemed abnormally low. The downward changes in "normal" limits can be frustrating to primary care physicians, but advances in treatment are redefining "normal" levels required to avoid complications in this high-risk population.

Expanded role for ARBs in cardiovascular and renal disease? Recent observations have far-reaching implications

The ARBs are a new class of drugs with broad therapeutic potential in cardiovascular disease. These agents act by selectively inhibiting the AT1 subtype of the angiotensin II receptors. They are effective antihypertensive agents with promise, theoretically, in the prevention and regression of ventricular hypertrophy. They are safe and well tolerated in patients with CHF and might be effective in improving survival and reducing morbidity. ARBs also might have a similar role in improving the clinical outcomes of patients with coronary artery disease and chronic nephropathy. Their precise role in the treatment and prevention of cardiovascular and renal disease should be established by several ongoing clinical trials.

Diabetes, hypertension, and cardiovascular disease: an update

Cardiovascular diseases (CVDs) are the major causes of mortality in persons with diabetes, and many factors, including hypertension, contribute to this high prevalence of CVD. Hypertension is approximately twice as frequent in patients with diabetes compared with patients without the disease. Conversely, recent data suggest that hypertensive persons are more predisposed to the development of diabetes than are normotensive persons. Furthermore, up to 75% of CVD in diabetes may be attributable to hypertension, leading to recommendations for more aggressive treatment (ie, reducing blood pressure to <130/85 mm Hg) in persons with coexistent diabetes and hypertension. Other important risk factors for CVD in these patients include the following: obesity, atherosclerosis, dyslipidemia, microalbuminuria, endothelial dysfunction, platelet hyperaggregability, coagulation abnormalities, and "diabetic cardiomyopathy." The cardiomyopathy associated with diabetes is a unique myopathic state that appears to be independent of macrovascular/microvascular disease and contributes significantly to CVD morbidity and mortality in diabetic patients, especially those with coexistent hypertension. This update reviews the current knowledge regarding these risk factors and their treatment, with special emphasis on the cardiometabolic syndrome, hypertension, microalbuminuria, and diabetic cardiomyopathy. This update also examines the role of the renin-angiotensin system in the increased risk for CVD in diabetic patients and the impact of interrupting this system on the development of clinical diabetes as well as CVD.

Are all angiotensin-converting enzyme inhibitors interchangeable?

In the treatment of most medical conditions, there are many choices. A critical question for practicing clinicians is: "Are all drugs within a class interchangeable?" In the past decade, the market has seen a proliferation of drugs within popular drug classes. The original drugs within a class typically have better scientific documentation than the newer ones, which are often referred to as "me-too" drugs. Due to a lesser financial investment, the latter may be available at a lower cost. Good reasons exist for grouping drugs, however, there is no accepted definition of the term "class effect." Although members of a drug class share main actions, they may have clinically important differences in terms of efficacy and safety. There are many such examples in the literature. This article reviews the class effect concept as it applies to the angiotensin-converting enzyme (ACE) inhibitors. Only half of the 10 ACE inhibitors available in the U.S. have been shown to improve survival and reduce morbidity in patients with heart failure or myocardial infarction. It is unknown whether the other five have the same safety and efficacy profiles or what their optimal doses are. Thus, we do not know whether all ACE inhibitors are fully interchangeable. The practice of medicine ought to be based on solid scientific evidence, not on assumptions or extrapolations. For our patients, such practice is a legitimate expectation. Therefore, it seems prudent to recommend that patients requiring ACE inhibitor therapy be prescribed one that has been proven effective and safe.

Clinical reality of coronary prevention guidelines: a comparison of EUROASPIRE I and II in nine countries. EUROASPIRE I and II Group. European Action on Secondary Prevention by Intervention to Reduce Events

BACKGROUND

Patients with coronary heart disease (CHD) are the top priority for preventive cardiology. The first EUROASPIRE survey among patients with established CHD in nine countries in 1995-96 showed substantial potential for risk reduction. A second survey (EUROASPIRE II) was done in 1999-2000 in the same countries to see whether preventive cardiology had improved since the first. We compared the proportion of patients in both studies who achieved the lifestyle, risk-factor, and therapeutic goals recommended by the Joint European Societies report on coronary prevention.

METHODS

The surveys were undertaken in the same selected geographical areas and hospitals in the Czech Republic, Finland, France, Germany, Hungary, Italy, the Netherlands, Slovenia, and Spain. Consecutive patients (men and women < or = 70 years of age) were identified after coronary-artery bypass graft or percutaneous transluminal coronary angioplasty, or a hospital admission with acute myocardial infarction or ischaemia, and were interviewed at least 6 months later.

FINDINGS

3569 and 3379 patients were interviewed in the first and second surveys, respectively. The prevalence of smoking remained almost unchanged at 19.4% vs 20.8%. The prevalence of obesity (body-mass index > or = 30 kg/m2) increased substantially from 25.3% to 32.8%. The proportion with high blood pressure (> or = 140/90 mm Hg) was virtually the same (55.4% vs 53.9%), whereas the prevalence of high total cholesterol concentrations (> or = 5.0 mmol/L) decreased substantially from 86.2% to 58.8%. Aspirin or other antiplatelet therapy was as widely used in the second survey as the first (83.9% overall), and reported use of beta-blockers, angiotensin-converting-enzyme inhibitors, and especially lipid-lowering drugs increased.

INTERPRETATION

The adverse lifestyle trends among European CHD patients are a cause for concern, as is the lack of any improvement in blood-pressure management, and the fact that most CHD patients are still not achieving the cholesterol goal of less than 5 mmol/L. There is a collective failure of medical practice in Europe to achieve the substantial potential among patients with CHD to reduce the risk of recurrent disease and death.

Antihypertensive drug therapy in older patients

Elevated pulse pressure is an important cardiovascular risk factor in the elderly, and it remains to be determined whether this can be reversed. Drug treatment is justified in older patients with isolated systolic hypertension whose systolic blood pressure is 160 mmHg or higher on repeated measurement. Absolute benefit is greater in men, in patients aged 70 years or more, and in those with previous cardiovascular complications or greater pulse pressure. In the recently published comparative trials blood pressure gradients largely accounted for most, if not all, of the differences in outcome. In hypertensive patients, calcium-channel blockers may offer greater protection against stroke than against myocardial infarction, resulting in an overall cardiovascular benefit similar to that provided by older drug classes. The hypothesis that angiotensin-converting enzyme inhibitors or alpha-blockers might influence outcome over and beyond that expected on the basis of their blood pressure lowering effects still remains to be proved.

ABCs of cardiovascular disease risk management

The past 20 years have witnessed a marked decline in morbidity and mortality from cardiovascular disease. This decline has been due in large part to advances in coronary risk factor modification and a better understanding of the atherosclerotic process. Compelling scientific and clinical trial evidence proves that comprehensive risk factor modification extends patient survival and reduces cardiovascular and cerebrovascular events. This article reviews the ABCs of optimal medical and lifestyle management in patients with documented atherosclerotic vascular disease as well as in those adults who are at increased risk for the development of cardiovascular disease, based on contemporary clinical trial evidence.

What is the optimal medical management of ischemic heart failure?

Ischemic heart disease is an important and common contributor to the development of heart failure. Theoretically, all patients with heart failure may benefit from treatment designed to retard progressive ventricular dysfunction and arrhythmias. Patients with ischemic heart disease may also theoretically benefit from the relief of ischemia, the prevention of coronary occlusion, and revascularization. However, there is little evidence to show that the presence or absence of coronary disease modifies the benefits of effective treatments such as angiotensin-converting enzyme inhibitors and beta-blockers. Moreover, there is no evidence that treatment directed specifically at myocardial ischemia or coronary disease alters outcome in patients with heart failure. Treatments aimed at relieving painless myocardial ischemia have not been shown to alter prognosis. Lipid-lowering therapy is theoretically attractive for patients with heart failure and coronary disease; however, theoretical concerns also exist about the safety of such agents, and patients with heart failure have been excluded from large outcome studies very effectively. Some agents, such as aspirin, designed to reduce the risk of coronary occlusion seem ineffective or harmful in patients with heart failure, although warfarin may be safe and possibly effective. There is no evidence yet that revascularization improves prognosis in patients with heart failure, even in patients who are shown to have extensive myocardial hibernation. On current evidence, revascularization should be reserved for the relief of angina. Large-scale, randomized controlled trials are currently underway that are investigating the role of specific treatments targeted at coronary syndromes. The Carvedilol Hibernation Reversible Ischemia Trial: Marker of Success study is investigating the effects of carvedilol in a large cohort of patients with and without hibernating myocardium. The Warfarin and Antiplatelet Therapy in Chronic Heart Failure study is comparing the efficacy of aspirin, clopidogrel, and warfarin. The Heart Revascularization Trial-United Kingdom study is assessing the effect of revascularization on mortality in patients with heart failure and myocardial hibernation. Smaller scale studies are assessing the safety and efficacy of statin therapy in patients with heart failure. Only once the outcomes to these and other planned trials are known can the medical community know how best to treat their patients.

Prevention of atherosclerosis by specific AT1-receptor blockade with candesartan cilexetil

Several studies indicate that blockade of the renin-angiotensin-aldosterone system (RAAS) can prevent atherosclerosis and vascular events, but the precise mechanisms involved are still unclear. In this study, we investigated the effect of the AT 1-receptor blocker, candesartan, in the prevention of atherosclerosis in Watanabe heritable hyperlipidaemic (WHHL) rabbits and also the effect of AT1-receptor blockade in the uptake of oxidised LDL by macrophage cell cultures. In the first set of experiments, 12 WHHL rabbits were randomly assigned to three groups: placebo, atenolol 5 mg/kg daily or candesartan 2 mg/kg daily for six months. Compared with controls and atenolol-treated rabbits, candesartan treatment resulted in a significant 50-60% reduction of atherosclerotic plaque formation and a 66% reduction in cholesterol accumulation in the thoracic aorta. Studies in macrophage cultures indicated that candesartan prevented uptake of oxidised LDL-(oxLDL)-cholesterol by cultured macrophages. Candesartan inhibited the uptake of oxLDL in a dose-dependent manner, reaching a maximum inhibition of 70% at concentrations of 5.6 µg/ml. Further studies in other animal models and well-designed trials in humans are warranted to further explore the role of AT1-receptor blockade in the prevention of atherosclerosis.

Oxidative stress and vascular damage in hypertension

Oxidative stress, a state of excessive reactive oxidative species activity, is associated with vascular disease states such as hypertension. In this review, we discuss the recent advances in the field of reactive oxidative species-mediated vascular damage in hypertension. These include the identification of redox-sensitive tyrosine kinases, the characterization of enzymatic sources of superoxide production in human blood vessels, and their relationship with vascular damage in atherosclerosis and hypertension. Finally, recent developments in the search for strategies to attenuate vascular oxidative stress are reviewed.

Cardiovascular disease in type 2 diabetes: challenge for treatment and prevention

Type 2 diabetes increases the risk of cardiovascular disease (CVD) two- to fourfold compared with the risk in non-diabetic subjects. Although type 2 diabetes is associated with a clustering of risk factors (small, dense low-density lipoprotein [LDL] particles, low high-density lipoprotein [HDL] cholesterol, high triglycerides, elevated blood pressure, obesity, central obesity, hyperinsulinaemia, hyperglycaemia, etc.), the cause for an excess risk of CVD remains unknown. Recent drug treatment trials have indicated that the lowering of total and LDL cholesterol and blood pressure is similarly beneficial in diabetic and non-diabetic subjects. The treatment of hyperglycaemia reduces micro- and macrovascular complications in type 2 diabetic patients. Beta-blocking agents, angiotensin-converting enzyme inhibitors, aspirin, and thrombolytic therapy are also effective in the treatment of CVD amongst diabetic patients.

Ace-inhibition with quinapril modulates the nitric oxide pathway in normotensive rats

Angiotensin-converting enzyme (ACE) inhibitors exert some cardiovascular benefits by improving endothelial function. We evaluated the effects of chronic treatment with quinapril (Q) on the l -arginine/nitric oxide (NO) pathway in normotensive rats under baseline and inflammatory conditions. The role of bradykinin was also investigated. The animals received for 1 week either the ACE-inhibitor Q (1 and 10 mg/kg/day), the B(2)receptor antagonist HOE 140, Q+HOE 140, or no drug. At the end of chronic treatment, rats underwent either a 6-h placebo or an E. coli endotoxin challenge. The following measurements were made: (i) endothelial and inducible NO synthase (eNOS and iNOS) protein expression; (ii) eNOS/iNOS activity; (iii) serum levels of nitrite/nitrate and tumour necrosis factor (TNF)- alpha; (iv) NO in the expired air (eNO). Q increased baseline aortic eNOS protein expression (up to 99%, P<0.001) and activity (l -citrulline synthesis up to 94%, P<0.01; serum nitrite/nitrate up to 55%, P<0.05). HOE 140 partially reversed Q-induced upregulation of eNOS (P<0.05). Moreover, Q counteracted LPS effects, i.e. increased the impaired eNOS pathway and limited iNOS induction (up to 94 and 24%, respectively), and reduced the increased nitrite/nitrate and TNF- alpha serum levels as well as eNO (up to 25, 38 and 28%, respectively, P<0.01 for all comparisons). HOE 140 did not influence Q effects on iNOS during endotoxaemia. In conclusion, in (patho)physiological conditions in rats, Q up-regulated eNOS with a bradykinin-mediated mechanism, while downregulated iNOS with a possible TNF- alpha -mediated mechanism.

Cardiovascular disease determinants in chronic renal failure: clinical approach and treatment

INTRODUCTION

Cardiovascular disease (CVD), as the leading cause of morbidity and mortality in patients on renal replacement therapy (RRT), has a central role in everyday nephrological practice.

METHODS

Consensus was reached on key points relating to the clinical approach and treatment of the main cardiovascular risk factors in RRT patients (hypertension, anaemia, hyperparathyroidism, dyslipidaemia, new emerging risk factors). In addition, the role of convective treatments on cardiovascular outcomes was examined.

RESULTS

Hypertension should be managed by aiming at blood pressure values of < or =140/90 mmHg (< or =160/90 mmHg in the elderly), firstly by ensuring target dry body weight is achieved. No single class of drug has proved superior to others in RRT patients, provided that the blood pressure target is achieved, although ACE inhibitors have shown specific organ protection in high-risk patients (HOPE study) and are well tolerated. Anaemia should be managed by using erythropoietin and iron supplements, aiming at haemoglobin levels of 12 g/dl and keeping serum ferritin levels < 500 ng/ml. The management of hyperparathyroidism is currently unsatisfactory, as calcium supplements have the potential to increase cardiovascular calcification. While awaiting new calcium- and aluminium-free phosphate binders, it is essential to ensure dialysis adequacy. Clinical studies are in progress to assess the real impact of lipid-lowering drugs in RRT. In the meantime, serum LDL-cholesterol < 160 mg/dl and triglycerides < 500 mg/dl may be desirable targets. The impact of new emerging risk factors (inflammation and chronic infection, hyperhomocysteinaemia, metabolic waste-product accumulation) and their proper management are still under research. Convective dialysis treatments may confer some degree of protection from dialysis-related amyloidosis and mortality, but clinical data on this important issue are still controversial and no definitive conclusions can be drawn at present.

CONCLUSION

CVD prevention and treatment is a great challenge for the nephrologist. Achieving evidence-based consensus can help in encouraging the implementation of best clinical practice in line with the progress of current knowledge.

Effects of ramipril and vitamin E on atherosclerosis: the study to evaluate carotid ultrasound changes in patients treated with ramipril and vitamin E (SECURE)

BACKGROUND

Activation of the renin-angiotensin-aldosterone system and oxidative modification of LDL cholesterol play important roles in atherosclerosis. The Study to Evaluate Carotid Ultrasound changes in patients treated with Ramipril and vitamin E (SECURE), a substudy of the Heart Outcomes Prevention Evaluation (HOPE) trial, was a prospective, double-blind, 3x2 factorial design trial that evaluated the effects of long-term treatment with the angiotensin-converting enzyme inhibitor ramipril and vitamin E on atherosclerosis progression in high-risk patients.

METHODS AND RESULTS

A total of 732 patients >/=55 years of age who had vascular disease or diabetes and at least one other risk factor and who did not have heart failure or a low left ventricular ejection fraction were randomly assigned to receive ramipril 2.5 mg/d or 10 mg/d and vitamin E (RRR-alpha-tocopheryl acetate) 400 IU/d or their matching placebos. Average follow-up was 4.5 years. Atherosclerosis progression was evaluated by B-mode carotid ultrasound. The progression slope of the mean maximum carotid intimal medial thickness was 0.0217 mm/year in the placebo group, 0.0180 mm/year in the ramipril 2.5 mg/d group, and 0.0137 mm/year in the ramipril 10 mg/d group (P=0.033). There were no differences in atherosclerosis progression rates between patients on vitamin E and those on placebo.

CONCLUSIONS

Long-term treatment with ramipril had a beneficial effect on atherosclerosis progression. Vitamin E had a neutral effect on atherosclerosis progression.

Impact of aortic stiffness attenuation on survival of patients in end-stage renal failure

BACKGROUND

Aortic pulse wave velocity (PWV) is a predictor of mortality in patients with end-stage renal failure (ESRF). The PWV is partly dependent on blood pressure (BP), and a decrease in BP can attenuate the stiffness. Whether the changes in PWV in response to decreases in BP can predict mortality in ESRF patients has never been investigated.

METHODS AND RESULTS

One hundred fifty ESRF patients (aged 52+/-16 years) were monitored for 51+/-38 months. From entry until the end of follow-up, the changes of PWV in response to decreased BP were measured ultrasonographically. BP was controlled by adjustment of "dry weight" and, when necessary, with ACE inhibitors, calcium antagonists, and/or beta-blockers, in combination if necessary. Fifty-nine deaths occurred, including 40 cardiovascular and 19 noncardiovascular events. Cox analyses demonstrated that independent of BP changes, the predictors of all-cause and cardiovascular mortality were as follows: absence of PWV decrease in response to BP decrease, increased left ventricular mass, age, and preexisting cardiovascular disease. Survival was positively associated with ACE inhibitor use. After adjustment for all confounding factors, the risk ratio for the absence of PWV decrease was 2.59 (95% CI 1.51 to 4.43) for all-cause mortality and 2.35 (95% CI 1.23 to 4.41) for cardiovascular mortality. The risk ratio for ACE inhibitor use was 0.19 (95% CI 0.14 to 0.43) for all-cause mortality and 0.18 (95% CI 0.06 to 0.55) for cardiovascular mortality.

CONCLUSIONS

These results indicate that in ESRF patients, the insensitivity of PWV to decreased BP is an independent predictor of mortality and that use of ACE inhibitors has a favorable effect on survival that is independent of BP changes.

Canine ventricular myocytes possess a renin-angiotensin system that is upregulated with heart failure

Ventricular pacing leads to a dilated myopathy in which cell death and myocyte hypertrophy predominate. Because angiotensin II (Ang II) stimulates myocyte growth and triggers apoptosis, we tested whether canine myocytes express the components of the renin-angiotensin system (RAS) and whether the local RAS is upregulated with heart failure. p53 modulates transcription of angiotensinogen (Aogen) and AT(1) receptors in myocytes, raising the possibility that enhanced p53 function in the decompensated heart potentiates Ang II synthesis and Ang II-mediated responses. Therefore, the presence of mRNA transcripts for Aogen, renin, angiotensin-converting enzyme, chymase, and AT(1) and AT(2) receptors was evaluated by reverse transcriptase-polymerase chain reaction in myocytes. Changes in the protein expression of these genes were then determined by Western blot in myocytes from control dogs and dogs affected by congestive heart failure. p53 binding to the promoter of Aogen and AT(1) receptor was also determined. Ang II in myocytes was measured by ELISA and by immunocytochemistry and confocal microscopy. Myocytes expressed mRNAs for all the constituents of RAS, and heart failure was characterized by increased p53 DNA binding to Aogen and AT(1). Additionally, protein levels of Aogen, renin, cathepsin D, angiotensin-converting enzyme, and AT(1) were markedly increased in paced myocytes. Conversely, chymase and AT(2) proteins were not altered. Ang II quantity and labeling of myocytes increased significantly with cardiac decompensation. In conclusion, dog myocytes synthesize Ang II, and activation of p53 function with ventricular pacing upregulates the myocyte RAS and the generation and secretion of Ang II. Ang II may promote myocyte growth and death, contributing to the development of heart failure.

Comparative effect of ace inhibition and angiotensin II type 1 receptor antagonism on bioavailability of nitric oxide in patients with coronary artery disease: role of superoxide dismutase

BACKGROUND

Flow-dependent, endothelium-mediated vasodilation (FDD) and activity of extracellular superoxide dismutase (EC-SOD), the major antioxidative enzyme of the arterial wall, are severely impaired in patients with coronary artery disease (CAD). We hypothesized that both ACE inhibitor (ACEI) and angiotensin II type 1 receptor antagonist (AT(1)-A) increase bioavailability of nitric oxide (NO) by reducing oxidative stress in the vessel wall, possibly by increasing EC-SOD activity.

METHODS AND RESULTS

Thirty-five patients with CAD were randomized to 4 weeks of ACEI (ramipril 10 mg/d) or AT(1)-A (losartan 100 mg/d). FDD of the radial artery was determined by high-resolution ultrasound before and after intra-arterial N-monomethyl-L-arginine (L-NMMA) to inhibit NO synthase and before and after intra-arterial vitamin C to determine the portion of FDD inhibited by oxygen free radicals. EC-SOD activity was determined after release from endothelium by heparin bolus injection. FDD was improved after ramipril and losartan (each group P<0.01), and in particular, the portion of FDD mediated by NO, ie, inhibited by L-NMMA, was increased by >75% (each group P<0.01). Vitamin C improved FDD initially, an effect that was lost after ramipril or losartan. After therapy, EC-SOD activity was increased by >200% in both groups (ACEI, 14.4+/-1.1 versus 3.8+/-0.9 and AT(1)-A, 13.5+/-1.0 versus 3.9+/-0.9 U. mL(-1). min(-1); each P<0.01). CONCLUSIONS-Four weeks of therapy with ramipril or losartan improves endothelial function to similar extents in patients with CAD by increasing the bioavailability of NO. Our results suggest that beneficial long-term effects of interference with the renin-angiotensin system may be related to reduction of oxidative stress within the arterial wall, mediated in part by increased EC-SOD activity.

Reliable assessment of the effects of treatment on mortality and major morbidity, II: observational studies

Observational studies and randomised trials can contribute complementary evidence about the effects of treatment on mortality and on major non-fatal outcomes. In particular, observational studies have an important role in the identification of large adverse effects of treatment on infrequent outcomes (ie, rare, but serious, side-effects) that are not likely to be related to the indications for (or contraindications to) the treatment of interest. Such studies can also provide useful information about the risks of death and disability in particular circumstances that can help to generalise from clinical trials to clinical practice. But, due to their inherent potential for moderate or large biases, observational studies have little role in the direct assessment of any moderate effects of treatment on major outcomes that might exist. Instead, sufficiently large-scale evidence from randomised trials is needed to assess such treatment effects appropriately reliably. Wider appreciation of the different strengths and weaknesses of these two types of epidemiological study should increase the likelihood that the most reliable evidence available informs decisions about the treatments doctors use--and patients receive--for the management of a wide range of life-threatening conditions.

The Year in Review: Cardiology

Overall, the evolution of the management of a broad spectrum of cardiovascular disease states has occurred primarily as a result of randomized, controlled clinical trials that have been conducted and published over time. During the past two years, the results of numerous clinical trials have certainly had a significant impact on the ways in which practitioners have treated conditions such as chronic heart failure, cardiac arrhythmias, ischemic heart disease, dyslipidemias, and hypertension. This review article summarizes the results of several key clinical trials that evaluated various treatment strategies for these five cardiovascular disease states and attempts to provide insight as to how these findings can be incorporated into clinical practice.

The smooth muscle cell membrane during atherogenesis: a potential target for amlodipine in atheroprotection

BACKGROUND

Atherosclerotic disease has been present in the human population apparently from the beginning of time. However, it has only been in the 20th century that improvements in the control of infectious diseases have allowed the average life span to increase to the point where atherosclerosis has been able to affect the general population. By the middle of the 20th century, atherosclerosis had reached epidemic levels, and it is currently pandemic and increasing worldwide. Despite its growing significance to health care, we still know relatively little about the cellular basis for plaque genesis in the vessel wall. Current thinking holds that atherosclerosis is caused by an unchecked chronic inflammatory process involving the cells of the arterial wall and their interaction with LDL and various inflammatory cells. Considerable evidence suggests that the principal insults underlying atherogenesis are serum dyslipidemias and oxidative stress mediated primarily by oxidized LDL. However, just how these insults alter the cell biology of vascular cells and lead to the atherosclerotic phenotype is still under intense investigation. Moreover, recent clinical trials have provided evidence that certain classes of drugs, including newer calcium channel blockers (CCBs), can remodel the arterial smooth muscle cell (SMC) membrane and inhibit the progression of atherosclerotic disease.

METHODS

This review summarizes our current thinking on atherogenesis in the arterial SMC and considers recent developments regarding alterations in the SMC membrane during the very early period of atherogenesis. We also discuss how certain CCBs might operate to produce atheroprotection.

RESULTS

The SMC membrane becomes enriched in unesterified cholesterol soon after the development of serum hypercholesterolemia. With excess membrane cholesterol, the membrane becomes thicker and develops distinct cholesterol domains. These alterations in the membrane increase the permeability of SMC to calcium and induce a variety of alterations in SMC function that contribute to cellular atherogenic processes during plaque genesis. Amlodipine, a third-generation CCB, markedly inhibits the progression of lesions. The explanation of this novel action may lie in the effects of this drug on various potential cellular targets.

CONCLUSIONS

Evidence is accumulating that excess membrane cholesterol may contribute to the cellular defects responsible for the transformation of the SMC to the atherosclerotic phenotype. Amlodipine, which has membrane-remodeling properties, is emerging as an important atheroprotective drug.

Rationale and design of the LURIC study--a resource for functional genomics, pharmacogenomics and long-term prognosis of cardiovascular disease

BACKGROUND AND AIM

Coronary artery disease (CAD), arterial hypertension and Type 2 diabetes mellitus are common polygenetic disorders which have a major impact on public health. Disease prevalence and progression to cardiovascular complications, such as myocardial infarction (MI), stroke or heart failure, are the product of environment and gene interaction. The LUdwigshafen RIsk and Cardiovascular Health (LURIC) study aims to provide a well-defined resource for the study of environmental and genetic risk factors, and their interactions, and the study of functional relationships between gene variation and biochemical phenotype (functional genomics) or response to medication (pharmacogenomics). Long-term follow-up on clinical events will allow us to study the prognostic importance of common genetic variants (polymorphisms) and plasma biomarkers.

SETTING

Cardiology unit in tertiary care medical centre in south-west Germany.

STUDY DESIGN

Prospective cohort study of individuals with and without cardiovascular disease at baseline.

PATIENTS AND METHODS

LURIC is an ongoing prospective study of currently > 3300 individuals in whom the cardiovascular and metabolic phenotypes CAD, MI, dyslipidaemia, hypertension, metabolic syndrome and diabetes mellitus have been defined or ruled out using standardised methodologies in all study participants. Inclusion criteria for LURIC were: German ancestry (limitation of genetic heterogeneity) clinical stability (except for acute coronary syndromes [ACSs]) availability of a coronary angiogram (this inclusion criterium was waived for family members provided that they met all other inclusion and exclusion criteria) Exclusion criteria were: any acute illness other than ACSs any chronic disease where non-cardiac disease predominated a history of malignancy within the past five years. Exclusion criteria were pre-specified in order to minimise the impact of concomitant non-cardiovascular disease on intermediate biochemical phenotypes or on clinical prognosis (limitation of clinical heterogeneity). A standardised personal and family history questionnaire and an extensive laboratory work-up (including glucose tolerance testing in non-diabetics and objective assessment of smoking exposure by determination of cotinine plasma levels) was obtained from all individuals after informed consent. A total of 115 ml of fasting venous blood was sampled for the determination of a pre-specified wide range of intermediate biochemical phenotypes in serum, plasma or whole blood, for leukocyte DNA extraction and immortalisation of B-lymphocytes. Biochemical phenotypes measured included markers of endothelial dysfunction, inflammation, oxidative status, coagulation, lipid metabolism and flow cytometric surface receptor expression of lympho-, mono- and thrombocytes. In addition, multiple aliquots of blood samples were stored for future analyses.

RESULTS

A total of 3500 LURIC baseline measurements were performed in 3316 individuals between July 1997 and January 2000. The baseline examination was repeated within a median of 35 days in 5% of study participants (n = 166, including a third examination in 18 after a median of 69 days) for pharmacogenomic assessment of lipid-lowering therapy and for quality control purposes. A five-year follow-up on major clinical events (death, any cardiovascular event including MI, stroke and revascularisation, malignancy and any hospitalisation) is ongoing. The clinical phenotypes prevalent at baseline in the cohort of 2309 men (70%) with a mean age of 62 +/- 11 years and 1007 women (30%), mean age 65 +/- 10 years, were angiographically-documented CAD in 2567 (79%), MI in 1368 (41%), dyslipidaemia in 2050 (62%) with hypercholesterolaemia > or = 240 mg/dl (27%), hypertriglyceridaemia > or = 150 mg/dl (44%) and HDL-cholesterol < or = 35 mg/dl (38%) in individuals not treated with lipid-lowering agents, systemic hypertension in 1921 (58%), metabolic syndrome in 1591 (48%), Type 2 diabetes in 1063 (32%) and obesity defined by body mass index > or = 30 kg/m2 in 770 (23%). Control patients in whom CAD had been ruled out angiographically were five years younger than those with CAD (59 +/- 12 and 64 +/- 10 years, respectively; p < 0.001), twice as often females (48% compared to 25% females in the CAD group, p < 0.001) and had significantly less cardiovascular risk factors than individuals with CAD. The prevalence of specific cardiovascular risk subsets in LURIC, such as the elderly (> or = 75 years), was 375 (11%), while 213 (6%) were young adults (< 45 years) and 904 (27%) were postmenopausal women (90% of all females). A low risk status (< or = 1 out of the four traditional risk factors: dyslipidaemia, smoking, hypertension and diabetes mellitus) was identified in 314 (9%) individuals of the entire cohort (5% in CAD and 26% in controls, p < 0.001) and 97 (3%) carried none of the four risk factors (1% in CAD and 9% in controls, p < 0.001). (ABSTRACT TRUNCATED)