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

Role of ACE inhibitors in treating hypertensive diabetic patients

Cardiovascular disease (CVD) is a major determining factor of morbidity and mortality in type 2 diabetic patients. Hypertension, which accompanies diabetes in more than 70% of cases, contributes to increased prevalence of CVD events in this group of patients. Results from the United Kingdom Prospective Diabetes Study (UKPDS) indicated that reduction of elevated blood pressure might decrease CVD morbidity and mortality more than reduction of hyperglycemia. Activation of circulating and tissue renin-angiotensin system (RAS) contributes to the development of both hypertension and insulin resistance in patients with the cardiometabolic syndrome. Angiotensin-converting enzyme (ACE) inhibitor therapy in patients with the cardiometabolic syndrome may improve insulin action as well as lessen CVD. In clinical trials, ACE inhibitors have been shown to be more efficient than other antihypertensive medications (i.e., calcium channel blockers) in the reduction of CVD morbidity and mortality in hypertensive diabetics. In this article, we summarize possible mechanisms by which ACE inhibition may improve insulin resistance, coagulation/clotting, and vascular function abnormalities, and postpone or even prevent the development of type 2 diabetes in hypertensive patients.

Identification of a novel redox-sensitive gene, Id3, which mediates angiotensin II-induced cell growth

BACKGROUND

Reactive oxygen species, such as superoxide (O(2)(-)), are involved in the abnormal growth of various cell types. Angiotensin II (Ang II) is one of the most potent inducers of oxidative stress in the vasculature. The molecular events involved in Ang II-induced proliferation of vascular smooth muscle cells (VSMCs) are only partially understood.

METHODS AND RESULTS

Ang II as well as xanthine/xanthine oxidase (X/XO) led to enhanced DNA synthesis and proliferation of VSMCs. The effect of Ang II was abolished by diphenylene iodonium. Consequently, VSMCs were incubated with X/XO, and modulation of gene expression was monitored by differential display, leading to the identification of a novel redox-sensitive gene, the dominant-negative helix-loop-helix protein Id3, which was upregulated within 30 minutes by X/XO and Ang II. Superoxide dismutase but not catalase inhibited this effect. Overexpression of antisense Id3 via transfection in VSMCs completely abolished Ang II- and X/XO-induced cell proliferation. Ang II, X/XO, and overexpression of sense Id3 downregulated protein expression of p21(WAF1/Cip1), p27(Kip1), and p53. Overexpression of antisense Id3 abrogated the effect of Ang II on the expression of p21(WAF1/Cip1), p27(Kip1), and p53. Ang II and overexpression of sense Id3 caused hyperphosphorylation of the retinoblastoma protein. Ang II-induced phosphorylation of the retinoblastoma protein was decreased by overexpression of antisense Id3.

CONCLUSIONS

Ang II induces proliferation of VSMCs via production of superoxide, which enhances the expression of Id3. Id3 governs the downstream mitogenic processing via depression of p21(WAF1/Cip1), p27(Kip1), and p53. These findings reveal a novel redox-sensitive pathway involved in growth control.

Reducing the knowledge-practice gap in the management of patients with cardiovascular disease

Despite major progress in the development of effective therapy to reduce mortality and morbidity from cardiovascular disease, it remains the leading cause of mortality in this country. One aspect of this problem is represented by the lag in adoption of treatments with documented efficacy in large clinical trials. This "knowledge-practice gap" has been attributed to factors at multiple levels of the health care system that impede implementation of optimal therapy. Although there is evidence of progress in the use of recommended therapeutic modalities in the past decade, this has been modest. Recent approaches to assessment of patient care by physicians, health plans, and institutions through the tracking of clinical performance have been instituted to promote optimal patient care. They are being increasingly utilized for purposes of accreditation and will also provide guidance for consumer purchasing of health care. Such methods have the potential to promote increased adherence to current standards of care.

Novel mode of action of angiotensin I converting enzyme inhibitors: direct activation of bradykinin B1 receptor

Angiotensin I converting enzyme (kininase II; ACE) inhibitors are important therapeutic agents widely used for treatment in cardiovascular and renal diseases. They inhibit angiotensin II release and bradykinin inactivation; these actions do not explain completely the clinical benefits. We found that enalaprilat and other ACE inhibitors in nanomolar concentrations activate human bradykinin B(1) receptors directly in the absence of ACE and the B(1) agonist des-Arg(10)-Lys(1)-bradykinin. These inhibitors activate at the Zn(2+)-binding consensus sequence HEXXH (195-199) in B(1), which is present also in ACE but not in the B(2) receptor. Activation elevates [Ca(2+)](i) and releases NO from endothelial or transfected cells expressing the B(1) receptor but is blocked by Ca-EDTA, a B(1) receptor antagonist, the synthetic undecapeptide sequence (192-202) of B(1), and the mutagenesis of His(195) to Ala(195). Except for the B(1) antagonist, these agents and manipulations did not block activation by a peptide ligand. Thus, Zn(2+) is essential for B(1) receptor activation by ACE inhibitors at the zinc-binding consensus sequence. Ischemia or cytokines induce abundant B(1) receptor expression. B(1) receptor activation by ACE inhibitors, a novel mode of action reported here first, can contribute to their therapeutic effects by releasing NO in the heart and to some side effects.

Is there a clinically significant gender bias in post-myocardial infarction pharmacological management in the older (>60) population of a primary care practice?

BACKGROUND

Differences in the management of coronary artery disease between men and women have been reported in the literature. There are few studies of potential inequalities of treatment that arise from a primary care context. This study investigated the existence of such inequalities in the medical management of post myocardial infarction in older patients.

METHODS

A comprehensive chart audit was conducted of 142 men and 81 women in an academic primary care practice. Variables were extracted on demographic variables, cardiovascular risk factors, medical and non-medical management of myocardial infarction.

RESULTS

Women were older than men. The groups were comparable in terms of cardiac risk factors. A statistically significant difference (14.6%: 95% CI 0.048-28.7 p = 0.047) was found between men and women for the prescription of lipid lowering medications. 25.3% (p = 0.0005, CI 11.45, 39.65) more men than women had undergone angiography, and 14.4 % (p = 0.029, CI 2.2, 26.6) more men than women had undergone coronary artery bypass graft surgery.

CONCLUSION

Women are less likely than men to receive lipid-lowering medication which may indicate less aggressive secondary prevention in the primary care setting.

Percutaneous coronary intervention vs. medical therapy: what are the implications for women?

There have been eight major studies assessing percutaneous coronary intervention (PCI) vs. medical therapy in the past 10 years. Women were inadequately represented in many of these studies, but because of similar long-term survival curves in women and men, most of the PCI data can be applied to women until more trials are published. According to currently available data, PCI offers greater angina relief and improvement in exercise tolerance than medicine alone, but has a greater risk of procedure-related complications in women. As a result of the rapid advancement of cardiovascular therapy, many of these studies did not incorporate optimal medical therapy or current PCI therapies. It is likely that for most patients (including women) with moderate angina, the best management may be a combination of PCI, medical therapy, and lifestyle changes.

Hypertension in special populations

This article discusses various aspects of hypertension in selected special populations. The groups discussed herein are children, pregnant women, African Americans, persons with kidney insufficiency, kidney transplant survivors, and persons with diabetes mellitus. These groups present unique epidemiological, diagnostic and therapeutic challenges for the practitioner. The detection of reduced kidney function merits special attention since it attenuates the blood pressure response to antihypertensive therapy, affects therapeutic decision-making, is both a cause and consequence of poorly controlled hypertension, often lurks undetected, and is excessively prevalent in some special populations.

C-reactive protein is an independent predictor of risk for the development of diabetes in the West of Scotland Coronary Prevention Study

Accumulating evidence implicates inflammation as a potential pathway in the pathogenesis of type 2 diabetes. The objective of the present study was to assess the ability of C-reactive protein (CRP) to predict the development of diabetes in middle-aged men in the West of Scotland Coronary Prevention Study. Baseline plasma samples for CRP measurement were available for 5,245 men of whom 127 were classified as having a transition from normal glucose control to overt diabetes during the study, based on American Diabetes Association criteria. Baseline CRP was an important predictor of the development of diabetes in univariate analysis (hazard ratio [HR] for an increase of 1 SD = 1.55; 95% CI 1.32-1.82; P < 0.0001). In multivariate analysis, CRP remained a predictor of diabetes development (HR 1.30; 95% CI 1.07-1.58; P = 0.0075) independent of other clinically employed predictors, including baseline BMI and fasting triglyceride and glucose concentrations. Moreover, there was a graded increase in risk across CRP quintiles throughout the study, evident at even 1 year of follow-up. The highest quintile (CRP >4.18 mg/l) was associated with a greater than threefold risk of developing diabetes (HR 3.07; 95% CI 1.33-7.10) in a multivariate analysis at 5 years. Thus, CRP predicts the development of type 2 diabetes in middle-aged men independently of established risk factors. Because CRP, the most commonly used acute-phase protein in clinical practice, is very stable in serum, our observations have clinical potential in helping to better predict individuals destined to develop type 2 diabetes. They also add to the notion that low-grade inflammation is important in the pathogenesis of type 2 diabetes.

Premature termination of clinical trials--lessons learned

Controlled clinical trials in cardiovascular disease are the cornerstone for therapeutic advances in this field of medicine. Since the introduction of the concept of controlled clinical trials there has been substantial progress in the design, conduct, and analysis of such studies. A growing awareness of ethical issues emerging from such trials has heightened public awareness, increased investigator scrutiny, and reinforced the need for interim data analysis. A benefit of such interim analyses is that either an entire clinical trial or a specific treatment limb can be stopped if the observed findings argue for premature termination. For example, highly positive findings, as were noted in the HOPE Study (Heart Outcomes Prevention Evaluation), led to its being stopped after 4.5 years of treatment, which was 1 year early. Alternatively, the doxazosin treatment limb of the ALLHAT (Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial) and the amlodipine treatment limb of AASK (African American Study of Kidney Disease and Hypertension) were stopped early because of negative findings with each respectively. Finally, economic considerations can enter into the decision to close a study early as was the case in the CONVINCE (Controlled Onset Verapamil Investigation of Cardiovascular End Points) trial. Most such decisions rely heavily on information obtained from independent data and safety monitoring boards. Such boards ensure patient safety by providing an unbiased ongoing review of data, which would otherwise be unavailable until a study's completion. Early termination of a clinical trial can have important clinical implications and, in particular, can redirect patterns of clinical practice.

Pharmacogenomics in cardiovascular diseases

Considerable heterogeneity exists in the way individuals respond to medications, in terms of both efficacy and safety. Inherited differences in the absorption, metabolism, excretion, and target for drug therapy have important effects on drug efficacy and safety. Pharmacogenomics aims to discover new therapeutic targets and understand genetic polymorphisms that determine the safety and efficacy of medications. The goal of pharmaco-genomics is customization of drug therapy with administration of a medication in an optimum dose that will be safe and effective with reduction in morbidity and mortality.

Is heart failure with preserved systolic function an overlooked enigma?

Heart failure with preserved systolic function, or diastolic heart failure, represents the neglected other half of the pandemic of heart failure. Unlike previously held beliefs, diastolic heart failure carries with it the same connotation of morbidity and mortality as systolic heart failure, particularly in the elderly. Due to lack of standards in application of the diagnosis of diastolic heart failure, studies are difficult to interpret due to heterogeneity in the clinical criteria applied to the patient enrollment. It is imperative that preventive efforts be implemented in high-risk groups, and screening measures with newer biomarkers be considered for identifying underlying structural heart disease in order to employ preventive therapy early in the course of illness. No evidence-based therapeutic strategy to reduce morbidity and mortality has been established, even after the diagnosis of diastolic heart failure is manifest. Current therapy targets lusitropic abnormalities in the realm of impaired relaxation, abnormal diastolic compliance, avoidance of tachycardia, and restoration of atrial booster pump function. Outcomes-based placebo-controlled clinical trials are currently underway to define appropriate therapeutic strategies in diastolic heart failure.

Diabetes and macrovascular disease

Cardiovascular disease (CVD) is the major cause of morbidity and mortality in patients with diabetes. Macrovascular events, including stroke, myocardial infarction (MI), and peripheral arterial disease (PAD), occur earlier than in nondiabetics and the underlying pathologies are often more diffuse and severe. Diabetic arteriopathy, which encompasses endothelial dysfunction, hypercoagulability, changes in blood flow, and platelet abnormalities, contributes to the early evolution of these events. Tight glucose and blood pressure control improves the vascular status of these patients by varying degrees. Antiplatelet agents have also been shown to be effective in the secondary prevention of cardiovascular events. In the ideal world, every risk factor would be addressed and each diabetic would have excellent glycemic control, a low normal blood pressure, a low LDL, and be prescribed an ACE inhibitor, together with aspirin and clopidogrel. If this is done, this emerging epidemic of macrovascular disease will be contained.

Blood pressure and clinical outcomes in the International Stroke Trial

BACKGROUND AND PURPOSE

Among patients with acute stroke, high blood pressure is often associated with poor outcome, although the reason is unclear. We analyzed data from the International Stroke Trial (IST) to explore the relationship between systolic blood pressure (SBP), subsequent clinical events over the next 2 weeks, and functional outcome at 6 months in patients with acute stroke.

METHODS

We included in the analysis 17 398 patients from IST with confirmed ischemic stroke. A single measurement of SBP was made immediately before randomization. Clinical events within 14 days of randomization were recorded: recurrent ischemic stroke, symptomatic intracranial hemorrhage, death resulting from presumed cerebral edema, fatal coronary heart disease, and death. Survival and dependency were assessed at 6 months. Outcomes were adjusted for age, sex, clinical stroke syndrome, time to randomization, consciousness level, atrial fibrillation, and treatment allocation (aspirin, unfractionated heparin, both, or neither).

RESULTS

A U-shaped relationship was found between baseline SBP and both early death and late death or dependency: early death increased by 17.9% for every 10 mm Hg below 150 mm Hg (P<0.0001) and by 3.8% for every 10 mm Hg above 150 mm Hg (P=0.016). The rate of recurrent ischemic stroke within 14 days increased by 4.2% for every 10-mm Hg increase in SBP (P=0.023); this association was present in both fatal and nonfatal recurrence. Death resulting from presumed cerebral edema was independently associated with high SBP (P=0.004). No relationship between symptomatic intracranial hemorrhage and SBP was seen. Low SBP was associated with a severe clinical stroke (total anterior circulation syndrome) and an excess of deaths from coronary heart disease (P=0.002).

CONCLUSIONS

Both high blood pressure and low blood pressure were independent prognostic factors for poor outcome, relationships that appear to be mediated in part by increased rates of early recurrence and death resulting from presumed cerebral edema in patients with high blood pressure and increased coronary heart disease events in those with low blood pressure. The occurrence of symptomatic intracranial hemorrhage within 14 days was independent of SBP.

Blood pressure-independent attenuation of cardiac hypertrophy by AT(1)R-AS gene therapy

Our studies have established that a single intracardiac administration of the retroviral vector containing angiotensin II type I receptor antisense gene causes prolonged antihypertensive actions in the spontaneously hypertensive rat. These results suggest that antisense gene therapy is a conceptually valid strategy for the control of hypertension at the genetic level. To evaluate whether attenuation of the pathophysiological aspects of hypertension are dependent on the blood pressure lowering actions of antisense gene therapy, we chose the renin transgenic rat as a hypertensive animal model and cardiac hypertrophy as the hypertension-associated pathophysiology. A single intracardiac administration of the retroviral vector containing angiotensin II type I receptor antisense in the neonatal rat resulted in long-term expression of the antisense transgene in various cardiovascular-relevant tissues, including the heart. This expression was associated with a significant attenuation of cardiac hypertrophy despite its failure to normalize high blood pressure. Developmental studies indicated that cardiac hypertrophy was evident as early as 16 days of age in viral vector-treated control transgenic rats, despite these animals exhibiting normal blood pressure. These observations demonstrate that, in the renin-transgenic rat, the onset of cardiac hypertrophy occurs during development and is prevented without normalization of high blood pressure. Collectively, these results provide further proof of the concept and indicate that antisense gene therapy could successfully target the local tissues' renin-angiotensin system to produce beneficial cardiovascular outcomes.

Chronic dialysis patients have high risk for pulmonary embolism

Pulmonary embolism has been considered uncommon in chronic dialysis patients, but has not been adequately studied in a large population. In the US Renal Data System (USRDS), 76,718 patients presenting with end-stage renal disease (ESRD) between January 1, 1996, and December 31, 1996, were analyzed in an historical cohort study. The outcome was hospitalizations with a primary discharge diagnosis of pulmonary embolism (International Classification of Diseases, Ninth Revision code 415.1x) occurring within 1 year of the first ESRD treatment and excluding those occurring after renal transplantation. For dialysis patients, hospitalization rates for pulmonary embolism were obtained from the hospitalization section of the 1999 USRDS. For the general population, hospitalization rates for pulmonary embolism were obtained from the National Hospital Discharge Survey for 1996. Comorbidities from the Medical Evidence Form (Centers for Medicare and Medicaid Services, previously known as the Health Care Financing Administration; form 2728) were used to generate approximated stratified models of adjusted incidence ratios for pulmonary embolism (comorbidities could not be stratified for the general population). In 1996, the overall incidence rate of pulmonary embolism was 149.90/100,000 dialysis patients compared with 24.62/100,000 persons in the US population, with an age-adjusted incidence ratio of 2.34 in dialysis patients. Younger dialysis patients had the greatest relative risk for pulmonary embolism. The age-adjusted incidence ratio of pulmonary embolism after excluding dialysis patients with known risk factors for pulmonary embolism was 2.11. Ninety-five percent confidence intervals for all age categories in both models were statistically significant. Chronic dialysis patients have high risk for pulmonary embolism, independent of comorbidity.

Prevention of heart failure

In light of the increasing prevalence, morbidity, and mortality of heart failure, preventative strategies are urgently needed. Risk factors include coronary artery disease, renal insufficiency, diabetes, and smoking. Essential strategies for prevention of heart failure are modification of risk factors for its development, and detection and treatment of asymptomatic left ventricular dysfunction (ALVD). In patients with ALVD, angiotensin-converting enzyme (ACE) inhibitor and beta-blocker therapy can prevent progression to symptomatic heart failure. Additional recently identified preventative strategies include ACE inhibitor therapy for all coronary artery disease and diabetic patients, clopidogrel therapy in acute coronary syndromes, and avoidance of calcium channel blockers and alpha-blockers as first-line antihypertensive therapy.

Clinical pharmacology of antihypertensive drugs

Systemic hypertension is a major public health problem and is perhaps the most common chronic disorder in most societies. Most patients with vascular disease report hypertension in their medical history. Irrespective of the specialty that one practices, every physician will likely encounter patients with systemic hypertension. Unfortunately, an overwhelming number have so-called "primary" or "essential" hypertension for which a cure has yet to be found. Fortunately, excellent therapy is available to control this modern malady. The field of hypertension continues to evolve rapidly, particularly in the field of therapy. During the past two decades, the treatment of hypertension has moved from a cookbook approach to more scientifically based individualized management. This paradigm shift requires the practitioner to acquire sufficient knowledge about individual drugs and how they work in a given patient. Rapid expansion of available drugs has placed a burden on the clinician to keep up with these advances. We hope that the discussions contained herein will ease that burden somewhat and make the treatment options less cumbersome. This article addresses the practical issues related to selection of antihypertensive drugs and provides an overview of advantages and disadvantages of individual drug classes. The reader should also refer to the JNC VI document [1] to further understand the selection of drug therapy based upon compelling indications. The ultimate aim of hypertension management should always be to achieve target or goal blood pressure levels.

Reducing global risk for cardiovascular disease: using lifestyle changes and pharmacotherapy

Cardiovascular disease (CVD) is the leading cause of death and disability in industrialized societies, due in large part to the lack of a comprehensive approach to control the risk factors for atherosclerosis. One strategy for reducing an individual's global CVD risk relies on a targeted approach that modifies each of the major independent risk factors prevalent in both symptomatic (secondary prevention) and asymptomatic (primary prevention) patients. These interventions include lipid lowering, smoking cessation, blood pressure control, glycemic control, regular exercise, and the use of various medications. This review offers an evidence-based strategy toward reducing an individual's global risk for CVD by addressing the modifiable, major independent risk factors.

Clinical applications of arterial stiffness; definitions and reference values

Arterial stiffening is the most important cause of increasing systolic and pulse pressure, and for decreasing diastolic pressure beyond 40 years of age. Stiffening affects predominantly the aorta and proximal elastic arteries, and to a lesser degree the peripheral muscular arteries. While conceptually a Windkessel model is the simplest way to visualize the cushioning function of arteries, this is not useful clinically under changing conditions when effects of wave reflection become prominent. Many measures have been applied to quantify stiffness, but all are approximations only, on account of the nonhomogeneous structure of the arterial wall, its variability in different locations, at different levels of distending pressure, and with changes in smooth muscle tone. This article summarizes the methods and indices used to estimate arterial stiffness, and provides values from a survey of the literature, followed by recommendations of an international group of workers in the field who attended the First Consensus Conference on Arterial Stiffness, which was held in Paris during 2000, under the chairmanship of M.E. Safar and E.D. Frohlich.

Pretreatment with angiotensin-converting enzyme inhibitors attenuates ischemia-reperfusion injury

BACKGROUND

The Heart Outcomes Prevention Evaluation (HOPE) trial demonstrated that ischemic events are decreased in patients receiving angiotensin-converting enzyme (ACE) inhibitors. This study sought to determine whether pretreatment with ACE inhibitors would attentuate ischemic injury during surgical revascularization of ischemic myocardium.

METHODS

In a porcine model, the second and third diagonal vessels were occluded for 90 minutes, followed by 45 minutes of cardioplegic arrest, and 180 minutes of reperfusion. Ten pigs received quinapril (20 mg p.o. q.d.) for 7 days prior to surgery; 10 others received no-ACE inhibitors.

RESULTS

Quinapril-treated animals required less cardioversions for ventricular arrhythmias (1.58 +/- 0.40 vs 2.77 +/- 0.22; p < 0.05), had higher wall motion scores assessed by two-dimensional echocardiography (4 = normal to -1 = dyskinesia; 2.11 +/- 0.10 vs 1.50 +/- 0.07; p < 0.05), more complete coronary artery endothelial relaxation to bradykinin (45% +/- 3% vs 7% +/- 4%; p < 0.005), and lower infarct size (24.0% +/- 3.0% vs 40.0% +/- 1.7%; p < 0.0001).

CONCLUSIONS

ACE inhibition prior to coronary revascularization enhances myocardial protection by decreasing ventricular irritability, improving regional wall motion, lowering infarct size, and preserving endothelial function.

Comparative antihypertensive efficacy of olmesartan: comparison with other angiotensin II receptor antagonists

Hypertension is a major risk factor for cardiovascular morbidity and mortality. Effective control of elevated blood pressure (BP) has been shown to reduce this risk. Early studies of risk reduction assumed that the mechanism by which BP was lowered had little impact on the benefit obtained. Recent evidence, however, suggests that agents that inhibit the renin-angiotensin system may be particularly beneficial. The results of the recent Heart Outcomes Prevention Evaluation (HOPE) trial suggest that angiotensin-converting enzyme (ACE) inhibitors have a greater impact on cardiovascular morbidity and mortality than would be anticipated from their antihypertensive effects alone. Angiotensin receptor blockers, the other major class of antihypertensive drugs that inhibit the renin-angiotensin system, have not been widely tested in outcomes trials, but early results suggest that they are beneficial for controlling target organ damage that is related to hypertension. Furthermore, unlike ACE inhibitors, these agents have a side-effect profile that is similar to that of placebo. Based on their efficacy in controlling hypertension and their wider health benefits, together with minimal side effects, angiotensin II (A II) receptor blockers should be considered as first-line agents for the treatment of hypertension, particularly in patients with other cardiovascular risk factors. Preliminary evidence suggests that olmesartan, an A II receptor blocker currently being evaluated for approval for clinical use, may provide antihypertensive efficacy that is superior to other members of the class.

Angiotensin II receptor-independent antiinflammatory and antiaggregatory properties of losartan: role of the active metabolite EXP3179

Angiotensin II (Ang II) type 1 receptor (AT(1)) antagonists such as losartan (LOS) are widely used for the treatment of hypertension and elicit antiinflammatory and antiaggregatory in vitro and in patients, although the underlying mechanism are unclear. Following computer-based molecule similarity, we proposed that on cytochrome-P450 degradation, the LOS metabolite EXP3179 is generated, which shows molecule homology to indomethacin, a cyclooxygenase inhibitor with antiinflammatory and antiaggregatory properties. Subsequently, serum-levels of EXP3179 were determined for 8 hours in patients receiving a single oral dose of 100 mg LOS. High-performance liquid chromatography followed by liquid chromatography-mass spectrometry (GC-MS) [corrected] from serum samples revealed a maximum of 10(-7) mol/L for EXP3179 peaking between 3 to 4 hours. The increase in serum-EXP3179 levels was associated with a significant reduction in platelet aggregation in vivo (-35+/-4%, P<0.001 versus control). EXP3179 generation was investigated in a chemical reaction mimicking the liver cytochrome-P450-dependent LOS-degradation and human endothelial cells were exposed to Ang II or lipopolysaccharides (LPS) in the presence of EXP3179 (10(-7) mol/L). LPS- and Ang II-induced COX-2 transcription was abolished by EXP3179. Moreover, EXP3179 significantly reduced Ang II- and LPS-induced formation of prostaglandin F2alpha as determined by GC-MS [corrected]. Thus, antiinflammatory properties of LOS are mediated via its EXP3179 metabolite by abolishing COX-2 mRNA upregulation and COX-dependent TXA2 and PGF2alpha generation. Serum levels of EXP3179 are detectable in patients in concentrations that exhibit antiinflammatory and antiaggregatory properties in vitro.

Severity of meningococcal disease in children and the angiotensin-converting enzyme insertion/deletion polymorphism

Critical illness outcome may be causally related to inflammatory response severity. Given that tissue angiotensin-converting-enzyme (ACE) regulates such responses and that the deletion (D) [rather than insertion (I)] variant of the ACE gene is associated with higher tissue ACE levels, DD genotype might be associated with a poorer outcome in a uniform infectious disease state. Illness severity (Pediatric RIsk of Mortality score, the Glasgow Meningococcal Septicaemia Prognostic Score [GMSPS], and clinical course) was recorded for consecutive white patients with meningococcal disease (n = 110, 34 DD genotype, 61 male, aged 49.4 +/- 5.4 months) referred to the Royal Liverpool Children's Hospital, UK. Compared with children with > or = I allele, DD genotype was associated with 14% higher predicted risk of mortality (p = 0.038), higher GMSPS (DD 9.4 +/- 0.5, ID/II 7.7+/- 0.4 [mean +/- SEM], p = 0.013), greater prevalence of inotropic support (76% versus 55%, p = 0.03) and ventilation (82% versus 63%, p = 0.04), and longer Pediatric Intensive Care Unit (PICU) stay (5.8 versus 3.9, p = 0.02). DD genotype frequency was 6% (1 case) for the 18 children who did not require PICU care, 33% for the 84 PICU survivors, and 45% for those who died (p = 0.01). ACE DD is associated with increased illness severity in meningococcal disease.

Effect of nicorandil on coronary events in patients with stable angina: the Impact Of Nicorandil in Angina (IONA) randomised trial

BACKGROUND

In addition to its anti-ischaemic effects, the antianginal drug nicorandil is thought to have cardioprotective properties. We did a randomised trial to find out whether nicorandil could reduce the frequency of coronary events in men and women with stable angina and additional risk factors.

METHODS

5126 patients were randomly assigned 20 mg nicorandil twice daily (n=2565) or identical placebo (n=2561) in addition to standard antianginal therapy. The primary composite endpoint was coronary heart disease death, non-fatal myocardial infarction, or unplanned hospital admission for cardiac chest pain. The secondary endpoint was the combined outcome of coronary heart disease death or non-fatal myocardial infarction. Other outcomes reported include all-cause mortality, all cardiovascular events, and acute coronary syndromes. Mean follow-up was 1.6 years (SD 0.5). Analysis was by intention to treat.

FINDINGS

There were 398 (15.5%) primary endpoint events in the placebo group and 337 (13.1%) in the nicorandil group (hazard ratio 0.83, 95% CI 0.72-0.97; p=0.014). The frequency of the secondary endpoint was not significantly different between the groups (134 events [5.2%] vs 107 events [4.2%]; 0.79, 0.61-1.02; p=0.068). The rate of acute coronary syndromes was 195 (7.6%) in the placebo group and 156 (6.1%) in the nicorandil group (0.79, 0.64-0.98; p=0.028), and the corresponding rates for all cardiovascular events were 436 (17.0%) and 378 (14.7%; 0.86, 0.75-0.98; p=0.027).

INTERPRETATION

We showed a significant improvement in outcome due to a reduction in major coronary events by antianginal therapy with nicorandil in patients with stable angina.

Aspirin-resistant thromboxane biosynthesis and the risk of myocardial infarction, stroke, or cardiovascular death in patients at high risk for cardiovascular events

BACKGROUND

We studied whether aspirin resistance, defined as failure of suppression of thromboxane generation, increases the risk of cardiovascular events in a high-risk population.

METHODS AND RESULTS

Baseline urine samples were obtained from 5529 Canadian patients enrolled in the Heart Outcomes Prevention Evaluation (HOPE) Study. Using a nested case-control design, we measured urinary 11-dehydro thromboxane B2 levels, a marker of in vivo thromboxane generation, in 488 cases treated with aspirin who had myocardial infarction, stroke, or cardiovascular death during 5 years of follow-up and in 488 sex- and age-matched control subjects also receiving aspirin who did not have an event. After adjustment for baseline differences, the odds for the composite outcome of myocardial infarction, stroke, or cardiovascular death increased with each increasing quartile of 11-dehydro thromboxane B2, with patients in the upper quartile having a 1.8-times-higher risk than those in the lower quartile (OR, 1.8; 95% CI, 1.2 to 2.7; P=0.009). Those in the upper quartile had a 2-times-higher risk of myocardial infarction (OR, 2.0; 95% CI, 1.2 to 3.4; P=0.006) and a 3.5-times-higher risk of cardiovascular death (OR, 3.5; 95% CI, 1.7 to 7.4; P<0.001) than those in the lower quartile.

CONCLUSIONS

In aspirin-treated patients, urinary concentrations of 11-dehydro thromboxane B2 predict the future risk of myocardial infarction or cardiovascular death. These findings raise the possibility that elevated urinary 11-dehydro thromboxane B2 levels identify patients who are relatively resistant to aspirin and who may benefit from additional antiplatelet therapies or treatments that more effectively block in vivo thromboxane production or activity.

Tratamento de Diabetes e Hipertensão no Paciente Obeso

A obesidade é um fator de risco independente para doença coronariana. A resistência à insulina associada à obesidade contribui para o desenvolvimento de dislipidemia, hipertensão arterial e diabetes tipo 2. A coexistência de hipertensão e diabetes aumenta o risco para complicações micro e macrovasculares, predispondo os indivíduos à insuficiência cardíaca congestiva, doença coronariana e cerebrovascular, insuficiência arterial periférica, nefropatia e retinopatia. Em pacientes diabéticos obesos a redução do peso, bem como o uso de metiformina, melhoram a sensibilidade à insulina, o controle da glicemia e da pressão arterial. O tratamento anti-hipertensivo em diabéticos reduz a mortalidade cardiovascular e retarda o declínio da função glomerular. Deve-se considerar os efeitos dos agentes anti-hipertensivos sobre a sensibilidade à insulina e o perfil lipídico. Diuréticos e b-bloqueadores podem reduzir a sensibilidade à insulina, enquanto bloqueadores de canais de cálcio são metabolicamente neutros e os iECA aumentam a sensibilidade à insulina, além de conferir proteção adicional cardiovascular e renal para diabéticos. O bloqueio da angiotensina II tem mostrado benefícios semelhantes.

Role of nitric oxide in the regulation of substrate metabolism in heart failure

Solid experimental evidence indicates that nitric oxide (NO) inhibits oxygen utilization in vitro and in vivo. The role played by NO in cellular metabolism is likely extended to the control of substrate utilization. Studies performed in normal hearts show that NO inhibits glucose uptake and that a reduced synthesis of NO impairs free fatty acid consumption. Interestingly, we found also that myocardial free fatty acid utilization decreases while glucose consumption is enhanced in end stage heart failure, when cardiac NO production falls dramatically. This phenomenon led us to the hypothesis that the reduced synthesis of NO could be at least in part responsible for myocardial metabolic alterations occurring in severe heart failure. The present review mentions some of the seminal studies that defined the function of NO as metabolic modulator. A particular emphasis is put on available data suggesting a role for NO in the control of cardiac substrate utilization in normal and failing hearts.

Diabetes, diversity, and disparity: what do we do with the evidence?

The US Department of Health and Human Services has developed an initiative called "Eliminating Racial and Ethnic Disparities in Health," which parallels Healthy People 2010, the nation's health goals for the next decade. The initiative focuses on areas of health disparity that are known to affect racially and ethnically diverse groups of the population yet hold the promise of improvement. The first step to addressing such health inequities is to understand the scope and nature of the diseases that contribute to such disparities. This commentary reviews the epidemiology and consequences of type 2 diabetes, particularly as it is manifested in socially and culturally diverse groups, and offers recommendations for actions to address the disparities resulting from diabetes.

ACE inhibition and cardiovascular mortality and morbidity in essential hypertension: the end of the search or a need for further investigations?

Scientific evidence currently available supports the concept that renin-angiotensin blockade with angiotensin converting enzyme inhibitors as a first-line treatment exhibits in arterial hypertension beneficial effects in the prevention of mortality and morbidity comparable to those achieved with diuretics and beta-blockers. In addition, the renin-angiotensin blockade has also proved to be beneficial in the secondary prevention of several complications of hypertensive disease such as after myocardial infarction and congestive heart failure, as well as in the prevention of the incidence of type 2 diabetes, and the progression of diabetic and nondiabetic nephropathy. In this later regard, recent evidence with angiotensin II receptor antagonists in reducing the progression of nephropathy in type 2 diabetes strongly confirms that antagonism of the renin-angiotensin system is an effective approach to cardiovascular and renal disease. Finally, the renin-angiotensin blockade in high-risk patients may reduce cardiovascular mortality independently of the effect on blood pressure (BP). The effect of other antihypertensive drugs on cardiovascular risk in patients with high-normal BP should be investigated to establish whether they exhibit a comparable effect or whether there is a class-related benefit of drugs blocking the renin-angiotensin system. Such a strategy could also be encouraged to design future interventional studies with the newer classes of compounds (angiotensin II AT1-receptor antagonists, vasopeptidase inhibitors, endothelin antagonists), which would have the additional potential advantage of providing information more easily transferable to large-scale clinical practice.

The impact of JNC-VI guidelines on treatment recommendations in the US population

Using epidemiological and clinical trial evidence, the sixth report of the Joint National Committee on Prevention, Detection, and Treatment of High Blood Pressure (JNC-VI) updated previous guidelines to suggest that in addition to blood pressure, decisions on initial treatment should emphasize absolute cardiovascular disease risk. We estimated the impact of using cardiovascular disease risk on treatment recommendations for the US population using data from 16 527 participants in the Third National Health and Nutrition Examination Survey. In the US population > or =20 years of age, 36% (62 million) had high-normal blood pressure or greater (systolic/diastolic blood pressure > or =130 mm Hg/> or =85 mm Hg) or were taking antihypertensive medication. Of this population, 5.1% (3.2 million) were stratified into risk group A (no cardiovascular disease risk factors or prevalent cardiovascular disease), 66.3% (41.4 million) into risk group B (> or =1 major risk factor), and 28.6% (17.9 million) into risk group C (diabetes mellitus, clinical cardiovascular disease, target organ damage). Also, 26% of this group (16.2 million) had high-normal blood pressure and were in risk groups A or B, a context in which vigorous lifestyle modification is recommended in the JNC-VI guidelines. Additionally, 11% (7.0 million) had high-normal blood pressure (systolic/diastolic, 130 to 139 mm Hg/85 to 89 mm Hg, respectively) or stage-1 hypertension (140 to 159 mm Hg/90 to 99 mm Hg), and at least 1 factor, placing them in risk group C, but they were not currently on antihypertensive medication. JNC-VI, but not previous JNC guidelines, specifically recommends drug therapy as initial treatment for these patients. We conclude that JNC-VI refines cardiovascular risk and enfranchises more Americans to undertake more aggressive risk reduction maneuvers.

ACE inhibition and atherogenesis

Recent clinical studies such as HOPE, SECURE, and APRES show that angiotensin-converting enzyme (ACE) inhibitors like ramipril improve the prognosis of patients with a high risk of atherothrombotic cardiovascular events. Atherosclerosis, as a chronic inflammatory condition of the vascular system, can turn into an acute clinical event through the rupture of a vulnerable atherosclerotic plaque followed by thrombosis. ACE inhibition has a beneficial effect on the atherogenic setting and on fibrinolysis. Endothelial dysfunction is the end of a common process in which cardiovascular risk factors contribute to inflammation and atherogenesis. By inhibiting the formation of angiotensin II, ACE inhibitors prevent any damaging effects on endothelial function, vascular smooth muscle cells, and inflammatory vascular processes. An increase in the release of NO under ACE inhibition has a protective effect. Local renin-angiotensin systems in the tissue are involved in the inflammatory processes in the atherosclerotic plaque. Circulating ACE-containing monocytes, which adhere to endothelial cell lesions, differentiate within the vascular wall to ACE-containing macrophages or foam cells with increased local synthesis of ACE and angiotensin II. Within the vascular wall, angiotensin II decisively contributes to the instability of the plaque by stimulating growth factors, adhesion molecules, chemotactic proteins, cytokines, oxidized LDL, and matrix metalloproteinases. Suppression of the increased ACE activity within the plaque can lead to the stabilization and deactivation of the plaque by reducing inflammation in the vascular wall, thus lessening the risk of rupture and thrombosis and the resultant acute clinical cardiovascular events. The remarkable improvement in the long-term prognosis of atherosclerotic patients with increased cardiovascular risk might be the clinical result of the contribution made by ACE inhibition in the vascular wall.

Elevated levels of acute-phase proteins and plasminogen activator inhibitor-1 predict the development of type 2 diabetes: the insulin resistance atherosclerosis study

Elevated serum levels of acute-phase proteins, indicating chronic subclinical inflammation, have been associated with cardiovascular disease as well as the insulin resistance syndrome. Chronic inflammation may also be a risk factor for developing type 2 diabetes. We studied the concentrations of C-reactive protein (CRP), fibrinogen, and plasminogen activator inhibitor-1 (PAI-1) in 1,047 nondiabetic subjects in relation to incident diabetes within 5 years in the Insulin Resistance Atherosclerosis Study. Subjects with diabetes at follow-up (n = 144) had higher baseline levels of fibrinogen (mean +/- SD; 287.8 +/- 58.8 vs. 275.1 +/- 56.0 mg/dl; P = 0.013) as well as of CRP (median [interquartile range]; 2.40 [1.29, 5.87] vs. 1.67 mg/l [0.75, 3.41]; P = 0.0001) and PAI-1 (24 [15, 37.5] vs. 16 ng/ml [9, 27]; P = 0.0001) than nonconverters. The odds ratio (OR) of converting to diabetes was significantly increased with increasing baseline concentrations of the inflammatory markers. In contrast to PAI-1, the association of CRP and fibrinogen with incident diabetes was significantly attenuated after adjustment for body fat (BMI or waist circumference) or insulin sensitivity (S(I)), as assessed by a frequently sampled intravenous glucose tolerance test. In a logistic regression model that included age, sex, ethnicity, clinical center, smoking, BMI, S(I), physical activity, and family history of diabetes, PAI-1 still remained significantly related to incident type 2 diabetes (OR [95% CI] for 1 SD increase: 1.61 [1.20-2.16]; P = 0.002). Chronic inflammation emerges as a new risk factor for the development of type 2 diabetes; PAI-1 predicts type 2 diabetes independent of insulin resistance and other known risk factors for diabetes.

Selenium and vitamin E supplements for prostate cancer: evidence or embellishment?

Selenium and vitamin E are probably 2 of the most popular dietary supplements considered for use in the reduction of prostate cancer risk. This enthusiasm is reflected in the initiation of the Selenium and Vitamin E Chemoprevention Trial (SELECT). Is there sufficient evidence to support the use of these supplements in a large-scale prospective trial for patients who want to reduce the risk of prostate cancer? Results from numerous laboratory and observational studies support the use of these supplements, and data from recent prospective trials also add partial support. However, a closer analysis of the data reveals some interesting and unique associations. Selenium supplements provided a benefit only for those individuals who had lower levels of baseline plasma selenium. Other subjects, with normal or higher levels, did not benefit and may have an increased risk for prostate cancer. The concept that supplements reduce prostate cancer risk only in those at a higher risk and/or those with lower plasma levels of these compounds is supported by trials examining beta-carotene supplements. Smokers may be the only individuals who benefit, as has also been shown with vitamin E supplementation. In 4 recent prospective studies, vitamin E was found to reduce the risk of prostate cancer in past/recent and current smokers and those with low levels of this vitamin. Vitamin E supplements in higher doses (> or =100 IU) were also associated with a higher risk of aggressive or fatal prostate cancer in nonsmokers from a past prospective study. The dose of vitamin E in the SELECT trial (400 IU/day) is 8 times higher than what has been suggested to be effective (50 IU/day) by the largest randomized prospective trial in which the incidence rate of prostate cancer was used as an endpoint. Recent research also suggests that dietary vitamin E may be associated with a lower risk of prostate cancer than the vitamin E supplement. Additionally, recent results from all past cardiovascular prospective, randomized trials suggest that vitamin E shows little benefit for cardiovascular disease risk, especially at the dose being used in the SELECT trial. Other intriguing positive findings from past prospective studies of supplements suggest that aspirin and other nonsteroidal anti-inflammatory drugs have a role in reducing the risk of prostate cancer or other types of cancer (eg, colon cancer). It may be time to conduct a large costly trial to reconsider the use of selenium and vitamin E supplements for the reduction of prostate cancer risk. Some evidence for the use of these supplements exists, but serious embellishment of study findings may be leading to an inappropriate use of these supplements in a clinical setting.

Endocrine Heart Disease

With the increasing prevalence of obesity and diabetes mellitus in the United States, associated cardiovascular disease is reaching epidemic proportions with staggering economic and societal impact. Numerous studies have demonstrated the poorer prognosis associated with chronic coronary artery disease and acute coronary syndromes in patients with diabetes compared with nondiabetic patients. Although the therapeutic strategy is largely the same for the two populations, proper management of the diabetic patient with cardiovascular disease must account for the associated metabolic disturbances. Thyroid disease is the next most common endocrine disorder that affects proper function of cardiovascular patients; all patients presenting with coronary artery disease or cardiac arrhythmias should undergo screening with a sensitive thyroid-stimulating hormone assay and appropriate treatment when necessary. Though these areas are the most common points of intersection between the cardiologist and endocrinologist, a thorough understanding of the impacts of each endocrine system on cardiac function is essential to recognize disease entities that often present with a cardiovascular manifestation or affect patients with a primary cardiovascular disease.