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

Prevention of Left Ventricular Remodeling After Myocardial Infarction

Postinfarction left ventricular remodeling begins early after acute myocardial infarction and may continue for months to years afterward. Early re-establishment of flow in the occluded artery is associated with smaller left ventricular cavity volumes and reduced remodeling. Acute percutaneous coronary intervention (PCI) or thrombolytic therapy (for patients more than 1 hour away from a catheterization facility) as early as possible after symptoms is critical. Late reperfusion (PCI more than 12 hours after infarction) may prove useful, and this will be determined by the results of ongoing clinical trials. Recurrent MI is reduced by antiplatelet agents (aspirin in most patients) and by 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors. Intravenous nitroglycerin may limit early (initial 24 hours) dilatation following infarction, but long-term use in asymptomatic patients is not efficacious. Beta- adrenergic receptor antagonists and angiotensin-converting enzyme (ACE) inhibitors have independent efficacy in attenuating the early and late phases of remodeling. The combined use of a beta-blocker and an ACE inhibitor has greater efficacy than either agent alone, provided they are tolerated hemodynamically. Although angiotensin II receptor antagonists have similar efficacy to ACE inhibitors and have fewer side effects, the angiotensin II receptor blockers should be reserved for patients intolerant to ACE inhibitors. In patients requiring diuretic therapy, spironolactone is preferred because of its salutary properties regarding extracellular matrix remodeling, specifically in reducing fibrosis. Surgical revascularization with or without associated mitral valve repair is useful in selected patients with severe ischemic mitral regurgitation or hibernating myocardium. New therapies directed at modulating the remodeling process may focus on manipulating the components of the extracellular matrix to reduce the deleterious impact of this process.

Losartan titration versus diuretic combination in type 2 diabetic patients

METHODS

We compared the effects of Losartan dose titration to 100 mg versus the addition of 12.5 mg of hydrochlorothiazide, in 90 type 2 diabetic patients with microalbuminuria and blood pressure > 130/85 mmHg, receiving losartan 50 mg as initial treatment during 4 weeks.

RESULTS

With the first dose of losartan, systolic (SBP) and diastolic blood pressure (DBP) decreased from 154.5 (152.1-157.5) to 144.4 (141.3-147.5) mmHg (P < 0.001) and from 91.1 (89.4-92.8) to 84.6 (82.8-86.4) mmHg (P < 0.001), with 20 patients attaining the expected goal blood pressure (< 130/85 mmHg); albuminuria decreased from 109.8 (90.5-133.3) to 83.5 (63.6-109.5) mg per 24 h (P = 0.006). Patients not attaining the target blood pressure were randomly allocated to titration or to the combination arm. After an additional 4 weeks, patients titrated exhibited a fall in SBP and DBP from 157.1 (152.7-161.5) to 142.1 (136.4-147.8) mmHg (P < 0.001) and from 92.4 (89.5-95.3) to 83.6 (81.1-86.1) mmHg (P < 0.001); albuminuria decreased from 136.3 (97.8-189.9) to 99.7 (69.3-143.4) mg per 24 h (P = 0.002). In the combination arm, there were similar reductions in SBP and DBP from 155.3 (151.5-159.1) to 139.1 (132.1-146.1) mmHg (P < 0.001) and from 92.1 (89.3-94.9) to 80.9 (77.4-84.4) mmHg (P < 0.001); while albuminuria fell from 107.7 (82.2-141.0) to 64.2 (45.9-89.9) mg per 24 h (P = 0.001).

CONCLUSIONS

Losartan 50 mg was effective in reducing blood pressure and albuminuria in type 2 diabetic patients. When the blood pressure target was not reached, the two strategies tested seem to contribute similarly to further reductions in blood pressure and albuminuria.

Use of ramipril in preventing stroke: double blind randomised trial

OBJECTIVE

To determine the effect of the angiotensin converting enzyme inhibitor ramipril on the secondary prevention of stroke.

DESIGN

Randomised controlled trial with 2x2 factorial design.

SETTING

267 hospitals in 19 countries.

PARTICIPANTS

9297 patients with vascular disease or diabetes plus an additional risk factor, followed for 4.5 years as part of the HOPE study.

OUTCOME MEASURES

Stroke (confirmed by computed tomography or magnetic resonance imaging when available), transient ischaemic attack, and cognitive function. Blood pressure was recorded at entry to the study, after 2 years, and at the end of the study.

RESULTS

Reduction in blood pressure was modest (3.8 mm Hg systolic and 2.8 mm Hg diastolic). The relative risk of any stroke was reduced by 32% (156 v 226) in the ramipril group compared with the placebo group, and the relative risk of fatal stroke was reduced by 61% (17 v 44). Benefits were consistent across baseline blood pressures, drugs used, and subgroups defined by the presence or absence of previous stroke, coronary artery disease, peripheral arterial disease, diabetes, or hypertension. Significantly fewer patients on ramipril had cognitive or functional impairment.

CONCLUSION

Ramipril reduces the incidence of stroke in patients at high risk, despite a modest reduction in blood pressure.

Cardiovascular morbidity and mortality in patients with diabetes in the Losartan Intervention For Endpoint reduction in hypertension study (LIFE): a randomised trial against atenolol

BACKGROUND

The most suitable antihypertensive drug to reduce the risk of cardiovascular disease in patients with hypertension and diabetes is unclear. In prespecified analyses, we compared the effects of losartan and atenolol on cardiovascular morbidity and mortality in diabetic patients.

METHODS

As part of the LIFE study, in a double-masked, randomised, parallel-group trial, we assigned a group of 1195 patients with diabetes, hypertension, and signs of left-ventricular hypertrophy (LVH) on electrocardiograms losartan-based or atenolol-based treatment. Mean age of patients was 67 years (SD 7) and mean blood pressure 177/96 mm Hg (14/10) after placebo run-in. We followed up patients for at least 4 years (mean 4.7 years [1.1]). We used Cox regression analysis with baseline Framingham risk score and electrocardiogram-LVH as covariates to compare the effects of the drugs on the primary composite endpoint of cardiovascular morbidity and mortality (cardiovascular death, stroke, or myocardial infarction).

FINDINGS

Mean blood pressure fell to 146/79 mm Hg (17/11) in losartan patients and 148/79 mm Hg (19/11) in atenolol patients. The primary endpoint occurred in 103 patients assigned losartan (n=586) and 139 assigned atenolol (n=609); relative risk 0.76 (95% CI 0.58-.98), p=0.031. 38 and 61 patients in the losartan and atenolol groups, respectively, died from cardiovascular disease; 0.63 (0.42-0.95), p=0.028. Mortality from all causes was 63 and 104 in losartan and atenolol groups, respectively; 0.61 (0.45-0.84), p=0.002.

INTERPRETATION

Losartan was more effective than atenolol in reducing cardiovascular morbidity and mortality as well as mortality from all causes in patients with hypertension, diabetes, and LVH. Losartan seems to have benefits beyond blood pressure reduction.

Cardiovascular morbidity and mortality in the Losartan Intervention For Endpoint reduction in hypertension study (LIFE): a randomised trial against atenolol

BACKGROUND

Blood pressure reduction achieved with beta-blockers and diuretics is the best recorded intervention to date for prevention of cardiovascular morbidity and death in patients with hypertension. Left ventricular hypertrophy (LVH) is a strong independent indicator of risk of cardiovascular morbidity and death. We aimed to establish whether selective blocking of angiotensin II improves LVH beyond reducing blood pressure and, consequently, reduces cardiovascular morbidity and death.

METHODS

We did a double-masked, randomised, parallel-group trial in 9193 participants aged 55-80 years with essential hypertension (sitting blood pressure 160-200/95-115 mm Hg) and LVH ascertained by electrocardiography (ECG). We assigned participants once daily losartan-based or atenolol-based antihypertensive treatment for at least 4 years and until 1040 patients had a primary cardiovascular event (death, myocardial infarction, or stroke). We used Cox regression analysis to compare regimens.

FINDINGS

Blood pressure fell by 30.2/16.6 (SD 18.5/10.1) and 29.1/16.8 mm Hg (19.2/10.1) in the losartan and atenolol groups, respectively. The primary composite endpoint occurred in 508 losartan (23.8 per 1000 patient-years) and 588 atenolol patients (27.9 per 1000 patient-years; relative risk 0.87, 95% CI 0.77-0.98, p=0.021). 204 losartan and 234 atenolol patients died from cardiovascular disease (0.89, 0.73-1.07, p=0.206); 232 and 309, respectively, had fatal or non-fatal stroke (0.75, 0.63-0.89, p=0.001); and myocardial infarction (non-fatal and fatal) occurred in 198 and 188, respectively (1.07, 0.88-1.31, p=0.491). New-onset diabetes was less frequent with losartan. Interpretation Losartan prevents more cardiovascular morbidity and death than atenolol for a similar reduction in blood pressure and is better tolerated. Losartan seems to confer benefits beyond reduction in blood pressure.

Secondary prevention of stroke and the expanding role of the neurologist

Stroke is the leading cause of adult disability and dependency in western society. Following stroke, the risk of myocardial infarction (MI) is increased by a factor of around 2-3 compared with baseline. Indeed, after the first 30 days, stroke survivors are more likely to die from a cardiac event than from a cerebrovascular event. In patients with atherothrombotic stroke, preventing subsequent manifestations of the underlying disease is therefore an important therapeutic goal. A number of options have been shown to reduce the risk of stroke. Aggressively controlling stroke risk factors, such as hypertension, diabetes and smoking, should provide significant benefit in reducing stroke risk; however, it is difficult to realize the full potential of these approaches in routine clinical practice. A number of classes of medication can reduce the risk of stroke and other vascular events, including antiplatelet agents, anticoagulants, angiotensin-converting enzyme inhibitors and statins. Several antiplatelet agents are approved to reduce the risk of recurrent stroke, although only clopidogrel and acetylsalicylic acid (ASA) are approved for the reduction of both stroke and MI in such patients. In the CAPRIE study, clopidogrel showed a statistically significant relative risk reduction of 8.7% (p = 0.043) compared with ASA for the composite endpoint of ischaemic stroke, MI or vascular death. Evidence from animal studies, ex vivo models in humans, and patients undergoing coronary stent insertion or patients with unstable angina/non-Q-wave MI clearly demonstrates the synergistic antiplatelet effect of using clopidogrel with ASA. In summary, most patients with an ischaemic stroke should be treated with an antiplatelet agent to reduce their risk of recurrent stroke, MI, or vascular death. The use of aggressive antiplatelet therapy has the potential to become a new paradigm for managing patients with vascular disease due to atherothrombosis.

Refractory angina pectoris: mechanism and therapeutic options

As the survival of patients with primary coronary events continues to increase, the number of patients presenting with coronary artery disease unsuitable to further revascularization techniques and symptoms refractory to medical therapy also continues to rise. The aims of this review were to define the population of patients with refractory angina pectoris and to present the therapeutic options currently available for this condition. Refractory angina pectoris is defined, and traditional medical therapies are discussed. Then, current therapeutic options for patients with refractory angina are extensively reviewed. A multitude of therapeutic options exist for patients with refractory angina pectoris. Small, uncontrolled studies have shown a potential benefit for additional antiplatelet and antithrombotic therapy. In randomized trials, neurostimulation has been shown to be effective in reducing angina symptoms. Enhanced external counterpulsation is a viable treatment option for select patients with refractory angina. In many randomized trials, laser revascularization has been shown to diminish angina symptoms, although no placebo-controlled studies exist to date. Gene therapy is a promising area of research in this field. Percutaneous in situ coronary venous arterialization is in its infancy, but may be able to treat many patients if proved successful. No data support the role of chelation therapy in this population. Heart transplantation remains a final option for these patients. Further research of the techniques mentioned in this review is warranted. The importance of randomized, double-blinded, placebo-controlled trials cannot be overemphasized, as the placebo effect of these therapies is probably marked.

Pathophysiology of sodium and water retention in heart failure

Heart failure is a leading cause of morbidity and mortality. In the United States, there are more than 5 million patients with heart failure and over 500,000 newly diagnosed cases each year. Numerous advances have been made in our understanding of the pathophysiologic mechanisms contributing to sodium and water retention in this condition. Important alterations in the sympathetic nervous system and the renin-angiotensin-aldosterone system have been described in heart failure, allowing the use of mechanism-specific treatments such as beta-adrenergic receptor antagonism and angiotensin-converting enzyme inhibition. As our understanding of the roles of the natriuretic peptides and the arginine vasopressin-aquaporin-2 system in the pathophysiology of heart failure evolves, treatments directed toward the alterations in these systems in heart failure can be further developed.

Treatment of heart failure in patients with diabetes mellitus

Patients with diabetes mellitus have an increased morbidity and mortality from cardiovascular disease. Both coronary artery disease and congestive heart failure (CHF) are largely responsible for the increased cardiovascular adverse events in patients with diabetes. This review discusses the pathophysiology of CHF, the mechanisms of left ventricular (LV) dysfunction and the neurohormonal mechanisms involved in both LV dysfunction and CHF. Diabetes with and without hypertension is an important cause of LV dysfunction and CHF. Diabetes may be responsible for the metabolic and ultrastructural causes of LV dysfunction, while hypertension may be responsible for the marked fibrotic changes that are found. Experimental induction of diabetes in animals has shed light on the biochemical and ultrastructural changes seen. The role of insulin to reverse both metabolic and structural changes is reviewed both from experimental data and with the limited amount of clinical data available. The therapy of CHF in patients with diabetes is similar to that of patients without diabetes, with therapy directed toward the use of beta-blockers and angiotensin converting enzyme (ACE) inhibitors. As the morbidity and mortality are higher in patients with diabetes, several studies have pointed out the importance of this subgroup where the opportunity to make a significant clinical impact exists. A significant opportunity exists to reduce morbidity and mortality with beta-blockers and ACE inhibitors when ischaemia and CHF are both present. However, studies in patients diabetes have been limited to post hoc subgroup analyses and rarely as predefined subgroups. Clinical trials involving patients with diabetes with and without hypertension and LV dysfunction are clearly needed in the future to adequately address the needs of this high risk subgroup.

Effects of eprosartan versus hydrochlorothiazide on markers of vascular oxidation and inflammation and blood pressure (renin-angiotensin system antagonists, oxidation, and inflammation)

Antagonists of the renin-angiotensin system, such as angiotensin type 1 (AT(1)) receptor inhibitors and angiotensin-converting enzyme inhibitors, are becoming increasingly popular agents in treating patients with systemic hypertension and minimizing organ damage. In the present study, we compared the effects of eprosartan, an AT(1) receptor inhibitor, with the diuretic hydrochlorothiazide in a group of newly diagnosed hypertensive patients with multiple risk factors for atherosclerosis. The subjects were monitored and tested at 0 and 4 weeks to determine their individual effects on vascular and inflammatory markers. Although blood pressure reduction was comparable between the 2 agents, there were notable differences in their effects on markers of inflammation and oxidation. We observed a 28% reduction in neutrophil superoxide anion generating capacity, a 34% reduction in soluble monocyte chemotactic protein-1, and a 35% reduction in soluble vascular cell adhesion molecule with eprosartan therapy (all p <0.05 from the start of therapy). In addition, eprosartan showed further benefit in its ability to increase low-density lipoprotein oxidation lag time, suggesting an increased resistance to oxidation and/or modification of low-density lipoprotein. Although hydrochlorothiazide was effective in blood pressure reduction, there were no significant changes in any of the above parameters after 4 weeks of treatment. These findings suggest that eprosartan, an AT(1) receptor inhibitor, effectively reduces systemic blood pressure and, compared with hydrochlorothiazide, suggests additional benefits in the vasculature by inhibiting mechanisms of inflammation and oxidation.

[Significant incidence of type 2 diabetes on high-risk Spanish population. The IGT Study (2)]

BACKGROUND

Our purpose was to estimate the incidence of type 2 diabetes among a high risk population with or without impaired glucose tolerance (IGT), analysing the progression to diabetes.

PATIENTS AND METHOD

Multicenter cohort study on high risk individuals without diabetes (WHO-85 criteria) in primary health care. Subjects underwent an oral glucose tolerance test measuring fasting plasma glucose (FPG) and plasma glucose at 2 hours (2hPG). Mean follow-up was 37.2 months (4.3-69.7). Phenotypic features, diagnostic variation, diabetes incidence and predictive factors (multivariate analysis and Cox proportional hazards model) were assessed.

RESULTS

We included 243 individuals (148 females), aged 59.7 (10) years, with FPG < 7.8 mM and 2hPG < 11.1 mM. 137 IGT subjects (56.4%) and 106 (43.6%) normal glucose tolerance (NGT) subjects with a similar risk factor impact were evaluated. After the study was closed, 63 (25.9%) subjects developed diabetes: 43 (31.4%) with baseline IGT and 20 (18.9%) with NGT. Overall diabetes incidence increased over time but not proportionally. Mean annual incidence was 9.2% and it dropped to 4.6% when FPG was used as the unique diagnosis criterion (ADA-97). Male under 65 years with both overweight and IGT reported the highest incidence. HbA1c, FPG and 2hPG were independent predictors. Increased HDL cholesterol showed a protective effect on diabetes incidence. The IGT diagnosis interval was a much better predictor [OR = 2.06 (1.56-2.72)] of diabetes development than the impaired FPG diagnosis interval [OR = 1.37 (0.93-2.04)].

CONCLUSIONS

FPG predicted but undervalued diabetes incidence in high risk population. The IGT (2hPG) diagnosis interval predicted diabetes development better than the impaired fasting plasma glucose diagnosis interval. Increased diabetes incidence in high risk Spanish population, particularly with regard to IGT, means that primary preventive resources should be increased.

Antihypertensive therapy and cancer risk

The aim of this article is to provide an overview of the available data linking antihypertensive drug therapy to cancer risk. In recent years, a number of mainly retrospective studies have reached different conclusions on the risk of cancer in patients with hypertension being treated with different antihypertensive drugs. At some point or another nearly all antihypertensive drugs have been suggested to increase the risk of cancer. Some studies have even found an association between hypertension itself and increased carcinogenesis. For calcium channel antagonists, beta-blockers and alpha-blockers, the available evidence seems to favour a neutral effect on cancer development and death rate. For ACE inhibitors, the overall data suggest a similar neutral effect on cancer or, possibly, a small protective effect. Perhaps the strongest evidence in favour of a link, although probably weak, between cancer and antihypertensive drugs is with the diuretics. Until further solid data are available from prospective clinical trials, we suggest that the management of hypertension should continue according to current treatment guidelines with little fear of any substantial cancer risk.

alpha-Tocopherol supplementation decreases plasminogen activator inhibitor-1 and P-selectin levels in type 2 diabetic patients

OBJECTIVE

Type 2 diabetic subjects have an increased propensity to premature atherothrombosis. alpha-Tocopherol (AT), a potent antioxidant, has anti-inflammatory properties at high doses. The aim of the study was to test the effect of natural (RRR)-AT supplementation (1,200 IU/day) on markers of thrombosis, plasminogen activator inhibitor-1 (PAI-1), and soluble P-selectin (sP-selectin) in type 2 diabetic patients with and without macrovascular complications (MVCs) compared with matched control subjects.

RESEARCH DESIGN AND METHODS

The volunteers comprised type 2 diabetic patients with (n=23) and without (n=24) MVCs and matched control subjects (n=25). Plasma levels of PAI-1 and P-selectin were assayed at baseline, after 3 months of supplementation, and after a 2-month washout phase.

RESULTS

Both diabetic groups had significantly increased levels of PAI-1 compared with control subjects (P < 0.025), whereas only type 2 diabetic patients with MVCs had significantly elevated levels of sP-selectin compared with control subjects. AT supplementation significantly lowered levels of PAI-1 and sP-selectin in all three groups. The reduction in PAI-1 levels with AT supplementation was significantly greater in type 2 diabetic patients with MVCs than in those without MVCs (P=0.005).

CONCLUSIONS

Thus, AT therapy decreases markers of thrombosis in diabetic patients and control subjects and could be an adjunctive therapy in the prevention of atherosclerosis.

Selective cyclooxygenase-2 (COX-2) inhibitors and potential risk of cardiovascular events

Selective cyclooxygenase-2 (COX-2) inhibitors were developed as a response to the gastrointestinal toxicity of conventional nonsteroidal anti-inflammatory agents (NSAIDs). However, COX-2 inhibitors decrease vascular prostacyclin (PGI(2)) production and may disrupt the homeostatic mechanisms that limit the effects of platelet activation. Basic and clinical data raise concerns about a potential prothrombotic effect of this class of drugs. The widespread popularity of these agents mandates their prospective evaluation in patients with cardiovascular diseases or who are at risk for cardiovascular events.

Effect of the Heart At Work program on awareness of risk factors, self-efficacy, and health behaviors

This study evaluates the effects of the American Heart Association's Heart At Work program on cardiovascular disease risk factor awareness, self-efficacy, and health behaviors. A prospective, quasi-experimental research design was used to assess the impact of the program at two factory sites (one intervention and one control). A total of 633 employees participated. Intervention site respondents significantly improved their knowledge of blood pressure management, the relationship between nutrition and cardiovascular disease, and heart attack risk factors. They also were more likely to begin treatment for hypertension, to report fewer sick days, and to have plans to improve their diet and lose weight. These findings suggest that the Heart At Work program had a favorable overall impact.

Considerations for treating dyslipidemia in special diabetic populations

This is a review of the problem of dyslipidemia and cardiovascular disease (CVD) in special diabetic populations. Clearly all patients with diabetes are at increased risk for CVD compared to non-diabetic populations. But within the subset that is patients with diabetes there are individuals who are particularly vulnerable. These groups include women, who are often overlooked and undertreated for their cardiovascular risk. Additionally, it includes those with fewer resources, many from minority populations, who are at very high risk for poor preventive care and serious cardiovascular morbidity. This review details the risk for CVD in a variety of different diabetic high-risk groups. It then discusses treatment options and approaches that should be employed in these populations.

Interactions of nitric oxide and peroxynitrite with low-density lipoprotein

Nitric oxide (*NO) is a free radical species that diffuses and concentrates in the hydrophobic core of low-density lipoprotein (LDL) to serve as a potent inhibitor of lipid oxidation processes. Peroxynitrite (PN), the product of the diffusion-limited reaction between *NO and superoxide (O2*-) represents a relevant mediator of oxidative modifications in LDL. The focus of this review is the analysis of interactions between *NO and PN and its secondary reactions with oxygen radicals on LDL oxidation, which are relevant in the development of the early steps as well as progression of atherosclerosis. We propose that the balance between rates of PN and *NO production, which greatly depends on oxidative stress processes within the vascular wall, will critically determine the final extent of oxidative LDL modifications leading or not to scavenger receptor-mediated LDL uptake and foam cell formation.

Hypertension and diabetes

Hypertension is often associated clinically with diabetes either as part of the insulin resistance syndrome or as a manifestation of renal disease. Elevated systemic blood pressure accelerates the progression of both microvascular and macrovascular complications in diabetes. Agents that interrupt the renin-angiotensin system confer renoprotection via a range of hemodynamic and nonhemodynamic mechanisms. Recent clinical trials confirm that these agents confer renoprotection in type 1 and type 2 diabetic patients with early or advanced renal disease. Hypertension also appears to accelerate vascular and cardiac abnormalities in diabetes, including increased atherosclerosis, arterial stiffness, left ventricular hypertrophy and diastolic dysfunction. A number of recently published and ongoing trials are exploring the role of aggressive antihypertensive treatment with a range of antihypertensive drugs in diabetic subjects at risk of or with macrovascular disease.

Endothelial dysfunction, angiotensin-converting enzyme inhibitors and calcium antagonists

The endothelium plays a crucial role in the pathogenesis of cardiovascular disease. Endothelial function is attenuated by the presence of different well known cardiovascular risk factors. Evaluation of endothelial vasodilator function serve as an index integrating the overall stress imposed by cardiovascular risk factors and reinforce the suggestion that endothelial dysfunction is an early marker of cardiovascular disease that precedes clinical manifestations. Angiotensin-converting enzyme inhibitors have been shown to reduce the cardiovascular mortality, an effect that could be the consequence of an improvement in the endothelial function. Recent studies have shown that a calcium antagonist might improve the endothelial function, however, there is controversy about this action and also about the potential mechanisms for the effect of a calcium antagonist in the regulation of endothelial function.

Impact of angiotensin converting enzyme inhibition on post-coronary artery bypass interleukin 6 release

BACKGROUND

Angiotensin 1 converting enzyme (ACE) inhibitors reduce morbidity and mortality after coronary artery bypass graft surgery (CABG). This benefit may result from an anti-inflammatory action.

OBJECTIVE

To examine the effect of ACE inhibition on interleukin 6 (IL-6) concentrations after CABG.

PATIENTS AND METHODS

161 patients undergoing elective first time CABG were recruited, of whom 41 (25%) were receiving ACE inhibitor treatment; 21 patients with confounding postoperative complications were excluded. After these exclusions there were 33 patients (24%) on ACE inhibitor treatment. Plasma IL-6 was measured preoperatively and again six hours after CABG.

RESULTS

Baseline IL-6 concentrations (geometric mean (SEM)) were non-significantly lower among the patients receiving ACE inhibitors (3.7 (0.1) v 4.3 (0.1) pg/ml, p = 0.12). Overall, post-CABG IL-6 concentrations increased significantly (mean rise 177 (12) pg/ml, p < 0.0005). This response was blunted among ACE inhibitor treated patients. Median increases in IL-6 concentrations were 117 v 193 pg/ml, for treated v non-treated patients, respectively (Kruskal-Wallis, p = 0.02), with peak postoperative IL-6 concentrations lower among the subjects receiving ACE inhibitors than in untreated subjects (142 (19) v 196 (13) pg/ml, p = 0.02). The effect of ACE inhibitors remained significant after multivariate analysis (p = 0.018).

CONCLUSIONS

ACE inhibitor treatment is associated with a reduction in IL-6 response to CABG. The data suggest that this class of drug may have a direct anti-inflammatory effect, which could explain some of its clinical benefit.

Ramipril administration to atherosclerotic mice reduces oxidized low-density lipoprotein uptake by their macrophages and blocks the progression of atherosclerosis

Foam cell formation, the hallmark of early atherosclerosis, results from cholesterol accumulation in arterial macrophages. Angiotensin-II stimulates foam cell formation and angiotensin converting enzyme (ACE) inhibitors reduce atherosclerosis in animal models. The goal of the present study was to determine the effect of the ACE inhibitor Ramipril on the progression of atherosclerosis in apolipoprotein-E-deficient (E0) mice with already advanced atherosclerosis. Therefore, 4-month-old atherosclerotic E0 mice were treated with Ramipril for 2 and 4 months and compared to age-matched placebo-treated mice, as well as to control young (4-month-old) non-treated E0 mice, for their atherosclerosis. Histomorphometry showed that Ramipril treatment substantially inhibited atherogenesis as shown by 48 and 72% reduction in lesion size at 6 and 8 months of age, respectively, compared to the lesion size in age-matched placebo-treated mice. Moreover, the size of the atherosclerotic lesions in 6- and 8-month-old Ramipril-treated mice was almost identical to the size of atherosclerosis of the 4-month-old control mice. Moreover, Ramipril treatment of E0 mice, significantly reduced oxidized low-density lipoprotein (Ox-LDL) uptake by their peritoneal macrophages (MPM) by 32%, compared to Ox-LDL uptake by MPM from 6-month-old placebo mice, and even reduced it by 12% in comparison to Ox-LDL uptake by MPM from 4-month-old control mice. A significant decrease in the mRNA levels of the Ox-LDL receptor CD36 by 58% was observed in macrophages from 6-month-old Ramipril-treated mice compared to macrophages from the 6-month-old placebo-treated mice. There was even a significant reduction (by 32%) in CD36 mRNA levels in macrophages from the 6-month-old Ramipril-treated mice, compared to the CD36 mRNA levels in macrophages from the 4-month-old control mice. We thus conclude that administration of the ACE inhibitor Ramipril to E0 mice, which already exhibit significant atherosclerosis, blocked the progression of the atherosclerotic lesion build-up, a phenomenon that could be related to Ramipril-induced inhibition of Ox-LDL uptake by macrophages.

Prevention of ischemic stroke

The primary risk factors for stroke are known, and attention to primary care of these disorders should reduce the incidence of stroke significantly. Control of hypertension, diabetes, and hyperlipidemia have all been shown to reduce the rate of stroke. Identification of potential cardioembolic sources of stroke, particularly atrial fibrillation, can prevent stroke with appropriate application of anticoagulation. Duplex Doppler B-mode sonography can establish the extent of carotid artery disease in patients with cervical bruit or risk factors for atherosclerosis, and indicate which conditions should be managed medically or surgically. Patients with a history suggestive of transient ischemic attacks can also be screened noninvasively with duplex sonography to determine if they have a critical carotid stenosis and require carotid endarterectomy. New advances in platelet antiaggregant therapy with ticlopidine, clopidegril, and the combination of aspirin with dipyridamole have also reduced the rate of stroke to a greater degree than standard treatment with aspirin. The incidence of this devastating illness could possibly be reduced by 50% with attentive primary care management. The cardiologist is often involved in the treatment of patients at risk for stroke, and is in an ideal position to provide this care.

Blockade of endothelial enzymes: new therapeutic targets

Nitric oxide (NO) is the principal vasoactive substance produced by the vascular endothelium with antitrombotic, antiatherogenic and vasodilator actions. The loss of these functions is now known as endothelial dysfunction (ED) and it has been proposed that it is the final common pathway in cardiovascular disease. At the moment there is an important body of evidence that supports the proposal that ED is a consequence of an imbalance between the free radicals, NO, superoxide (O(-)(2)) and peroxynitrate (ONOO(-)). This imbalance is the result of the actions of well known risk factors associated with an inappropriate diet and infection-inflammation. Angiotensin-converting enzyme (ACE) inhibitors are highly effective against a variety of cardiovascular disorders. Experimental and clinical studies have demonstrated a beneficial effect of ACE inhibition on endothelial function. This action is mainly due to an increase in the concentration of bradykinin, which stimulates NO production. ACE inhibitors also block the formation of angiotensin II that results in a lower production of O(-)(2). These effects lead to improve the imbalance between NO and O(-)(2) observed in cardiovascular disease. This proposal is supported by different clinical trials that have shown that the ACE inhibitors with higher affinity by the tissular ACE, such as quinapril, are the most effective in reversing ED principally by accumulating bradykinin. Recently, the HOPE study conducted in patients at a high risk of cardiovascular events, showed how ramipril, an ACE inhibitor with high affinity by tissular ACE, decreased the mortality rate due to cardiovascular disease independently of changes in blood pressure.

Cardiovascular disease: much more aggressive in patients with type 2 diabetes

It is estimated that 80% of individuals with type 2 diabetes die of coronary heart disease. Several factors have been found to contribute to the accelerated atherosclerosis present in diabetic patients. These include hyperglycemia-induced endothelial cell dysfunction, impaired fibrinolysis, increased platelet aggregation, and dysfunctional arterial remodeling. The evidence supports that a healthy lifestyle, statin drugs, angiotensin-converting enzyme inhibitors, and aspirin can modify these factors and slow the atherosclerosis process observed in type 2 diabetes. Because of the high prevalence of cardiovascular disease in people with type 2 diabetes, early cardiac testing is indicated. The optimal strategy for coronary revascularization in diabetic patients remains controversial and is discussed in detail in this review.

Atherothrombosis: plaque instability and thrombogenesis

Hemostasis involves a carefully regulated balance between circulating and endothelium-derived prothrombotic and antithrombotic factors. The unstable or vulnerable plaque facilitates thrombosis, clinically manifest as an acute coronary syndrome (ACS), by creating an environment that favors thrombus formation over prevention of lysis. Endothelial cell dysfunction is integral to both the development of the atherosclerotic lesion as well as its destabilization. The transformation of a stable plaque to an unstable one involves complex interactions among T lymphocytes, macrophages, endothelial cells, and smooth muscle cells. Degradation of the fibrous cap of the atherosclerotic lesion as well as the overexpression of prothrombotic and underexpression of antithrombotic factors by cells within the plaque precede thrombus formation. Accordingly, pharmacological interventions for the treatment of ACS are directed against the initiation and propagation of thrombosis, as well as toward improvement of endothelial function.

Glucose, blood pressure, and lipid control in older people with and without diabetes mellitus: the Cardiovascular Health Study

OBJECTIVES

To determine the prevalence of cardiovascular risk-factor treatment and control in older adults with normal fasting glucose, impaired fasting glucose, and diabetes mellitus and whether those with diabetes mellitus had better risk factor control than older adults with normal fasting glucose.

DESIGN

Secondary analysis of data from population-based, prospective cohort study of risk factors for cardio-vascular and cerebrovascular disease in older people (Cardiovascular Health Study).

SETTING

Community-based.

PARTICIPANTS

Community-dwelling adults aged 65 and older.

MEASUREMENTS

Fasting plasma glucose, serum cholesterol and its subfractions, systolic and diastolic blood pressures, and body mass index.

RESULTS

There were 579 (18%) cohort members with diabetes mellitus (77% receiving antidiabetic medication, 23% with fasting glucose > or =126 mg/dL and no treatment), 213 (6%) with impaired fasting glucose, and 2,582 (77%)with normal fasting glucose. Of diabetic participants, 12% had recommended fasting glucose levels of less than 110 mg/dL. Of participants with hypertension, a larger proportion of diabetic participants than nondiabetic participants (89% versus 75%, P < .01) was treated with antihypertensive agents, but a smaller proportion of diabetic participants had recommended blood pressure levels of 129/85 mmHg or lower than nondiabetic participants had recommended blood pressure levels of 139/89 mmHg or lower (27% vs 48%, P < .01). Diabetic dyslipidemic participants were treated less often with lipid-lowering therapy (26% versus 55%, P < .01) and achieved recommended low-density lipoprotein goals less often (8%versus 54%, P < .01) than nondiabetic dyslipidemic participants.

CONCLUSIONS

Overall, treatment and control of cardiovascular risk factors were suboptimal in this older population, especially among those with diabetes mellitus. Optimizing risk-factor control can improve health outcomes in older adults with and without diabetes mellitus.

Stroke prevention therapy beyond antithrombotics: unifying mechanisms in ischemic stroke pathogenesis and implications for therapy: an invited review

BACKGROUND

It is estimated that about half of cardiovascular disease risk is explained by conventional risk factors. The realization that atherosclerosis is an inflammatory disease has led to a search for new stroke and cardiovascular disease risk factors and treatments. As such, the vulnerable atherosclerotic plaque has become the main focus for new medical strategies for plaque stabilization and stroke prevention.

SUMMARY OF REVIEW

In this invited review, I discuss inflammation as a possible risk factor for stroke, unifying mechanisms in ischemic stroke pathogenesis, and new avenues for stroke prevention---statin agents, angiotensin-converting enzyme inhibitors, and vitamins. These new stroke prevention therapies may help to reduce inflammation, serve to stabilize the atherosclerotic plaque, or act by other protective mechanisms.

CONCLUSION

Beyond the traditional antithrombotic agents, statin agents, angiotensin-converting enzyme inhibitors, and vitamins may prove to be important additions to our armamentarium for stroke prevention.

Aldosterone and D-glucose stimulate the proliferation of human cardiac myofibroblasts in vitro

The renin-angiotensin-aldosterone-system appears to be involved in the development of cardiac fibrosis in rodents, characterized by nonepithelial cell proliferation and changes in the extracellular matrix. The aim of our study was to investigate the effect of high aldosterone concentrations on the proliferation of human cardiac interstitial cells in vitro. In addition, the effect of D-glucose as another risk factor for fibrosis, eg, in the diabetic heart, was investigated. Human cardiac myofibroblast cultures were established, and growth rates were measured by WST-1 assay in fetal calf serum-free Dulbecco's modified Eagle's medium (DMEM). Cells in culture showed a significant increase in number between 24 to 72 hours of cultivation under basal conditions (DMEM, 10% fetal calf serum). Aldosterone at high concentrations (10(-8) and 10(-7) mol/L) significantly (P<0.01) increased the proliferation of cultured cardiac myofibroblasts. Comparable effects were observed after incubation of the cells with high D-glucose concentrations (15 and 25 mmol/L, P<0.01). No additive growth stimulation was evident when the cells were incubated in medium containing both aldosterone and D -glucose. These results suggest a role for aldosterone and glucose in mediating the cardiac fibrosis through stimulation of myofibroblast growth in patients with dysregulated renin-angiotensin-aldosterone-system (especially hyperaldosteronism) and impaired glucose homeostasis.

Renin-angiotensin system blockade and the risk of hyperkalemia in chronic hemodialysis patients

BACKGROUND

Blockade of the renin-angiotensin system by angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers can cause hyperkalemia in patients with chronic renal insufficiency who are not on dialysis, but the risk of hyperkalemia in hemodialysis patients is unknown.

SUBJECTS AND METHODS

We conducted a prospective study of 251 adult hemodialysis patients to determine if renin-angiotensin system blockade was associated with hyperkalemia, defined as a predialysis serum potassium concentration of 5.5 mmol/L or higher. Medication use was determined by chart review and patient interview. Predialysis serum potassium concentration was measured monthly.

RESULTS

There were 367 episodes of hyperkalemia during 1877 person-months of follow-up. After adjustment for potential confounding variables and for clustering of episodes by patient, use of an ACE inhibitor or an angiotensin receptor blocker was associated with a significantly higher risk of hyperkalemia (odds ratio [OR] = 2.2; 95% confidence interval [CI]: 1.4 to 3.4). The increased risk of hyperkalemia with renin-angiotensin system blockade was seen in anuric dialysis patients (OR = 2.3; 95% CI: 1.3 to 4.2), as well as those with residual renal function (OR = 2.1; 95% CI: 1.0 to 4.1).

CONCLUSION

The use of ACE inhibitors or angiotensin receptor blockers is independently associated with an increased risk of developing hyperkalemia in chronic hemodialysis patients. The serum potassium concentration should be closely monitored when these medications are prescribed for hemodialysis patients.

Perindopril alters vascular angiotensin-converting enzyme, AT(1) receptor, and nitric oxide synthase expression in patients with coronary heart disease

Angiotensin-converting enzyme inhibitors (ACEi) reduce cardiovascular morbidity and mortality by improving coronary perfusion, reducing ventricular hypertrophy and remodeling, and preventing progression of coronary atherosclerosis. However, the cellular mechanisms underlying the beneficial effects of ACEi are not fully understood. We studied the in vivo effects of ACE inhibition with perindopril on cellular expression of ACE, AT(1) receptors and 2 nitric oxide synthase (NOS) isoforms, endothelial (eNOS) and inducible NOS (iNOS), in human blood vessels using quantitative in vitro autoradiography and immunocytochemistry. Seven patients with ischemic heart disease were treated with perindopril (4 mg/d) for up to 5 weeks before elective coronary bypass surgery, whereas controls did not receive the ACEi (n=7). Perindopril decreased plasma ACE by 70% and the plasma angiotensin II to angiotensin I ratio by 57% and reduced vascular ACE to approximately 65% of control levels in both endothelium and adventitia. By contrast, AT(1) receptor binding in vascular smooth muscle cells was increased by 80% in patients treated with perindopril as confirmed by immunocytochemistry. eNOS was expressed primarily in endothelial cells, whereas little iNOS expression occurred in vascular smooth muscle cells of untreated patients. Both eNOS and iNOS expression seemed to increase during perindopril treatment. These results suggest that suppression of angiotensin II formation in the vascular wall and increased expression of eNOS and iNOS during ACE inhibition may be beneficial in reversing endothelial dysfunction in patients with cardiovascular disease. Because vascular AT(1) receptor expression is increased during chronic ACE inhibition, more clinical studies are required to determine whether it is necessary to combine ACE inhibitors and AT(1) receptor antagonists in clinical management of heart failure, coronary heart disease, and hypertension

The use of ACE inhibitors on diabetic patients without renal disease

Strategies that interrupt the renin-angiotensin system, especially with angiotensin-converting enzyme (ACE) inhibition, reduce cardiovascular disease mortality and morbidity in high-risk persons such as those with the insulin resistance syndrome and diabetes mellitus. In the 1980s emphasis was placed on the renal protective effects of ACE inhibitors in patients with diabetes and proteinuria. During the past several years controlled clinical trials have demonstrated that ACE inhibition reduces cardiovascular disease (CVD) mortality and morbidity. This is especially important in patients in the United States, where 80% of excess mortality for diabetes mellitus is attributed to CVD. This article reviews the clinical trials in high-risk patients, especially those with diabetes, that shown beneficial CVD risk reduction with ACE inhibitors.

Design of the Omapatrilat in Persons with Enhanced Risk of Atherosclerotic events (OPERA) trial

The Omapatrilat in Persons with Enhanced Risk of Atherosclerotic events (OPERA) trial is a large clinical trial of omapatrilat, a vasopeptidase inhibitor, in patients with stage 1 isolated systolic hypertension (ISH). OPERA is the first study to examine whether effective antihypertensive treatment can provide survival and clinical end point benefits in older persons with this common condition. This 5-year multinational, randomized, double-blind, parallel-group, placebo-controlled, forced-titration study will be conducted in approximately 12,600 subjects randomized by approximately 1100 study centers worldwide over a recruitment period of approximately 2 years. The primary objective of OPERA is to determine whether treatment with once-daily omapatrilat (target dose 40 mg) will reduce cardiovascular (CV) morbidity and mortality in older (> or = 65 years) men and women with enhanced risk for atherosclerotic events due to stage 1 ISH plus other risk factors for which currently there is no evidence-based requirement for treatment. Blood pressure inclusion criteria are systolic blood pressure (SBP) 140 to 159 mm Hg (SBP 125 to 139 mm Hg in diabetic individuals) and diastolic blood pressure (DBP) <90 mm Hg. The primary end point is defined as the composite of fatal/nonfatal stroke, fatal/nonfatal myocardial infarction, fatal/nonfatal heart failure, and other CV mortality. Secondary end points include the individual components of the primary end point, CV mortality, and major cardiovascular end points, as well as effects on cognitive function and initiation of treatment for diabetes. Additional analyses will be conducted in men and women, in diabetic patients, in different risk classes and according to prior evidence of vascular disease.

Spironolactone abolishes the relationship between aldosterone and plasminogen activator inhibitor-1 in humans

Recent studies have defined a link between the renin-angiotensin-aldosterone system and fibrinolysis. The present study tests the hypothesis that endogenous aldosterone regulates plasminogen activator inhibitor-1 (PAI-1) production in humans. Hemodynamic parameters, PAI-1 and tissue-type plasminogen activator (t-PA) antigen, potassium, PRA, angiotensin II, and aldosterone were measured in nine male hypertensive subjects after a 3-wk washout, after 2 wk of hydrochlorothiazide (HCTZ; 25 mg plus 20 mmol KCl/d), and after 2 wk of spironolactone (100 mg/d plus KCl placebo). Spironolactone (P = 0.04), but not HCTZ (P = 0.57 vs. baseline; P = 0.1 vs. spironolactone), significantly lowered systolic blood pressure. Angiotensin II increased from baseline during both HCTZ (P = 0.02) and spironolactone (P = 0.02 vs. baseline; P = 0.19 vs. HCTZ) treatments. Although both HCTZ (P = 0.004) and spironolactone (P < 0.001 vs. baseline) increased aldosterone, the effect was greater with spironolactone (P < 0.001 vs. HCTZ). HCTZ increased PAI-1 antigen (P = 0.02), but did not alter t-PA antigen. In contrast, there was no effect of spironolactone on PAI-1 antigen (P = 0.28), whereas t-PA antigen was increased (P = 0.01). There was a significant correlation between PAI-1 antigen and serum aldosterone during both baseline and HCTZ study days (r(2) = 0.57; P = 0.0003); however, treatment with spironolactone abolished this correlation (r(2) = 0.13; P = 0.33). This study provides evidence that endogenous aldosterone influences PAI-1 production in humans.

Inhibition of the renin-angiotensin system ameliorates genetically determined hyperinsulinemia

This study was performed in order to assess the potentially different effects of the angiotensin-converting enzyme inhibitor captopril and of the angiotensin II receptor antagonist irbesartan on the metabolic syndrome in an animal model. Male NZO/BL6 F1 mice were treated with captopril, irbesartan, or placebo for 10 months: Control animals treated with placebo developed a metabolic syndrome with obesity (55.5+/-6.3 g), hypertension (146+/-10 mm Hg), hyperinsulinemia (7.2+/-5.7 ng/ml), hypercholesterolemia (5.1+/-0.7 mmol/l), cardiac hypertrophy (269+/-44 mg) and atherosclerotic plaques in the ascending aorta (3.6+/-1.5 microm(2)). Treatment with angiotensin-converting enzyme inhibitor or angiotensin II receptor antagonist significantly (p<0.001) reduces hypertension (73+/-5 and 78+/-11 mm Hg), cardiac hypertrophy (203+/-26 and 202+/-18 mg) and atherosclerosis (2.2+/-0.9 and 1.8+/-0.8 microm(2)). In addition, they prevented the development of obesity (42.2+/-3.5 and 38.3+/-2.8 g) and hyperinsulinemia (3.6+/-1.5 and 1.8+/-0.4 ng/ml). In conclusion, long-term treatment with an angiotensin-converting enzyme inhibitor or an angiotensin II receptor antagonist can ameliorate obesity and hyperinsulinemia in a genetically determined mouse model.

C-reactive protein predicts death in patients with previous premature myocardial infarction--a 10 year follow-up study

Atherosclerosis is an inflammatory disease. C-reactive protein (CRP), a marker of inflammation, is associated with coronary heart disease (CHD). We measured CRP in a cohort of 247 patients (193 males and 54 females) who had had their first myocardial infarction (MI) at age < or = 55 (males) or < or = 60 (females). The cut-off values of the 25th, 50th and 75th centiles of CRP were 1.20, 2.37 and 4.20 mg/l. After 10 years, a total of 44 patients (17.8%) had died, 36 (81.8%) of cardiac causes. Unadjusted and adjusted (i.e. for age, ejection fraction (EF), serum total cholesterol (TC), fibrinogen, smoking and hypertension) relative risks (RRs) for total and cardiac mortality were generated. CRP was a strong predictor of death of all causes due to its strength as predictor of cardiac death. The RR of cardiac death was doubled with increasing CRP quartiles, and patients in the top quartile had six times as high risk of cardiac death as patients in the lowest quartile. The RRs were moderately attenuated after adjustment, but still significant. We conclude that CRP is a strong predictor of mortality in patients with premature MI. Thus, inflammation appears to be a critical prognostic factor in patients with previous premature MI.

Potential indications for angiotensin-converting enzyme inhibitors in atherosclerotic vascular disease

Angiotensin-converting enzyme (ACE) inhibitors are well established as first-line therapy for patients with left ventricular dysfunction, diabetic patients with hypertension or renal disease, and patients recovering from myocardial infarction. Angiotensin II and bradykinin regulate cellular proliferation, inflammation, and endothelial function, thus playing an important role in the pathogenesis of atherosclerosis. A large body of experimental evidence reporting that ACE inhibitors limit these effects has formed the rationale for major clinical trials of these drugs in the management of atherosclerotic vascular disease. The first trial to be completed demonstrated that ACE inhibition improves the prognosis of patients who have, or are at risk of, atherosclerotic vascular disease, independent of its effects on left ventricular function and hypertension. Expanding the indications for ACE inhibitors is now evidence driven, although the choice of agent for these new indications remains to be determined by further research.