Blood-pressure reduction and cardiovascular risk in HOPE study

Metabolic syndrome in South Asians

Metabolic syndrome (MS) is a cluster of multiple cardio-metabolic risk factors in the same individual. People with MS are at high risk for the development of cardiovascular disease (CVD), chronic kidney disease (CKD), and cerebrovascular disease (CeVD). The excessive presence of MS in South Asians is likely responsible for significant morbidity in this population. This review discusses the scope of MS in South Asians and measures to combat its effects by preventive and therapeutic measures.

Beyond blood pressure: evidence for cardiovascular, cerebrovascular, and renal protective effects of renin-angiotensin system blockers

For patients with hypertension, effective control of blood pressure (BP) reduces cardiovascular (CV), and renal risk. Antihypertensive agents that offer benefits that extend beyond those associated with BP reduction alone, to include tissue protective effects and effects on the vasculature, may be of benefit for many patients with increased CV risk due to comorbidities or prior history of CV events. Renin-angiotensin system (RAS) blockers [angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs)] are guideline-recognized, highly effective antihypertensive agents that exert their BP-lowering action through different mechanisms at different levels of the RAS. Large-scale clinical studies suggest that small, between-treatment differences in BP lowering do not account for observed outcome differences between RAS blockers and other antihypertensive agents. Analysis of data from seminal clinical studies and meta-analyses identify that, controlling for effects on BP control, RAS blockers may be more effective than calcium channel blockers (CCBs) in reducing risk of myocardial infarction and congestive heart failure; ARBs may be more effective than either ACEIs or β blockers in stroke prevention; CCBs may be more effective than RAS blockers in stroke prevention; and ARBs may be more effective than β blockers in reducing left ventricular hypertrophy. This review considers the rationale and evidence for benefits of RAS blockade beyond BP lowering, and highlights the differences between ARBs and ACEIs, and between agents within these drug classes.

Renin-Angiotensin system modulators modestly reduce vascular risk in persons with prior stroke

BACKGROUND AND PURPOSE

Although the efficacy of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers in reducing future vascular events for patients with coronary heart disease is established, less is known about the precise benefit of these agents among patients with stroke. We evaluated whether use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers reduces future vascular events in persons with prior stroke.

METHODS

We searched PubMed, Cochrane Central Register of Controlled Trials, and bibliographies of relevant trials and recent review articles to identify randomized controlled trials. Relative risk with 95% CI was used as a measure of the association between use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers and risks of major vascular event (nonfatal stroke, nonfatal myocardial infarction, or death from cardiovascular causes) or stroke (ischemic or hemorrhagic) after pooling data across trials.

RESULTS

Eight randomized controlled trials with 29 667 participants were identified. Use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers in persons with prior stroke was associated with lower risks of future major vascular events (relative risk, 0.91; 95% CI, 0.87-0.97; P=0.001; number needed to treat=71) and recurrent stroke (relative risk, 0.93; 95% CI, 0.86-0.99; P=0.03; number needed to treat=143). Heterogeneity was found among studies for end points of major vascular events (P=0.02, I(2)=61%) but not recurrent stroke (P=0.38, I(2)=6%). In subgroup analyses, there was generally no obvious heterogeneity among different study characteristics.

CONCLUSIONS

Treatment with an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker has a clear but rather modest effect on reducing vascular risk in persons with prior stroke.

Angiotensin-converting enzyme inhibitors or angiotensin receptor blockers are beneficial in normotensive atherosclerotic patients: a collaborative meta-analysis of randomized trials

AIMS

It is unclear whether angiotensin-converting enzyme inhibitors (ACE-I) or angiotensin receptor blockers (ARB) are beneficial in individuals with, or at increased risk for, atherosclerotic vascular disease who are normotensive.

METHODS AND RESULTS

Two investigators independently searched MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials from 1980 to 2011, bibliographies, and contacted primary study authors for randomized placebo-controlled outcome trials evaluating ACE-I or ARB which enrolled at least 1000 patients with, or at increased risk for, atherosclerotic vascular disease and followed them for at least 12 months. We approached all eligible trials to obtain data stratified by baseline systolic pressures. We pooled data from 13 trials of 80 594 patients; outcomes included 9043 all-cause deaths, 5674 cardiovascular deaths, 3106 myocardial infarctions, and 4452 strokes. Angiotensin-converting enzyme inhibitors or ARB reduced the composite primary outcome of cardiovascular death, non-fatal myocardial infarction, or non-fatal stroke by 11% (95% confidence interval 7-15%), with no variation in efficacy across baseline systolic blood pressure strata. In patients with baseline systolic pressure <130 mmHg, ACE-I or ARB reduced the composite primary outcome by 16% (10-23%) and all-cause mortality by 11% (4-18%)-this benefit was consistent across all subgroups examined including those without systolic heart failure (OR: 0.81, 95% CI: 0.75-0.88) and those without diabetes (OR: 0.79, 95% CI: 0.70-0.89).

CONCLUSION

Angiotensin-converting enzyme inhibitors or ARB are beneficial in patients with, or at increased risk for, atherosclerotic disease even if their systolic pressure is <130 mmHg before treatment.

Statistics-based research--a pig in a poke?

Much of medical research involves large-scale randomized controlled trials designed to detect small differences in outcome between the study groups. This approach is believed to produce reliable evidence on which the management of patients is based. But can we be sure that the demonstration of a small, albeit statistically significant, difference is sufficient to infer the presence of a causal relationship between the drug and the outcome? A study is claimed to have internal validity when other explanations for the observed difference - namely, inequalities between the groups, bias in the assessment of the outcome and chance - have been excluded. Despite the various processes that are put into place - including, for example, randomization, allocation concealment, double-blinding and intention-to-treat analysis - it remains doubtful whether the groups are equal in terms of all factors relevant to the outcome and whether bias has been excluded. As for the exclusion of chance, not only may inappropriate statistical tests be used, but also frequentist statistics has been subjected to serious criticisms in recent years that further bring internal validity into question. But the problems do not end with the flaws in internal validity. The philosophical basis of large-scale randomized controlled trials and epidemiological studies is unsound. When examined closely, many obstacles emerge that threaten the inference from a small, statistically significant difference to the presence of a causal relationship between the drug and the outcome. Given the influence of statistics-based research on the practice of medicine, it is of the utmost importance that the flaws in this methodology are brought to the fore.

[Blood pressure goals on the test bench]

There is little evidence from controlled prospective studies to support the low blood pressure goals stipulated for the treatment of hypertension by present guidelines, especially in high-risk patients with diabetes, renal insufficiency or coronary heart disease. Aim of this review is to scrutinize the potential benefit and risk of low blood pressure on the basis of recent studies and secondary analyses of older studies.

RESULTS

In patients with coronary heart disease or equivalent or with diabetes lowering systolic blood pressure to 130 to 135 mmHg reduced primary or secondary cardiovascular endpoints in the majority of studies. Between 120 and 129 mmHg some positive effects could be shown in patients with coronary heart disease but not in patients with diabetes or metabolic syndrome. In patients with diabetic or nondiabetic nephropathy including those with proteinurea no convincing data exist which show a better outcome with systolic blood pressure below 130 versus below 140 mmHg. However, several studies suggest that the risk of stroke may decrease by lowering systolic pressure to 120 mmHg or even lower. Below 120 mmHg an increased risk of cardiac and noncardiac events or death was shown in quite a number of studies. In patients between 70 and 80 years, current evidence suggests lowering systolic blood pressure to 135 to 145 mmHg and in those above 80 years to 145 to 155 mmHg. No evidence was found to justify different diastolic pressure goals for different groups of patients; optimal values fall between 70 and 85 mmHg. Limitations of recent studies are short follow-up, few event rates and small differences in achieved pressure between groups leaving uncertainty about long-term effects.

PRACTICAL CONSEQUENCES

Apart from prevention of stroke there is sparse evidence that lowering systolic blood pressure below 130 mmHg may be beneficial. Current evidence suggests that lowering systolic and diastolic pressure into a range of 130 to 140/70 to 85 may be adequate for all patients with the exception of children, adolescents and patients over 80 years. Further lowering of systolic pressure seems to offer little additional benefit and lowering diastolic pressure below 70 mmHg might increase risk.

Metabolic and cardiovascular outcomes in patients with Cushing's syndrome of different aetiologies during active disease and 1 year after remission

OBJECTIVE

Cushing's syndrome is associated with several comorbidities responsible for the increased cardiovascular risk, not only during the active phase but also after disease remission.

DESIGN

In 29 patients with Cushing's syndrome (14 Cushing's diseases and 15 adrenal adenomas), waist circumference, fasting and 2-h glucose after oral glucose tolerance test (OGTT), lipid profile and blood pressure were evaluated during the active disease and 1 year after remission and compared with those in 29 sex-, age- and BMI-matched controls.

RESULTS

During the active disease, waist circumference, 2-h glucose after OGTT, total and LDL cholesterol were higher in patients with Cushing's syndrome than in controls (P < 0·001) but similar in Cushing's disease and adrenal adenomas. The prevalence of impaired glucose tolerance (IGT), diabetes mellitus, dyslipidaemia and hypertension was higher (P < 0·001) in patients with Cushing's syndrome (27%, 24%, 59% and 72%) than in controls (10%, 0%, 21% and 10%), with no significant difference between Cushing's disease and adrenal adenomas. One year following hormonal remission, waist circumference persisted higher than in controls (P < 0·05) in both Cushing's disease and adrenal adenomas. Metabolic and cardiovascular abnormalities were still present in both groups, although with a lower prevalence, as well as with a more marked decrease in adrenal adenomas (P < 0·05 vs active disease for IGT, dyslipidaemia and hypertension).

CONCLUSIONS

These results show that chronic hypercortisolism, independently of its aetiology, contributes to metabolic impairment and increased cardiovascular risk, while these abnormalities mostly persist in patients with previous Cushing's disease after hormonal remission. Pituitary hormonal deficiencies, hormonal replacement treatments and/or incomplete cure from Cushing's disease may account for these findings.

Plasminogen activator inhibitor-1 deficient mice are protected from angiotensin II-induced fibrosis

PAI-1 has been shown to be both profibrotic and antifibrotic in animal models of hepatic fibrosis. Although these models have similarities to human fibrotic liver disease, no rodent model completely recapitulates the clinical situation; indeed, transaminase values in most models of hepatic fibrosis are much higher than in chronic liver diseases in humans. Here, wild-type and PAI-1(-/-) mice were administered AngII (500 ng/kg/min) for 4 weeks. ECM accumulation was evaluated by Sirius red staining, hydroxyproline content, and fibrin and collagen immunostaining. Induction of pro-fibrotic genes was assessed by real-time RT-PCR. Despite the absence of any significant liver damage, AngII infusion increased the deposition of hepatic collagen and fibrin ECM, with a perisinusoidal pattern. PAI-1(-/-) mice were protected from these ECM changes, indicating a causal role of PAI-1 in this fibrosis model. Protection in the knockout strain correlated with a blunted increase in αSMA, and elevated activities of matrix metalloproteinases (MMP2, MMP9). These data suggest that PAI-1 plays a critical role in mediating fibrosis caused by AngII and lends weight-of-evidence to a pro-fibrotic role of this protein in liver. Furthermore, the current study proposes a new model of 'pure' hepatic fibrosis in mice with little inflammation or hepatocyte death.

Antihypertensive treatment and secondary prevention of cardiovascular disease events among persons without hypertension: a meta-analysis

CONTEXT

Cardiovascular disease (CVD) risk increases beginning at systolic blood pressure levels of 115 mm Hg. Use of antihypertensive medications among patients with a history of CVD or diabetes and without hypertension has been debated.

OBJECTIVE

To evaluate the effect of antihypertensive treatment on secondary prevention of CVD events and all-cause mortality among persons without clinically defined hypertension.

DATA SOURCES

Meta-analysis with systematic search of MEDLINE (1950 to week 3 of January 2011), EMBASE, and the Cochrane Collaboration Central Register of Controlled Clinical Trials and manual examination of references in selected articles and studies.

STUDY SELECTION

From 874 potentially relevant publications, 25 trials that fulfilled the predetermined inclusion and exclusion criteria were included in the meta-analysis.

DATA EXTRACTION

Information on participant characteristics, trial design and duration, treatment drug, dose, control, and clinical events were extracted using a standardized protocol. Outcomes included stroke, myocardial infarction (MI), congestive heart failure (CHF), composite CVD outcomes, CVD mortality, and all-cause mortality.

RESULTS

Compared with controls, participants receiving antihypertensive medications had a pooled relative risk of 0.77 (95% confidence interval [CI], 0.61 to 0.98) for stroke, 0.80 (95% CI, 0.69 to 0.93) for MI, 0.71 (95% CI, 0.65 to 0.77) for CHF, 0.85 (95% CI, 0.80 to 0.90) for composite CVD events, 0.83 (95% CI, 0.69 to 0.99) for CVD mortality, and 0.87 (95% CI, 0.80 to 0.95) for all-cause mortality from random-effects models. The corresponding absolute risk reductions per 1000 persons were -7.7 (95% CI, -15.2 to -0.3) for stroke, -13.3 (95% CI, -28.4 to 1.7) for MI, -43.6 (95% CI, -65.2 to -22.0) for CHF events, -27.1 (95% CI, -40.3 to -13.9) for composite CVD events, -15.4 (95% CI, -32.5 to 1.7) for CVD mortality, and -13.7 (95% CI, -24.6 to -2.8) for all-cause mortality. Results did not differ according to trial characteristics or subgroups defined by clinical history.

CONCLUSIONS

Among patients with clinical history of CVD but without hypertension, antihypertensive treatment was associated with decreased risk of stroke, CHF, composite CVD events, and all-cause mortality. Additional randomized trial data are necessary to assess these outcomes in patients without CVD clinical recommendations.

Quantifying the cost in power of ignoring continuous covariate imbalances in clinical trial randomization

Motivated by potentially serious imbalances of continuous baseline covariates in clinical trials, we investigated the cost in statistical power of ignoring the balance of these covariates in treatment allocation design for a logistic regression model. Based on data from a clinical trial of acute ischemic stroke treatment, computer simulations were used to create scenarios varying from the best possible baseline covariate balance to the worst possible imbalance, with multiple balance levels between the two extremes. The likelihood of each scenario occurring under simple randomization was evaluated. The power of the main effect test for treatment was examined. Our simulation results show that the worst possible imbalance is highly unlikely, but it can still occur under simple random allocation. Also, power loss could be nontrivial if balancing distributions of important continuous covariates were ignored even if adjustment is made in the analysis for important covariates. This situation, although unlikely, is more serious for trials with a small sample size and for covariates with large influence on primary outcome. These results suggest that attempts should be made to balance known prognostic continuous covariates at the design phase of a clinical trial even when adjustment is planned for these covariates at the analysis.

ACE inhibition reduces infarction in normotensive but not hypertensive rats: correlation with cortical ACE activity

Angiotensin-converting enzyme (ACE) inhibition can reduce stroke risk by up to 43% in humans and reduce the associated disability, and hence understanding the mechanism of improvement is important. In animals and humans, these effects may be independent of the blood pressure-lowering effects of ACE inhibition. Normotensive (Wistar-Kyoto (WKY)) and hypertensive (spontaneously hypertensive rat (SHR)) animals were treated with the ACE inhibitors ramipril or lisinopril for 7 or 42 days before 2 hours of transient middle cerebral artery occlusion (MCAo). Blood pressure, serum ACE, and blood glucose levels were measured and stroke infarct volume was recorded 24 hours after stroke. Despite greater reductions in blood pressure, infarct size was not improved by ACE inhibition in hypertensive animals. Short-term ACE inhibition produced only a modest reduction in blood pressure, but WKY rats showed marked reductions in infarct volume. Long-term ACE inhibition had additional reductions in blood pressure; however, infarct volumes in WKY rats did not improve further but worsened. WKY rats differed from SHR in having marked cortical ACE activity that was highly sensitive to ACE inhibition. The beneficial effects of ACE inhibition on infarct volume in normotensive rats do not correlate with changes in blood pressure. However, WKY rats have ACE inhibitor-sensitive cortical ACE activity that is lacking in the SHR.

Angiotensin II receptor blocker telmisartan enhances running endurance of skeletal muscle through activation of the PPAR-δ/AMPK pathway

Clinical trials have shown that angiotensin II receptor blockers reduce the new onset of diabetes in hypertensives; however, the underlying mechanisms remain unknown. We investigated the effects of telmisartan on peroxisome proliferator activated receptor γ (PPAR-δ) and the adenosine monophosphate (AMP)-activated protein kinase (AMPK) pathway in cultured myotubes, as well as on the running endurance of wild-type and PPAR-δ-deficient mice. Administration of telmisartan up-regulated levels of PPAR-δ and phospho-AMPKα in cultured myotubes. However, PPAR-δ gene deficiency completely abolished the telmisartan effect on phospho-AMPKαin vitro. Chronic administration of telmisartan remarkably prevented weight gain, enhanced running endurance and post-exercise oxygen consumption, and increased slow-twitch skeletal muscle fibres in wild-type mice, but these effects were absent in PPAR-δ-deficient mice. The mechanism is involved in PPAR-δ-mediated stimulation of the AMPK pathway. Compared to the control mice, phospho-AMPKα level in skeletal muscle was up-regulated in mice treated with telmisartan. In contrast, phospho-AMPKα expression in skeletal muscle was unchanged in PPAR-δ-deficient mice treated with telmisartan. These findings highlight the ability of telmisartan to improve skeletal muscle function, and they implicate PPAR-δ as a potential therapeutic target for the prevention of type 2 diabetes.

Effect on the atherogenic marker plasminogen activator inhibitor type-1 of addition of the ACE inhibitor imidapril to angiotensin II type 1 receptor antagonist therapy in hypertensive patients with abnormal glucose metabolism: a prospective cohort study in primary care

BACKGROUND AND OBJECTIVE

Renin-angiotensin system (RAS) inhibitors, such as angiotensin-converting enzyme (ACE) inhibitors and angiotensin II type 1 receptor antagonists (angiotensin receptor blockers [ARBs]), are recommended by the American Diabetes Association for blood pressure control and prevention or management of cardiovascular disease in patients with diabetes mellitus. However, some investigators have suggested that ARBs may increase the risk of myocardial infarction in hypertensive patients. Activation of the RAS is associated with an increased risk of ischaemic events. Angiotensin II stimulates the production of plasminogen activator inhibitor type-1 (PAI-1), a powerful predictor of cardiovascular disease. ACE inhibitors are reported to reduce PAI-1 levels and activity, while ARBs do not reduce or may even elevate levels of this atherogenic marker. The objective of this study was to determine whether the ACE inhibitor imidapril reduces PAI-1 levels in hypertensive patients already being treated with an ARB.

METHODS

This was a prospective cohort study carried out in primary care with a follow-up period of 6 months. Estimating the alpha error (p-value) at 0.05, the power of the test as 80%, and the difference in PAI-1 levels as 10 + or - 15 ng/mL, the required sample size was calculated to be 40. Participants were hypertensive patients taking ARBs for more than 8 weeks, and having dyslipidaemia, obesity or abnormal glucose metabolism. Imidapril 5-10 mg/day was prescribed for 6 months to reduce blood pressure to <130/80 mmHg. The main outcome measure, PAI-1 level, was measured before and 6 months after the addition of imidapril to ARBs in 21 subjects (13 men, eight women), all with abnormal glucose metabolism, nine with dyslipidaemia, and six who were obese. Bodyweight, body mass index, blood pressure, homeostasis model assessment of insulin resistance, glycosylated haemoglobin, creatinine, potassium, high sensitivity C-reactive protein (hs-CRP), and high molecular weight adiponectin levels were measured as secondary outcomes.

RESULTS

PAI-1 level was not significantly changed overall. Hs-CRP level was also not significantly changed; however, the high molecular weight adiponectin level was significantly increased (p = 0.044), especially in men (p = 0.026). There were no significant changes in the other outcomes measured.

CONCLUSION

The current study showed that imidapril added to ARBs did not decrease PAI-1 levels in hypertensive patients with abnormal glucose metabolism; however, this combination therapy significantly increased high molecular weight adiponectin levels in men.

On target to dual block RAS?

Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers are thought to possess cardioprotective, cerebroprotective, and nephroprotective properties. Both classes of agents can prevent or reverse endothelial dysfunction and atherosclerosis, thereby potentially reducing the risk of cardiovascular events. Such a reduction has been shown with angiotensin-converting enzyme inhibitors in patients with coronary artery disease, but no such data are scarce with angiotensin receptor blockers (Valsartan in Acute Myocardial Infarction study). Both angiotensin-converting enzyme inhibitors and angiotensin receptor blockers have been shown to reduce damage in target organs, such as the heart and kidney, and to decrease cardiovascular mortality and morbidity in patients with congestive heart failure. These drugs (especially angiotensin receptor blockers) may successfully prevent atrial fibrillation and play a protective role in metabolic syndrome. In some clinical settings, combined therapy angiotensin-converting enzyme inhibitors with angiotensin receptor blocker (double blockade of the renin-angiotensin- aldosterone system) may appear the most effective.

Review of nifedipine GITS in the treatment of high risk patients with coronary artery disease and hypertension

Nifedipine is a dihydropyridine calcium-channel blocker (CCB) introduced approximately 30 years ago for the prophylaxis of angina symptoms, and then later utilized as an anti-hypertensive agent. In the 1990s, several meta-analyses and a case-control study were published which raised concern regarding increased mortality and increased risk for myocardial infarction with short-acting nifedipine. Further evaluation of these meta-analyses and case control study underscores some important limitations and the need to further elucidate the role of this class of medications in high-risk patients. Until 2000, there was a paucity of data on the long-term effects as well as the long-term outcomes of CCBs in the treatment of stable coronary disease or in patients with manifestations of the disease such as hypertension or angina. While it has been well established that nifedipine and other dihydropyridines lower blood pressure and improve symptoms of angina, several studies were designed to evaluate the effect of dihydropyridines on "hard" outcomes, specifically cardiovascular and cerebrovascular events. In this review, we describe the clinical studies evaluating the use of nifedipine when compared to placebo as well as other anti-hypertensive therapies in an attempt to identify the most appropriate place in therapy for this class of medications and to further clarify its utilization in high-risk patients.

Aliskiren

Aliskiren is the first orally active inhibitor of renin to be approved for clinical use as an antihypertensive agent. The development program has established that at the licensed doses of 150 mg and 300 mg, there are dose-related falls in blood pressure comparable to those seen with other major classes of antihypertensive drugs and that these falls are associated with a placebo level of side effects. Aliskiren was found to be effective either as monotherapy or in combination with drugs from the other major classes. As expected, there was a greater benefit from adding aliskiren to natriuretic drugs than to other blockers of the renin system. However, there was also some consistent benefit from dual renin blockade. Aliskiren is likely to be of most value in patients uncontrolled by, or intolerant of, other classes. Rational understanding of the renin system will maximize its value, for instance, by encouraging greater use of natriuretic agents in patients with resistant hypertension to render their hypertension renin dependent. Whether there are cardiovascular benefits other than blood pressure control in blocking the renin system remains to be demonstrated. It is hoped that long-term outcome studies with aliskiren will finally allow this question to be answered.

Arterial stiffness and central hemodynamics in treated hypertensive subjects according to brachial blood pressure classification

BACKGROUND

International recommendations have classified brachial blood pressure (BP) in subgroups enabling better cardiovascular risk stratification. Central BP is an independent predictor of cardiovascular risk, differing from brachial BP through the predominant influence of arterial stiffness and wave reflections. Central BP has never been studied in relation to international guidelines for brachial BP classification.

METHODS

In 580 chronically treated hypertensive subjects we measured: carotid-femoral pulse wave velocity (PWV), carotid artery augmentation index (AI) and carotid blood pressures, using applanation tonometry and pulse wave analysis, and using brachial BP for carotid pressure wave calibration.

RESULTS

For each given brachial value, carotid systolic blood pressure (SBP) and PP were significantly lower than the corresponding brachial SBP and PP. This pressure amplification was significantly lower in the 'optimal' and 'normal' BP ranges (6.8-7.4 mmHg) than in the higher BP ranges (10.1-11.3 mmHg), mainly depending on heart rate (HR) and PWV levels. PWV gradually increased as a function of brachial BP classification and was a significant predictor of this classification independently of age, drug treatment, atherosclerotic lesions and even mean BP. Finally, PWV was a highly sensitive marker of the effective BP control throughout all decades of age.

CONCLUSION

Under chronic antihypertensive therapy, central BP does not strictly parallel the corresponding brachial BP classification, depending on differences in aortic stiffness and HR. Whether aortic PWV might predict the brachial BP classification and/or the presence of effective BP control, as suggested in this study, needs further confirmation.

Lessons from ONTARGET

The recently published results of the ONTARGET trial shed a new light on the cardiovascular protection of patients at high risk of a cardiovascular event. Despite a number of trials looking at the efficacy of Angiotensin Converting Enzyme inhibitors (ACEis) or Angiotensin Receptor Blockers (ARBs) in the prevention of cardiovascular events in patients with specific high risk profiles, the question of the equivalence of ACEis and ARBs remained unanswered. The ONTARGET trial has shown that telmisartan 80 mg administered for a median duration of 4.5 years to patients at high risk of developing a major cardiovascular event, is equally effective to ramipril 10 mg. In addition, telmisartan was slightly better tolerated. The comparator ramipril has been chosen as it is currently the gold standard ACEi since the results of the HOPE study, in terms of the composite outcome of cardiovascular death, myocardial infarction and stroke. Moreover, ONTARGET is the first trial to test the hypothesis of superiority of adding an ARB (telmisartan 80 mg) to an ACEi (ramipril 10 mg) over the ACEi ramipril monotherapy in cardiovascular protection of the same broad range of high-risk patients. Surprisingly, despite a more pronounced blood pressure lowering, the combination of the two agents did not lead to an additional decrease in the number of events, but had significantly more side-effects compared to ramipril monotherapy. ONTARGET is a landmark study, performed according to the highest statistical and clinical standards, providing compelling evidence and clear answers to two important clinical questions.

Circulating Markers Reflect Both Anti- and Pro-Atherogenic Drug Effects in ApoE-Deficient Mice

Background

Current drug therapy of atherosclerosis is focused on treatment of major risk factors, e.g. hypercholesterolemia while in the future direct disease modification might provide additional benefits. However, development of medicines targeting vascular wall disease is complicated by the lack of reliable biomarkers. In this study, we took a novel approach to identify circulating biomarkers indicative of drug efficacy by reducing the complexity of the in vivo system to the level where neither disease progression nor drug treatment was associated with the changes in plasma cholesterol.

Results

ApoE−/− mice were treated with an ACE inhibitor ramipril and HMG-CoA reductase inhibitor simvastatin. Ramipril significantly reduced the size of atherosclerotic plaques in brachiocephalic arteries, however simvastatin paradoxically stimulated atherogenesis. Both effects occurred without changes in plasma cholesterol. Blood and vascular samples were obtained from the same animals. In the whole blood RNA samples, expression of MMP9, CD14 and IL-1RN reflected pro-and anti-atherogenic drug effects. In the plasma, several proteins, e.g. IL-1β, IL-18 and MMP9 followed similar trends while protein readout was less sensitive than RNA analysis.

Conclusion

In this study, we have identified inflammation-related whole blood RNA and plasma protein markers reflecting anti-atherogenic effects of ramipril and pro-atherogenic effects of simwastatin in a mouse model of atherosclerosis. This opens an opportunity for early, non-invasive detection of direct drug effects on atherosclerotic plaques in complex in vivo systems.

The management of hypertension in ischaemic heart disease

PURPOSE OF REVIEW

Patients with hypertension and coronary artery disease are often inadequately treated. Blood pressure levels remain unacceptably high in about half of such patients. A significant shortfall exists between guidelines and practice in implementing evidence-based drug therapy.

RECENT FINDINGS

Recent trials underscore the importance of blood pressure reduction. The purported superiority of specific drug classes, notably angiotensin-converting enzyme inhibitors and beta-blockers, is increasingly debated. Conversely, the benefits of calcium channel blockers are increasingly recognized. Irrespective of differences, all three agents are frequently required to achieve blood pressure targets. Beyond blood pressure reduction, statin therapy is undoubtedly the single most important risk factor intervention. New studies suggest that intensive lipid lowering and greater reductions in low-density lipoprotein cholesterol will further reduce major cardiovascular events. Finally, the impact of smoking cessation, exercise, and diet is often underestimated.

SUMMARY

The prognosis for patients is critically dependent on reducing global cardiovascular risk by addressing all modifiable risk factors. The cornerstone of treatment remains blood pressure reduction, using agents with both antihypertensive and antianginal properties.

Telmisartan reduced blood pressure and HOMA-IR with increasing plasma leptin level in hypertensive and type 2 diabetic patients

Telmisartan, a new angiotensin II type 1 receptor blocker (ARB), was recently reported to stimulate PPARgamma, and stronger effects of Telmisartan on insulin sensitivity has been expected than the class effect of ARB. In the present study, we examined the effects of Telmisartan on insulin sensitivity and adipokine levels in hypertensive and type 2 diabetic patients. Outpatients with both hypertension and type 2 diabetes mellitus (n=36; male 23, female 13), received 20-40mg Telmisartan orally once daily for 6 months. Physical examinations and blood or urine tests were performed before and 3 or 6 months after starting Telmisartan treatment. Results were statistically compared using Wilcoxon analysis. Telmisartan treatment for 3 or 6 months reduced systolic and diastolic blood pressure and urinary albumin excretion. Fasting plasma glucose, HbA1c, total and HDL-cholesterol, triglyceride, body weight, BMI and waist length were not changed. Fasting IRI and HOMA-IR were significantly decreased after Telmisartan treatment, suggesting the improved insulin sensitivity. Total and high molecular adiponectin were not changed. Interestingly, serum leptin was significantly increased by 3 months Telmisartan treatment, suggesting a possible involvement of leptin in improved insulin sensitivity. In conclusion, Telmisartan improved insulin resistance with increased serum leptin level in hypertensive and type 2 diabetic patients.

Effects of the renin-angiotensin system genes and salt sensitivity genes on blood pressure and atherosclerosis in the total population and patients with type 2 diabetes

Most studies on the genetic determinants of blood pressure and vascular complications of type 2 diabetes have focused on the effects of single genes. These studies often have yielded conflicting results. Therefore, we examined the combined effects of three renin-angiotensin system (RAS) genes and three salt sensitivity genes in relation to blood pressure and atherosclerosis in the total population and type 2 diabetic patients. The study was a part of the Rotterdam Study, a population-based cohort study. We have genotyped three RAS gene polymorphisms and three salt sensitivity gene polymorphisms. Diabetic patients with three risk genotypes of the RAS genes had a 6.9 mmHg higher systolic blood pressure (P for trend = 0.04) and a 6.0 mmHg higher pulse pressure (P for trend = 0.03) than those who did not carry any risk genotypes. Diabetic patients with three risk genotypes of the salt sensitivity genes had a 9.0 mmHg higher systolic blood pressure (P = 0.19) and a 13.1 mmHg higher pulse pressure (P = 0.02). Diabetic patients who carried three risk genotypes for the RAS genes had a higher mean intima-media thickness than those with two risk genotypes (mean difference 0.04 mm, P = 0.02). We found that among type 2 diabetic patients, mean systolic blood pressure, pulse pressure, and risk of hypertension increased with the number of risk genotypes for the RAS genes and the salt sensitivity genes.

EUROPA: Has Anything New Been Learned With Angiotensin‐Converting Enzyme Inhibitors?

The European Trial on Reduction of Cardiac Events with Perindopril in Stable Coronary Artery Disease (EUROPA) involved 12,218 patients with stable coronary artery disease. Patients in this trial were randomized to the angiotensin-converting enzyme inhibitor perindopril (8 mg/d) or placebo in addition to optimized conventional therapy and followed for an average of 4 years. Perindopril reduced the primary end points of cardiovascular disease, myocardial infarction, and cardiac arrest by 20% (p=0.0003). Moreover, the angiotensin-converting enzyme inhibitor reduced the rate of fatal and nonfatal myocardial infarction by 24% (p=0.001). The results from EUROPA complement those observed in the Heart Outcomes and Prevention Evaluation (HOPE) study and provide further support for the concept of angiotensin-converting enzyme inhibitors conferring cardiovascular protection as a class effect.

Assessment of single versus twice daily dosing of ramipril by ambulatory blood pressure monitoring in patients similar to those included in the HOPE study

Ramipril has been used in twice daily dose of 5 mg in most heart failure trials, whereas the dose used in Heart Outcomes Prevention Evaluation (HOPE) study was 10 mg once at bedtime. The HOPE investigators in an ambulatory blood pressure (ABP) substudy observed a fall of nighttime but not daytime blood pressure (BP). We examined the effects of once daily ramipril 10 mg versus 5 mg twice a day. Twenty-nine patients were recruited based on the original criteria for the HOPE study and were given ramipril either in twice-daily dose (5 mg b.d.) or once daily (10 mg o.d.) each morning in randomized, prospective crossover trial. Twenty-four hour ABP recordings were taken just before commencement of ramipril therapy and after treatment with twice-daily and once-daily ramipril. Our results show that ramipril causes a significant reduction of BP over 24-h period as compared with baseline. The mean baseline ABP was 124/73 mm Hg, which reduced to 117/69 mm Hg for the twice-a-day regimen (P<0.001) and 115/68 mm Hg for the once a day regimen (P<0.001). Both regimes effectively lower BP to a similar extent. Ramipril causes significant BP reduction in both once- and twice-daily dosing. The fall in BP after daytime dosing is greater than that observed in the HOPE study (including ABP substudy). Once-daily dosing in the morning seems to be effective in causing a significant reduction in the ABP profile of patients at high-risk of a future vascular event.

Central blood pressures: do we need them in the management of cardiovascular disease? Is it a feasible therapeutic target?

It is well established that in young and healthy individuals central (aortic or carotid) systolic and pulse pressures are different from peripheral (brachial) corresponding pressures as a consequence of progressive changes in arterial stiffness and pressure wave reflections along the arterial tree. There is evidence indicating that in interventions with pharmaceutical and non-pharmaceutical agents, central pressures are subjected to greater changes than peripheral pressures, and they are more closely related to the pathophysiology of end-organ damage or cardiovascular risk. Therefore central blood pressures may be of higher clinical importance than peripheral pressures. The present review aims to provide an insight into the (patho)physiology of central blood pressures, to present the most accurate techniques for their estimation, and to discuss the available experimental and epidemiological data that support the emerging need for the evaluation of central blood pressures in clinical practice.

Effects of an angiotensin-converting enzyme inhibitor (ramipril) on inflammatory markers in secondary prevention patients: RAICES Study

AIMS

To evaluate the hypothesis that angiotensin-converting enzyme inhibitor therapy with ramipril reduces baseline levels of C-reactive protein in patients at high cardiovascular risk.

METHODS

Secondary prevention patients were screened for eligibility and treated with ramipril for 6 month. Baseline and 6-month highly sensitive C-reactive protein levels were determined.

RESULTS

A total of 77 patients were analyzed. The median highly sensitive C-reactive protein concentration at baseline was 2.17 mg/l (interquartile interval 0.97-4.54); whereas in post-treatment, the median was 1.70 mg/l (interquartile interval 0.88-3.41), P=0.0009. Patients were stratified according to risk level determined by baseline highly sensitive C-reactive protein levels: low-risk (<1 mg/l), intermediate risk (1-3 mg/l) and high risk (>3 mg/l) The reduction in highly sensitive C-reactive protein occurred at the expense of the high-risk group (baseline 5.02 mg/l, post-treatment 3.3 mg/l, P<0.0001), with no differences in the other groups. In multiple regression analysis, the reduction observed in the high-risk group could not be explained by baseline treatment or change in any of the variables analyzed.

CONCLUSION

Highly sensitive C-reactive protein levels were reduced after a 6-month ramipril therapy in secondary prevention patients, suggesting an anti-inflammatory effect of angiotensin-converting enzyme inhibitors. Future investigations will be done to confirm these results, and to investigate how angiotensin-converting enzyme inhibitor treatment elicits anti-inflammatory effects.

Blood Pressure Level and Outcomes in Adults Aged 65 and Older with Prior Ischemic Stroke

OBJECTIVES

To examine the association between blood pressure (BP) levels and long-term stroke outcomes in elderly stroke survivors.

DESIGN

Observational study.

SETTING

The Cardiovascular Health Study (CHS) of 5,888 community-dwelling adults.

PARTICIPANTS

Two hundred fifty-four adults aged 65 and older (mean age 78.6) who sustained a nonfatal first ischemic stroke.

MEASUREMENTS

BP levels assessed at prestroke and poststroke CHS visits were examined as predictors of stroke recurrence, coronary heart disease (CHD), combined vascular events (CVEs), and mortality.

RESULTS

Higher poststroke BP level, assessed 261.6 days (mean) after stroke, was associated with higher risk of stroke recurrence over 5.4 years (mean) of follow-up. The multivariate-adjusted hazard ratio for stroke recurrence was 1.42 (95% confidence interval (CI) = 1.03-1.99) per standard deviation (SD) of systolic BP (P = .04) and 1.39 (95% CI = 1.01-1.91) per SD of diastolic BP (P = .04). Mortality was significantly greater in patients with low or high poststroke BP than in those with intermediate BP. Poststroke BP was not associated with risk of CHD or CVE, although further analyses suggested that high systolic BP predicted CHD and CVE in younger but not older subjects. Prestroke BP did not predict poststroke outcomes.

CONCLUSION

In this observational study of adults aged 65 and older assessed approximately 8 months after stroke, low BP was associated with favorable risk of recurrent stroke, although high and low poststroke BP levels were associated with greater mortality. Long-term antihypertensive trials in older stroke survivors would increase knowledge about the benefits of lowering BP in this population.

Endothelial function and cerebrovascular disease: Implications for diagnosis and treatment

Cerebrovascular disease remains one of the most common causes of morbidity and mortality in the United States. There is strong evidence to implicate endothelial dysfunction in the initiation and progression of atherosclerosis and its complications. It is now well known that endothelial dysfunction represents a systemic syndrome involving multiple vascular beds, including the cerebral vasculature. Currently, no gold standard treatment for endothelial dysfunction exists. Nonetheless, several treatment strategies have been found to be helpful in improving endothelial function. A few of these strategies have been implicated in stroke risk reduction as well, adding another line of evidence to the relationship between endothelial function and cerebrovascular disease.

Targeting the renin-angiotensin system for the reduction of cardiovascular outcomes in hypertension: angiotensin-converting enzyme inhibitors and angiotensin receptor blockers

Agents that counteract the negative impact of the renin-angiotensin-aldosterone system (RAAS) are effective antihypertensives and reduce the risk of developing Type 2 diabetes. Contrary to common perception, angiotensin-converting enzyme inhibitors do not share the apparent benefit of angiotensin II receptor blockers (ARBs) in reducing risk of cardiovascular-disease outcomes, particularly stroke, in randomised clinical trials. RAAS agents, especially ARBs, are well tolerated. Use of ARBs alone or in combination with other classes of antihypertensive agents to lower blood pressure and/or medications to control other conditions (e.g., insulin sensitivity) reduces risk of cardiovascular disease outcomes and Type 2 diabetes with excellent tolerability. Selected issues related to use of RAAS agents as antihypertensive therapies (e.g., Type 2 diabetes, global risk management, multiple drug therapy and coronary heart disease) are addressed.

Blood Pressure as a Risk Factor for Stroke and the Impact of Antihypertensive Treatment

We review hypertension and blood pressure levels as risk factors for stroke and the impact of antihypertensive treatment on the prevention of first stroke event and of recurrent stroke, not only with respect to the prevention of vascular events but also the prevention of cognitive deterioration, dementia, and physical disability. We review whether pharmacological blockage of the renin-angiotensin system has additional long-term effects over that of control of blood pressure levels alone, and the benefit of treatment with antihypertensive drugs in normotensive patients. Therapeutic objectives for blood pressure levels after stroke are defined together with recommendations of drugs and doses which have been demonstrated to have the greatest benefit in the prevention of stroke.

The HOPE (Heart Outcomes Prevention Evaluation) Study and its consequences

The HOPE study was a 19 country, prospective randomized trial in which the ACE-inhibitor Ramipril but not Vitamin E significantly reduced the risk of future cardiovascular events in a high-risk population of men and women, including many with diabetes. The benefits were present in all sub-groups, independent of the presence or absence of diabetes, hypertension, evidence of cardiovascular disease, microalbuminuria, blood pressure lowering, the use of aspirin, lipid-lowering or antihypertensive medication. It provided clear evidence that Ramipril should safely and cost-effectively be used in individuals not known to have low ventricular ejection fraction or heart failure but at high-risk of cardiovascular events. It was also beneficial in patients with renal insufficiency, reducing progression of proteinuria and development of new microalbuminuria. It provided micro- and macrovascular benefits in people with diabetes, reduced the development of new cases of diabetes and showed a positive and graded association between the waist-to-hip ratio and the risk of developing diabetes. Sub-studies completed and on-going into the predictive role of natriuretic peptides, infectious and inflammatory markers, provide insight into possible mechanisms of action of Ramipril.

Apparent effect on blood pressure is only partly responsible for the risk reduction due to antihypertensive treatments

The mechanism of risk reduction obtained by blood pressure-lowering pharmacological treatment remains unclear. We explored the amount of risk reduction attributable to the apparent effect of antihypertensive medicines on blood pressure by using the capture approach. Five randomized, placebo or nil controlled trials with a total of 28,997 subjects and 1,935 cardiovascular fatal or non-fatal events from the INDANA database met the eligibility criteria. Computations were performed on the original individual records using multiple Cox's proportional hazard regression models designed for meeting the assumed treatment mode of action and comparing relevant assumptions. For coronary event, the results are inconclusive essentially because the risk reduction is mild. However, for stroke the risk reduction adjusted for baseline risk factors is 34% (P<0.0001). The part explained by the effect of treatment on systolic blood pressure is 49% of this reduction, with 95% confidence interval not including 100%. This result suggests that the apparent effect on blood pressure is not the only cause of stroke risk reduction in hypertensive subjects submitted to an antihypertensive medicine.

Role of blood pressure and other variables in the differential cardiovascular event rates noted in the Anglo-Scandinavian Cardiac Outcomes Trial-Blood Pressure Lowering Arm (ASCOT-BPLA)

BACKGROUND

Results of the Anglo-Scandinavian Cardiac Outcomes Trial-Blood Pressure Lowering Arm (ASCOT-BPLA) show significantly lower rates of coronary and stroke events in individuals allocated an amlodipine-based combination drug regimen than in those allocated an atenolol-based combination drug regimen (HR 0.86 and 0.77, respectively). Our aim was to assess to what extent these differences were due to significant differences in blood pressures and in other variables noted after randomisation.

METHODS

We used data from ASCOT-BPLA (n=19 257) and compared differences in accumulated mean blood pressure levels at sequential times in the trial with sequential differences in coronary and stroke events. Serial mean matching for differences in systolic blood pressure was used to adjust HRs for differences in these events. We used an updated Cox-regression model to assess the effects of differences in accumulated mean levels of various measures of blood pressure, serum HDL-cholesterol, triglycerides and potassium, fasting blood glucose, heart rate, and bodyweight on differences in event rates.

FINDINGS

We noted no temporal link between size of differences in blood pressure and different event rates. Serial mean matching for differences in systolic blood-pressure attenuated HRs for coronary and stroke events to a similar extent as did adjustments for systolic blood-pressure differences in Cox-regression analyses. HRs for coronary events and stroke adjusted for blood pressure rose from 0.86 (0.77-0.96) to 0.88 (0.79-0.98) and from 0.77 (0.66-0.89) to 0.83 (0.72-0.96), respectively. Multivariate adjustment gave HRs of 0.94 (0.81-1.08) for coronary events (HDL cholesterol being the largest contributor) and 0.87 (0.73-1.05) for stroke events.

INTERPRETATION

Multivariate adjustment accounted for about half of the differences in coronary events and for about 40% of the differences in stroke events between the treatment regimens tested in ASCOT-BPLA, but residual differences were no longer significant. These residual differences could indicate inadequate statistical adjustment, but it remains possible that differential effects of the two treatment regimens on other variables also contributed to the different rates noted, particularly for stroke.

Relationship between C-Reactive Protein and the Electrocardiographic Pattern on Admission in Patients with Acute Coronary Syndrome

BACKGROUND

In patients with acute coronary syndrome (ACS), the prevalence of a primary inflammatory pathogenic component of coronary instability, as detectable by elevated C-reactive protein (CRP), varies considerably. The aim of the present study was to assess the prevalence of inflammation in patients with ACS according to the different electrocardiographic (ECG) patterns on admission.

METHODS

Hundred and thirty-six consecutive patients with the diagnosis of acute myocardial infarction were divided in three groups according to the ECG pattern on admission. Group 1 included 59 patients with ST segment elevation, group 2 included 50 patients with ST depression and/or T wave inversion and group 3 included 27 patients with no ECG changes. CRP was measured on admission in all patients. For the prevalence of inflammation analysis, we used a cutoff value of 3 mg/l.

RESULTS

CRP was above cutpoint significantly more often in patients with ST depression and/or T wave inversion (44.1% in group 1, 70% in group 2 and 40.7% in group 3; p=0.009). Patients with similar ECG pattern and CRP levels above the cutpoint presented a poorer outcome (coronary death, myocardial infarction and recurrence of instability) at one-year follow-up: 54 versus 27% for group 1, 74 versus 27% for group 2 and 45 versus 31% for group 3.

CONCLUSIONS

Patients with ST depression and/or T wave inversion on admission exhibit a higher prevalence of elevated CRP than those with ST elevation or no ECG changes, suggesting an important heterogeneity of the role of inflammatory triggers of the clinical syndromes of coronary instability.

Protective Effects of Angiotensin II Interruption: Evidence for Antiinflammatory Actions

Angiotensin II, the major effector molecule produced from the renin-angiotensin-aldosterone axis, is a vasoconstrictor contributing to hypertension. Evidence indicates, however, that angiotensin II also is a potent proinflammatory mediator with growth and remodeling effects. In vitro and in vivo studies have shown that angiotensin II blockade significantly reduces concentrations of proinflammatory mediators and oxidative stress products in numerous inflammatory models. Interruption of angiotensin II activity with angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers has been beneficial for patients with inflammatory diseases. Much of this benefit occurs independent of the antihypertensive effect of angiotensin II interruption, suggesting a distinctive protective mechanism. Angiotensin II receptor blockers may represent a novel class of antiinflammatory drugs with indications far beyond cardiovascular diseases.