Which inhibitor of the renin-angiotensin system should be used in chronic heart failure and acute myocardial infarction?

Perioperative Renin-Angiotensin System Inhibitors Improve Major Outcomes of Heart Failure Patients Undergoing Cardiac Surgery: A Propensity-Adjusted Cohort Study

OBJECTIVE

The aim of this study was to study the association of perioperative administration of renin angiotensin system inhibitors (RASi) and clinical outcomes of patients with heart failure (HF) undergoing cardiac surgery.

SUMMARY BACKGROUND DATA

It is controversial whether the perioperative RASi should be administered in HF patients undergoing cardiac surgery.

METHODS

A total of 2338 patients with HF and undergoing CABG and/or valve surgeries at multiple hospitals from 2001 to 2015 were identified from STS database. After adjustment using propensity score and instrumental variable, logistic regression was conducted to analyze the influence of preoperative continuation of RASi (PreRASi) on short-term in-hospital outcomes. Independent risk factors of 30-day mortality, major adverse cardiovascular events (MACE), and renal failure were analyzed by use of stepwise logistic regression. The effects of pre- and postoperative use of RASi (PostRASi) on long-term mortality were analyzed using survival analyses. Stepwise Cox regression was conducted to analyze the independent risk factors of 6-year mortality. The relationships of HF status and surgery type with perioperative RASi, as well as PreRASi-PostRASi, were also evaluated by subgroup analyses.

RESULTS

PreRASi was associated with lower incidences of 30-day mortality [ P < 0.0001, odds ratio (OR): 0.556, 95% confidence interval (CI) 0.405-0.763], stroke ( P =0.035, OR: 0.585, 95% CI: 0.355-0.962), renal failure ( P =0.007, OR: 0.663, 95% CI: 0.493-0.894). Both PreRASi ( P =0.0137) and PostRASi ( P =0.007) reduced 6-year mortality compared with the No-RASi groups.

CONCLUSIONS

Pre- and postoperative use of RASi was associated with better outcomes for the patients who have HF and undergo CABG and/or valve surgeries. Preoperative continuation and postoperative restoration are warranted in these patients.

Electroacupuncture Treats Myocardial Infarction by Influencing the Regulation of Substance P in the Neurovascular to Modulate PGI2/TXA2 Metabolic Homeostasis via PI3K/AKT Pathway: A Bioinformatics-Based Multiomics and Experimental Study

Acute myocardial infarction (AMI) is the most severe form of coronary heart disease caused by ischemia and hypoxia. The study is aimed at investigating the role of neuropeptides and the mechanism of electroacupuncture (EA) in acute myocardial infarction (AMI) treatment. Compared with the normal population, a significant increase in substance P (SP) was observed in the serum of patients with AMI. PGI2 expression was increased in the SP-treated AMI mouse model, and TXA2 expression was decreased. And PI3K pathway-related genes, including Pik3ca, Akt, and Mtor, were upregulated in myocardial tissue of SP-treated AMI patients. Human cardiomyocyte cell lines (HCM) treated with SP increased mRNA and protein expression of PI3K pathway-related genes (Pik3ca, Pik3cb, Akt, and Mtor). Compared to MI control and EA-treated MI rat models, Myd88, MTOR, Akt1, Sp, and Irak1 were differentially expressed, consistent with in vivo and in vitro studies. EA treatment significantly enriched PI3K/AKT signaling pathway genes within MI-associated differentially expressed genes (DEGs) according to Kyoto Encyclopedia of Genes and Genomes (KEGG). Furthermore, it was confirmed by molecular docking analysis that PIK3CA, AKT1, and mTOR form stable dockings with neuropeptide SP. PI3K/AKT pathway activity may be affected directly or indirectly by EA via SP, which corrects the PGI2/TXA2 metabolic imbalance in AMI. MI treatment is now better understood as a result of this finding.

Macrophage-produced VEGFC is induced by efferocytosis to ameliorate cardiac injury and inflammation

Clearance of dying cells by efferocytosis is necessary for cardiac repair after myocardial infarction (MI). Recent reports have suggested a protective role for vascular endothelial growth factor C (VEGFC) during acute cardiac lymphangiogenesis after MI. Here, we report that defective efferocytosis by macrophages after experimental MI led to a reduction in cardiac lymphangiogenesis and Vegfc expression. Cell-intrinsic evidence for efferocytic induction of Vegfc was revealed after adding apoptotic cells to cultured primary macrophages, which subsequently triggered Vegfc transcription and VEGFC secretion. Similarly, cardiac macrophages elevated Vegfc expression levels after MI, and mice deficient for myeloid Vegfc exhibited impaired ventricular contractility, adverse tissue remodeling, and reduced lymphangiogenesis. These results were observed in mouse models of permanent coronary occlusion and clinically relevant ischemia and reperfusion. Interestingly, myeloid Vegfc deficiency also led to increases in acute infarct size, prior to the amplitude of the acute cardiac lymphangiogenesis response. RNA-Seq and cardiac flow cytometry revealed that myeloid Vegfc deficiency was also characterized by a defective inflammatory response, and macrophage-produced VEGFC was directly effective at suppressing proinflammatory macrophage activation. Taken together, our findings indicate that cardiac macrophages promote healing through the promotion of myocardial lymphangiogenesis and the suppression of inflammatory cytokines.

Angiotensin converting enzyme inhibitors and angiotensin II receptor blockers and outcomes in patients with acute decompensated heart failure: a systematic review and meta-analysis

BACKGROUND

Angiotensin-converting enzyme inhibitor (ACEi) and angiotensin-receptor blocker (ARB) are cornerstones in the treatment of heart failure with reduced ejection (HFrEF). However, there are limited data on their risk-benefit profile in patients with acute heart failure requiring hospitalizations.

METHODS

We did a meta-analysis pooling data from all studies examining the use of ACEi/ARB in patients hospitalized for heart failure compared to patients without ACEi/ARB use. We calculated pooled hazard ratios (HR) and their 95% confidence intervals (CI) using a random-effects model.

RESULTS

Twenty-five studies were included in the meta-analysis. Continued use of ACEi/ARBs in hospitalized patients with HFrEF was associated with lower 1-year mortality risk (pooled HR 0.68 [0.60-0.77] p < 0.001) and with lower 1-6-year mortality risk in those with heart failure preserved ejection fraction (HFpEF) (pooled HR 0.86 [0.78-0.94] p = 0.002). There were significant reductions in 1-year HF readmissions among hospitalized HFrEF patients (pooled HR 0.83 [0.73-0.95] p = 0.005).

CONCLUSION

Maintaining or initiating patients with HFrEF hospitalized for acute decompensated heart failure (ADHF) on ACEi/ARB is associated with a reduce risk of mortality and 1-year admissions, but the effect size is lower among those with HFpEF with more heterogeneous outcomes.

Efficacy of Add-on Therapy with Carvedilol and the Direct Renin Inhibitor Aliskiren for Improving Cardiac Sympathetic Nerve Activity, Cardiac Function, Symptoms, Exercise Capacity and Brain Natriuretic Peptide in Patients with Dilated Cardiomyopathy

Purpose/Method: Aliskiren is a direct renin inhibitor that has been reported to be effective for CHF, but the usefulness of combined therapy with carvedilol and aliskiren has not been reported. Forty-four patients with dilated cardiomyopathy (DCM) were randomized into a group receiving add-on therapy with carvedilol plus aliskiren and another group receiving carvedilol alone for 6 months. Nuclear imagings with ¹²³I-Metaiodobenzylguanidine (MIBG) and ^99mTc-Sestamibi were performed. Exercise capacity using a specific activity scale (SAS) and the New York Heart Association (NYHA) class were evaluated. Cardiac sympathetic nerve activity was evaluated by ¹²³I-MIBG imaging, with the delayed heart-to-mediastinum activity ratio (H/M), delayed total defect score (TDS), and washout rate (WR). Results: Combined add-on therapy with carvedilol and aliskiren improved several parameters much more than carvedilol alone (p<0.05) with respect to TDS, ejection fraction (EF), NYHA, SAS on 6 months and the changes in TDS, EF, end-diastolic volume and brain natriuretic peptide (BNP). Conclusion: Add-on therapy with carvedilol and aliskiren is more effective than carvedilol alone for improving cardiac sympathetic nerve activity, cardiac function, symptoms, exercise capacity, and brain natriuretic peptide in patients with DCM.

Role of angiotensin II in the development of subcellular remodeling in heart failure

The development of heart failure under various pathological conditions such as myocardial infarction (MI), hypertension and diabetes are accompanied by adverse cardiac remodeling and cardiac dysfunction. Since heart function is mainly determined by coordinated activities of different subcellular organelles including sarcolemma, sarcoplasmic reticulum, mitochondria and myofibrils for regulating the intracellular concentration of Ca2+, it has been suggested that the occurrence of heart failure is a consequence of subcellular remodeling, metabolic alterations and Ca2+-handling abnormalities in cardiomyocytes. Because of the elevated plasma levels of angiotensin II (ANG II) due to activation of the renin-angiotensin system (RAS) in heart failure, we have evaluated the effectiveness of treatments with angiotensin converting enzyme (ACE) inhibitors and ANG II type 1 receptor (AT1R) antagonists in different experimental models of heart failure. Attenuation of marked alterations in subcellular activities, protein content and gene expression were associated with improvement in cardiac function in MI-induced heart failure by treatment with enalapril (an ACE inhibitor) or losartan (an AT1R antagonist). Similar beneficial effects of ANG II blockade on subcellular remodeling and cardiac performance were also observed in failing hearts due to pressure overload, volume overload or chronic diabetes. Treatments with enalapril and losartan were seen to reduce the degree of RAS activation as well as the level of oxidative stress in failing hearts. These observations provide evidence which further substantiate to support the view that activation of RAS and high level of plasma ANG II play a critical role in inducing subcellular defects and cardiac dys-function during the progression of heart failure.

Beta-blockers and inhibitors of the renin-angiotensin aldosterone system for chronic heart failure with preserved ejection fraction

BACKGROUND

Beta-blockers and inhibitors of the renin-angiotensin-aldosterone system improve survival and reduce morbidity in people with heart failure with reduced left ventricular ejection fraction (LVEF); a review of the evidence is required to determine whether these treatments are beneficial for people with heart failure with preserved ejection fraction (HFpEF).

OBJECTIVES

To assess the effects of beta-blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, angiotensin receptor neprilysin inhibitors, and mineralocorticoid receptor antagonists in people with HFpEF.

SEARCH METHODS

We updated searches of CENTRAL, MEDLINE, Embase, and one clinical trial register on 14 May 2020 to identify eligible studies, with no language or date restrictions. We checked references from trial reports and review articles for additional studies.  SELECTION CRITERIA: We included randomised controlled trials with a parallel group design, enrolling adults with HFpEF, defined by LVEF greater than 40%.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included 41 randomised controlled trials (231 reports), totalling 23,492 participants across all comparisons. The risk of bias was frequently unclear and only five studies had a low risk of bias in all domains. Beta-blockers (BBs) We included 10 studies (3087 participants) investigating BBs. Five studies used a placebo comparator and in five the comparator was usual care. The mean age of participants ranged from 30 years to 81 years. A possible reduction in cardiovascular mortality was observed (risk ratio (RR) 0.78, 95% confidence interval (CI) 0.62 to 0.99; number needed to treat for an additional benefit (NNTB) 25; 1046 participants; three studies), however, the certainty of evidence was low. There may be little to no effect on all-cause mortality (RR 0.82, 95% CI 0.67 to 1.00; 1105 participants; four studies; low-certainty evidence). The effects on heart failure hospitalisation, hyperkalaemia, and quality of life remain uncertain. Mineralocorticoid receptor antagonists (MRAs) We included 13 studies (4459 participants) investigating MRA. Eight studies used a placebo comparator and in five the comparator was usual care. The mean age of participants ranged from 54.5 to 80 years. Pooled analysis indicated that MRA treatment probably reduces heart failure hospitalisation (RR 0.82, 95% CI 0.69 to 0.98; NNTB = 41; 3714 participants; three studies; moderate-certainty evidence). However, MRA treatment probably has little or no effect on all-cause mortality (RR 0.91, 95% CI 0.78 to 1.06; 4207 participants; five studies; moderate-certainty evidence) and cardiovascular mortality (RR 0.90, 95% CI 0.74 to 1.11; 4070 participants; three studies; moderate-certainty evidence). MRA treatment may have little or no effect on quality of life measures (mean difference (MD) 0.84, 95% CI -2.30 to 3.98; 511 participants; three studies; low-certainty evidence). MRA treatment was associated with a higher risk of hyperkalaemia (RR 2.11, 95% CI 1.77 to 2.51; number needed to treat for an additional harmful outcome (NNTH) = 11; 4291 participants; six studies; high-certainty evidence). Angiotensin-converting enzyme inhibitors (ACEIs) We included eight studies (2061 participants) investigating ACEIs. Three studies used a placebo comparator and in five the comparator was usual care. The mean age of participants ranged from 70 to 82 years. Pooled analyses with moderate-certainty evidence suggest that ACEI treatment likely has little or no effect on cardiovascular mortality (RR 0.93, 95% CI 0.61 to 1.42; 945 participants; two studies), all-cause mortality (RR 1.04, 95% CI 0.75 to 1.45; 1187 participants; five studies) and heart failure hospitalisation (RR 0.86, 95% CI 0.64 to 1.15; 1019 participants; three studies), and may result in little or no effect on the quality of life (MD -0.09, 95% CI -3.66 to 3.48; 154 participants; two studies; low-certainty evidence). The effects on hyperkalaemia remain uncertain. Angiotensin receptor blockers (ARBs) Eight studies (8755 participants) investigating ARBs were included. Five studies used a placebo comparator and in three the comparator was usual care. The mean age of participants ranged from 61 to 75 years. Pooled analyses with high certainty of evidence suggest that ARB treatment has little or no effect on cardiovascular mortality (RR 1.02, 95% 0.90 to 1.14; 7254 participants; three studies), all-cause mortality (RR 1.01, 95% CI 0.92 to 1.11; 7964 participants; four studies), heart failure hospitalisation (RR 0.92, 95% CI 0.83 to 1.02; 7254 participants; three studies), and quality of life (MD 0.41, 95% CI -0.86 to 1.67; 3117 participants; three studies). ARB was associated with a higher risk of hyperkalaemia (RR 1.88, 95% CI 1.07 to 3.33; 7148 participants; two studies; high-certainty evidence). Angiotensin receptor neprilysin inhibitors (ARNIs) Three studies (7702 participants) investigating ARNIs were included. Two studies used ARBs as the comparator and one used standardised medical therapy, based on participants' established treatments at enrolment. The mean age of participants ranged from 71 to 73 years. Results suggest that ARNIs may have little or no effect on cardiovascular mortality (RR 0.96, 95% CI 0.79 to 1.15; 4796 participants; one study; moderate-certainty evidence), all-cause mortality (RR 0.97, 95% CI 0.84 to 1.11; 7663 participants; three studies; high-certainty evidence), or quality of life (high-certainty evidence). However, ARNI treatment may result in a slight reduction in heart failure hospitalisation, compared to usual care (RR 0.89, 95% CI 0.80 to 1.00; 7362 participants; two studies; moderate-certainty evidence). ARNI treatment was associated with a reduced risk of hyperkalaemia compared with valsartan (RR 0.88, 95% CI 0.77 to 1.01; 5054 participants; two studies; moderate-certainty evidence).

AUTHORS' CONCLUSIONS

There is evidence that MRA and ARNI treatment in HFpEF probably reduces heart failure hospitalisation but probably has little or no effect on cardiovascular mortality and quality of life. BB treatment may reduce the risk of cardiovascular mortality, however, further trials are needed. The current evidence for BBs, ACEIs, and ARBs is limited and does not support their use in HFpEF in the absence of an alternative indication. Although MRAs and ARNIs are probably effective at reducing the risk of heart failure hospitalisation, the treatment effect sizes are modest. There is a need for improved approaches to patient stratification to identify the subgroup of patients who are most likely to benefit from MRAs and ARNIs, as well as for an improved understanding of disease biology, and for new therapeutic approaches.

Monotherapy versus combination therapy of statin and renin-angiotensin system inhibitor in ST-segment elevation myocardial infarction

Background

The beneficial effects of statin and renin–angiotensin system inhibitor (RASI) are well-known. In this retrospective cohort study, 2-year clinical outcomes were compared between monotherapy and combination therapy with statin and RASI in ST-segment elevation myocardial infarction (STEMI) patients after stent implantation.

Methods

A total of 17,414 STEMI patients were enrolled and divided into the three groups (group A: 2448 patients, statin alone; group B: 2431 patients, RASI alone; and group C: 12,535 patients, both statin and RASI). The principal clinical endpoint was the occurrence of major adverse cardiac events (MACEs) defined as all-cause death, recurrent myocardial infarction, and any repeat revascularization.

Results

After adjustment, the cumulative incidences of MACEs in group A (adjusted hazard ratio [aHR] 1.337; 95% confidence interval [CI] 1.064–1.679; p = 0.013) and in group B (aHR 1.375; 95% CI 1.149–1.646; p = 0.001) were significantly higher than in group C. The cumulative incidence of all-cause death in group A was significantly higher than that in group C (aHR 1.539; 95% CI 1.014–2.336; p = 0.043). The cumulative incidences of any repeat revascularization (aHR 1.317; 95% CI 1.031–1.681; p = 0.028), target lesion vascularization, and target vessel vascularization in group B were significantly higher than in group C.

Conclusions

A statin and RASI combination therapy significantly reduced the cumulative incidence of MACEs compared with a monotherapy of these drugs. Moreover, the combination therapy showed a reduced all-cause death rate compared with statin monotherapy, and a decreased repeat revascularization rate compared with RASI monotherapy.

Beta-blockers and inhibitors of the renin-angiotensin aldosterone system for chronic heart failure with preserved ejection fraction

BACKGROUND

Beta-blockers and inhibitors of the renin-angiotensin aldosterone system improve survival and reduce morbidity in people with heart failure with reduced left ventricular ejection fraction. There is uncertainty whether these treatments are beneficial for people with heart failure with preserved ejection fraction and a comprehensive review of the evidence is required.

OBJECTIVES

To assess the effects of beta-blockers, angiotensin converting enzyme inhibitors, angiotensin receptor blockers, angiotensin receptor neprilysin inhibitors, and mineralocorticoid receptor antagonists in people with heart failure with preserved ejection fraction.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase and two clinical trial registries on 25 July 2017 to identify eligible studies. Reference lists from primary studies and review articles were checked for additional studies. There were no language or date restrictions.

SELECTION CRITERIA

We included randomised controlled trials with a parallel group design enrolling adult participants with heart failure with preserved ejection fraction, defined by a left ventricular ejection fraction of greater than 40 percent.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion and extracted data. The outcomes assessed included cardiovascular mortality, heart failure hospitalisation, hyperkalaemia, all-cause mortality and quality of life. Risk ratios (RR) and, where possible, hazard ratios (HR) were calculated for dichotomous outcomes. For continuous data, mean difference (MD) or standardised mean difference (SMD) were calculated. We contacted trialists where neccessary to obtain missing data.

MAIN RESULTS

37 randomised controlled trials (207 reports) were included across all comparisons with a total of 18,311 participants.Ten studies (3087 participants) investigating beta-blockers (BB) were included. A pooled analysis indicated a reduction in cardiovascular mortality (15% of participants in the intervention arm versus 19% in the control arm; RR 0.78; 95% confidence interval (CI) 0.62 to 0.99; number needed to treat to benefit (NNTB) 25; 1046 participants; 3 studies). However, the quality of evidence was low and no effect on cardiovascular mortality was observed when the analysis was limited to studies with a low risk of bias (RR 0.81; 95% CI 0.50 to 1.29; 643 participants; 1 study). There was no effect on all-cause mortality, heart failure hospitalisation or quality of life measures, however there is uncertainty about these effects given the limited evidence available.12 studies (4408 participants) investigating mineralocorticoid receptor antagonists (MRA) were included with the quality of evidence assessed as moderate. MRA treatment reduced heart failure hospitalisation (11% of participants in the intervention arm versus 14% in the control arm; RR 0.82; 95% CI 0.69 to 0.98; NNTB 41; 3714 participants; 3 studies; moderate-quality evidence) however, little or no effect on all-cause and cardiovascular mortality and quality of life measures was observed. MRA treatment was associated with a greater risk of hyperkalaemia (16% of participants in the intervention group versus 8% in the control group; RR 2.11; 95% CI 1.77 to 2.51; 4291 participants; 6 studies; high-quality evidence).Eight studies (2061 participants) investigating angiotensin converting enzyme inhibitors (ACEI) were included with the overall quality of evidence assessed as moderate. The evidence suggested that ACEI treatment likely has little or no effect on cardiovascular mortality, all-cause mortality, heart failure hospitalisation, or quality of life. Data for the effect of ACEI on hyperkalaemia were only available from one of the included studies.Eight studies (8755 participants) investigating angiotensin receptor blockers (ARB) were included with the overall quality of evidence assessed as high. The evidence suggested that treatment with ARB has little or no effect on cardiovascular mortality, all-cause mortality, heart failure hospitalisation, or quality of life. ARB was associated with an increased risk of hyperkalaemia (0.9% of participants in the intervention group versus 0.5% in the control group; RR 1.88; 95% CI 1.07 to 3.33; 7148 participants; 2 studies; high-quality evidence).We identified a single ongoing placebo-controlled study investigating the effect of angiotensin receptor neprilysin inhibitors (ARNI) in people with heart failure with preserved ejection fraction.

AUTHORS' CONCLUSIONS

There is evidence that MRA treatment reduces heart failure hospitalisation in heart failure with preserverd ejection fraction, however the effects on mortality related outcomes and quality of life remain unclear. The available evidence for beta-blockers, ACEI, ARB and ARNI is limited and it remains uncertain whether these treatments have a role in the treatment of HFpEF in the absence of an alternative indication for their use. This comprehensive review highlights a persistent gap in the evidence that is currently being addressed through several large ongoing clinical trials.

Activation pattern of ACE2/Ang-(1-7) and ACE/Ang II pathway in course of heart failure assessed by multiparametric MRI in vivo in Tgαq*44 mice

Here, we analyzed systemic (plasma) and local (heart/aorta) changes in ACE/ACE-2 balance in Tgαq*44 mice in course of heart failure (HF). Tgαq*44 mice with cardiomyocyte-specific Gαq overexpression and late onset of HF were analyzed at different age for angiotensin pattern in plasma, heart, and aorta using liquid chromatography/mass spectrometry, for progression of HF by in vivo magnetic resonance imaging under isoflurane anesthesia, and for physical activity by voluntary wheel running. Six-month-old Tgαq*44 mice displayed decreased ventricle radial strains and impaired left atrial function. At 8-10 mo, Tgαq*44 mice showed impaired systolic performance and reduced voluntary wheel running but exhibited preserved inotropic reserve. At 12 mo, Tgαq*44 mice demonstrated a severe impairment of basal cardiac performance and modestly compromised inotropic reserve with reduced voluntary wheel running. Angiotensin analysis in plasma revealed an increase in concentration of angiotensin-(1-7) in 6- to 10-mo-old Tgαq*44 mice. However, in 12- to 14-mo-old Tgαq*44 mice, increased angiotensin II was noted with a concomitant increase in Ang III, Ang IV, angiotensin A, and angiotensin-(1-10). The pattern of changes in the heart and aorta was also compatible with activation of ACE2, followed by activation of the ACE pathway. In conclusion, mice with cardiomyocyte Gαq protein overexpression develop HF that is associated with activation of the systemic and the local ACE/Ang II pathway. However, it is counterbalanced by a prominent ACE2/Ang-(1-7) activation, possibly allowing to delay decompensation. NEW & NOTEWORTHY Changes in ACE/ACE-2 balance were analyzed based on measurements of a panel of nine angiotensins in plasma, heart, and aorta of Tgαq*44 mice in relation to progression of heart failure (HF) characterized by multiparametric MRI and exercise performance. The early stage of HF was associated with upregulation of the ACE2/angiotensin-(1-7) pathway, whereas the end-stage HF was associated with downregulation of ACE2/angiotensin-(1-7) and upregulation of the ACE/Ang II pathway. ACE/ACE-2 balance seems to determine the decompensation of HF in this model.

Review: Effective Implementation of the New ESC Guidelines for the Management of Chronic Heart Failure in Routine Clinical Practice

European guidelines for the management of chronic heart failure (CHF) have been recently updated. Key changes include emphasis on CHF with preserved ejection fraction, and recognition of the role of angiotensin receptor blockers (ARBs) in the management of CHF patients with left ventricular systolic dysfunction who remain symptomatic despite optimal therapy, or who are intolerant to angiotensin-converting enzyme (ACE) inhibitors.

Recent trials that clearly demonstrated significant mortality and morbidity benefits were integral to these new recommendations. Additionally, a high dose of an ARB, as demonstrated in the Candesartan in Heart Failure Assessment of Reduction in Mortality and morbidity (CHARM) programme, can significantly reduce hospitalisation for heart failure in these settings. The guidelines recommend that only those ARBs and doses used in clinical trials should be considered, taking into account current licensed indications. Clinicians who are directly involved in the management of CHF must play a key role in the dissemination of these guidelines to colleagues to ensure that optimal CHF management is integrated into standard practice.

The natriuretic peptides system in the pathophysiology of heart failure: from molecular basis to treatment

After its discovery in the early 1980s, the natriuretic peptide (NP) system has been extensively characterized and its potential influence in the development and progression of heart failure (HF) has been investigated. HF is a syndrome characterized by the activation of different neurohormonal systems, predominantly the renin-angiotensin (Ang)-aldosterone system (RAAS) and the sympathetic nervous system (SNS), but also the NP system. Pharmacological interventions have been developed to counteract the neuroendocrine dysregulation, through the down modulation of RAAS with ACE (Ang-converting enzyme) inhibitors, ARBs (Ang receptor blockers) and mineralcorticoid antagonists and of SNS with β-blockers. In the last years, growing attention has been paid to the NP system. In the present review, we have summarized the current knowledge on the NP system, focusing on its role in HF and we provide an overview of the pharmacological attempts to modulate NP in HF: from the negative results of the study with neprilysin (NEP) inhibitors, alone or associated with an ACE inhibitor and vasopeptidase inhibitors, to the most recently and extremely encouraging results obtained with the new pharmacological class of Ang receptor and NEP inhibitor, currently defined ARNI (Ang receptor NEP inhibitor). Indeed, this new class of drugs to manage HF, supported by the recent results and a vast clinical development programme, may prompt a conceptual shift in the treatment of HF, moving from the inhibition of RAAS and SNS to a more integrated target to rebalance neurohormonal dysregulation in HF.

Modulation of the renin-angiotensin-aldosterone system in heart failure

The renin-angiotensin-aldosterone system (RAAS) is well-established and continues to be pursued as a therapeutic target in the treatment of heart failure, predominantly due to the success of agents that block RAAS in clinical trials of systolic heart failure. The optimal treatment of heart failure patients with preserved ejection fraction (HFpEF), however, remains unclear. Early trials of direct renin inhibitors have suggested that these agents may play a role in HFpEF, but recent clinical trial results have not been encouraging. Preliminary trials of angiotensin-receptor/neprilysin inhibitors look promising. Whether results with these or other drugs will alter current recommendations remains to be seen. In this review, we assess the current understanding of the role of RAAS modulation in heart failure.

Prednisolone attenuates improvement of cardiac and skeletal contractile function and histopathology by lisinopril and spironolactone in the mdx mouse model of Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is an inherited disease that causes striated muscle weakness. Recently, we showed therapeutic effects of the combination of lisinopril (L), an angiotensin converting enzyme (ACE) inhibitor, and spironolactone (S), an aldosterone antagonist, in mice lacking dystrophin and haploinsufficient for utrophin (utrn(+/-);mdx, het mice); both cardiac and skeletal muscle function and histology were improved when these mice were treated early with LS. It was unknown to what extent LS treatment is effective in the most commonly used DMD murine model, the mdx mouse. In addition, current standard-of-care treatment for DMD is limited to corticosteroids. Therefore, potentially useful alternative or additive drugs need to be both compared directly to corticosteroids and tested in presence of corticosteroids. We evaluated the effectiveness of this LS combination in the mdx mouse model both compared with corticosteroid treatment (prednisolone, P) or in combination (LSP). We tested the additional combinatorial treatment containing the angiotensin II receptor blocker losartan (T), which is widely used to halt and treat the developing cardiac dysfunction in DMD patients as an alternative to an ACE inhibitor. Peak myocardial strain rate, assessed by magnetic resonance imaging, showed a negative impact of P, whereas in both diaphragm and extensor digitorum longus (EDL) muscle contractile function was not significantly impaired by P. Histologically, P generally increased cardiac damage, estimated by percentage area infiltrated by IgG as well as by collagen staining. In general, groups that only differed in the presence or absence of P (i.e. mdx vs. P, LS vs. LSP, and TS vs. TSP) demonstrated a significant detrimental impact of P on many assessed parameters, with the most profound impact on cardiac pathology.

Enhanced efferocytosis of apoptotic cardiomyocytes through myeloid-epithelial-reproductive tyrosine kinase links acute inflammation resolution to cardiac repair after infarction

RATIONALE

Efficient clearance of apoptotic cells (efferocytosis) is a prerequisite for inflammation resolution and tissue repair. After myocardial infarction, phagocytes are recruited to the heart and promote clearance of dying cardiomyocytes. The molecular mechanisms of efferocytosis of cardiomyocytes and in the myocardium are unknown. The injured heart provides a unique model to examine relationships between efferocytosis and subsequent inflammation resolution, tissue remodeling, and organ function.

OBJECTIVE

We set out to identify mechanisms of dying cardiomyocyte engulfment by phagocytes and, for the first time, to assess the causal significance of disrupting efferocytosis during myocardial infarction.

METHODS AND RESULTS

In contrast to other apoptotic cell receptors, macrophage myeloid-epithelial-reproductive tyrosine kinase was necessary and sufficient for efferocytosis of cardiomyocytes ex vivo. In mice, Mertk was specifically induced in Ly6c(LO) myocardial phagocytes after experimental coronary occlusion. Mertk deficiency led to an accumulation of apoptotic cardiomyocytes, independently of changes in noncardiomyocytes, and a reduced index of in vivo efferocytosis. Importantly, suppressed efferocytosis preceded increases in myocardial infarct size and led to delayed inflammation resolution and reduced systolic performance. Reduced cardiac function was reproduced in chimeric mice deficient in bone marrow Mertk; reciprocal transplantation of Mertk(+/+) marrow into Mertk(-/-) mice corrected systolic dysfunction. Interestingly, an inactivated form of myeloid-epithelial-reproductive tyrosine kinase, known as solMER, was identified in infarcted myocardium, implicating a natural mechanism of myeloid-epithelial-reproductive tyrosine kinase inactivation after myocardial infarction.

CONCLUSIONS

These data collectively and directly link efferocytosis to wound healing in the heart and identify Mertk as a significant link between acute inflammation resolution and organ function.

Targeting the renin-angiotensin-aldosterone system in heart failure

The renin-angiotensin-aldosterone system is a well-established therapeutic target in the treatment of heart failure (HF). Substantial advances have been made with existing agents--angiotensin-converting enzyme (ACE) inhibitors, angiotensin II-receptor blockers (ARBs), and mineralocorticoid-receptor antagonists (MRAs)--and new data continue to emerge. The indication for the use of MRAs has been broadened to include potentially all patients who have HF with reduced ejection fraction (HFrEF), and ACE inhibitors might have a novel application in patients who are at risk of left ventricular dysfunction (those with aortic valvular disease or pacing-induced heart disease). ARBs have been shown to be a beneficial alternative to ACE inhibitors in HFrEF, but their value when added to ACE inhibitors has been questioned. Upstream, direct renin blockade with aliskiren is being pursued in two large trials of HF, despite the premature halting of a third study. A substantial, unmet need remains in patients who have HF with preserved ejection fraction (HFpEF). New data on spironolactone and LCZ696 (a combined ARB and neprilysin inhibitor) show promise for these patients. Results of the TOPCAT study of spironolactone in patients with HFpEF are awaited, and LCZ696 is now being tested in a large trial in patients with HFrEF.

Cardiac ryanodine receptor in metabolic syndrome: is JTV519 (K201) future therapy?

Metabolic syndrome is characterized by a combination of obesity, hypertension, insulin resistance, dyslipidemia, and impaired glucose tolerance. This multifaceted syndrome is often accompanied by a hyperdynamic circulatory state characterized by increased blood pressure, total blood volume, cardiac output, and metabolic tissue demand. Experimental, epidemiological, and clinical studies have demonstrated that patients with metabolic syndrome have significantly elevated cardiovascular morbidity and mortality rates. One of the main and frequent complications seen in metabolic syndrome is cardiovascular disease. The primary endpoints of cardiometabolic risk are coronary and peripheral arterial disease, myocardial infarction, congestive heart failure, arrhythmia, and stroke. Alterations in expression and/or functioning of several key proteins involved in regulating and maintaining ionic homeostasis can cause cardiac disturbances. One such group of proteins is known as ryanodine receptors (intracellular calcium release channels), which are the major channels through which Ca(2+) ions leave the sarcoplasmic reticulum, leading to cardiac muscle contraction. The economic cost of metabolic syndrome and its associated complications has a significant effect on health care budgets. Improvements in body weight, blood lipid profile, and hyperglycemia can reduce cardiometabolic risk. However, constant hyperadrenergic stimulation still contributes to the burden of disease. Normalization of the hyperdynamic circulatory state with conventional therapies is the most reasonable therapeutic strategy to date. JTV519 (K201) is a newly developed 1,4-benzothiazepine drug with antiarrhythmic and cardioprotective properties. It appears to be very effective in not only preventing but also in reversing the characteristic myocardial changes and preventing lethal arrhythmias. It is also a unique candidate to improve diastolic heart failure in metabolic syndrome.

CONSENSUS to EMPHASIS: the overwhelming evidence which makes blockade of the renin-angiotensin-aldosterone system the cornerstone of therapy for systolic heart failure

We will shortly celebrate the 25th anniversary of the publication of the Co-operative North Scandinavian Enalapril Survival Study (CONSENSUS), a clinical trial which revolutionized the treatment of heart failure and highlighted the importance of the renin-angiotensin-aldosterone system (RAAS) in the pathophysiology of heart failure (Figure 1). In this article I will give a brief, historical overview of this exciting quarter-century of discovery related to the RAAS. My focus is on the treatment of heart failure in patients with a low left ventricular ejection fraction.

Lack of fibronectin-EDA promotes survival and prevents adverse remodeling and heart function deterioration after myocardial infarction

RATIONALE

The extracellular matrix may induce detrimental inflammatory responses on degradation, causing adverse cardiac remodeling and heart failure. The extracellular matrix protein fibronectin-EDA (EIIIA; EDA) is upregulated after tissue injury and may act as a "danger signal" for leukocytes to cause adverse cardiac remodeling after infarction.

OBJECTIVE

In the present study, we evaluated the role of EDA in regulation of postinfarct inflammation and repair after myocardial infarction.

METHODS AND RESULTS

Wild-type and EDA(-/-) mice underwent permanent ligation of the left anterior coronary artery. Despite equal infarct size between groups (38.2±4.6% versus 38.2±2.9% of left ventricle; P=0.985), EDA(-/-) mice exhibited less left ventricular dilatation and enhanced systolic performance compared with wild-type mice as assessed by serial cardiac MRI measurements. In addition, EDA(-/-) mice exhibited reduced fibrosis of the remote area without affecting collagen production, cross-linking, and deposition in the infarct area. Subsequently, ventricular contractility and relaxation was preserved in EDA(-/-). At tissue level, EDA(-/-) mice showed reduced inflammation, metalloproteinase 2 and 9 activity, and myofibroblast transdifferentiation. Bone marrow transplantation experiments revealed that myocardium-induced EDA and not EDA from circulating cells regulates postinfarct remodeling. Finally, the absence of EDA reduced monocyte recruitment as well as monocytic Toll-like receptor 2 and CD49d expression after infarction.

CONCLUSIONS

Our study demonstrated that parenchymal fn-EDA plays a critical role in adverse cardiac remodeling after infarction. Absence of fn-EDA enhances survival and cardiac performance by modulating matrix turnover and inflammation via leukocytes and fibroblasts after infarction.

Differential regulation of inducible and endothelial nitric oxide synthase by kinin B1 and B2 receptors

Kinins are vasoactive peptides that play important roles in cardiovascular homeostasis, pain and inflammation. After release from their precursor kininogens, kinins or their C-terminal des-Arg metabolites activate two distinct G protein-coupled receptors (GPCR), called B2 (B2R) or B1 (B1R). The B2R is expressed constitutively with a wide tissue distribution. In contrast, the B1R is not expressed under normal conditions but is upregulated by tissue insult or inflammatory mediators. The B2R is considered to mediate many of the acute effects of kinins while the B1R is more responsible for chronic responses in inflammation. Both receptors can couple to Galphai and Galphaq families of G proteins to release mediators such as nitric oxide (NO), arachidonic acid, prostaglandins, leukotrienes and endothelium-derived hyperpolarizing factor and can induce the release of other inflammatory agents. The focus of this review is on the different transduction events that take place upon B2R and B1R activation in human endothelial cells that leads to generation of NO via activation of different NOS isoforms. Importantly, B2R-mediated eNOS activation leads to a transient ( approximately 5min) output of NO in control endothelial cells whereas in cytokine-treated endothelial cells, B1R activation leads to very high and prolonged ( approximately 90min) NO production that is mediated by a novel signal transduction pathway leading to post-translational activation of iNOS.

Angiotensin I-converting enzyme inhibitors are allosteric enhancers of kinin B1 and B2 receptor function

The beneficial effects of angiotensin I-converting enzyme (ACE) inhibitors go beyond the inhibition of ACE to decrease angiotensin (Ang) II or increase kinin levels. ACE inhibitors also affect kinin B1 and B2 receptor (B1R and B2R) signaling, which may underlie some of their therapeutic usefulness. They can indirectly potentiate the actions of bradykinin (BK) and ACE-resistant BK analogs on B2Rs to elevate arachidonic acid and NO release in laboratory experiments. Studies indicate that ACE inhibitors and some Ang metabolites increase B2R functions as allosteric enhancers by inducing a conformational change in ACE. This is transmitted to B2Rs via heterodimerization with ACE on the plasma membrane of cells. ACE inhibitors are also agonists of the B1R, at a Zn-binding sequence on the second extracellular loop that differs from the orthosteric binding site of the des-Arg-kinin peptide ligands. Thus, ACE inhibitors act as direct allosteric B1R agonists. When ACE inhibitors enhance B2R and B1R signaling, they augment NO production. Enhancement of B2R signaling activates endothelial NO synthase, yielding a short burst of NO; activation of B1Rs results in a prolonged high output of NO by inducible NO synthase. These actions, outside inhibiting peptide hydrolysis, may contribute to the pleiotropic therapeutic effects of ACE inhibitors in various cardiovascular disorders.

Effects of aldosterone blockade on left ventricular function and clinical status during acute myocardial infarction

OBJECTIVE

Heart failure is frequently a serious complication of acute myocardial infarction (AMI). ACE inhibitors, Angiotensin II receptor blockers, beta-blockers and aldosterone receptor blockers have been shown to improve outcomes in this setting. This study aimed to determine the effect of spironolactone on the frequency of clinical heart failure, mortality, rehospitalization and left ventricular functions determined by echocardiography.

MATERIAL AND METHODS

A total of 82 patients with STEMI hospitalized within 6-12 h of debut of symptoms were included in the study. The patients were randomly assigned into spironolactone (group A) or placebo (group B) groups after informed consent had been obtained.

RESULTS

All patients were followed for 6 months. There were no statistically significant differences between the two groups when demographic criteria were compared. The incidence of post-MI angina pectoris, rhythm and conduction disturbance during hospitalization was significantly higher in Group B than in Group A. Although not statistically significant, the incidence of clinical heart failure was slightly lower in Group A than in Group B (5% versus 11%). Left ventricular end-diastolic volumes were slightly lower in Group A than in Group B, although statistically this was not significant.

CONCLUSIONS

In concordance with these findings, the ejection fraction was slightly higher in Group A than in Group B, although this was not statistically significant (47% versus 44%). This trend continued during a 6-month follow-up after randomization. Our findings suggest that early administration of aldosterone blockers provides additional benefits after AMI, reducing the incidence of post-MI angina pectoris and rhythm and conduction disturbances.

High prevalence of abnormal glucose metabolism in young adult patients with complex congenital heart disease

BACKGROUND

Abnormal glucose metabolism (AGM) adversely impacts morbidity and mortality in patients with chronic heart failure. No data on AGM in adult patients with congenital heart disease (ACHD) are available.

METHODS

To assess the AGM in ACHD and compare the results with their clinical characteristics, we performed a 75-g oral glucose tolerance test to detect AGM, that is, insulin resistance, impaired glucose tolerance, and diabetes mellitus, in 205 consecutive ACHD (24 +/- 8 years), including 16 unrepaired patients, 67 Fontan patients, 122 postbiventricular (BV) patients, and 27 healthy controls (27 +/- 5 years).

RESULTS

All ACHD groups had a high prevalence of AGM (unrepaired, 43.8%; Fontan, 43.3%; BV, 46.7%; control, 3.7%; P < .001). In the 2 postoperative groups, the Matsuda index was decreased (P < .0001), and greater waist circumference, liver dysfunction, higher plasma renin activity, and diuretic use were associated with AGM. Although male gender was associated with AGM (P < .01), baseline glucose and lipid metabolic variables did not correlate with the 75-g oral glucose tolerance test-induced hyperglycemia (area under the plasma glucose curve [AUC-PG]) in the Fontan patients but did correlate in the BV patients. The AUC-PG correlated inversely with exercise capacity (P < .05) in the 2 postoperative ACHD groups, and the AGM ACHD had a high incidence of future cardiac events (P < .05), especially the Fontan patients with diabetes mellitus (P < .01).

CONCLUSIONS

Complex ACHD have a high prevalence of AGM, and this newly recognized pathophysiology should be considered in managing long-term survivors of complex ACHD.

Interaction between bradykinin subtype 2 and angiotensin II type 2 receptors during post-MI left ventricular remodeling

Angiotensin II type 2 receptor (AT2R) overexpression (AT2TG) attenuates left ventricular remodeling in a mouse model of anterior myocardial infarction (MI). We hypothesized that the beneficial effects of cardiac AT2TG are mediated via the bradykinin subtype 2 receptor (B2R). Fourteen transgenic mice overexpressing the AT2R (AT2TG mice), 10 mice with a B2R deletion (B2KO mice), 13 AT2TG mice with B2R deletion (AT2TG/B2KO mice), and 11 wild-type (WT) mice were studied. All mice were on a C57BL/6 background. Mice were studied by cardiac magnetic resonance imaging at baseline and days 1, 7, and 28 after MI induced by 1 h of occlusion of the left anterior descending artery followed by reperfusion. Short-axis images from apex to base were used to compare ventricular volumes and ejection fraction (EF). At baseline, end-diastolic volume index (EDVI) and end-systolic volume index (ESVI) were lower and EF higher in AT2TG mice compared with the other three strains. Infarct size was similar between groups. No differences were observed in global remodeling parameters at day 28 between AT2TG and AT2TG/B2KO mice; however, EDVI and ESVI were lower and EF higher in both transgenic groups than in WT or B2KO mice. Both strains lacking B2R demonstrated increased collagen content and less hypertrophy in adjacent noninfarcted regions at day 28. Attenuation of postinfarct remodeling by overexpression of AT2R is not directly mediated via a B2R pathway. However, B2R does appear to have a role in the smaller cavity size and hyperdynamic function observed at baseline in AT2TG mice and in limiting collagen deposition during postinfarct remodeling.

Hormonal and hemodynamic effects of aliskiren and valsartan and their combination in sodium-replete normotensive individuals

BACKGROUND AND OBJECTIVES

An AT1 receptor antagonist induces a counterregulatory renin release whose intensity and duration reflect the magnitude of the renin-angiotensin blockade. We investigated whether a renin inhibitor may neutralize this counterregulation and amplify the effects of AT1 receptor antagonists.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In 12 normotensive male individuals who were on a high-sodium diet, a double-blind, placebo-controlled, randomized, crossover design was used to study the hormonal and BP effects of single oral administrations of 300 mg of the renin inhibitor aliskiren, 320 mg of valsartan, and a combination of these two drugs, each at half dosage (150 mg of aliskiren and 160 mg of valsartan).

RESULTS

Valsartan (320 mg) increased plasma renin activity and angiotensin I and angiotensin II levels, but 300 mg of aliskiren decreased them for 48 h. Aliskiren (300 mg) stimulated immunoreactive renin release more strongly than 320 mg of valsartan, decreased urinary aldosterone excretion for longer than 320 mg of valsartan, and had a similar BP-lowering effect as 320 mg of valsartan. In combination, 150 mg of aliskiren neutralized the valsartan (160 mg)-induced increase in plasma angiotensins for 48 h. The renin and aldosterone effects of the combination of 150 mg of aliskiren and 160 mg of valsartan were similar to those of 300 mg of aliskiren and greater than those of 320 mg of valsartan. When plasma drug concentrations were taken into account, the combination of 150 mg of aliskiren and 160 mg of valsartan had a synergistic effect on renin release. The BP-lowering effect of 150 mg of aliskiren and 160 mg of valsartan was similar to that of 300 mg of aliskiren and 320 mg of valsartan at peak but was more prolonged.

CONCLUSION

The stronger and longer lasting effects on plasma active renin and urinary aldosterone of aliskiren, alone or in combination, demonstrate a more effective blockade of the renin-angiotensin system than that obtained with 320 mg of valsartan alone.

The CHARM program: study design leads to findings of clinical and public health importance

In large-scale randomized trials and their meta-analyses, beta-adrenergic blockers and angiotensin-converting enzyme inhibitors provide statistically significant and clinically important additive mortality and morbidity benefits in the treatment of heart failure. The CHARM trials were designed to test whether the angiotensin-receptor blocker candesartan would provide statistically significant and clinically important additive mortality and morbidity benefits to patients with heart failure as an alternative or in addition to angiotensin-converting enzyme inhibitors. CHARM demonstrated that an angiotensin-receptor blocker at a proven dose is an effective and safe therapy as an alternative or in addition to angiotensin-converting enzyme inhibitors in patients with heart failure, 55% of whom were receiving beta-adrenergic blockers. These benefits include reductions in cardiovascular mortality rate as well as in hospitalization for heart failure. Such patients have a 50% mortality rate at 5 years, and heart failure is the leading cause of hospitalization for patients 65 years of age and older.

Trends and outcomes associated with angiotensin-converting enzyme inhibitors

BACKGROUND

Limited recent data are available describing the patterns of use of angiotensin converting enzyme inhibitor (ACEI) therapy in patients with acute myocardial infarction (AMI), particularly from the more generalizable population-based setting. The purpose of this study was to examine trends in the receipt of ACEIs and associated short-term outcomes in patients hospitalized with AMI in a large Northeastern community.

METHODS

We conducted a community-wide study of 7991 patients hospitalized with AMI in all metropolitan Worcester, Massachusetts, medical centers during 8 annual periods between 1990 and 2003.

RESULTS

Among all patients, 44% received ACEI therapy during their acute hospitalization. There was a marked increase in the use of ACEIs between 1990 (23%) and 2003 (68%), particularly among those who were not on ACEIs before hospitalization. Patients who were previously on ACEIs were more likely to receive this therapy during hospitalization for AMI than were patients who were not previously on this therapy. Patients treated with ACEIs were significantly less likely to die (adjusted odds ratio [OR] 0.33; 95% confidence interval [CI] 0.27-0.41) during hospitalization than were patients who did not receive this therapy, with benefits observed across all subgroups examined.

CONCLUSIONS

The results of this observational study demonstrate marked increases in the use of ACEIs in patients with AMI in the community setting and demonstrate the benefits to be gained from use of this therapy. Despite these encouraging trends, there remains room for more optimal use of this therapy.

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.

The effect of valsartan, captopril, or both on atherosclerotic events after acute myocardial infarction: an analysis of the Valsartan in Acute Myocardial Infarction Trial (VALIANT)

OBJECTIVES

We attempted to compare the effect of an angiotensin-converting enzyme (ACE) inhibitor and angiotensin receptor blocker (ARB) on atherosclerotic events.

BACKGROUND

Angiotensin-converting enzyme inhibitors and ARBs interrupt the renin-angiotensin system by distinct mechanisms. It is not clear whether ARBs reduce atherosclerotic events such as myocardial infarction (MI) like ACE inhibitors. This evidence gap may reflect the nature of the studies conducted, to date. Placebo-controlled studies enrolled cohorts at low risk of atherosclerotic events (e.g., patients with chronic heart failure, most treated with an ACE inhibitor). One of the main active controlled trials was confounded by a blood pressure difference between treatments.

METHODS

We compared the effects of captopril, valsartan, and their combination on atherosclerotic events in 14,703 patients randomized in the Valsartan in Acute Myocardial Infarction Trial (VALIANT).

RESULTS

The number of individuals adjudicated as having a fatal or non-fatal MI in the captopril group was 559 (total investigator reported events 798), 587 (796) in the valsartan group, and 554 (756) in the combination group; valsartan versus captopril, p = 0.651 (0.965); combination versus captopril, p = 0.187 (0.350). Overall, all atherosclerotic events examined occurred at a similar frequency in the captopril and valsartan groups.

CONCLUSIONS

Angiotensin receptor blockers appear to be as effective as ACE inhibitors in reducing atherosclerotic events, even when used in addition to other secondary preventive treatments. These data, although not conclusive, also support the hypothesis that adding an ARB to an ACE inhibitor may have a small additional anti-infarction effect, a possibility that needs to be prospectively tested.

Angiotensin receptor blockers: therapeutic targets and cardiovascular protection

In the prevention and treatment of cardiovascular disease, pharmacological treatment strategies should have several aims: (i) in individuals without overt cardiovascular disease, but with risk factors such as hypertension and/or diabetes, pharmacotherapy should prevent or delay disease development; (ii) in patients who have already progressed to cardiovascular disease, pharmacotherapy should help either to prevent or regress target organ damage (TOD); and (iii) in patients with TOD, pharmacotherapy should prevent events. Any medication intended for long-term therapy also should be well tolerated. Inhibiting the renin-angiotensin system has proven a successful therapeutic strategy in cardiovascular and renal medicine. Angiotensin-converting enzyme (ACE) inhibitors have demonstrated important advantages over conventional agents such as beta-blockers and thiazide diuretics, and have become a relevant part of treatment for heart failure post-myocardial infarction, left ventricular dysfunction and renal disease. Tolerability concerns may prevent their use in some patients, however. Angiotensin AT1 receptor blockers (ARBs) provide a different form of blockade of the renin-angiotensin system and a growing body of evidence suggests that this alternative approach may confer additional cardiovascular protection for some patient subgroups. In addition, ARBs generally are better tolerated than ACE inhibitors, enhancing patient compliance and persistence with long-term therapy. Furthermore, evidence in favour of combining an ACE inhibitor and an ARB in certain circumstances is continuously growing.