Effects of losartan and captopril on left ventricular systolic and diastolic function after acute myocardial infarction: results of the Optimal Trial in Myocardial Infarction with Angiotensin II Antagonist Losartan (OPTIMAAL) echocardiographic substudy

Reducing Cardiac Steatosis: Interventions to Improve Diastolic Function - A Narrative Review

Heart failure is one of the main causes of morbidity and mortality around the globe. Heart failure with preserved ejection fraction is primarily caused by diastolic dysfunction. Adipose tissue deposition in the heart has been previously explained in the pathogenesis of diastolic dysfunction. In this article, we aim to discuss the potential interventions that can reduce the risk of diastolic dysfunction by reducing cardiac adipose tissue. A healthy diet with reduced dietary fat content can reduce visceral adiposity and improve diastolic function. Aerobic and resistance exercises also reduce visceral and epicardial fat and ameliorate diastolic dysfunction. Some medications, include metformin, glucagon-like peptide-1 analogues, dipeptidyl peptidase-4 inhibitors, thiazolidinediones, sodium-glucose co-transporter-2, inhibitors, statins, ACE-Is, and ARBs, have shown different degrees of effectiveness in improving cardiac steatosis and diastolic function. Bariatric surgery has also shown promising results in this field.

Mechanisms for the development of heart failure and improvement of cardiac function by angiotensin-converting enzyme inhibitors

Angiotensin-converting enzyme (ACE) inhibitors, which prevent the conversion of angiotensin I to angiotensin II, are well-known for the treatments of cardiovascular diseases, such as heart failure, hypertension and acute coronary syndrome. Several of these inhibitors including captopril, enalapril, ramipril, zofenopril and imidapril attenuate vasoconstriction, cardiac hypertrophy and adverse cardiac remodeling, improve clinical outcomes in patients with cardiac dysfunction and decrease mortality. Extensive experimental and clinical research over the past 35 years has revealed that the beneficial effects of ACE inhibitors in heart failure are associated with full or partial prevention of adverse cardiac remodeling. Since cardiac 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+ and myocardial metabolism, there is ample evidence to suggest that adverse cardiac remodelling and cardiac dysfunction in the failing heart are the consequence of subcellular defects. In fact, the improvement of cardiac function by different ACE inhibitors has been demonstrated to be related to the attenuation of abnormalities in subcellular organelles for Ca2+-handling, metabolic alterations, signal transduction defects and gene expression changes in failing cardiomyocytes. Various ACE inhibitors have also been shown to delay the progression of heart failure by reducing the formation of angiotensin II, the development of oxidative stress, the level of inflammatory cytokines and the occurrence of subcellular defects. These observations support the view that ACE inhibitors improve cardiac function in the failing heart by multiple mechanisms including the reduction of oxidative stress, myocardial inflammation and Ca2+-handling abnormalities in cardiomyocytes.

Non-transmural myocardial infarction associated with regional contractile function is an independent predictor of positive outcome: an integrated approach to myocardial viability

BACKGROUND

Cardiovascular magnetic resonance permits assessment of irreversible myocardial fibrosis and contractile function in patients with previous myocardial infarction. We aimed to assess the prognostic value of myocardial fibrotic tissue with preserved/restored contractile activity.

METHODS

In 730 consecutive myocardial infarction patients (64 ± 11 years), we quantified left ventricular (LV) end-diastolic (EDV) and end-systolic (ESV) volumes, ejection fraction (EF), regional wall motion (WM) (1 normal, 2 hypokinetic, 3 akinetic, 4 dyskinetic), and WM score index (WMSI), and measured the transmural (1-50 and 51-100) and global extent of the infarct scar by late gadolinium enhancement (LGE). Contractile fibrotic (CT-F) segments were identified as those showing WM-1 and WM-2 with LGE ≤ or ≥ 50%.

RESULTS

During follow-up (median 2.5, range 1-4.7 years), cardiac events (cardiac death or appropriate implantable defibrillator shocks) occurred in 123 patients (17%). At univariate analysis, age, LVEDV, LVESV, LVEF, WMSI, extent of LGE, segments with transmural extent > 50%, and CT-F segments were associated with cardiac events. At multivariate analysis, age > 65 years, LVEF < 30%, WMSI > 1.7, and dilated LVEDV independently predicted cardiac events, while CT-F tissue was the only independent predictor of better outcome. After adjustment for LVEF < 30% and LVEDV dilatation, the presence of CT-F tissue was associated with good prognosis.

CONCLUSIONS

In addition to CMR imaging parameters associated with adverse outcome (severe LV dysfunction, poor WM, and dilated EDV), the presence of fibrotic myocardium showing contractile activity in patients with previous myocardial infarction yields a beneficial effect on patient survival.

Imaging tools for assessment of myocardial fibrosis in humans: the need for greater detail

Myocardial fibrosis is recognized as a key pathological process in the development of cardiac disease and a target for future therapeutics. Despite this recognition, the assessment of fibrosis is not a part of routine clinical practice. This is primarily due to the difficulties in obtaining an accurate assessment of fibrosis non-invasively. Moreover, there is a clear discrepancy between the understandings of myocardial fibrosis clinically where fibrosis is predominately studied with comparatively low-resolution medical imaging technologies like MRI compared with the basic science laboratories where fibrosis can be visualized invasively with high resolution using molecularly specific fluorescence microscopes at the microscopic and nanoscopic scales. In this article, we will first review current medical imaging technologies for assessing fibrosis including echo and MRI. We will then highlight the need for greater microscopic and nanoscopic analysis of human tissue and how this can be addressed through greater utilization of human tissue available through endomyocardial biopsies and cardiac surgeries. We will then describe the relatively new field of molecular imaging that promises to translate research findings to the clinical practice by non-invasively monitoring the molecular signature of fibrosis in patients.

Pharmacological interventions for heart failure in people with chronic kidney disease

BACKGROUND

Approximately half of people with heart failure have chronic kidney disease (CKD). Pharmacological interventions for heart failure in people with CKD have the potential to reduce death (any cause) or hospitalisations for decompensated heart failure. However, these interventions are of uncertain benefit and may increase the risk of harm, such as hypotension and electrolyte abnormalities, in those with CKD.

OBJECTIVES

This review aims to look at the benefits and harms of pharmacological interventions for HF (i.e., antihypertensive agents, inotropes, and agents that may improve the heart performance indirectly) in people with HF and CKD.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies through 12 September 2019 in consultation with an Information Specialist and using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

We included randomised controlled trials of any pharmacological intervention for acute or chronic heart failure, among people of any age with chronic kidney disease of at least three months duration.

DATA COLLECTION AND ANALYSIS

Two authors independently screened the records to identify eligible studies and extracted data on the following dichotomous outcomes: death, hospitalisations, worsening heart failure, worsening kidney function, hyperkalaemia, and hypotension. We used random effects meta-analysis to estimate treatment effects, which we expressed as a risk ratio (RR) with 95% confidence intervals (CI). We assessed the risk of bias using the Cochrane tool. We applied the GRADE methodology to rate the certainty of evidence.

MAIN RESULTS

One hundred and twelve studies met our selection criteria: 15 were studies of adults with CKD; 16 studies were conducted in the general population but provided subgroup data for people with CKD; and 81 studies included individuals with CKD, however, data for this subgroup were not provided. The risk of bias in all 112 studies was frequently high or unclear. Of the 31 studies (23,762 participants) with data on CKD patients, follow-up ranged from three months to five years, and study size ranged from 16 to 2916 participants. In total, 26 studies (19,612 participants) reported disaggregated and extractable data on at least one outcome of interest for our review and were included in our meta-analyses. In acute heart failure, the effects of adenosine A1-receptor antagonists, dopamine, nesiritide, or serelaxin on death, hospitalisations, worsening heart failure or kidney function, hyperkalaemia, hypotension or quality of life were uncertain due to sparse data or were not reported. In chronic heart failure, the effects of angiotensin-converting enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARB) (4 studies, 5003 participants: RR 0.85, 95% CI 0.70 to 1.02; I² = 78%; low certainty evidence), aldosterone antagonists (2 studies, 34 participants: RR 0.61 95% CI 0.06 to 6.59; very low certainty evidence), and vasopressin receptor antagonists (RR 1.26, 95% CI 0.55 to 2.89; 2 studies, 1840 participants; low certainty evidence) on death (any cause) were uncertain. Treatment with beta-blockers may reduce the risk of death (any cause) (4 studies, 3136 participants: RR 0.69, 95% CI 0.60 to 0.79; I² = 0%; moderate certainty evidence). Treatment with ACEi or ARB (2 studies, 1368 participants: RR 0.90, 95% CI 0.43 to 1.90; I² = 97%; very low certainty evidence) had uncertain effects on hospitalisation for heart failure, as treatment estimates were consistent with either benefit or harm. Treatment with beta-blockers may decrease hospitalisation for heart failure (3 studies, 2287 participants: RR 0.67, 95% CI 0.43 to 1.05; I² = 87%; low certainty evidence). Aldosterone antagonists may increase the risk of hyperkalaemia compared to placebo or no treatment (3 studies, 826 participants: RR 2.91, 95% CI 2.03 to 4.17; I² = 0%; low certainty evidence). Renin inhibitors had uncertain risks of hyperkalaemia (2 studies, 142 participants: RR 0.86, 95% CI 0.49 to 1.49; I² = 0%; very low certainty). We were unable to estimate whether treatment with sinus node inhibitors affects the risk of hyperkalaemia, as there were few studies and meta-analysis was not possible. Hyperkalaemia was not reported for the CKD subgroup in studies investigating other therapies. The effects of ACEi or ARB, or aldosterone antagonists on worsening heart failure or kidney function, hypotension, or quality of life were uncertain due to sparse data or were not reported. Effects of anti-arrhythmic agents, digoxin, phosphodiesterase inhibitors, renin inhibitors, sinus node inhibitors, vasodilators, and vasopressin receptor antagonists were very uncertain due to the paucity of studies.

AUTHORS' CONCLUSIONS

The effects of pharmacological interventions for heart failure in people with CKD are uncertain and there is insufficient evidence to inform clinical practice. Study data for treatment outcomes in patients with heart failure and CKD are sparse despite the potential impact of kidney impairment on the benefits and harms of treatment. Future research aimed at analysing existing data in general population HF studies to explore the effect in subgroups of patients with CKD, considering stage of disease, may yield valuable insights for the management of people with HF and CKD.

Effect of Losartan on Mitral Valve Changes After Myocardial Infarction

BACKGROUND

After myocardial infarction (MI), mitral valve (MV) tethering stimulates adaptive leaflet growth, but counterproductive leaflet thickening and fibrosis augment mitral regurgitation (MR), doubling heart failure and mortality. MV fibrosis post-MI is associated with excessive endothelial-to-mesenchymal transition (EMT), driven by transforming growth factor (TGF)-β overexpression. In vitro, losartan-mediated TGF-β inhibition reduces EMT of MV endothelial cells.

OBJECTIVES

This study tested the hypothesis that profibrotic MV changes post-MI are therapeutically accessible, specifically by losartan-mediated TGF-β inhibition.

METHODS

The study assessed 17 sheep, including 6 sham-operated control animals and 11 with apical MI and papillary muscle retraction short of producing MR; 6 of the 11 were treated with daily losartan, and 5 were untreated, with flexible epicardial mesh comparably limiting left ventricular (LV) remodeling. LV volumes, tethering, and MV area were quantified by using three-dimensional echocardiography at baseline and at 60 ± 6 days, and excised leaflets were analyzed by histopathology and flow cytometry.

RESULTS

Post-MI LV dilation and tethering were comparable in the losartan-treated and untreated LV constraint sheep. Telemetered sensors (n = 6) showed no significant losartan-induced changes in arterial pressure. Losartan strongly reduced leaflet thickness (0.9 ± 0.2 mm vs. 1.6 ± 0.2 mm; p < 0.05; 0.4 ± 0.1 mm sham animals), TGF-β, and downstream phosphorylated extracellular-signal-regulated kinase and EMT (27.2 ± 12.0% vs. 51.6 ± 11.7% α-smooth muscle actin-positive endothelial cells, p < 0.05; 7.2 ± 3.5% sham animals), cellular proliferation, collagen deposition, endothelial cell activation (vascular cell adhesion molecule-1 expression), neovascularization, and cells positive for cluster of differentiation (CD) 45, a hematopoietic marker associated with post-MI valve fibrosis. Leaflet area increased comparably (17%) in constrained and losartan-treated sheep.

CONCLUSIONS

Profibrotic changes of tethered MV leaflets post-MI can be modulated by losartan without eliminating adaptive growth. Understanding the cellular and molecular mechanisms could provide new opportunities to reduce ischemic MR.

Importance of endogenous compensatory vasoactive peptides in broadening the effects of inhibitors of the renin-angiotensin system for the treatment of heart failure

The magnitude of the clinical benefits produced by inhibitors of the renin-angiotensin system in heart failure has been modest, possibly because of the ability of renin-angiotensin activity to escape from suppression during long-term treatment. Efforts to intensify pharmacological blockade by use of dual inhibitors that interfere with the renin-angiotensin system at multiple sites have not yielded consistent incremental clinical benefits, but have been associated with serious adverse reactions. By contrast, potentiation of endogenous compensatory vasoactive peptides can act to enhance the survival effects of inhibitors of the renin-angiotensin system, as evidenced by trials that have compared angiotensin-converting enzyme inhibitors with drugs that inhibit both the renin-angiotensin system and neprilysin. Several endogenous vasoactive peptides act as adaptive mechanisms, and their augmentation could help to broaden the benefits of renin-angiotensin system inhibitors for patients with heart failure.

Left Ventricular Tonic Contraction as a Novel Biomarker of Cardiomyopathy in Duchenne Muscular Dystrophy

Dilated cardiomyopathy (DCM) inevitably afflicts patients with Duchenne muscular dystrophy (DMD) as a consequence of cell death induced by unguarded calcium influx into cardiomyocytes. This mechanism may also inhibit muscle relaxation in early stages of cardiomyopathy. ACE inhibition (ACEi) is known to delay the onset and slow the progression of DCM in DMD. The objective of this study is to use echocardiography to assess for preclinical cardiac changes consistent with intracellular calcium dysregulation before the onset of overt ventricular dysfunction, and to evaluate how prophylactic ACEi may alter these pre-cardiomyopathic changes in the pediatric DMD population. We examined 263 echocardiograms from 70 pediatric patients with DMD. We defined abnormal tonic contraction (TC) as left ventricular internal dimension in diastole (LVIDd) Z-score < -1.5. In our cohort, we found that TC is detectable as early as 8 years of age, and most commonly affects patients between 11 and 15 years. This effect was independent of LV mass and systolic function. Prophylactic ACEi decreased the incidence of TC (p = 0.007) and preserved cardiac function (p < 0.0001). Left ventricular TC often precedes DCM in DMD, most commonly affecting the 11- to 15-year-old age range. TC is not related to ventricular hypertrophy, but rather may be a clinical correlate of the "calcium hypothesis" of DMD pathophysiology. LV TC is thus a promising biomarker for early detection of cardiomyopathy in DMD. ACEi prophylaxis suppresses LV TC and delays the development of DCM in DMD.

Myocardial Performance Index in Childhood Onset Essential Hypertension and White Coat Hypertension

BACKGROUND

As a global measure of ventricular systolic and diastolic function, the myocardial performance index (MPI) can be an early indicator of hypertensive cardiomyopathy in children with essential hypertension (EH).

METHODS

Children with untreated newly diagnosed EH and white coat hypertension (WCH) by a 24-hour ambulatory blood pressure monitoring (ABPM), both groups without any identifiable etiology for the hypertension, were enrolled for the study. Echocardiograms and vascular ultrasounds for carotid artery intimal medial thickness were performed on all children prior to therapy. Diastolic function (peak E and A velocities, E/A ratio, isovolumic relaxation time, and deceleration times) and MPI were evaluated by simultaneous transmitral and transaortic spectral Doppler flow velocities. Systolic function was evaluated by shortening fraction and ejection fraction.

RESULTS

A cohort of 66 children (24 with EH, 42 with WCH, males 61%, median age of 13 years, range 10-17 years) were enrolled in the study. The demographic, anthropometric, laboratory tests, vascular ultrasound, and conventional echocardiographic parameters were similar between the 2 groups. There was a very small difference in MPI between the EH and WCH children (0.28 SD: 0.07 vs. 0.31 SD: 0.08, P = 0.045). However, in EH children, MPI increased by 0.14 units for every 10 unit increase in mean ABPM systolic BP (95% confidence interval: 0.03-0.25).

CONCLUSIONS

We found the increasing MPI was associated with increasing 24-hour mean systolic BP in children with EH. Therefore, MPI may have utility as a single, quick, noninvasive method of detection and tracking of subclinical hypertensive heart disease.

Improvement of the myocardial performance index in atrial fibrilation patients treated with amiodarone after cardioversion

PURPOSE

This study evaluated the response to electrical cardioversion (EC) and the effect on the myocardial performance index (MPI) in patients with persistent and long-standing persistent atrial fibrillation (AF).

METHODS

We enrolled 103 patients (mean age 69.6 ± 8.9 years, 40.7% males) with a diagnosis of persistent and long-standing persistent AF. EC was applied to all patients after one g of amiodarone administration. Echocardiographic findings before EC were compared in patients with successful versus unsuccessful cardioversions and in patients with maintained sinus rhythm (SR) versus those with AF recurrence at the end of the first month. We also compared echocardiographic data before EC versus at the end of the first month in the same patients with maintained SR.

RESULTS

SR was achieved in 72.8% of patients and was continued at the end of the first month in 69.3% of the patients. The MPI value of all patients was found to be 0.73 ± 0.21. The size of the left atrium was determined to be an independent predictor of the maintenance of SR at 1 month. In subgroup analyses, when we compared echocardiographic findings before EC and at the end of the first month in patients with maintained SR, the MPI (0.66 ± 0.14 vs 0.56 ± 0.09, p < 0.001) values were significantly decreased.

CONCLUSIONS

Our study is the first to show impairment of the MPI, which is an indicator of systolic and diastolic function, in patients with persistent and long-standing persistent AF and improvement of the MPI after successful EC.

Vitamin D signaling pathway plays an important role in the development of heart failure after myocardial infarction

Accumulating evidence suggests that vitamin D deficiency plays a crucial role in heart failure. However, whether vitamin D signaling itself plays an important role in cardioprotection is poorly understood. In this study, we examined the mechanism of modulating vitamin D signaling on progression to heart failure after myocardial infarction (MI) in mice. Vitamin D signaling was activated by administration of paricalcitol (PC), an activated vitamin D analog. Wild-type (WT) mice underwent sham or MI surgery and then were treated with either vehicle or PC. Compared with vehicle group, PC attenuated development of heart failure after MI associated with decreases in biomarkers, apoptosis, inflammation, and fibrosis. There was also improvement of cardiac function with PC treatment after MI. Furthermore, vitamin D receptor (VDR) mRNA and protein levels were restored by PC treatment. Next, to explore whether defective vitamin D signaling exhibited deleterious responses after MI, WT and VDR knockout (KO) mice underwent sham or MI surgery and were analyzed 4 wk after MI. VDR KO mice displayed a significant decline in survival rate and cardiac function compared with WT mice after MI. VDR KO mice also demonstrated a significant increase in heart failure biomarkers, apoptosis, inflammation, and fibrosis. Vitamin D signaling promotes cardioprotection after MI through anti-inflammatory, antifibrotic and antiapoptotic mechanisms.

Differential effects of antihypertensive treatment on left ventricular diastolic function: an ASCOT (Anglo-Scandinavian Cardiac Outcomes Trial) substudy

OBJECTIVES

We hypothesized that an amlodipine-based regimen would have more favorable effects on left ventricular (LV) diastolic function.

BACKGROUND

Different antihypertensive therapies may vary in their effect on LV diastolic function.

METHODS

The HACVD (Hypertension Associated Cardiovascular Disease) substudy of ASCOT (Anglo-Scandinavian Cardiac Outcomes Trial) collected detailed cardiovascular phenotypic data on a subset of 1,006 participants recruited from 2 centers (St. Mary's Hospital, London, and Beaumont Hospital, Dublin). Conventional and tissue Doppler echocardiography and measurement of plasma B-type natriuretic peptide (BNP) were performed approximately 1 year after randomization to atenolol-based or amlodipine-based antihypertensive treatment to assess LV diastolic function.

RESULTS

On-treatment blood pressure (BP) (mean +/- SD) was similar in both groups: atenolol-based regimen, systolic BP of 137 +/- 17 mm Hg, diastolic BP of 82 +/- 9 mm Hg; amlodipine-based regimen, systolic BP of 136 +/- 15 mm Hg, diastolic BP of 80 +/- 9 mm Hg. Ejection fraction did not differ between groups, but early diastolic mitral annular velocity (E'), a measure of diastolic relaxation, was lower in patients on the atenolol-based regimen: atenolol-based regimen, 7.9 +/- 1.8; amlodipine-based regimen, 8.8 +/- 2.0. A measure of left ventricular filling pressure, E/E', and BNP were significantly higher in patients on the atenolol-based regimen. Differences in E', E/E', and BNP remained significant after adjustment for age and sex. Further adjustment for systolic BP, LV mass index, and heart rate had no impact on differences in mean E' or BNP. The difference in E/E' was attenuated.

CONCLUSIONS

Patients receiving treatment with an amlodipine-based regimen had better diastolic function than patients treated with the atenolol-based regimen. Treatment-related differences in diastolic function were independent of BP reduction and other factors that are known to affect diastolic function.

Interventional Case Series: Angiotensin-Converting Enzyme Inhibitor (ACE-I)–Induced Cough: Is Rechallenge With a Second ACE-I Worthwhile?

Angiotensin-converting enzyme inhibitors (ACE-Is) are a cornerstone of therapy with proven morbidity and mortality benefit in many disease states. The unpredictable, bothersome cough that occurs in 15% to 41% of patients oftentimes leads to noncompliance or discontinuation. Management of ACE-I-induced cough remains controversial. The authors’ objective was to determine whether patients experiencing an ACE-I-induced cough could be successfully switched to a different ACE-I without recurrent cough. A total of 10 participants deemed to have ACE-I-induced cough were enrolled in an interventional case series to assess whether they could tolerate rechallenge with an alternative ACE-I. During phase 1, ACE-I therapy was stopped for up to 4 weeks to allow the cough to resolve. During phase 2, participants were rechallenged with an alternative ACE-I and followed for 4 months. Of the 10 participants who consented to enroll, 6 were rechallenged with a second ACE-I. Cough recurred in 4 of these within 1 week (5-7 days), whereas 2 participants continued ACE-I therapy cough-free. Results suggest that a small percentage of patients with ACE-I-induced cough tolerate an alternative ACE-I. For patients with a true ACE-I-induced cough who are motivated to continue an ACE-I, a trial of a second ACE-I may be worthwhile.

Doppler-derived myocardial performance index in patients with impaired left ventricular relaxation and preserved systolic function

BACKGROUND

The Doppler-derived myocardial performance index (MPI) has been used in the evaluation of left ventricular (LV) function in several diseases. In patients with isolated diastolic dysfunction, the diagnostic utility of this index remains unclear. The aim of this study was to determine the diagnostic utility of MPI in patients with systemic hypertension, impaired LV relaxation, and normal ejection fraction.

METHODS

Thirty hypertensive patients with impaired LV relaxation were compared to 30 control subjects. MPI and its components, isovolumetric relaxation time (IRT), isovolumetric contraction time (ICT), and the ejection time (ET), were measured from LV outflow and mitral inflow Doppler velocity profiles.

RESULTS

MPI was higher in patients than in control subjects (0.45 +/- 0.13 vs 0.37 +/- 0.07 P < 0.0029). The increase in MPI was due to the prolongation of IRT without significant change of ICT and ET. MPI cutoff value of > or =0.40 identified impaired LV relaxation with a sensitivity of 63% and specificity of 70% while an IRT >94 ms had a sensitivity of 67% and specificity of 80%. Multivariate analysis identified relative wall thickness, mitral early filling wave velocity (E), and systolic myocardial velocity (Sm) as independent predictors of MPI in patients with hypertension.

CONCLUSIONS

MPI was increase in patients with hypertension, diastolic dysfunction, and normal ejection fraction but was not superior to IRT to detect impaired LV relaxation.

Effects of enalapril, candesartan or both on neurohumoral activation and LV volumes and function in patients with heart failure not treated with a beta-blocker

Background: The long-term effects of the angiotensin-receptor blocker candesartan, the angiotensin-converting enzyme inhibitor enalapril or their combination have been incompletely studied in a large cohort of patients with heart failure not treated with beta-blockers. The objective of this study was to investigate the changes in neurohormones and LV volumes and ejection fraction in patients treated with enalapril, candesartan, or enalapril plus candesartan without concomitant beta-blocker therapy.

Methods: Three hundred and ninety-two patients from the RESOLVD pilot study not treated with a beta-blocker at baseline or at any time during the trial were analyzed. Norepinephrine, endothelin-1, big endothelin-1, angiotensin-II, aldosterone, N-terminal proANP, BNP, and radionuclide angiography were measured before and after 43 weeks of treatment with candesartan alone ( n = 162), or enalapril alone ( n = 45), or candesartan plus enalapril ( n = 185). Endpoints were assessed at baseline and after 43 weeks of therapy.

Results: LV end-diastolic and end-systolic volumes increased significantly at 43 weeks in all groups except for patients treated with enalapril plus candesartan. BNP decreased at 43 weeks only in patients receiving dual angiotensin-II suppression (-6.1 ± 37.8 pmol/l). Angiotensin-II levels were significantly increased in patients treated with candesartan (+23.6 ± 47.1 pg/ml; p<0.05).

Conclusion: We conclude that angiotensin-II modulation, with enalapril and candesartan, without concomitant utilization of beta-blocker lead to a decrease in BNP and an attenuation of the increase in LV end-diastolic and end-systolic volumes without a reversal of this process in the long term.

Independent prognostic importance of a restrictive left ventricular filling pattern after myocardial infarction: an individual patient meta-analysis: Meta-Analysis Research Group in Echocardiography acute myocardial infarction

BACKGROUND

Restrictive mitral filling pattern (RFP), the most severe form of diastolic dysfunction, is a predictor of outcome after acute myocardial infarction (AMI). Low power has precluded a definite conclusion on the independent importance of RFP, especially when overall systolic function is preserved. We undertook an individual patient meta-analysis to determine whether RFP is predictive of mortality independently of LV ejection fraction (LVEF), end-systolic volume index, and Killip class in patients after AMI.

METHODS AND RESULTS

Twelve prospective studies (3396 patients) assessing the relationship between prognosis and Doppler echocardiographic LV filling pattern in patients after AMI were included. Individual patient data from each study were extracted and collated into a single database for analysis. RFP was associated with higher all-cause mortality (hazard ratio, 2.67; 95% CI, 2.23 to 3.20; P<0.001) and remained an independent predictor in multivariate analysis with age, gender, and LVEF. The overall prevalence of RFP was 20% but was highest (36%) in the quartile of patients with lowest LVEF (<39%) and lowest (9%) in patients with the highest LVEF (>53%; P<0.0001). RFP remained significant within each quartile of LVEF, and no interaction was found for RFP and LVEF (P=0.42). RFP also predicted mortality in patients with above- and below-median end-systolic volume index (1575 patients) and in different Killip classes (1746 patients). Importantly, when diabetes, current medication, and prior AMI were included in the model, RFP remained an independent predictor of outcome.

CONCLUSIONS

Restrictive filling is an important independent predictor of mortality after AMI regardless of LVEF, end-systolic volume index, and Killip class.

Secondary prevention after acute myocardial infarction and coronary revascularisation: focus on Angiotensin converting enzyme inhibitors

INTRODUCTION

Cardiovascular disease (CVD) is responsible for an estimated one third of all deaths worldwide.

PATIENTS AND METHODS

One group of patients who are at a particularly high risk of cardiovascular events and death are those with stable coronary artery disease (CAD), especially if they have had a previous myocardial infarction (MI) or revascularisation.

DISCUSSION

Lifestyle changes (smoking, alcohol intake, diet, exercise) and cardiac rehabilitation play an important part in reducing risk of recurrent events. In patients with a history of MI and/or those who underwent myocardial revascularisation these have to be supplemented with medication. Several pharmacological agents are known to improve prognosis in these patients, i.e. beta-blockers, antiplatelet agents, statins, and angiotensin converting enzyme inhibitors (ACEi). The present article focuses mainly on the role of ACEi in the prevention of cardiovascular events in patients with a history of MI or myocardial revascularization.

Individual patient meta-analyses of restrictive diastolic filling pattern and mortality in patients post acute myocardial infarction and in patients with chronic heart failure

BACKGROUND AND OBJECTIVE

Doppler echocardiographic assessment of diastolic filling provides a non-invasive estimate of left ventricular (LV) filling pressure and the most advanced diastolic filling grade, the restrictive filling pattern (RFP), has been linked to prognosis in patients post acute myocardial infarction (AMI) and with heart failure (HF). There remains some uncertainty about the prognostic role of RFP in patients with varied levels of systolic function. The objective of this collaboration is to determine whether the presence of RFP offers additional prognostic information over LV systolic function, symptoms or other clinical factors in patients post AMI or with HF.

METHODS

The Meta-analysis Research Group in Echocardiography (MeRGE) has been established in order to test this through two individual patient meta-analyses. Prospective studies that enrolled patients with either established HF or post AMI and included Doppler-echocardiography and outcome data will be merged into two large datasets (3739 AMI patients and 3540 HF patients) in order to evaluate the independent effects of RFP upon total and cardiovascular mortality using Kaplan-Meier survival analysis methods and Cox proportional hazards model for multi-variate analysis. Survival will be examined within different bands of LV systolic function based upon ejection fraction (EF).

IMPLICATIONS

This unique dataset will provide a very large cohort of patients, which will be adequately powered to provide new and prognostically important information to further aid risk stratification in these two high-risk patient groups.

Restrictive Filling Pattern is a Powerful Predictor of Heart Failure Events Postacute Myocardial Infarction and in Established Heart Failure: A Literature-Based Meta-Analysis

BACKGROUND

Two recent literature-based meta-analyses revealed that restrictive filling pattern (RFP) was associated with a 4-fold increase in the risk of death in patients with heart failure (HF) and postacute myocardial infarction (AMI). This similar but unique analysis evaluated the link between RFP and morbidity.

METHODS AND RESULTS

Prospective echocardiographic studies of patients post-AMI and with HF that reported HF morbidity were identified. Events (post-AMI: development of HF; HF: HF readmission) were compared between patients with and without RFP in both patient groups. Review Manager version 4.2.7 software was used for the analysis. Twelve post-AMI studies (1286 patients, 271 events) and 5 HF studies (647 patients, 176 events) were identified. RFP was associated with HF readmission in the HF patients (OR 2.96 [2.02-4.33] and development of HF post-AMI (OR 10.10 [7.02-14.51]). The event rate in the RFP group was the same regardless of disease category (49% post-AMI, 42% HF); however, RFP was less prevalent in the post-AMI group (22% versus 39%).

CONCLUSIONS

This literature-based meta-analysis confirms that RFP is a powerful predictor of HF hospitalization in patients with HF and especially the development of HF post-AMI. This is an important prognostic sign and should be incorporated into routine clinical practice.

Systemic inhibition of the angiotensin-converting enzyme limits lipopolysaccharide-induced lung neutrophil recruitment through both bradykinin and angiotensin II-regulated pathways

Recruitment of neutrophils to the lung is a sentinel event in acute lung inflammation. Identifying mechanisms that regulate neutrophil recruitment to the lung may result in strategies to limit lung damage and improve clinical outcomes. Recently, the renin angiotensin system (RAS) has been shown to regulate neutrophil influx in acute inflammatory models of cardiac, neurologic, and gastrointestinal disease. As a role for the RAS in LPS-induced acute lung inflammation has not been described, we undertook this study to examine the possibility that the RAS regulates neutrophil recruitment to the lung after LPS exposure. Pretreatment of mice with the angiotensin-converting enzyme (ACE) inhibitor enalapril, but not the anti-hypertensive hydralazine, decreased pulmonary neutrophil recruitment after exposure to LPS. We hypothesize that inhibition of LPS-induced neutrophil accumulation to the lung with enalapril occurred through both an increase in bradykinin, and a decrease in angiotensin II (ATII), mediated signaling. Bradykinin receptor blockade reversed the inhibitory effect of enalapril on neutrophil recruitment. Similarly, pretreatment with bradykinin receptor agonists inhibited IL-8-induced neutrophil chemotaxis and LPS-induced neutrophil recruitment to the lung. Inhibition of ATII-mediated signaling, with the ATII receptor 1a inhibitor losartan, decreased LPS-induced pulmonary neutrophil recruitment, and this was suggested to occur through decreased PAI-1 levels. LPS-induced PAI-1 levels were diminished in animals pretreated with losartan and in those deficient for the ATII receptor 1a. Taken together, these results suggest that ACE regulates LPS-induced pulmonary neutrophil recruitment via modulation of both bradykinin- and ATII-mediated pathways, each regulating neutrophil recruitment by separate, but distinct, mechanisms.

Bone marrow mesenchymal stem cell transplantation combined with perindopril treatment attenuates infarction remodelling in a rat model of acute myocardial infarction

OBJECTIVE

This study was performed to evaluate whether implantation of mesenchymal stem cell (MSC) would reduce left ventricular remodelling from the molecular mechanisms compared with angiotensin-converting enzyme inhibitors (ACEIs) perindopril into ischemic myocardium after acute myocardial infarction.

METHODS

Forty rats were divided into four groups: control, MSC, ACEI, MSC+ACEI groups. Bone marrow stem cell derived rat was injected immediately into a zone made ischemic by coronary artery ligation in MSC group and MSC+ACEI group. Phosphate-buffered saline (PBS) was injected into control group. Perindopril was administered p.o. to ACEI group and MSC+ACEI group. Six weeks after implantation, the rats were killed and heart sample was collected. Fibrillar collagen was observed by meliorative Masson's trichome stain. Western Blotting was employed to evaluate the protein expression of matrix metalloproteinase (MMP)-2, matrix metalloproteinase (MMP)-9 in infarction zone. The transcriptional level of MMP2, MMP9 and tissue inhibitor of matrix metalloproteinase (TIMP)-1 in infarction area was detected by reverse transcriptase PCR (RT-PCR) analysis.

RESULTS

The fibrillar collagen area, the protein expression of MMP2, MMP9 and the transcriptional level of MMP2, MMP9 mRNA in infarction zone reduced in MSC group, ACEI group, and MSC+ACEI group. No significant difference was detected in the expression of TIMP1 mRNA among the 4 groups.

CONCLUSION

Both MSC and ACEI could reduce infarction remodelling by altering collagen metabolism.

Restrictive diastolic filling predicts death after acute myocardial infarction: systematic review and meta-analysis of prospective studies

OBJECTIVE

To determine, through a systematic review and meta-analysis, the magnitude of the survival deficit associated with a restrictive filling pattern after acute myocardial infarction (AMI).

METHODS

Online databases were searched for prospective echocardiography outcome studies of patients after AMI. All authors were contacted to seek confirmation of their data. Restrictive filling was compared with all non-restrictive filling patterns. Review Manager Version 4.2.7 software was used for analysis.

RESULTS

3855 patients in 16 studies were identified. Follow up varied from two weeks to five years (> 1 year, 10 studies; and > 4 years, four studies). 776 (20%) of patients had a restrictive filling pattern at baseline. 580 patients died (247 in the restrictive group), and the overall odds ratio for death (restrictive filling worse) was 4.10 (95% confidence interval 3.38 to 4.99).

CONCLUSIONS

Mortality is about four times higher in patients with a restrictive filling pattern than in those with non-restrictive filling patterns after AMI. Echocardiographic assessment of diastolic filling pattern is an important part of the echocardiographic assessment of patients after myocardial infarction and provides important prognostic information about such patients.

Managing the post-myocardial infarction patient with asymptomatic left ventricular dysfunction

The percentage of post-myocardial infarction (MI) patients with asymptomatic left ventricular dysfunction (ALVD) is now estimated at 10%, and that number is expected to grow as reperfusion procedures increasingly become routine. Since average all-cause mortality risk in these patients is high (up to 27%), definitive diagnostics are recommended to screen all post-MI patients for ALVD, defined as left ventricular systolic dysfunction in the absence of heart failure symptoms. Post-MI management strategies for patients with ALVD target the two routes of progression to heart failure: (1) cardiac remodeling mediated by neurohormonal activation, and (2) continued and recurrent myocardial ischemic events. Clinical trials of neurohormonal antagonists in post-MI ALVD patients have shown that angiotensin-converting enzyme inhibitors attenuate left ventircular remodeling and that beta-blocker therapy reverses remodeling for patients already on angiotensin-converting enzyme inhibitor therapy. Neurohormonal antagonist therapy is also associated with significant reductions in sudden death in post-MI ALVD patients.

Influence of angiotensin II receptors blocking on overall left ventricle's performance of patients with acute myocardial infarction of limited extent. Echocardiographic assessment

INTRODUCTION

Recent studies documented the beneficial effect of angiotensin-receptor blockers (ARBs) on patients (pts) with acute myocardial infarction (AMI) combined with left ventricle (LV) systolic dysfunction. The present study intended to assess the impact of the ARB irbesartan, on the overall LV performance in pts with uncomplicated AMI of limited extent.

METHODS

Forty consecutive pts with first inferior AMI (AMI-I) and preserved LV-systolic function were enrolled. They were allocated into two groups: (a) 20 pts received the conventional treatment of AMI-I and placebo (CT) and (b) 20 pts administered irbesartan additionally to the conventional treatment (IR). Twenty four healthy individuals of matching age and sex were recruited as control group (CG). Complete echocardiographic examination, Tei index of overall LV function and systolic blood pressure (SBP) were measured on the 8th post-infarct day.

RESULTS

The Tei index of IR group (0.53+/-0.03) was significantly lower compared to that of CT group (0.78+/-0.05) (p<0.001) and was similar to that of CG (0.45+/-0.03)(p=NS). Irbesartan induced a considerable decrease in both isovolumic relaxation (115+/-7 ms vs 140+/-7 ms; p<0.01) and contraction time (52+/-2 ms vs 64+/-3 ms; p<0.01) and a significant increase in ejection time (279+/-6 ms vs 256+/-8 ms; p<0.05). SBP in pts of IR group was similar to that of CT group (112+/-3 mmHg vs 113+/-4 mmHg; p=NS).

CONCLUSIONS

Therapy with Irbesartan improves overall LV function of pts with AMI-I. Irbesartan leads to acceleration of the LV relaxation, which possibly indirectly ameliorates LV systolic performance too. This beneficial influence is possible attributed to a direct tissue effect of the drug and not to its hemodynamic action.

Angiotensin II receptor blockade and ventricular remodelling

Cardiac remodelling is the expression of molecular, cellular and interstitial changes in response to cardiac injury, manifesting as adverse alterations in the size, shape and function of the ventricle. Several clinical studies have documented significant elevations in the levels of renin, angiotensin II (Ang II) and aldosterone attending acute myocardial infarction and/or congestive heart failure. Similar to catecholamines, markedly elevated activity of the renin-angiotensin-aldosterone system (RAAS) is associated with poor prognosis. The effects of Ang II upon cardiac tissue are related to two primary receptors, Ang II type 1 (AT1) and Ang II type 2 (AT2). The AT1-receptor appears to mediate many of the deleterious effects of chronic RAAS activity, while the AT2-receptor is increasingly shown to have potential cardioprotective effects. Attenuating the deleterious effects of sustained Ang II stimulation can be achieved by direct inhibition of angiotensin- converting enzyme (ACE) and/or direct antagonism of AT receptors. ACE inhibition reduces left ventricular (LV) volumes, retards the progression of LV dilatation and hypertrophy and increases systolic function in systolic dysfunction. By blocking at the receptor level, Ang II receptor blockers (ARBs) provide an alternative and more direct approach to inhibiting the effects of Ang II; however, data relating to their effects upon ventricular remodelling, whether used in isolation or in combination with ACE inhibitors (ACE-Is), are less convincing. Data arising from several recent clinical trials suggest that simultaneous use of ACE-Is and ARBs maybe of more benefit in attenuating ventricular remodelling than either agent alone.

Hypertension and the Kidney

Hypertension is an important and widely prevalent risk factor for the development of chronic kidney disease (CKD), which unfortunately may progress to end-stage renal disease. CKD is a progressive condition that causes significant morbidity and mortality. Diabetes is the leading cause of end-stage renal disease in the Western world. Both hypertension and diabetes are the causative factors for the occurrence of CKD and its consequences. Aggressive control of hypertension and diabetes is indicated to reduce the risk for kidney disease in the community. Certainly, effective control of hypertension is a proven modality to prevent renal disease. The concept of decreasing the systemic blood pressure as well as the intraglomerular pressure has led to the application of rational therapeutic options in patients with renal insufficiency. Although treatment of hypertension alone is critical, drugs that block the renin-angiotensin system have been shown to have special renal (and cardiovascular) benefits. Early detection and treatment of microalbuminuria is an integral part of disease management. This article reviews the pathophysiologic and therapeutic implications of the link between hypertension and the kidney.

Changes in Ventricular Size and Function in Patients Treated With Valsartan, Captopril, or Both After Myocardial Infarction

Background— Angiotensin-converting enzyme (ACE) inhibitors have been shown to attenuate left ventricular (LV) enlargement in association with reducing mortality after myocardial infarction (MI). Preclinical data suggest that angiotensin receptor blockers (ARBs) may have similar structural and functional effects after MI. The Valsartan in Acute Myocardial Infarction (VALIANT) Echo study was designed to test the hypothesis that the ARB valsartan, either alone or in combination with captopril, could attenuate progressive LV enlargement or improve LV ejection fraction to a greater extent than captopril alone.

Methods and Results— Six hundred ten patients enrolled in the main VALIANT study who experienced MI and evidence of LV dysfunction, heart failure, or both were enrolled in the VALIANT Echo study. Patients were randomized to receive valsartan 160 mg PO BID, captopril 50 mg PO TID, or valsartan 80 mg PO BID plus captopril 50 mg PO TID between 1 and 10 days after MI. Six hundred three patients had echocardiograms of sufficient quality for quantitative analysis. Echocardiograms were digitized, and endocardial borders were traced manually from 2 short-axis and 2 apical views. Ventricular volumes, ejection fractions, combined areas, and infarct segment length were measured, and changes in echocardiographic measures from baseline to 20 months were compared between treatment groups. Baseline clinical and echocardiographic characteristics were similar in the 3 treatment arms. The changes from baseline to 20 months in all echocardiographic parameters were similar in all 3 treatment arms. Baseline echocardiographic measures of ejection fraction, end-diastolic volume, and infarct segment length were highly predictive of outcomes including total mortality, death or hospitalization for heart failure, or death or any cardiovascular event (heart failure, MI, stroke, resuscitated sudden death), even after adjustment for known covariates.

Conclusions— Treatment with the ACE inhibitor captopril, valsartan, or the combination of captopril plus valsartan resulted in similar changes in cardiac volume, ejection fraction, and infarct segment length between baseline and 20 months after MI. Baseline echocardiographic measures were powerfully and independently predictive of all major outcomes.

Angiotensin Receptor Blockers versus ACE Inhibitors: Prevention of Death and Myocardial Infarction in High-Risk Populations

OBJECTIVE:

To determine, through a review of the medical literature, whether there is adequate evidence to support the use of angiotensin receptor blockers (ARBs) in place of angiotensin-converting enzyme (ACE) inhibitors in high-risk populations, focusing on the prevention of death and myocardial infarction (MI).

DATA SOURCES:

Original investigations, reviews, and meta-analyses were identified from the biomedical literature via a MEDLINE search (1966–August 2004). Published articles were also cross-referenced for pertinent citations, and recent meeting abstracts were searched for relevant data.

STUDY SELECTION AND DATA EXTRACTION:

All articles identified during the search were evaluated. Preference was given to prospective, randomized, controlled trials that evaluated major cardiovascular endpoints and compared ARBs with ACE inhibitors, active controls, or placebo.

DATA SYNTHESIS:

The renin—angiotensin system plays a pivotal role in the continuum of cardiovascular disease and represents a major therapeutic target in the treatment of patients at risk for vascular events. While ACE inhibitors have been definitively shown to prevent death and MI, studies with ARBs in similar populations have not reduced these endpoints. In clinical trials that enrolled patients with heart failure, post-MI, diabetes, and hypertension, ARBs did not prevent MI or prolong survival compared with ACE inhibitors, other antihypertensives, or placebo.

CONCLUSIONS:

ACE inhibitors and ARBs should not be considered interchangeable, even among patients with a documented history of ACE inhibitor intolerance. ARBs can be considered a second-line alternative in such patients with the realization that they have not been shown to prevent MI or prolong survival.

Validation of echocardiographic methods for assessing left ventricular dysfunction in rats with myocardial infarction

The rat infarct model is widely used in heart failure research, but few echocardiographic indexes of left ventricular (LV) function are validated in this model. Accordingly, the objective of this study was to validate a 13-segment LV wall motion score index (WMSI) and the myocardial performance index (MPI) in infarcted rats. Twenty-nine male Wistar rats underwent left coronary artery ligation or sham operation and were evaluated with two-dimensional and Doppler flow echocardiography 8 wk later. After echocardiography, invasive indexes were obtained using a high-fidelity catheter. WMSI and MPI were correlated with the invasive and noninvasive measurements of LV function. WMSI and MPI significantly correlated directly with end-diastolic pressure (r=0.72 and 0.42 for WMSI and MPI, respectively) and the time constant of isovolumic relaxation (r=0.68 and 0.48) and inversely with peak rate of rise of LV pressure (+dP/dt; r=-0.68 and -0.50), peak rate of decline in LV pressure (r=-0.57 and -0.44), LV developed pressure (r=-0.58 and -0.42), area fractional shortening (r=-0.85 and -0.53), and cardiac index (r=-0.74 and -0.74). Stepwise linear regression analyses revealed that LV end-diastolic pressure, +dP/dt, area fractional shortening, and cardiac index were independent determinants of WMSI (r=0.994) and that cardiac index and +dP/dt were independent determinants of MPI (r=0.781). We conclude that the 13-segment WMSI and MPI are reproducible and correlate strongly with established echocardiographic and invasive indexes of systolic and diastolic function. These findings support the use of WMSI and MPI as indexes of global LV function in the rat infarction model of heart failure.