ACE inhibitor use in patients with myocardial infarction. Summary of evidence from clinical trials

In silico development of novel angiotensin-converting-enzyme-I inhibitors by Monte Carlo optimization based QSAR modeling, molecular docking studies and ADMET predictions

Within the realm of pharmacological strategies for cardiovascular diseases (CVD) like hypertension, stroke, and heart failure, targeting the angiotensin-converting enzyme I (ACE-I) stands out as a significant treatment approach. This study employs QSAR modeling using Monte Carlo optimization techniques to investigate a range of compounds known for their ACE-I inhibiting properties. The modeling process involved leveraging local molecular graph invariants and SMILES notation as descriptors to develop conformation-independent QSAR models. The dataset was segmented into distinct sets for training, calibration, and testing to ensure model accuracy. Through the application of various statistical analyses, the efficacy, reliability, and predictive capability of the models were evaluated, showcasing promising outcomes. Additionally, molecular fragments derived from SMILES notation descriptors were identified to elucidate the activity changes observed in the compounds. The validation of the QSAR model and designed inhibitors was carried out via molecular docking, aligning well with the QSAR results. To ascertain the drug-worthiness of the designed molecules, their physicochemical properties were computed, aiding in the prediction of ADME parameters, pharmacokinetic attributes, drug-likeness, and medicinal chemistry compatibility.

Chronic mitochondrial dynamic-targeted therapy alleviates left ventricular dysfunction by reducing multiple programmed cell death in post-myocardial infarction rats

Mitochondrial dysfunction and the activation of multiple programmed cell death (PCD) have been shown to aggravate the severity and mortality associated with the progression of myocardial infarction (MI). Although pharmacological modulation of mitochondrial dynamics, including treatment with the fusion promoter (M1) and the fission inhibitor (Mdivi-1), exerted cardioprotection against several cardiac complications, their roles in the post-MI model have never been investigated. Using a MI rat model instigated by permanent left-anterior descending (LAD) coronary artery occlusion, post-MI rats were randomly assigned to receive one of 4 treatments (n = 10/group): vehicle (DMSO 3%V/V), enalapril (10 mg/kg), Mdivi-1 (1.2 mg/kg) and M1 (2 mg/kg), while a control group of sham operated rats underwent surgery without LAD occlusion (n = 10). After 32-day treatment, cardiac and mitochondrial function, and histopathological morphology were investigated and molecular analysis was performed. Treatment with enalapril, Mdivi-1, and M1 significantly mitigated cardiac pathological remodeling, reduced myocardial injury, and improved left ventricular (LV) function in post-MI rats. Importantly, all interventions also attenuated mitochondrial dynamic imbalance and mitigated activation of apoptosis, necroptosis, and pyroptosis after MI. This investigation demonstrated for the first time that chronic mitochondrial dynamic-targeted therapy mitigated mitochondrial dysfunction and activation of PCD, leading to improved LV function in post-MI rats.

Acute Myocardial Infarction and Risk of Cognitive Impairment and Dementia: A Review

Cognitive impairment (CI) shares common cardiovascular risk factors with acute myocardial infarction (AMI), and is increasingly prevalent in our ageing population. Whilst AMI is associated with increased rates of CI, CI remains underreported and infrequently identified in patients with AMI. In this review, we discuss the evidence surrounding AMI and its links to dementia and CI, including pathophysiology, risk factors, management and interventions. Vascular dysregulation plays a major role in CI, with atherosclerosis, platelet activation, microinfarcts and perivascular inflammation resulting in neurovascular unit dysfunction, disordered homeostasis and a dysfunctional neurohormonal response. This subsequently affects perfusion pressure, resulting in enlarged periventricular spaces and hippocampal sclerosis. The increased platelet activation seen in coronary artery disease (CAD) can also result in inflammation and amyloid-β protein deposition which is associated with Alzheimer's Dementia. Post-AMI, reduced blood pressure and reduced left ventricular ejection fraction can cause chronic cerebral hypoperfusion, cerebral infarction and failure of normal circulatory autoregulatory mechanisms. Patients who undergo coronary revascularization (percutaneous coronary intervention or bypass surgery) are at increased risk for post-procedure cognitive impairment, though whether this is related to the intervention itself or underlying cardiovascular risk factors is debated. Mortality rates are higher in dementia patients with AMI, and post-AMI CI is more prevalent in the elderly and in patients with post-AMI heart failure. Medical management (antiplatelet, statin, renin-angiotensin system inhibitors, cardiac rehabilitation) can reduce the risk of post-AMI CI; however, beta-blockers may be associated with functional decline in patients with existing CI. The early identification of those with dementia or CI who present with AMI is important, as subsequent tailoring of management strategies can potentially improve outcomes as well as guide prognosis.

Prognostic Impact of Different Types of Ventricular Tachyarrhythmias Stratified by Underlying Cardiac Disease

Limited data regarding the outcome of patients with different types of ventricular tachyarrhythmias is available. This study sought to assess the prognostic impact of different types of ventricular tachyarrhythmias stratified by underlying cardiac disease. A large retrospective registry was used including all consecutive patients presenting with ventricular tachycardia (VT) and fibrillation (VF) on admission from 2002 to 2016. Patients with non-sustained VT (ns-VT), sustained VT (s-VT) and VF were compared using uni- and multivariable Cox regression models. Risk stratification was performed after stratification by underlying cardiac disease (i.e., acute myocardial infarction (AMI), ischemic heart disease (IHD), non-ischemic cardiomyopathy (NICM) and patients considered as lower-risk for ventricular tachyarrhythmias). The primary endpoint was defined as all-cause mortality at 2.5 years. Secondary endpoints were cardiac death at 24 h, all-cause mortality at 5 years, cardiac rehospitalization and a composite arrhythmic endpoint at 2.5 years. In 2422 consecutive patients with ventricular tachyarrhythmias, most patients were admitted with VF (44%), followed by ns-VT (30%) and s-VT (26%). Patients with VF suffered most commonly from AMI (42%), whereas heart failure was more common in s-VT patients (32%). In patients with AMI (HR = 1.146; 95% CI 0.751-1.750; p = 0.527) and in the lower-risk group (HR = 1.357; 95% CI 0.702-2.625; p = 0.364), the risk of all-cause mortality did not differ in VF and s-VT patients. In IHD patients, VF was associated with impaired prognosis compared to s-VT (HR = 2.502; 95% CI 1.936-3.235; p = 0.001). In conclusion, VF was associated with worse long-term prognosis compared to s-VT in IHD patients, whereas the risk of all-cause mortality among VF and s-VT patients did not differ in patients with AMI, NICM and in patients considered at lower risk for ventricular tachyarrhythmias.

Assessment of Myocardial Diastolic Dysfunction as a Result of Myocardial Infarction and Extracellular Matrix Regulation Disorders in the Context of Mesenchymal Stem Cell Therapy

The decline in cardiac contractility due to damage or loss of cardiomyocytes is intensified by changes in the extracellular matrix leading to heart remodeling. An excessive matrix response in the ischemic cardiomyopathy may contribute to the elevated fibrotic compartment and diastolic dysfunction. Fibroproliferation is a defense response aimed at quickly closing the damaged area and maintaining tissue integrity. Balance in this process is of paramount importance, as the reduced post-infarction response causes scar thinning and more pronounced left ventricular remodeling, while excessive fibrosis leads to impairment of heart function. Under normal conditions, migration of progenitor cells to the lesion site occurs. These cells have the potential to differentiate into myocytes in vitro, but the changed micro-environment in the heart after infarction does not allow such differentiation. Stem cell transplantation affects the extracellular matrix remodeling and thus may facilitate the improvement of left ventricular function. Studies show that mesenchymal stem cell therapy after infarct reduces fibrosis. However, the authors did not specify whether they meant the reduction of scarring as a result of regeneration or changes in the matrix. Research is also necessary to rule out long-term negative effects of post-acute infarct stem cell therapy.

Impact of Bisoprolol on Ventricular Arrhythmias in Experimental Myocardial Infarction

Following acute myocardial infarction (AMI), early use of beta-blockers (BBs) reduced the incidences of ventricular arrhythmia (VA) and death in the pre reperfusion era. However, some studies have reported a worsening of clinical outcomes and therefore, this study used a porcine model of AMI to evaluate the efficacy of bisoprolol on VAs and mortality. Twenty pigs were divided into two groups with one group using oral bisoprolol which was given for 3 hours before the experiment and then maintained for 7 days. A loop recorder was implanted, AMI was induced by balloon occlusion for 60 min, and then, reperfusion. One week later, the echocardiography and loop recorder data were analyzed in the surviving animals. Bisoprolol did not increase the heart rate (62.9±14.5 vs 79.0±20.3; p=0.048), lower the rate of premature ventricular contractions (PVC) (0.8±0.8 vs 11.0±12.8; p=0.021) or tend to lower recurrent VA (0.6±0.5 vs 1.1±1.1; p=0.131) during coronary artery occlusion. After reperfusion, bisoprolol did reduce VA in the early AMI period (0.1±0.3 vs 4.2±4.6; p=0.001) and it was not associated with the extent of myocardial recovery. In this porcine model, early oral bisoprolol might help reduce the incidences of PVC and recurrent VA and determine whether effects are more pronounced during the early AMI period. Our results suggest that bisoprolol might help reduce lethal VA and cardiac death following AMI in this reperfusion era.

Development of simultaneous interaction prediction approach (SiPA) for the expansion of interaction network of traditional Chinese medicine

Background

Due to the lack of enough interaction data among compositions, targets and diseases, it is difficult to construct a complete network of Traditional Chinese Medicine (TCM) that comprehensively reflects active compositions and their synergistic network in terms of specific diseases. Therefore, mapping of the full spectrum of interaction between compounds and their targets is of central importance when we use network pharmacology approach to explore the therapeutic potential of the TCM.

Methods

To address this challenge, we developed a large-scale simultaneous interaction prediction approach (SiPA) integrated one interaction network based simple inference model (SIM), focusing on ‘logical relevance’ between compounds, proteins or diseases, and another compound-target correlation space based interaction prediction model (CTCS-IPM) that was built on the basis of the canonical correlation analysis (CCA) to estimate the position of compounds (or targets) in compound-protein correlated space. Then SiPA was applied to discover reliable multiple interactions for interaction network expansion of a TCM, compound Salvia miltiorrhiza. By means of network analysis, potential active compounds and their related network synergy underlying cardiovascular diseases were evaluated between expanded and original interaction networks. Part of new interactions were validated with existing experimental evidence and molecular docking.

Results

As evaluated with known test dataset, the established combination approach was proved to make highly accurate prediction, showing a well prediction performance for the SIM and a high recall rate of 85.2% for the CTCS-IPM. Then 710 pairs of new compound-target interactions, 24 pairs of new compound-cardiovascular disease interactions and 294 pairs of new cardiovascular disease-protein interactions were predicted for compound Salvia miltiorrhiza. Results of network analysis suggested the network expansion could dramatically improve the completeness and effectiveness of the network. Validation results of literature and molecular docking manifested that inferred interactions had good reliability.

Conclusions

We provided a practical and efficient way for large-scale inference of multiple interactions of TCM ingredients, which was not limited by the lack of negative samples, sample size and target 3D structures. SiPA could help researchers more accurately prioritize the effective compounds and more completely explore network synergy of TCM for treating specific diseases, indicating a potential way for effectively identifying candidate compound (or target) in drug discovery.

Beta-Blockers and ACE Inhibitors Are Associated with Improved Survival Secondary to Ventricular Tachyarrhythmia

OBJECTIVE

The study sought to assess the impact of treatment with beta-blocker (BB) or ACE inhibitor/angiotensin receptor blocker (ACEi/ARB) on secondary survival in patients presenting with ventricular tachyarrhythmia.

BACKGROUND

Data regarding outcome of patients presenting with ventricular tachyarrhythmia treated with BB and ACEi/ARB is limited.

METHODS

A large retrospective registry was used including consecutive patients presenting with ventricular tachycardia and fibrillation from 2002 to 2016 on admission. Applying propensity-score matching for harmonization, the impact of "BB" and "ACEi/ARB" was comparatively evaluated. The primary prognostic outcome was long-term all-cause death at 3 years.

RESULTS

A total of 972 matched patients were included. Both patients with BB (long-term mortality rate 18 versus 27%; log rank p = 0.041; HR = 0.661; 95% CI = 0.443-0.986; p = 0.043) and with ACEi/ARB (long-term mortality rate 13 versus 23%; log rank p = 0.004; HR = 0.544; 95% CI = 0.359-0.824; p = 0.004) revealed better secondary survival compared to patients without after presenting with ventricular tachyarrhythmia on admission. The prognostic benefit of BB was comparable to ACEi/ARB (long-term mortality rate 21 versus 26%; log rank p = 0.539).

CONCLUSION

BB and ACEi/ARB were associated with improved secondary survival in patients surviving ventricular tachyarrhythmia on admission.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02982473.

Myocardial Infarction Injury in Patients with Chronic Lung Disease Entering Pulmonary Rehabilitation: Frequency and Association with Heart Rate Parameters

BACKGROUND

Myocardial infarction (MI) remains under-recognized in chronic lung disease (CLD) patients. Rehabilitation health professionals need accessible clinical measurements to identify the presence of prior MI in order to determine appropriate training prescription.

OBJECTIVES

To estimate prior MI in CLD patients entering a pulmonary rehabilitation program, as well as its association with heart rate parameters such as resting heart rate and chronotropic response index.

DESIGN

Retrospective cohort design.

SETTING

Pulmonary rehabilitation outpatient clinic in a tertiary care university-affiliated hospital.

PATIENTS

Eighty-five CLD patients were studied.

METHODS

Electrocardiograms at rest and peak cardiopulmonary exercise testing, performed before pulmonary rehabilitation, were analyzed. Electrocardiographic evidence of prior MI, quantified by the Cardiac Infarction Injury Score (CIIS), was contrasted with reported myocardial events and then correlated with resting heart rate and chronotropic response index parameters.

MAIN OUTCOME MEASUREMENTS

CIIS, resting heart rate, and chronotropic response index.

RESULTS

Sixteen CLD patients (19%) demonstrated electrocardiographic evidence of prior MI, but less than half (8%) had a reported MI history (P < .05). The Cohen's kappa test revealed poor level of agreement between CIIS and medical records (kappa = 0.165), indicating that prior MI diagnosis was under-reported in the medical records. Simple and multiple regression analyses showed that resting heart rate but not chronotropic response index was positively associated with CIIS in our population (R² = 0.29, P < .001). CLD patients with a resting heart rate higher than 80 beats/min had approximately 5 times higher odds of having prior MI, as evidenced by a CIIS ≥ 20.

CONCLUSIONS

CLD patients entering pulmonary rehabilitation are at risk of unreported prior MI. Elevated resting heart rate appears to be an indicator of prior MI in CLD patients; therefore, careful adjustment of training intensity is recommended under these circumstances.

LEVEL OF EVIDENCE

III.

Ventricular Arrhythmia after Acute Myocardial Infarction: 'The Perfect Storm'

Ventricular tachyarrhythmias (VAs) commonly occur early in ischaemia, and remain a common cause of sudden death in acute MI. The thrombolysis and primary percutaneous coronary intervention era has resulted in the modification of the natural history of an infarct and subsequent VA. Presence of VA could independently influence mortality in patients recovering from MI. Appropriate risk assessment and subsequent treatment is warranted in these patients. The prevention and treatment of haemodynamically significant VA in the post-infarct period and of sudden cardiac death remote from the event remain areas of ongoing study.

Atherogenic Cytokines Regulate VEGF-A-Induced Differentiation of Bone Marrow-Derived Mesenchymal Stem Cells into Endothelial Cells

Coronary artery stenting or angioplasty procedures frequently result in long-term endothelial dysfunction or loss and complications including arterial thrombosis and myocardial infarction. Stem cell-based therapies have been proposed to support endothelial regeneration. Mesenchymal stem cells (MSCs) differentiate into endothelial cells (ECs) in the presence of VEGF-A in vitro. Application of VEGF-A and MSC-derived ECs at the interventional site is a complex clinical challenge. In this study, we examined the effect of atherogenic cytokines (IL-6, TNFα, and Ang II) on EC differentiation and function. MSCs (CD44(+), CD73(+), CD90(+), CD14(-), and CD45(-)) were isolated from the bone marrow of Yucatan microswine. Naïve MSCs cultured in differentiation media containing VEGF-A (50 ng/mL) demonstrated increased expression of EC-specific markers (vWF, PECAM-1, and VE-cadherin), VEGFR-2 and Sox18, and enhanced endothelial tube formation. IL-6 or TNFα caused a dose-dependent attenuation of EC marker expression in VEGF-A-stimulated MSCs. In contrast, Ang II enhanced EC marker expression in VEGF-A-stimulated MSCs. Addition of Ang II to VEGF-A and IL-6 or TNFα was sufficient to rescue the EC phenotype. Thus, Ang II promotes but IL-6 and TNFα inhibit VEGF-A-induced differentiation of MSCs into ECs. These findings have important clinical implications for therapies intended to increase cardiac vascularity and reendothelialize coronary arteries following intervention.

Synergistic effect of angiotensin II on vascular endothelial growth factor-A-mediated differentiation of bone marrow-derived mesenchymal stem cells into endothelial cells

INTRODUCTION

Increased levels of angiotensin II (Ang II) and activity of Ang II receptor type 1 (AT1R) elicit detrimental effects in cardiovascular disease. However, the role of Ang II receptor type 2 (AT2R) remains poorly defined. Mesenchymal stem cells (MSCs) replenish and repair endothelial cells in the cardiovascular system. Herein, we investigated a novel role of angiotensin signaling in enhancing vascular endothelial growth factor (VEGF)-A-mediated differentiation of MSCs into endothelial cells (ECs).

METHODS

Bone marrow was aspirated from the femurs of Yucatan microswine. MSCs were extracted via ficoll density centrifugation technique and were strongly immunopositive for MSC markers, CD44, CD90, and CD105, but negative for hematopoietic markers, CD14 and CD45. Subsequently, naïve MSCs were differentiated for 10 days in varying concentrations and combinations of VEGF-A, Ang II, and AT1R or AT2R antagonists. Markers specific to ECs were determined by FACS analysis.

RESULTS

AT1R and AT2R expression and cellular localization was demonstrated in MSCs stimulated with VEGF-A and Ang II via quantitative RT-PCR and immunofluorescence, respectively. Differentiation of naïve MSCs in media containing Ang II (2 ng/ml) plus low-dose VEGF-A (2 ng/ml) produced a significantly higher percentage of cells that were positive for expression of EC markers (for example, platelet endothelial cell adhesion molecule, vascular endothelial Cadherin and von Willebrand factor) compared to VEGF-A alone. Ang II alone failed to induce EC marker expression. MSCs differentiated with the combination of Ang II and VEGF-A were capable of forming capillary tubes using an in vitro angiogenesis assay. Induction of EC marker expression was greatly attenuated by co-treatment of Ang II/VEGF-A with the AT2R antagonist PD123319, but not the AT1R antagonist telmisartan.

CONCLUSIONS

We report the presence of functional AT2R receptor on porcine bone marrow-derived MSCs, where it positively regulates EC differentiation. These findings have significant implications toward therapeutic approaches based on activation of AT2R, which could be a means to stimulate regeneration of damaged endothelium and prevent vascular thrombosis.

Comparison of outcomes in patients with ST-segment elevation myocardial infarction discharged on versus not on statin therapy (from the Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction Trial)

Statin therapy is indicated after ST-segment elevation myocardial infarction (STEMI) to reduce recurrent ischemic events, but approximately 6% of patients with STEMI do not receive a statin prescription at discharge. This substudy aimed to define the clinical outcomes and patient characteristics associated with statin nonprescription after STEMI. We compared clinical, angiographic, and procedural characteristics and in-hospital, 30-day, 1-year, 2-year, and 3-year outcomes in 3,512 patients discharged after STEMI with and without (6%) statin prescriptions in the harmonizing outcomes with revascularization and stents in acute myocardial infarction trial (www.clinicaltrials.gov, NCT00433966). Statin nonprescription was associated with female sex, nonwhite race, previous bypass surgery, heart failure, renal impairment, anemia, thrombocytopenia, care in the United States, lower prescription rates of antiplatelets and neurohormonal antagonists, less percutaneous coronary intervention and stents, and, in 26% of cases, angiographically normal or nonobstructed coronary arteries. At every time point of follow-up after discharge, patients with no discharge statin prescription had significantly higher rates of net adverse clinical events, major adverse cardiac events, major bleeding unrelated to bypass surgery, and death. After multivariable adjustment, absence of a discharge statin prescription independently predicted 3-year major adverse cardiac event (hazard ratio 1.54, 95% confidence interval 1.15 to 2.07, p=0.0037) and death (hazard ratio 2.30, 95% confidence interval 1.41 to 3.77, p=0.0009). In conclusion, within the framework of this randomized trial of patients presenting with STEMI, approximately 6% of patients were discharged without statin therapy. Absence of a discharge statin prescription after STEMI was an independent predictor of ischemic events including death.

The neurohormonal network in the RAAS can bend before breaking

The renin-angiotensin-aldosterone system (RAAS) has evolved in humans as one of the main physiological networks by which blood pressure and blood flow to vital organs is maintained. The RAAS has evolved to circumvent life-threatening events such as hemorrhage and starvation. Although short-term activation of this system had been well suited to counteract such catastrophes of early man, excessive chronic activation of the RAAS plays a fundamental role in the development and progression of cardiovascular disease in modern man. The RAAS is an intricate network comprising a number of major organ systems (heart, kidney, and vasculature) and signaling pathways. The main protagonists are renin, angiotensinogen (Ang), angiotensin I (Ang I), angiotensin II (Ang II), and aldosterone (Aldo). The study and delineation of each of these substances has allowed modern medicine to create targets by which cardiovascular disease can be treated. The main modulators that have been synthesized in this respect are angiotensin-converting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs), mineralocorticoid receptor blockers (MRBs), and direct renin inhibitors (DRIs). Over the past few decades, each of these substances has proven efficacious to varying degrees amongst a number of clinical settings. Additionally, there exists data for and against the use of these agents in combination. The use of these agents in combination poses a larger question conceptually: can excessive pharmacological inhibition of the RAAS lead to patient harm? This perspective will examine the concept of a neurohormonal inhibition ceiling in pertinent experimental and clinical trials.

ACE inhibition prevents diastolic Ca2+ overload and loss of myofilament Ca2+ sensitivity after myocardial infarction

Prevention of adverse cardiac remodeling after myocardial infarction (MI) remains a therapeutic challenge. Angiotensin-converting enzyme inhibitors (ACE-I) are a well-established first-line treatment. ACE-I delay fibrosis, but little is known about their molecular effects on cardiomyocytes. We investigated the effects of the ACE-I delapril on cardiomyocytes in a mouse model of heart failure (HF) after MI. Mice were randomly assigned to three groups: Sham, MI, and MI-D (6 weeks of treatment with a non-hypotensive dose of delapril started 24h after MI). Echocardiography and pressure-volume loops revealed that MI induced hypertrophy and dilation, and altered both contraction and relaxation of the left ventricle. At the cellular level, MI cardiomyocytes exhibited reduced contraction, slowed relaxation, increased diastolic Ca2+ levels, decreased Ca2+-transient amplitude, and diminished Ca2+ sensitivity of myofilaments. In MI-D mice, however, both mortality and cardiac remodeling were decreased when compared to non-treated MI mice. Delapril maintained cardiomyocyte contraction and relaxation, prevented diastolic Ca2+ overload and retained the normal Ca2+ sensitivity of contractile proteins. Delapril maintained SERCA2a activity through normalization of P-PLB/PLB (for both Ser16- PLB and Thr17-PLB) and PLB/SERCA2a ratios in cardiomyocytes, favoring normal reuptake of Ca2+ in the sarcoplasmic reticulum. In addition, delapril prevented defective cTnI function by normalizing the expression of PKC, enhanced in MI mice. In conclusion, early therapy with delapril after MI preserved the normal contraction/relaxation cycle of surviving cardiomyocytes with multiple direct effects on key intracellular mechanisms contributing to preserve cardiac function.

The role of renin angiotensin system intervention in stage B heart failure

This article outlines the link between the renin angiotensin aldosterone system (RAAS) and various forms of cardiomyopathy, and also reviews the understanding of the effectiveness of RAAS intervention in this phase of ventricular dysfunction. The authors focus their discussion predominantly on patients who have had previous myocardial infarction or those who have left ventricular hypertrophy and also briefly discuss the role of RAAS activation and intervention in patients with alcoholic cardiomyopathy.

Trends in the Use of Evidence-based Therapies Early in the Course of Acute Myocardial Infarction and its Influence on Short Term Patient Outcomes

AIM

To evaluate changes in management practices and its influence on short term hospital outcomes in patients with acute myocardial infarction (AMI) admitted during two different time periods, 2007 and 2004.

METHODS AND RESULTS

We studied AMI patients from two acute coronary syndrome registries carried out in Kuwait in 2007 and 2004. We included 1872 and 1197 patients from the 2007 and 2004 registries, respectively. When compared with 2004, patients from the 2007 registry had similar baseline clinical characteristics. In 2007 compared to 2004, during the in-hospital period, patients with AMI received significantly more statins (94% vs. 73%%, p<0.0001), Angiotensin converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARB) (70% vs. 47%, p<0.001), and Clopidogrel (38% vs. 4%, p<0.001), while beta-blockers use dropped in 2007 compared to 2004 (63% vs. 68%, p=0.0066). The rates of in-hospital mortality and recurrent ischemia were significantly lower in the 2007 cohort compared with the 2004 cohort (for mortality 2.2% vs. 3.9%, P=0.0008, for recurrent ischemia 13.7% vs. 20.4%, P=0<0.0001).Higher utilization of angiotensin converting enzyme inhibitors, angiotensin receptor blockers and statins were the main contributors to the improved in-hospital mortality and morbidity.

IN CONCLUSION

In the acute management of AMI, there was a significant increase in the use of statins, ACE inhibitors and Clopidogrel in 2007 compared to 2004. This was associated with a significant decrease in the in-hospital mortality and recurrent ischemia. Adherence to guidelines recommended therapies improved in-hospital outcomes.

Cardiac shock wave therapy ameliorates left ventricular remodeling after myocardial ischemia-reperfusion injury in pigs in vivo

OBJECTIVES

Left ventricular (LV) remodeling after acute myocardial infarction (AMI) is associated with a poor prognosis and an impaired quality of life. We have shown earlier that low-energy extracorporeal cardiac shock wave (SW) therapy improves chronic myocardial ischemia in pigs and humans and also ameliorates LV remodeling in a pig model of AMI induced by permanent coronary ligation. However, in the current clinical setting, most of the patients with AMI receive reperfusion therapy. Thus, in this study we examined whether our SW therapy also ameliorates LV remodeling after myocardial ischemia-reperfusion (I/R) injury in pigs in vivo.

METHODS

Pigs were subjected to a 90-min ischemia and reperfusion using a balloon catheter and were randomly assigned to two groups with or without SW therapy to the ischemic border zone (0.09 mJ/mm(2), 200 pulses/spot, 9 spots/animal, three times in the first week) (n = 15 each).

RESULTS

Four weeks after I/R, compared with the control group, the SW group showed significantly ameliorated LV remodeling in terms of LV enlargement (131 +/- 9 vs. 100 +/- 7 ml), reduced LV ejection fraction (28 +/- 2 vs. 36 +/- 3%), and elevated left ventricular end-diastolic pressure (11 +/- 2 vs. 4 +/- 1 mmHg) (all P <0.05, n = 8 each). The SW group also showed significantly increased regional myocardial blood flow (-0.06 +/- 0.11 vs. 0.36 +/- 0.13 ml/min/g, P < 0.05), capillary density (1.233 +/- 31 vs. 1.560 +/- 60/mm(2), P < 0.001), and endothelial nitric oxide synthase activity (0.24 +/- 0.03 vs. 0.41 +/- 0.05, P < 0.05) in the ischemic border zone compared with the control group (n = 7 each).

CONCLUSION

These results indicate that our SW therapy is also effective in ameliorating LV remodeling after myocardial I/R injury in pigs in vivo.

Percutaneous coronary intervention, comorbidities, and mortality among emergency department-admitted ST-elevation myocardial infarction patients in Florida

BACKGROUND

Risk of mortality following an ST-elevation myocardial infarction (STEMI) can be significantly reduced by prompt percutaneous coronary intervention (PCI). National guidelines specify primary PCI as the preferred recommended treatment for STEMI. In this study, we examined same-day PCI as an independent predictor of in-hospital mortality, after adjustment for comorbidities, other patient factors, and hospital PCI-volume using unselected surveillance data from Florida.

METHODS

We analyzed hospital discharge data for adults, 18+ years old, with a primary diagnosis of STEMI who were admitted to PCI-capable hospitals through the emergency department during 2001-2005 (n = 43,849). Hierarchical (multilevel) logistic regression models were used for analysis.

RESULTS

Overall, 4,143 STEMI patients (9.4%) did not survive to hospital discharge. In late 2005, the in-hospital mortality rates were 1.9% for those who received same-day PCI versus 13.0% for those who did not. After adjustment for multiple patient factors, same-day PCI was a significant predictor of in-hospital survival with a strong protective effect (adjusted OR = 0.35, 95% CI 0.31-0.38 P < 0.0001). Restriction of the analysis to those patients who survived the first day of admission did not appreciably change this result (adjust OR = 0.37, 95% CI 0.33-0.42, P < 0.0001). Hospital PCI-volume did not significantly impact mortality risk.

CONCLUSIONS

Same-day PCI markedly reduced the risk of in-hospital mortality among STEMI patients after multivariate adjustment. Serious comorbidities and complications, older age, and female gender continued to predict elevated risk of mortality after control for treatment status. Our results provide additional evidence in support of national clinical recommendations and aggressive treatment of STEMI.

Identification of patients at risk of ischemic events for long-term secondary prevention

PURPOSE

To review the identification of patients at risk of secondary ischemic events, discuss the therapies available for their medical management, and identify the role of the nurse practitioner (NP) in their primary and long-term care.

DATA SOURCES

ACC/AHA 2007 guidelines for the management of patients with unstable angina and non-ST-elevation myocardial infarction, ACC/AHA 2005 guidelines for the management of patients with peripheral arterial disease, AHA/ASA 2006 guidelines for patients with ischemic stroke, AHA/ACC 2006 guidelines update for patients with coronary and other atherosclerotic vascular disease, and selected clinical articles identified through PubMed.

CONCLUSIONS

Preventive therapy in patients with atherothrombotic vascular disease is critical for reducing the risk of recurrent events. Almost all patients with atherosclerotic disease will benefit from general lifestyle modifications, and most will also benefit from appropriate pharmacotherapies targeting dyslipidemia, diabetes, hypertension, and platelet function. However, evidence suggests that secondary prevention strategies may not be utilized effectively.

IMPLICATIONS FOR PRACTICE

Increased awareness and implementation of clinical practice guidelines can reduce the risk of recurrent atherothrombotic events. NPs in primary care settings or in long-term care facilities are well placed to determine whether patients are receiving appropriate preventive care and to implement improvements in their management.

Acute coronary syndromes: Diagnosis and management, part II

At the most severe end of the spectrum of acute coronary syndromes is ST-segment elevation myocardial infarction (STEMI), which usually occurs when a fibrin-rich thrombus completely occludes an epicardial coronary artery. The diagnosis of STEMI is based on clinical characteristics and persistent ST-segment elevation as demonstrated by 12-lead electrocardiography. Patients with STEMI should undergo rapid assessment for reperfusion therapy, and a reperfusion strategy should be implemented promptly after the patient's contact with the health care system. Two methods are currently available for establishing timely coronary reperfusion: primary percutaneous coronary intervention and fibrinolytic therapy. Percutaneous coronary intervention is the preferred method but is not always available. Antiplatelet agents and anticoagulants are critical adjuncts to reperfusion. This article summarizes the current evidence-based guidelines for the diagnosis and management of STEMI. This summary is followed by a brief discussion of the role of noninvasive stress testing in the assessment of patients with acute coronary syndrome and their selection for coronary revascularization.

Multiple renin-angiotensin-aldosterone-blocking agents in heart failure: how much is too much?

Angiotensin-converting enzyme inhibitors (ACE-Is) and beta-adrenergic receptor blockers (BBs) have been effective in reducing cardiovascular morbidity and mortality in patients with heart failure (HF) and left ventricular systolic dysfunction (LVSD). Angiotensin receptor blockers and aldosterone blockers have also been shown to be effective. Although ACE-Is and BBs remain the therapies of choice for patients with HF-LVSD, many clinicians have attempted to further reduce patient morbidity and mortality by adding another inhibitor or blocker of the renin-angiotensin-aldosterone system to an ACE-I or BB. This article reviews the efficacy and safety of adding another renin-angiotensin-aldosterone system inhibitor or blocker to an ACE-I or an angiotensin receptor blocker plus a BB in patients with HF-LVSD.

EUROASPIRE III: a survey on the lifestyle, risk factors and use of cardioprotective drug therapies in coronary patients from 22 European countries

AIM

The aim of the European Action on Secondary and Primary Prevention by Intervention to Reduce Events III (EUROASPIRE III) survey was to determine whether the Joint European Societies' guidelines on cardiovascular prevention are being followed in everyday clinical practice and to describe the lifestyle, risk factor and therapeutic management in patients with coronary heart disease (CHD) in Europe.

METHODS

The EUROASPIRE III survey was carried out in 2006-2007 in 76 centres from selected geographical areas in 22 countries in Europe. Consecutive patients, with a clinical diagnosis of CHD, were identified retrospectively and then followed up, interviewed and examined at least 6 months after their coronary event.

RESULTS

Thirteen thousand nine hundred and thirty-five medical records (27% women) were reviewed and 8966 patients were interviewed. At interview, 17% of patients smoked cigarettes, 35% were obese and 53% centrally obese, 56% had a blood pressure >or=140/90 mmHg (>or=130/80 in people with diabetes mellitus), 51% had a serum total cholesterol >or=4.5 mmol/l and 25% reported a history of diabetes of whom 10% had a fasting plasma glucose less than 6.1 mmol/l and 35% a glycated haemoglobin A1c less than 6.5%. The use of cardioprotective medication was: antiplatelets 91%; beta-blockers 80%; angiotensin-converting enzyme inhibitors/angiotensin-receptor blockers 71%; calcium channel blockers 25% and statins 78%.

CONCLUSION

The EUROASPIRE III survey shows that large proportions of coronary patients do not achieve the lifestyle, risk factor and therapeutic targets for cardiovascular disease prevention. Wide variations in risk factor prevalences and the use of cardioprotective drug therapies exist between countries. There is still considerable potential throughout Europe to raise standards of preventive care in order to reduce the risk of recurrent disease and death in patients with CHD.

Comparative analysis of beta-blockers with other antihypertensive agents on cardiovascular outcomes in hypertensive patients with diabetes mellitus: a systematic review and meta-analysis

OBJECTIVES

To analyze the effects of beta-blockers (BBs) on cardiovascular (CV) outcomes in diabetic patients with hypertension.

DATA SOURCE

Literature search was performed with relevant search words using PubMed and Ovid Gateway search engines for trials published in English from June 1996 to July 2007.

REVIEW METHODS

Systematic reviews of randomized control trials that used BBs as treatment or control therapy in diabetic patients with hypertension were included for the analysis. All the included studies use intention-to-treat analysis. Two individual authors procured the data. Myocardial infarction, stroke, CV mortality, and total mortality were the outcomes analyzed. Relative risk across the different groups was calculated using Mantel-Haenszel random- and fixed-effects model. Interstudy heterogeneity was computed by chi(2) test. Results were calculated with 95%confidence intervals (CIs) and were considered significant with double-sided alpha error less than 0.05. Funnel plot was used to assess for publication bias.

RESULTS

Eight trials (N = 130,270) met the inclusion criteria for the analysis. The relative risks for myocardial infarction, stroke, CV mortality, and total mortality were 1.08 (95% CI 0.82-1.42; P = 0.6), 1.13 (95% CI 0.95-1.36; P = 0.1), 1.15 (95% CI 0.83-1.6; P = 0.3), and 1.16 (95% CI 0.92-1.47; P = 0.2), respectively. BBs were associated with increased risk for CV mortality 1.39 (95% CI 1.07-1.804; P ,0.01) when compared with renin angiotensin blockade (RAS) therapy.

CONCLUSION

BBs have increased risk for CV mortality when compared with RAS blockade therapy in diabetic patients with hypertension. BBs do not have increased risk for myocardial infarction, stroke, CV mortality, and total mortality when compared with control antihypertensive therapy in diabetic patients with hypertension.

Early use of angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers: evidence from clinical trials

Following acute myocardial infarction, patients are at increased risk of developing heart failure, which is more prevalent in those with reduced ventricular systolic function. Activation of the renin-angiotensin-aldosterone system, which occurs early after myocardial injury, plays a central role in the pathogenesis of subsequent cardiac structural and functional abnormalities. The early use of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers has been tested in several large randomized clinical trials. The results of these trials show that this treatment strategy reduces the incidence of heart failure and mortality in the postmyocardial infarction patient. The magnitude of benefit is larger in patients with high-risk features, particularly those with large infarct size and the presence of heart failure or left ventricular systolic dysfunction at the time of myocardial injury. Careful use of these agents is essential in avoiding clinically significant hypotension in the critical period.

Continuum of care in the treatment of ST-segment elevation myocardial infarction (STEMI): importance of platelet and coagulation inhibition

ST-segment elevation myocardial infarction (STEMI) is a serious manifestation of atherothrombosis. Platelets play an important role in the pathogenesis of atherothrombosis, and the use of antiplatelet agents is associated with substantial improvements in clinical outcome. Current guidelines for the management of patients with STEMI stress the importance of using antiplatelet agents as an integral part of acute and long-term therapy. However, these and other recommended therapies are frequently underutilized. In-hospital quality improvement initiatives have been shown to substantially improve adherence to guideline-recommended therapies at the time of discharge. This review discusses the role of platelets in atherothrombosis and describes the medical management of patients with STEMI, highlighting current guideline recommendations, adherence in clinical practice, and the impact of quality improvement programs in maintaining the continuum of care into the ambulatory setting.

Weather-induced ischemia and arrhythmia in patients undergoing cardiac rehabilitation: another difference between men and women

Given the accumulating evidence that people with underlying heart disease are a particularly vulnerable group for triggers like changing meteorological parameters, the objective of this longitudinal study was to analyze the influence of weather parameters on blood pressure, arrhythmia and ischemia in cardiovascular patients. A panel study with repeated measurements was conducted in a rehabilitation clinic in Timmendorfer Strand (Baltic Sea, Germany) with 872 cardiovascular patients. Heart rate, blood pressure and electrocardiography changes were measured during repeated bicycle ergometries. Generalized Estimating Equations were used for regression analyses of immediate, delayed and cumulative influences of the daily measured meteorological data. For men, a decrease in air temperature and in water vapor pressure doubled the risk of ST-segment depression during ergometry [odds ratio (OR) for 1 day delay: 1.88 (1.24; 2.83) for air temperature] with a delay of 1-2 days. For women, an increase of their heart rate before the start of the ergometry [same day: 4.36 beats/min (0.99; 7.74) for air temperature] and a 2- to 3-fold higher risk for ventricular ectopic beats [1 day delay: OR 2.43 (1.17; 5.05) for air temperature] was observed with an increase in temperature and water vapor pressure in almost all analyzed time-windows. The study indicates that meteorological parameters can induce changes in heart function which may lead to adverse cardiovascular events especially in susceptible, diseased individuals. The observed effect on ST-segment depression could be a link between the association of weather changes and cardiovascular morbidity and mortality.

Pleiotropic effects of cardiac drugs on healing post-MI. The good, bad, and ugly

Healing after myocardial infarction (MI) is a well-orchestrated time-dependent process that involves inflammation, tissue repair with extracellular collagen matrix (ECCM) deposition and scar formation, and remodeling of myocardial structure, matrix, vasculature, and function. Rapid early ECCM degradation followed by slow ECCM replacement and maturation during post-MI healing results in a prolonged window of enhanced vulnerability to adverse remodeling. Decreased ECCM results in adverse ventricular remodeling, dysfunction, and rupture. Inflammation, a critical factor in normal healing, if impaired results in adverse remodeling and rupture. Several therapeutic drugs prescribed after MI exert pleiotropic effects that suppress ECCM and inflammation during healing and may have good, bad, or ugly consequences. This article reviews the potential impact of pleiotropic effects of some prototypic cardiac drugs such as renin-angiotensin-aldosterone system (RAAS) inhibitors, statins, and thrombolytics during healing post-ST-segment-elevation MI (STEMI), with special focus on inflammation, ECCM and remodeling, and implications in the elderly.

Causes of death in patients with acute myocardial infarction treated with angiotensin-converting enzyme inhibitors: findings from the Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto (GISSI)-3 trial

BACKGROUND

The causes of death occurring in clinical trials of myocardial infarction (MI) are scarcely reported in the literature. The present analysis is aimed to describe the inhospital causes of death in patients with acute MI stratified to angiotensin converting enzyme (ACE) inhibitor treatment/no treatment, as described in the GISSI-3 trial. Furthermore, the 5-year survival analysis of GISSI-3 patients is reported.

METHODS AND RESULTS

An independent committee assigned the definition of causes of death of GISSI-3 based on clinical and/or anatomical data. Univariate and multivariable analyses were performed to identify the predictors of early and late deaths. Kaplan-Meier mortality curves were used to describe the effects of ACE-I treatment on mortality on a median follow-up period of 56 months. Patients receiving lisinopril had fewer inhospital cardiac deaths than patients allocated to the no-lisinopril group (4.7% vs 5.3%, P = .052), corresponding to a 12% relative risk reduction. The risk of dying from cardiac rupture was reduced by 39% by lisinopril treatment. The improvement in survival associated with the lisinopril treatment was mainly due to a reduction in cardiac rupture, electromechanical dissociation, and pump failure occurring early (within 4 days) from the onset of MI symptoms. The beneficial effects of lisinopril observed at 6 weeks (8 fewer deaths per 1000 treated patients) were maintained up to nearly 5 years (10 fewer deaths per 1000).

CONCLUSIONS

Early administration of ACE inhibitors in unselected patients with acute MI should be considered standard therapy to reduce early deaths, specifically those due to cardiac rupture. The early beneficial effect persisted up to nearly 5 years.

Angiotensin-converting enzyme inhibitors in acute myocardial infarction: a clinical approach

Angiotensin-converting enzyme inhibitor therapy has been shown to be effective in treating patients across the spectrum of cardiac disease. Utility has been demonstrated for both prevention and treatment. This article reviews the data regarding angiotensin-converting enzyme inhibitor therapy in acute myocardial infarction, with emphasis on determining what is known regarding the mode of administration, optimal timing for initiation of treatment, and whether patients can be identified who are most likely to benefit from treatment.

Improvements in clinical outcomes with the use of angiotensin-converting enzyme inhibitors: cross-fertilization between clinical and basic investigation

The expanding clinical indications for the use of angiotensin-converting enzyme (ACE) inhibitors during the past three decades to reduce cardiovascular morbidity and mortality across a broad spectrum of cardiovascular diseases have been the consequence of impressively productive interchanges between basic science and clinical medicine. In some areas, the initial discovery from animal investigations produced the hypotheses that were confirmed and expanded in patients with specific disease processes. In the development of ACE inhibitors, there are also important examples where an unexpected discovery from clinical trials spurred a host of laboratory investigations that uncovered novel mechanisms to underpin the clinical observations. Although developed as an antihypertensive agent, these effective interchanges, termed “translational research,” have collectively produced convincing data to demonstrate that ACE inhibitors can and should be used to slow progression of renal disease, prevent and treat heart failure, attenuate adverse left ventricular remodeling after myocardial infarction and improve prognosis, reduce atherosclerotic complications in patients with coronary artery disease, and, even more recently, reduce the incidence of Type II diabetes.

Diagnosis and treatment of acute myocardial infarction in tertiary and secondary care hospitals in Estonia

AIM

To compare validity of AMI diagnosis and treatment of AMI patients between tertiary and secondary care hospitals in Estonia.

METHODS

Two tertiary and seven secondary care hospitals responsible for the treatment of most AMI patients in Estonia were included in the analysis. A random sample of 520 patients admitted to these hospitals with AMI in 2001 was taken from the Estonian Health Insurance Fund database. Medical records were reviewed by trained experts using a standardized data collection form.

RESULTS

Forty cases were excluded due to selection errors by the Health Insurance Fund. Of the remaining cases, a diagnosis of AMI was confirmed in 93.3% of cases in tertiary care hospitals and in 83.5% of cases in secondary care hospitals (p < 0.001). A total of 210 cases from tertiary and 213 cases from secondary care hospitals with confirmed AMI diagnoses were included in subsequent analysis. Utilization of beta-blockers, aspirin, and reperfusion therapy was similar in both types of hospitals. In tertiary care hospitals, ACE inhibitors and statins were more frequently used during hospital stay and recommended at discharge compared with secondary care hospitals. In-hospital mortality was similar in both types of hospitals both before and after adjustment.

CONCLUSIONS

Tertiary care physicians adhered more strictly to the current definition and guidelines for the management of AMI than did secondary care physicians. However, there is still a need for further improvement in both hospital settings according to international guidelines.

Explaining the decline in coronary heart disease mortality in Finland between 1982 and 1997

In Finland since the 1980s, coronary heart disease mortality has declined more than might be predicted by risk factor reductions alone. The aim of this study was to assess how much of the decline could be attributed to improved treatments and risk factor reductions. The authors used the cell-based IMPACT mortality model to synthesize effectiveness of treatments and risk factor reductions with data on treatments administered to patients and trends in cardiovascular risk factors in the population. Cardiovascular risk factors were measured in random samples of patients in 1982 (n=8,501) and 1997 (n=4,500). Mortality and treatment data were obtained from the National Causes of Death Register, Hospital Discharge Register, social insurance data, and medical records. Estimated and observed changes in coronary heart disease mortality were used as main outcome measures. Between 1982 and 1997, coronary heart disease mortality rates declined by 63%, with 373 fewer deaths in 1997 than expected from baseline mortality rates in 1982. Improved treatments explained approximately 23% of the mortality reduction, and risk factors explained some 53-72% of the reduction. These findings highlight the value of a comprehensive strategy that promotes primary prevention programs and actively supports secondary prevention. It also emphasizes the importance of maximizing population coverage of effective treatments.

[Acute coronary syndrome in the prehospital phase]

Cardiovascular diseases are the number one cause of death in Germany. In 2002 about 70,000 people died of acute myocardial infarction (AMI) and of these 37% died before arrival at hospital which underlines the relevance of adequate prehospital care. The generic term acute coronary syndrome (ACS) was introduced because a single pathomechanism accounts for the different forms and comprises unstable angina pectoris (iAP), non-ST-elevation myocardial infarction (NSTEMI), ST-elevation myocardial infarction (STEMI) and sudden cardiac death (SCD). Characteristic features are retrosternal pain, vegetative symptoms and radiation of pain into the adjoining regions. Further differentiation can only be achieved by the 12-lead ECG, as cardiac-specific enzymes do not play a role in prehospital decisions. Prehospital delays should be avoided, history and physical examination should be brief but focused, vital parameters should be assessed and monitored. Basic treatment for ACS should comprise inhalative oxygen, nitrates, morphine, aspirin and beta-blockers. If STEMI is diagnosed, patients with symptoms <12 h should undergo fibrinolytic therapy unless there is primary percutaneous coronary intervention (PCI) available within 90 min or if contraindicated. Heparin should be given to patients with STEMI depending on the choice of fibrinolytic agent, it otherwise results in a higher risk of bleeding, but in patients with iAP or NSTEMI it reduces mortality. All patients must be accompanied by the emergency physician during transportation and should be brought to a hospital with primary PCI, especially those with complicated ACS. Treatment of complications depends largely on the type, persistence and severity.

Administration of vascular endothelial growth factor adjunctive to fetal cardiomyocyte transplantation and improvement of cardiac function in the rat model

BACKGROUND

The functional impact of cellular transplantation and the potential role of the addition of angiogenic factors for survival of engrafts remain controversial.

METHODS

Vascular endothelial growth factor (VEGF) (25 ng/mL) was added to cultured fetal cardiomyocytes labeled with bromodeoxyuridine (BrDU), which was injected into the border zones of myocardial infarction 4 weeks after coronary occlusion in rat hearts. Group 1 (n = 12) received cells plus VEGF protein (100 ng), group 2 (n = 12) received cells without VEGF, group 3 (n = 10) received VEGF without cells, and group 4 (n = 12) received pure culture medium. Cardiac function was then assessed by transthoracic two-dimensional echocardiography and Langendorff perfusion system. In situ hybridization for Y chromosomes of transplanted cells, detection of BrDU-labeled cells, and platelet/endothelial cell adhesion molecule-1 (PECAM-1) staining for endothelial cells was performed.

RESULTS

Echocardiography revealed smaller end-diastolic left ventricular dimensions in transplanted hearts in group 1 (0.83 +/- 0.13 cm 4 weeks after coronary occlusion before transplantation and 0.69 +/- 0.14 cm 2 months after transplantation, P < .05) and in group 2 (0.88 +/- 0.09 cm after coronary occlusion before transplantation and 0.76 +/- 0.08 cm 2 months after transplant), and increases in fractional shortening (34.2% +/- 8.53% before transplant and 45.3% +/- 10.9% after [P < .05] in group 1; 26.9% +/- 6.02% before transplant and 37.15% +/-8.08% after [P < .005] in group 2), whereas groups 3 and 4 showed a decrease in fractional shortening. Transplanted hearts developed higher pressures at rest (group 1, 96.8 +/- 20.8 mm Hg; group 2, 98.6 +/- 21.9 mm Hg) compared with controls (group 4, 70.9 +/- 25 mm Hg) (P < .05) and during inotropic stimulation (group 1, 111 +/- 19.5 mm Hg and group 2, 113.3 +/- 32.6 vs group 4, 80.7 +/- 31.6 mm Hg, P < .05). Histologic analysis demonstrated the presence of transplanted cells in border zones of infarcted host myocardium with neovascularization in all transplanted hearts.

CONCLUSION

Transplantation of fetal cardiomyocytes results in improvement of left ventricular function. The addition of VEGF does not contribute to further improvement of left ventricular function and angiogenesis in the present model.

Serial changes in plasma brain natriuretic peptide concentration at the infarct and non-infarct sites in patients with left ventricular remodelling after myocardial infarction

OBJECTIVES

To clarify the role of infarct and non-infarct sites on left ventricular (LV) remodelling after myocardial infarction by measuring brain natriuretic peptide (BNP) from each site.

METHODS AND RESULTS

BNP from the aorta and the anterior interventricular vein (AIV) was measured in 45 patients with first anterior myocardial infarction at one, six, and 18 months. The LV was significantly dilated (> 10 ml/m(2) of end diastolic volume from one to 18 months) in 20 patients (remodelling (R) group) but not in 25 others (non-remodelling (NR) group). Patient characteristics and LV functions did not differ significantly at one month but plasma BNP concentration was higher in group R than in group NR (336 (288) v 116 (106) pg/ml, p < 0.01), predicting the degree of LV dilatation. The difference in BNP concentration between the aortic root and AIV (DeltaBNP), reflecting BNP secreted from the infarct site, did not differ at one month. In both groups BNP and DeltaBNP significantly decreased from one to six months (p < 0.05) and decreased from six months to 18 months, but the change was not significant. BNP and DeltaBNP were significantly higher in group R than in group NR after six months, when LV dilatation was not evident in both groups.

CONCLUSION

Enhanced BNP secretion at one month in the non-infarct and infarct ventricular sites predicts subsequent LV dilatation (that is, remodelling). The slower process of LV remodelling decreased BNP secretion at both sites. Thus, BNP concentration should be useful for monitoring ventricular remodelling after infarction.

Salutary effects of attenuation of angiotensin II on coronary perivascular fibrosis associated with insulin resistance and obesity

Obesity and insulin resistance confer increased risk for accelerated coronary disease and cardiomyopathic phenomena. We have previously shown that inhibition of angiotensin-converting enzyme (ACE) prevents coronary perimicrovascular fibrosis in genetically obese mice that develop insulin resistance. This study was performed to elucidate mechanism(s) implicated and to determine the effects of attenuation of angiotensin II (Ang) II. Genetically obese ob/ob mice were given ACE inhibitor (temocapril) or Ang II type 1 (AT(1)) receptor blocker (olmesartan) from 10 to 20 weeks. Cardiac expressions of plasminogen activator inhibitor (PAI)-1, the major physiologic inhibitor of fibrinolysis, and transforming growth factor (TGF)-beta(1), a prototypic profibrotic molecule, were determined and extent of perivascular coronary fibrosis was measured. Twenty-week-old obese mice exhibited increased plasma levels of PAI-1 and TGF-beta(1) compared with the values in lean counterpart. Perivascular coronary fibrosis in arterioles and small arteries was evident in obese mice that also showed increased left ventricular collagen as measured by hydroxyproline assay. Immunohistochemistry confirmed the deposition of perivascular type 1 collagen. Markedly increased PAI-1 and TGF-beta were seen immunohistochemically in coronary vascular wall and confirmed by western blotting. When obese mice were treated with temocapril or olmesartan from 10 to 20 weeks, both were equally effective and prevented increases in perivascular fibrosis, plasma PAI-1 and TGF-beta(1), left ventricular collagen and mural immunoreactivity for PAI-1, TGF-beta and collagen type 1. The c-Jun NH(2)-terminal kinase (JNK) activity was elevated in the left ventricle of obese mice (western) and blocked by temocapril and olmesartan. Ang II-mediated upregulation of PAI-1 and TGF-beta(1) with collagen deposition may explain the mechanism of perivascular fibrosis in obese mice. ACE inhibition and blockade of AT(1) receptor may prevent coronary perivascular fibrosis and collagen deposition even before development of overt diabetes. JNK activation may be a mediator of obesity-related cardiac dysfunction and a potential therapeutic target.

Antiarrhythmic drugs

Both supraventricular and ventricular arrhythmias are associated with increased mortality and morbidity. Numerous antiarrhythmics have been developed in an attempt to decrease the frequency of these arrhythmias, hoping to improve survival and improve quality of life. Antiarrhythmic agents are a diverse group of drugs that affect various cardiac ionic channels and block specific arrhythmias. However, despite the suppression of these potentially lethal cardiac arrhythmias, only the beta blockers have been shown to reduce sudden arrhythmic death, especially in patients with prior myocardial infarction or heart failure. Some antiarrhythmic agents can also worsen the index arrhythmia and caution must be used especially in the compromised patient. A simple guideline is as follows: For conversion of atrial fibrillation or flutter to sinus rhythm, in the absence of structural heart disease, intravenous ibutilide or oral propafenone or flecainide are good choices. For maintenance of sinus rhythm, propafenone or flecainide are logical choices. In the presence of structural heart disease, amiodarone, dofetilide, or dl sotalol are preferred. In heart failure, dofetilide or amiodarone are the logical choices. The role of antiarrhythmic therapy for ventricular arrhythmias is questionable and may be contraindicated, except for the use of beta blockers. The implantable cardioverter-defibrillator is often used in patients at high risk. At times, the addition of an antiarrhythmic agent such as amiodarone may be justified.

The clinical use of angiotensin-converting enzyme inhibitors

Through an integrative understanding of cardiovascular pathophysiologic characteristics at the multiorgan level, significant achievements in cardiovascular therapeutics have been achieved and enabled the rationale design and development of drugs such as the angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs). In this article, we present a detailed review of the physiologic features of the renin-angiotensin-aldosterone system (RAAS), ACE inhibitors and ARB clinical pharmacologic characteristics, and specific diseases in which they are considered to be the standard of the care as supported by important clinical trial data. It is envisioned that an updated and detailed understanding of ACE inhibitors and ARBs will facilitate their successful use in the treatment of heart failure, myocardial infarction, hypertension, renal failure, and diabetic nephropathy.

TRANSITORY REDUCTION IN ANGIOTENSIN AT2 RECEPTOR EXPRESSION LEVELS IN POSTINFARCT REMODELLING IN RAT MYOCARDIUM

1. Myocardial infarction (MI) poses a significant risk for sudden cardiac death. The effectiveness of angiotensin-converting enzyme (ACE) inhibitors and AT1 receptor blockade in attenuating unfavourable post-MI outcomes indicates an important role for angiotensin (Ang) II signalling in the post-MI remodelling process. 2. AT1 and AT2 receptor expression is known to be altered during the early postinjury period and at the later failure stage in the infarcted heart. The aim of the present investigation was to characterize AngII receptor expression shifts in the intermediate, adaptive phases of post-MI hypertrophic remodelling. 3. The present study investigated relative cardiac AT1 and AT2 receptor expression levels using semiquantitative reverse transcription-polymerase chain reaction (GAPDH normalized) in rats at 4 and 20 weeks after ligation of the left anterior descending coronary artery. 4. Heart weight and normalized heart weight were significantly higher in the MI group than in the sham group 4 weeks post-MI, with significant hypertrophy of the left ventricle, left atrium and right ventricle in MI rats. At 20 weeks post-MI, left ventricular hypertrophy remained significant, whereas the mass of the other cardiac tissues was not different to that of sham controls. 5. AT2 receptor expression was markedly reduced in both the non-infarct and infarcted areas of the left ventricular wall in the MI group compared with the sham-operated group 4 weeks after surgery. Expression levels were reduced to 8 and 13% of sham values in the viable and scar tissue regions, respectively. By 20 weeks post-MI, there was no evidence of AT2 receptor expression suppression in the left ventricle. No significant relative changes in AT1 receptor mRNA levels were observed at either 4 or 20 weeks post-MI. 6. The present study demonstrates, for the first time, a selective downregulation of left ventricular AT2 receptor expression in the intermediate phase of post-MI ventricular remodelling in the rat. This downregulation may provide an enhanced AT1 receptor-mediated compensatory progrowth signal in the early adaptive post-MI growth phase. A more detailed understanding of the time-course of differential AT1 and AT2 receptor expression regulation post-MI may potentially identify an optimal window for targeted pharmacological intervention in the treatment of MI.

Remodelage précoce du ventricule gauche après un accident coronarien aigu

Ventricular remodelling following acute coronary syndromes is both complex and multiform. It is due to the response of the myocardium to the different agressions associated with these syndromes, in particular the ischemia and necrosis downstream of the occluded artery. We must not however neglect the role of the remodelling of the lesions resulting from spontaneous reperfusion or provoked by the cells and tissues associated with coronary microcirculation embolisms and the no-reflow phenomenon. Acute post-infarct remodelling is dominated by early ventricular dilatation which largely affects late prognosis, necrosis elimination and its replacement by a fibrotic scar in parallel with a compensatory hypertrophy of the non-infarcted myocardium. The diverse cellular and molecular components of this remodelling are increasingly well-known, allowing us to better explain the beneficial effects of the currently available medications and providing us with new potential therapeutic targets. A grading of this knowledge associated with the identification of new risk factors and early therapeutic interventions should help us to further limit the deleterious aspects of this remodelling in the goal of preventing, or at least delaying, the devolution towards heart failure.