Therapeutic effects of captopril on ischemia and dysfunction of the left ventricle after Q-wave and non-Q-wave myocardial infarction

Isovaleroylbinankadsurin A ameliorates cardiac ischemia/reperfusion injury through activating GR dependent RISK signaling

Ischemia/reperfusion (I/R) injury is a pathological process caused by reperfusion. The prevention of I/R injury is of great importance as it would enhance the efficacy of myocardial infarction treatment in patients. Isovaleroylbinankadsurin A (ISBA) has been demonstrated to possess multiple bioactivities for treating diseases. However, its protective effect on myocardial I/R injury remains unknown. In this study, the cardiomyocytes hypoxia/reoxygenation (H/R) in vitro model and coronary artery ligation in vivo model were used to examine the protective effect of ISBA. Apoptosis was determined by flow cytometry and Caspase 3 activity. Protein level was determined by Western blot. The mitochondrial viability was examined with mitochondrial viability stain assay. Mitochondrial membrane potential was detected by JC-1 staining and reactive oxygen species (ROS) was stained with 2',7'-dichlorodihydrofluorescein diacetate (DCF-DA). The binding interactions between ISBA and receptors was simulated by molecular docking. Results showed that ISBA effectively protected cardiomyocytes from I/R injury in in vitro and in vivo models. It remarkably blocked the apoptosis induced by H/R injury through the mitochondrial dependent pathway. Activation of the reperfusion injury salvage kinase (RISK) pathway was demonstrated to be essential for ISBA to exert its protective effect on cardiomyocytes. Moreover, molecular docking indicated that ISBA could directly bind to glucocorticoid receptor (GR) and thus induce its activation. Furthermore, the treatment of GR inhibitor RU486 partially counteracted the protective effect of ISBA on cardiomyocytes, consistent with the results of docking.Most attractively, by activating GR dependent RISK pathway, ISBA significantly elevated the cellular anti-oxidative capacity and hence alleviated oxidative damage induced by I/R injury. In conclusion, our study proved that ISBA protected the heart from myocardial I/R injury through activating GR dependent RISK pathway and consequently inhibiting the ROS generation. It provides a valuable reference for ISBA to be developed as a candidate drug for cardiovascular diseases.

The revised role of ACE-inhibition after myocardial infarction in the thrombolytic/primary PCI era

Many studies have investigated the process of left ventricular (LV) dilatation and the effects of angiotensin-converting enzyme (ACE) inhibitors after myocardial infarction (MI). It has been generally accepted that progression of LV dilatation is a major predictor of heart failure and death after MI. Also, attenuation of LV dilatation is thought to be one of the main mechanisms by which ACE inhibitors (ACE-Is) produce their beneficial effects. However, evidence for this hypothesis came from studies that were performed before thrombolytic therapy and primary percutaneous coronary intervention (PCI) were routinely used after acute MI. Nowadays, reperfusion is obtained much more frequently and LV dilatation after MI has become less prevalent. Nevertheless, ACE-Is proved effective in reducing cardiac morbidity and mortality. Therefore, mechanisms other than attenuation of LV dilatation, such as anti-atherosclerotic effects or plaque stabilisation, may explain the long-term beneficial effects of ACE-Is after MI. In the present overview, we evaluate the role of LV dilatation and the effects of ACE-Is after MI in the thrombolytic/primary PCI era and provide recommendations on ACE-I use in clinical practice.

No effects on myocardial ischaemia in patients with stable ischaemic heart disease after treatment with ramipril for 6 months

OBJECTIVE: To assess the effects of a 6-month angiotensin-converting enzyme (ACE) inhibitor intervention on myocardial ischaemia. METHOD: We randomized 389 patients with stable coronary artery disease to double-blind treatment with ramipril 5 mg/day (n = 133), ramipril 1.25 mg/day (n = 133), or placebo (n = 123). Forty-eight-hour ambulatory electrocardiography was performed at baseline, and after 1 and 6 months. RESULTS: Relevant baseline variables were similar in all groups. Changes over 6 months in duration of >/= 1 mm ST-segment depression (STD), total ischaemic burden and maximum STD did not differ significantly between the treatment groups. There was no difference in the frequency of adverse events between the groups. CONCLUSION: ACE inhibitor treatment has little impact on incidence and severity of myocardial ischaemia in patients with stable ischaemic heart disease.

Evaluation of the effects of aspirin combined with angiotensin-converting enzyme inhibitors in patients with coronary artery disease

BACKGROUND

Several studies have suggested that there may be an interaction between angiotensin-converting enzyme (ACE) inhibitors and aspirin in patients with congestive heart failure, such that their benefits are attenuated when used in combination. Whether this interaction exists in patients with coronary artery disease is not known.

SUBJECTS AND METHODS

Patients enrolled in two large trials, Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries (GUSTO-I) and Evaluation in PTCA to Improve Long-Term Outcome with Abciximab GP IIb/IIIa Blockade (EPILOG), were stratified according to use of aspirin and ACE inhibitors on discharge from the hospital. In the EPILOG trial, left ventricular systolic function was assessed by contrast ventriculography. The primary endpoint was all-cause mortality at 1 year. EPILOG patients, all of whom were receiving aspirin, were also examined for the combined endpoint of death or nonfatal myocardial infarction. Stratified and multivariate analyses were used to adjust for baseline differences in patient characteristics.

RESULTS

We studied 31,622 patients in the GUSTO-I trial and 2,619 patients in the EPILOG trial. There were 615 deaths among the GUSTO-I patients and 45 deaths among the EPILOG patients at 1 year. Unadjusted mortality was greater among patients treated with both ACE inhibitors and aspirin than among patients treated with aspirin alone (3.3% versus 1.6%, P <0.001 for GUSTO-I; and 3.7% versus 1.2%, P <0.001 for EPILOG). Similarly, the composite endpoint of death or nonfatal myocardial infarction was more frequent among EPILOG patients who were taking ACE inhibitors (6.3% versus 3.3%, P = 0. 001). After adjusting for confounders, combined use of aspirin and ACE inhibitors was associated with increased mortality in GUSTO-I patients (hazard ratio [HR] = 2.2, 95% confidence interval [CI]: 1.1 to 4.3, P = 0.03) compared with aspirin alone. In EPILOG patients, after adjusting for clinical factors and extent of left ventricular dysfunction, the combination of aspirin and ACE inhibitors was associated with an increased risk of death (HR = 2.1, 95% CI: 1.1 to 3.8, P = 0.02) and of death or nonfatal myocardial infarction (HR = 1.5, 95% CI: 1.1 to 2.5, P = 0.02) compared with aspirin alone.

CONCLUSION

These observational findings suggest the possibility of an interaction between aspirin and ACE inhibitors among patients with ischemic heart disease. Further study of this issue is warranted.

Effect of ED management on ICU use in acute pulmonary edema

Acute pulmonary edema (APE) is a common Emergency Department (ED) presentation requiring admission to an intensive care unit (ICU). This study was undertaken to examine the effect of ED management on the need for ICU admission in patients with APE. ED records of APE patients were abstracted for patient age, prehospital and ED pharmacological treatment, diagnoses, airway interventions, and ICU length of stay (LOS). Statistical analysis was through multiple regression, logistic regression, chi-square, and ANOVA. One hundred eighty-one patients composed the study group. Pharmacological treatment included nitroglycerin (NTG), 147 patients (81%); morphine sulfate (MS), 88 (49%); loop diuretics (LD), 133 (73%); and captopril sublingual (CSL), 47 (26%). Use of CSL and MS were associated with opposing needs for ICU admission. MS use was associated with increased ICU admissions (odds ratio, 3.08; P = .002), whereas CSL use was associated with decreased ICU admissions (odds ratio, 0.29; P = .002). Morphine sulfate use also demonstrated an increased need for endotracheal intubation (ETI) (odds ratio, 5.04; P = .001), whereas CSL demonstrated a decreased need for ETI (odds ratio, 0.16; P = .008). Ninety-three patients required some form of respiratory support. Forty received noninvasive pressure support ventilation (NPSV) from a bilevel positive airway pressure system (BiPAP), and 60 received endotracheal intubation. Some patients received more than 1 form of respiratory support; all other patients received supplemental oxygen only. The ICU-LOS associated with different airway interventions were supplemental oxygen, 0.72 days; BiPAP, 1.48 days; and ETI, 3.70 days (P < .001). Specific ED pharmacological interventions are associated with a decreased need for ICU admission and endotracheal intubation in acute pulmonary edema patients, whereas use of noninvasive pressure support ventilation correlates with a reduction in the ICU length of stay for patients who do require critical care admission.

Early captopril prevents myocardial infarction-induced hypertrophy but not angiogenesis

Delayed captopril, started after the healing phase of myocardial infarction, improves perfusion by reducing tissue weight without affecting the vascular capacity of the heart. Early captopril, during the healing phase, prevents reactive hypertrophy, but the effects on angiogenesis are unknown. Therefore, the effects of early captopril (2 g/l drinking water, from 1 day until 3 weeks after myocardial infarction) on regional coronary flow related to tissue mass, were studied in isolated perfused hearts from rats, subjected to coronary artery ligation. Regional maximal vascular capacity was measured during nitroprusside-induced vasodilation, using radioactive microspheres. Maximal vascular capacity was not changed by captopril. Reactive hypertrophy in infarcted hearts only reached statistical significance in the left ventricular free wall. Since captopril prevented hypertrophy but did not affect regional capacity, peak tissue perfusion was improved. Indicating effects on metabolism, captopril restored the increased lactate/purine ratio in infarcted hearts. Thus, early captopril treatment prevented post-myocardial infarction hypertrophy but did not suppress angiogenesis, thus beneficially influencing the vascularization/tissue mass ratio, probably reflected by preservation of aerobic metabolism.

Evidence-based medicine and ACE inhibition

The use of angiotensin-converting enzyme (ACE) inhibitors has been generally beneficial in the treatment of many clinical conditions characterized by a significant degree of cardiovascular and renal involvement. Most of the available data on the benefits of ACE inhibitors have come from well-conducted large clinical trials that have provided much information supporting the use of ACE inhibitors, in agreement with the basic principles of evidence-based medicine. In particular, ACE inhibitors improve blood pressure control in patients with hypertension and have proved to be beneficial in patients with left ventricular (LV) systolic dysfunction and chronic congestive heart failure (CHF). Improved survival rates after the use of ACE inhibitors have been also demonstrated in patients with acute myocardial infarction (MI), whether or not the condition is complicated by acute CHF. More recently, some studies have demonstrated the ability of ACE inhibitors (particularly fosinopril) to prevent the long-term development of CHF in patients treated acutely during MI and without baseline LV dysfunction. ACE inhibitors appear to improve the long-term prognosis of patients with coronary artery disease (CAD) and to reduce the occurrence of re-infarction, as demonstrated in the Studies of Left Ventricular Dysfunction (SOLVD) trial and the Survival and Ventricular Enlargement study (SAVE). Finally, a protective role for ACE inhibitors has been reported even in diabetic hypertensive patients, in whom such agents can significantly reduce the occurrence of major cardiovascular events (CAD and stroke) with a pattern that is largely independent of blood pressure control and is not observed with the use of calcium antagonists. These data confirm the strong involvement of the renin-angiotensin system in the pathophysiology of vascular diseases and strongly support the role of ACE inhibitors as drugs for present and future therapy.

Clinical aspects of ACE inhibition in patients with acute myocardial infarction

The purpose of the present article was to review the current evidence on the use of angiotensin-converting enzyme (ACE) inhibitors in acute myocardial infarction (MI). This article is based on published information as well as on our personal experience derived from an extensive analysis of the SMILE study. All the randomized trials have been included irrespective of the primary endpoint, and the results are presented in terms of either hemodynamic or clinical benefit. Short- and long-term treatment with ACE inhibitors in patients with acute MI results in a significant reduction in mortality, which is more evident in high risk patients (i.e., patients with left ventricular dysfunction, congestive heart failure on admission, or anterior myocardial infarction). Development and progression of congestive heart failure after myocardial infarction was significantly reduced by ACE inhibition, which also reduced the rate of reinfarction, the need for revascularization procedures, as well as the occurrence of ventricular arrhythmias, probably through a mechanism involving some drug-dependent effects. In conclusion, the available data strongly support a wide benefit associated with the use of ACE inhibitors in patients with high-risk acute MI.

Aortic atheromas and acute ischemic stroke: a transesophageal echocardiographic study in an ethnically mixed population

PURPOSE

Proximal aortic atheromas have been suggested as a potential ischemic stroke determinant in the elderly, especially in cases of unexplained (cryptogenic) stroke. Our aim was to assess the potential role of proximal aortic atheromas as an independent risk factor for stroke by comparing their frequency in patients with acute ischemic stroke and in stroke-free control subjects. The frequency of atheromas was also compared among different ethnic groups.

PATIENTS AND METHODS

A case-control study was conducted in 106 patients with acute ischemic stroke and 114 stroke-free control subjects. The presence of atheromas of the proximal portion of the aorta was assessed by biplane transesophageal echocardiography. Atheromas were categorized on the basis of their thickness (0.2 to 0.4 cm, small; > or = 0.5 cm, large) and complexity (i.e., ulceration or mobility). The association between aortic atheromas and ischemic stroke was tested, controlling for patients' demographic variables and stroke risk factors. In stroke patients, subgroup analyses were performed to test the associations between aortic atheromas and stroke diagnostic subtypes (determined cause versus cryptogenic) and presence and degree of carotid stenoses by duplex Doppler examination.

RESULTS

The frequency of large aortic atheromas was greater in stroke patients than in controls (26% versus 13%; crude odds ratio [OR] 2.4, 95% CI 1.2 to 4.7); ulcerated or mobile atheromas also tended to be more frequent in stroke patients (12% versus 5%; OR 2.5, 95% CI 1.0 to 6.8). Differences were entirely attributable to the subgroup of patients aged 60 years or older, in whom the frequency of ulcerated or mobile atheromas was particularly high among cryptogenic stroke patients (22% versus 8% in control subjects; OR 3.4, 95% CI 1.1 to 11.2). Multivariate analysis showed the presence of large atheromas to be independently associated with stroke in the entire study group (adjusted OR 2.6, 95% CI 1.1 to 5.9) and in the older subgroup (OR 2.4, 95% CI 1.1 to 5.7). Carotid stenosis > or = 60% was more frequent with increasing size and complexity of aortic atheromas but had low predictive value (16%) for presence of large atheromas; moreover, 36% of patients with mild or no carotid stenosis had large or complex aortic atheromas. No significant differences were found in the frequency of atheromas by ethnic group.

CONCLUSIONS

Proximal aortic atheromas > or = 0.5 cm in size are a risk factor for ischemic stroke in patients aged 60 years or older. Ulcerated or mobile atheromas may play a role in explaining some cryptogenic strokes in the elderly. The risk for stroke of patients with aortic atheromas may be similar across different ethnic groups. The absence of carotid stenosis does not exclude aortic atheromas as a potential cause for ischemic stroke.

Lack of ventricular remodeling in non-Q-wave myocardial infarction

We prospectively examined 45 patients with serial echocardiography to measure left ventricular end-diastolic volume index within 1 week and at 6 weeks after infarction. Left ventricular volume increased in patients with Q-wave infarction but not in those with non-Q or in control patients without recent infarction. Peak creatine phosphokinase levels were greater in Q-wave infarction compared with those in non-Q-wave infarction. There was a strong correlation between the change in the left ventricular end-diastolic index and the peak creatine phosphokinase level. After correcting for infarct size, there was still a difference between the two groups. Our data indicate that ventricular remodeling does not occur in non-Q-wave as opposed to Q-wave infarcts, and this may be related both to the limited amount of myocardial necrosis and to the nontransmural extent of the necrosis.

The effect of the angiotensin-converting-enzyme inhibitor zofenopril on mortality and morbidity after anterior myocardial infarction. The Survival of Myocardial Infarction Long-Term Evaluation (SMILE) Study Investigators

BACKGROUND

Left ventricular dilatation and neuroendocrine activation are common after acute anterior myocardial infarction. Long-term treatment with an angiotensin-converting-enzyme (ACE) inhibitor may improve outcome by attenuating these processes. We investigated whether the ACE inhibitor zofenopril, administered for six weeks after anterior myocardial infarction, could improve both short-term and long-term outcome.

METHODS

A total of 1556 patients were enrolled within 24 hours after the onset of symptoms of acute anterior myocardial infarction, and they were randomly assigned in a double-blind fashion to receive either placebo (784 patients) or zofenopril (772 patients) for six weeks. At this time we assessed the incidence of death or severe congestive heart failure. The patients were reexamined after one year to assess survival.

RESULTS

The incidence of death or severe congestive heart failure at six weeks was significantly reduced in the zofenopril group (55 patients, 7.1 percent), as compared with the placebo group (83 patients, 10.6 percent); the cumulative reduction in the risk of death or severe congestive heart failure was 34 percent (95 percent confidence interval, 8 to 54 percent; P = 0.018). The reduction in risk was 46 percent (95 percent confidence interval, 11 to 71 percent; P = 0.018) for severe congestive heart failure and 25 percent (95 percent confidence interval, -11 to 60 percent; P = 0.19) for death. After one year of observation, the mortality rate was significantly lower in the zofenopril group (10.0 percent) than in the placebo group (14.1 percent); the reduction in risk was 29 percent (95 percent confidence interval, 6 to 51 percent; P = 0.011).

CONCLUSIONS

Treatment with zofenopril significantly improved both short-term and long-term outcome when this drug was started within 24 hours after the onset of acute anterior myocardial infarction and continued for six weeks.