"Cardioprotection" by ACE-inhibitors in acute myocardial ischemia and infarction?

Early Treatment With Zofenopril and Ramipril in Combination With Acetyl Salicylic Acid in Patients With Left Ventricular Systolic Dysfunction After Acute Myocardial Infarction: Results of a 5-Year Follow-up of Patients of the SMILE-4 Study

The SMILE-4 study showed that in patients with left ventricular dysfunction (LVD) after acute myocardial infarction, early treatment with zofenopril plus acetyl salicylic acid is associated with an improved 1-year survival, free from death or hospitalization for cardiovascular (CV) causes, as compared to ramipril plus acetyl salicylic acid. We now report CV outcomes during a 5-year follow-up of the patients of the SMILE-4 study. Three hundred eighty-six of the 518 patients completing the study (51.2%) could be tracked after the study end and 265 could be included in the analysis. During the 5.5 (±2.1) years of follow-up, the primary endpoint occurred in 27.8% of patients originally randomized and treated with zofenopril and in 43.8% of patients treated with ramipril [odds ratio (OR) and 95% confidence interval, 0.65 (0.43-0.98), P = 0.041]. Such a result was achieved through a significantly larger reduction in CV hospitalization under zofenopril [OR: 0.61 (0.37-0.99), P = 0.047], whereas reduction in mortality rate with zofenopril did not achieve statistical significance versus ramipril [OR: 0.75 (0.36-1.59), P = 0.459]. These results were in line with those achieved during the initial 1-year follow-up. Benefits of early treatment of patients with LVD after acute myocardial infarction with zofenopril are sustained over many years as compared to ramipril.

Efficacy of Zofenopril Compared With Placebo and Other Angiotensin-converting Enzyme Inhibitors in Patients With Acute Myocardial Infarction and Previous Cardiovascular Risk Factors: A Pooled Individual Data Analysis of 4 Randomized, Double-blind, Controlled, Prospective Studies

In the Survival of Myocardial Infarction Long-term Evaluation (SMILE) 1, 3, and 4 studies, early administration of zofenopril in acute myocardial infarction showed to be prognostically beneficial versus placebo or ramipril. The SMILE-2 showed that both zofenopril and lisinopril are safe and showed no significant differences in the incidence of major cardiovascular (CV) complications. In this pooled analysis of individual data of the SMILE studies, we evaluated whether the superior efficacy of zofenopril is maintained also in patients with ≥1 CV risk factor (CV+, n = 2962) as compared to CV− (n = 668). The primary study end point was set to 1-year combined occurrence of death or hospitalization for CV causes. The risk of CV events was significantly reduced with zofenopril versus placebo either in the CV+ (−37%; hazard ratio: 0.63; 95% confidence interval: 0.51–0.78; P = 0.0001) or in the CV− group (−55%; hazard ratio: 0.45; 0.26–0.78; P = 0.004). Also, the other angiotensin-converting enzyme inhibitors reduced the risk of major CV outcomes, though the reduction was not statistically significant versus placebo (CV+: 0.78; 0.58–1.05; P = 0.107; CV−: 0.71; 0.36–1.41; P = 0.334). The benefit was larger in patients treated with zofenopril than other angiotensin-converting enzyme inhibitors, with a statistically significant difference for CV+ (0.79; 0.63–0.99; P = 0.039) versus CV− (0.62; 0.37–1.06; P = 0.081). In conclusion, zofenopril administered to patients after acute myocardial infarction has a positive impact on prognosis, regardless of the patient's CV risk profile.

Effects of losartan and vanillic Acid co-administration on ischemia-reperfusion-induced oxidative stress in isolated rat heart

Background:

Experimental studies have demonstrated that angiotensin II (ANG-II)-induced oxidative stress contributes to the pathogenesis of I/R injury.

Objectives:

This study was aimed to investigate the protective effects of co-administration of losartan, as a selective ANG-II type 1 receptor (AT1R) blocker, and vanillic acid (VA), as an antioxidant, in I/R-induced oxidative stress in isolated rat heart.

Materials and Methods:

Adult male Wistar rats were randomly divided to sham, control, and five treatment groups (n = 10). Two doses of VA (5 and 10 mg/kg), one dose of losartan (20 mg/kg) alone, and one dose of losartan in combination with either doses of VA were administered orally for 10 days. The hearts were isolated and exposed to 30 minutes ischemia and 60 minutes reperfusion, using Langendorff apparatus. I/R-induced myocardial injury was assessed by estimating the release of lactate dehydrogenase (LDH), creatine phosphokinase (CPK) and myocardial creatine kinase (CK-MB) in coronary effluent at 5, 15, and 60 minutes of reperfusion. The oxidative stress in the hearts was assessed by estimating malondialdehyde (MDA). The effects of treatments on endogenous antioxidant enzymes were assessed by measuring superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT).

Results:

There was a more significant decrease in the levels of LDH, CPK, CK-MB, and MDA as well as increase in the levels of SOD, CAT and GPx in groups that had received combined treatment in comparison to VA or losartan alone.

Conclusions:

It may be concluded that combination of losartan with higher dose of VA decreases ischemic markers and lipid peroxidation and augments endogenous antioxidant and hence, protects myocardium against I/R-induced oxidative stress injuries.

Cost-effectiveness of zofenopril in patients with left ventricular systolic dysfunction after acute myocardial infarction: a post hoc analysis of SMILE-4

BACKGROUND

In SMILE-4 (the Survival of Myocardial Infarction Long-term Evaluation 4 study), zofenopril + acetylsalicylic acid (ASA) was superior to ramipril + ASA in reducing the occurrence of major cardiovascular events in patients with left ventricular dysfunction following acute myocardial infarction. The present post hoc analysis was performed to compare the cost-effectiveness of zofenopril and ramipril.

METHODS

In total, 771 patients with left ventricular dysfunction and acute myocardial infarction were randomized in a double-blind manner to receive zofenopril 60 mg/day (n = 389) or ramipril 10 mg/day (n = 382) + ASA 100 mg/day and were followed up for one year. The primary study endpoint was the one-year combined occurrence of death or hospitalization for cardiovascular causes. The economic analysis was based on evaluation of cost of medications and hospitalizations and was applied to the intention-to-treat population (n = 716). Cost data were drawn from the National Health Service databases of the European countries participating in the study. The incremental cost-effectiveness ratio was used to quantify the cost per event prevented with zofenopril versus ramipril.

RESULTS

Zofenopril significantly (P = 0.028) reduced the risk of the primary study endpoint by 30% as compared with ramipril (95% confidence interval, 4%-49%). The number needed to treat to prevent a major cardiovascular event with zofenopril was 13 less than with ramipril. The cost of drug therapies was higher with zofenopril (328.78 Euros per patient per year, n = 365) than with ramipril (165.12 Euros per patient per year, n = 351). The cost related to the occurrence of major cardiovascular events requiring hospitalization averaged 4983.64 Euros for zofenopril and 4850.01 Euros for ramipril. The incremental cost-effectiveness ratio for zofenopril versus ramipril was 2125.45 Euros per event prevented (worst and best case scenario in the sensitivity analysis was 3590.09 and 3243.96 Euros, respectively).

CONCLUSION

Zofenopril is a viable and cost-effective treatment for managing patients with left ventricular dysfunction after acute myocardial infarction.

Estrogen prevents intestinal inflammation after trauma-hemorrhage via downregulation of angiotensin II and angiotensin II subtype I receptor

Although angiotensin II (Ang II) plays a key role in development of organ ischemia-reperfusion injury, it remains unclear whether it is involved in development of intestinal injury following trauma-hemorrhage (T-H). Studies have shown that 17beta-estradiol (E2) administration following T-H improves small intestinal blood flow; however, it is unclear whether Ang II plays a role in this E2-mediated salutary effect. Male Sprague-Dawley rats underwent laparotomy and hemorrhagic shock (removal of 60% total blood volume, fluid resuscitation after 90 min). At onset of resuscitation, rats were treated with vehicle, E2, or E2 and estrogen receptor antagonist ICI 182,780 (ICI). A separate group of rats was treated with Ang II subtype I receptor (AT1R) antagonist losartan. At 24 h after T-H, plasma Ang II, IL-6, TNF-alpha, intercellular adhesion molecule (ICAM)-1, cytokine-induced neutrophil chemoattractant (CINC)-1 and CINC-3 levels, myeloperoxidase (MPO) activity, and AT1R expression were determined. T-H significantly increased plasma and intestinal Ang II, IL-6, TNF-alpha levels, intestinal ICAM-1, CINC-1, CINC-3 levels, MPO activity, and AT1R protein compared with shams. E2 treatment following T-H attenuated increased intestinal MPO activity, Ang II level, and AT1R protein expression. ICI administration abolished the salutary effects of E2. In contrast, losartan administration attenuated increased MPO activity without affecting Ang II and AT1R levels. Thus Ang II plays a role in producing small intestine inflammation following T-H, and the salutary effects of E2 on intestinal inflammation are mediated in part by Ang II and AT1R downregulation.

Apstatin, a selective inhibitor of aminopeptidase P, reduces myocardial infarct size by a kinin-dependent pathway

1. Inhibitors of the angiotensin converting enzyme (ACE) have been shown to exert their cardioprotective actions through a kinin-dependent mechanism. ACE is not the only kinin degrading enzyme in the rat heart. 2. Since aminopeptidase P (APP) has been shown to participate in myocardial kinin metabolism to the same extent as ACE, the aims of the present study were to investigate whether (a) inhibition of APP leads to a reduction of myocardial infarct size in a rat model of acute ischaemia and reperfusion, (b) reduction of infarct size is mediated by bradykinin, and (c) a combination of APP and ACE inhibition leads to a more pronounced effect than APP inhibition alone. 3. Pentobarbital-anaesthetized rats were subjected to 30 min left coronary artery occlusion followed by 3 h reperfusion. The APP inhibitor apstatin, the ACE-inhibitor ramiprilat, or their combination were administered 5 min before ischaemia. Rats receiving HOE140, a specific B(2) receptor antagonist, were pretreated 5 min prior to enzyme inhibitors. Myocardial infarct size (IS) was determined by tetrazolium staining and expressed as percentage of the area at risk (AAR). 4. IS/AAR% was significantly reduced in rats that received apstatin (18+/-2%), ramiprilat (18+/-3%), or apstatin plus ramiprilat (20+/-4%) as compared with those receiving saline (40+/-2%), HOE (43+/-3%) or apstatin plus HOE140 (49+/-4%). 5. Apstatin reduces IS in an in vivo model of acute myocardial ischaemia and reperfusion to the same extent than ramiprilat. Cardioprotection achieved by this selective inhibitor of APP is mediated by bradykinin. Combined inhibition of APP and ACE did not result in a more pronounced reduction of IS than APP-inhibition alone.