Effects of chronic subdepressor dose of angiotensin II type 1 receptor antagonist on endothelium-dependent vasodilation in patients with congestive heart failure

Molecular Mechanisms and Therapeutic Implications of Endothelial Dysfunction in Patients with Heart Failure

Heart failure is a complex medical syndrome that is attributed to a number of risk factors; nevertheless, its clinical presentation is quite similar among the different etiologies. Heart failure displays a rapidly increasing prevalence due to the aging of the population and the success of medical treatment and devices. The pathophysiology of heart failure comprises several mechanisms, such as activation of neurohormonal systems, oxidative stress, dysfunctional calcium handling, impaired energy utilization, mitochondrial dysfunction, and inflammation, which are also implicated in the development of endothelial dysfunction. Heart failure with reduced ejection fraction is usually the result of myocardial loss, which progressively ends in myocardial remodeling. On the other hand, heart failure with preserved ejection fraction is common in patients with comorbidities such as diabetes mellitus, obesity, and hypertension, which trigger the creation of a micro-environment of chronic, ongoing inflammation. Interestingly, endothelial dysfunction of both peripheral vessels and coronary epicardial vessels and microcirculation is a common characteristic of both categories of heart failure and has been associated with worse cardiovascular outcomes. Indeed, exercise training and several heart failure drug categories display favorable effects against endothelial dysfunction apart from their established direct myocardial benefit.

Stable Gastric Pentadecapeptide BPC 157 as Useful Cytoprotective Peptide Therapy in the Heart Disturbances, Myocardial Infarction, Heart Failure, Pulmonary Hypertension, Arrhythmias, and Thrombosis Presentation

In heart disturbances, stable gastric pentadecapeptide BPC 157 especial therapy effects combine the therapy of myocardial infarction, heart failure, pulmonary hypertension arrhythmias, and thrombosis prevention and reversal. The shared therapy effect occurred as part of its even larger cytoprotection (cardioprotection) therapy effect (direct epithelial cell protection; direct endothelium cell protection) that BPC 157 exerts as a novel cytoprotection mediator, which is native and stable in human gastric juice, as well as easily applicable. Accordingly, there is interaction with many molecular pathways, combining maintained endothelium function and maintained thrombocytes function, which counteracted thrombocytopenia in rats that underwent major vessel occlusion and deep vein thrombosis and counteracted thrombosis in all vascular studies; the coagulation pathways were not affected. These appeared as having modulatory effects on NO-system (NO-release, NOS-inhibition, NO-over-stimulation all affected), controlling vasomotor tone and the activation of the Src-Caveolin-1-eNOS pathway and modulatory effects on the prostaglandins system (BPC 157 counteracted NSAIDs toxicity, counteracted bleeding, thrombocytopenia, and in particular, leaky gut syndrome). As an essential novelty noted in the vascular studies, there was the activation of the collateral pathways. This might be the upgrading of the minor vessel to take over the function of the disabled major vessel, competing with and counteracting the Virchow triad circumstances devastatingly present, making possible the recruitment of collateral blood vessels, compensating vessel occlusion and reestablishing the blood flow or bypassing the occluded or ruptured vessel. As a part of the counteraction of the severe vessel and multiorgan failure syndrome, counteracted were the brain, lung, liver, kidney, gastrointestinal lesions, and in particular, the counteraction of the heart arrhythmias and infarction.

Angiotensin receptor blockers for heart failure

BACKGROUND

Chronic heart failure (HF) is a prevalent world-wide. Angiotensin receptor blockers (ARBs) are widely prescribed for chronic HF although their role is controversial.

OBJECTIVES

To assess the benefit and harm of ARBs compared with ACE inhibitors (ACEIs) or placebo on mortality, morbidity and withdrawals due to adverse effects in patients with symptomatic HF and left ventricular systolic dysfunction or preserved systolic function.

SEARCH METHODS

Clinical trials were identified by searching CENTRAL, HTA, and DARE , (The Cochrane Library 2010 Issue 3), as well as MEDLINE (2002 to July 2010), and EMBASE (2002 to July 2010). Reference lists of retrieved articles and systematic reviews were checked for additional studies not identified by the electronic searches.

SELECTION CRITERIA

Double blind randomised controlled trials in men and women of all ages who have symptomatic (NYHA Class II to IV) HF and: 1) left ventricular systolic dysfunction, defined as left ventricular ejection fraction (LVEF) ≤40%; or 2) preserved ejection fraction, defined as LVEF >40%.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed risk of bias and extracted data from included studies.

MAIN RESULTS

Twenty two studies evaluated the effects of ARBs in 17,900 patients with a LVEF ≤40% (mean 2.2 years). ARBs did not reduce total mortality (RR 0.87 [95% CI 0.76, 1.00]) or total morbidity as measured by total hospitalisations (RR 0.94 [95% CI 0.88, 1.01]) compared with placebo.Total mortality (RR 1.05 [95% CI 0.91, 1.22]), total hospitalisations (RR 1.00 [95% CI 0.92, 1.08]), MI (RR 1.00 [95% CI 0.62, 1.63]), and stroke (RR 1.63 [0.77, 3.44]) did not differ between ARBs and ACEIs but withdrawals due to adverse effects were lower with ARBs (RR 0.63 [95% CI 0.52, 0.76]). Combinations of ARBs plus ACEIs increased the risk of withdrawals due to adverse effects (RR 1.34 [95% CI 1.19, 1.51]) but did not reduce total mortality or total hospital admissions versus ACEI alone.Two placebo-controlled studies evaluated ARBs in 7151 patients with a LVEF >40% (mean 3.7 years). ARBs did not reduce total mortality (RR 1.02 [95% CI 0.93, 1.12]) or total morbidity as measured by total hospitalisations (RR 1.00 [95% CI 0.97, 1.05]) compared with placebo. Withdrawals due to adverse effects were higher with ARBs versus placebo when all patients were pooled irrespective of LVEF (RR 1.06 [95% CI 1.01, 1.12]).

AUTHORS' CONCLUSIONS

In patients with symptomatic HF and systolic dysfunction or with preserved ejection fraction, ARBs compared to placebo or ACEIs do not reduce total mortality or morbidity. ARBs are better tolerated than ACEIs but do not appear to be as safe and well tolerated as placebo in terms of withdrawals due to adverse effects. Adding an ARB in combination with an ACEI does not reduce total mortality or total hospital admission but increases withdrawals due to adverse effects compared with ACEI alone.

Angiotensin II does not affect endothelial tone in Type 1 diabetes-results of a double-blind placebo controlled trial

AIMS

Previously, we have demonstrated that patients with normoalbuminuric Type 1 diabetes are characterized by impaired nitric oxide bioavailability compensated for by increased vasodilatory prostanoid-mediated vasodilation. Experimental evidence suggests vascular responses to endogenous angiotensin II involve the nitric oxide and prostaglandin pathways. We examined whether selective blockade of angiotensin II influences endothelial tone with particular reference to the nitric oxide/prostaglandin pathways in patients with Type 1 diabetes free from vascular complications.

METHODS

At baseline, we studied changes in forearm blood flow in response to brachial arterial infusions of acetylcholine, l-NMMA, a combination of l-NMMA and the cyclo-oxygenase inhibitor indomethacin and nitroprusside in 30 patients with normoalbuminuric Type 1 diabetes [21 male, 9 female; age 38.5 +/- 1.9 years (mean +/- sem)]. Patients were randomized to 2 weeks' treatment with placebo or the selective angiotensin II receptor blocking agent irbesartan, 300 mg, prior to forearm vasoactive responses being re-examined.

RESULTS

The forearm responses to nitroprusside and acetylcholine were unchanged by both placebo (P = 0.23 and P = 0.36, respectively) and irbesartan (P = 0.41 and P = 0.36). Similarily, dose-response curves to acetylcholine in the presense of l-NMMA alone (P = 0.42) and a combination of l-NMMA and indomethacin (P = 0.44) were not altered by angiotensin II blockade.

CONCLUSION

This study demonstrated that physiological blockade of endogenous angiotensin II in Type 1 diabetes does not augment agonist-evoked vasodilation or the contribution of nitric oxides and prostanoids to endothelial tone.

Doxorubicine-congestive heart failure-increased big endothelin-1 plasma concentration: reversal by amlodipine, losartan, and gastric pentadecapeptide BPC157 in rat and mouse

Overall, doxorubicine-congestive heart failure (CHF) (male Wistar rats and NMRI mice; 6 challenges with doxorubicine (2.5 mg/kg, i.p.) throughout 15 days and then a 4-week-rest period) is consistently deteriorating throughout next 14 days, if not reversed or ameliorated by therapy (/kg per day): a stable gastric pentadecapeptide BPC157 (GEPPPGKPADDAGLV, MW 1419, promisingly studied for inflammatory bowel disease (Pliva; PL 10, PLD-116, PL 14736)) (10 microg, 10 ng), losartan (0.7 mg), amlodipine (0.07 mg), given intragastrically (i.g.) (once daily, rats) or in drinking water (mice). Assessed were big endothelin-1 (BET-1) and plasma enzyme levels (CK, MBCK, LDH, AST, ALT) before and after 14 days of therapy and clinical status (hypotension, increased heart rate and respiratory rate, and ascites) every 2 days. Controls (distilled water (5 ml/kg, i.g., once daily) or drinking water (2 ml/mouse per day) given throughout 14 days) exhibited additionally increased BET-1 and aggravated clinical status, while enzyme values maintained their initial increase. BPC157 (10 microg/kg) and amlodipine treatment reversed the increased BET-1 (rats, mice), AST, ALT, CK (rats, mice), and LDH (mice) values. BPC157 (10 ng/kg) and losartan opposed further increase of BET-1 (rats, mice). Losartan reduces AST, ALT, CK, and LDH serum values. BPC157 (10 ng/kg) reduces AST and ALT serum values. Clinical status of CHF-rats and -mice is accordingly improved by the BPC157 regimens and amlodipine.