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Query: UMLS:C0018801 (heart failure)
 72,216 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Functional angiotensin II receptors have been documented in cardiac fibroblasts as well as an intracardiac aldosterone system that responds to short- and long-term physiological stimuli. In vitro, angiotensin II increased cardiac fibroblast-mediated collagen synthesis and mRNA levels of collagen type I, type III, pro-alpha1 (I) collagen, pro-alpha1 (III) collagen and fibronectin, and inhibited matrix metalloproteinase I activity. The angiotensin II-stimulated secretion and expression of collagen was completely abolished by AT1 receptor antagonism, but not affected by AT2 receptor antagonism. In vivo, chronic infusion of angiotensin II increased the collagen volume fraction in the ventricles. Angiotensin-converting enzyme (ACE) inhibition and AT1 receptor antagonism, but not AT2 receptor antagonism, reduced collagen deposition in the myocardium in spontaneously hypertensive rats and in rat myocardium following myocardial infarction. During chronic aldosterone infusion in uninephrectomized rats on a high-salt diet, a marked accumulation of interstitial and to a lesser extent perivascular collagen occurs in the heart in both ventricles. The cardiac fibrosis in this aldosterone model is prevented by spironolactone. During the continuous infusion of aldosterone in the rat, the appearance of fibrosis was delayed and started 4 weeks after the beginning of the infusion, which argues against a direct effect of aldosterone. The mechanism of aldosterone-salt-induced cardiac fibrosis possibly involves angiotensin II acting through upregulated AT1 receptors and the cardiac AT1 receptor is the target for aldosterone. An accumulation of collagen in the heart has also been found in patients with adrenal adenomas and during chronic activation of the renin-angiotensin-aldosterone system such as in surgically-induced unilateral renal ischemia, unilateral renal artery banding or renovascular hypertension. Spironolactone prevents aortic collagen accumulation in spontaneously hypertensive rats. In patients with stable chronic heart failure, spironolactone treatment in addition to diuretics and ACE inhibition reduced circulating levels of procollagen type III N-terminal aminopeptide. Also, in the Randomized Aldactone Evaluation Study, spironolactone coadministered with conventional therapy of ACE inhibitors, loop diuretics and digitalis in patients with symptomatic heart failure defined as NYHA classes III-IV, reduced total mortality by 30%.
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PMID:Role of intracardiac renin-angiotensin-aldosterone system in extracellular matrix remodeling. 1457 Dec 85

In most countries the last two decades have seen a very substantial rise in the prevalence of heart failure, and in a majority of patients hypertension is both an antecedent condition and a contributing cause. Heart failure is also a major cause of hospital admissions; its amelioration and, as far as possible, prevention is therefore important in terms not only of morbidity and premature mortality for the individual patient, but also containment of healthcare costs. Over the past 5 years, mineralocorticoid receptor (MR) antagonists have been used in two major outcome trials (the Randomized Aldactone Evaluation Study [RALES] with spironolactone, and the Eplerenone Post-AMI Heart Failure Efficacy and Survival Study [EPHESUS]), in severe (New York Heart Association class III) and post-myocardial infarct heart failure, respectively. Experimental studies have largely focused, however, on various animal models of hypertension; on the basis of a portfolio of clinical studies on the efficacy of eplerenone, administered either alone and in combination as an antihypertensive agent, the novel MR antagonist was approved by the FDA for the treatment of hypertension, though it has yet to be launched. In this review, the two major outcome studies (RALES, EPHESUS) are discussed in the context of the new biology of aldosterone action. The relevance to heart failure of current experimental studies, largely on vascular protection, will also be discussed.
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PMID:The role of mineralocorticoid receptor antagonists in the treatment of cardiac failure. 1464 Sep 40

Aldosterone has a variety of detrimental effects on the heart and vasculature and is increasingly recognized as an important target in chronic heart failure, as illustrated by the Randomized Aldactone Evaluation Study. In this article, the evidence supporting the cardiovascular effects of aldosterone in humans and the proven benefits of aldosterone-receptor antagonists in heart failure shall be discussed.
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PMID:The role of aldosterone in heart failure and the clinical benefits of aldosterone blockade. 1503 11

Heart failure is a clinical syndrome that may result from different disease states or conditions that injure the myocardium. The activation of circulating neurohormones, particularly aldosterone, may play a pivotal role in left ventricular (LV) remodelling. The Randomized Aldactone Evaluation Study and Eplerenone Post-Acute Myocardial Infarction Heart Failure Efficacy and Survival trial have emphasised the clinical importance of aldosterone. This review addresses some of the proposed mechanisms of LV remodelling in heart failure.
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PMID:Aldosterone and cardiovascular remodelling: focus on myocardial failure. 1513 67

Half a century after the elucidation of its molecular structure, aldosterone is generating the greatest interest, not in the fields of endocrinology or renal medicine but in cardiology-where aldosterone over-activation is now perceived as detrimental in heart failure (HF) and ischaemic heart disease. Clinically, excess aldosterone is associated with higher morbidity and mortality after myocardial infarction (MI) and HF. The Randomised Aldactone Evaluation Study (RALES) study in severe chronic heart failure and the Eplerenone Post-Acute Myocardial Infarction Heart Failure Efficacy and Survival (EPHESUS) study in post-MI heart failure have shown that use of non-selective and selective aldosterone receptor antagonists, respectively, improves prognosis. The pathophysiological mechanisms underpinning these damaging aldosterone-mediated cardiovascular effects are still being elucidated, but prime candidates include cardiomyocyte necrosis and apoptosis, and myocardial fibrosis resulting in adverse cardiac remodelling, coronary vasculopathy, tachyarrhythmia and positive feedback activation of the renin-angiotensin-aldosterone system. Practical points for consideration when instigating therapy include preferential use of aldosterone receptor antagonists to maintain electrolyte balance whenever loop or thiazide diuretics are used (vulnerable HF patients require higher ranges of potassium and magnesium to minimise propensity for tachyarrthythmia), for renoprotection and for counteracting aldosterone breakthrough despite adequate ACE inhibition; use of the minimum doses of loop diuretics required to lessen activation of the renin-angiotensin-aldosterone system in HF; use of selective aldosterone receptor antagonists to avoid gynaecomastia/mastalgia and impotence; and prophylactic use of aldosterone receptor antagonists to improve prognosis.
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PMID:Fiftieth anniversary of aldosterone: from discovery to cardiovascular therapy. 1531 May 30

Aldosterone production in the heart as well as aldosterone plasma levels are increased after myocardial infarction and in congestive heart failure, correlating with the severity of disease. Aldosterone promotes sodium and water retention, sympathoadrenergic activation, endothelial dysfunction, and cardiovascular fibrosis and hypertrophy. Even maximally recommended doses of ACE inhibitors do not completely prevent formation of aldosterone. The Randomized Aldactone Evaluation Study (RALES) and the Eplerenone Post acute myocardial infarction Heart failure Efficacy and SUrvival Study (EPHESUS) demonstrated that aldosterone receptor blockade markedly reduces mortality among patients with heart failure. This review summarizes recent clinical and experimental data on the effect of aldosterone antagonists on left ventricular remodeling and function in ischemic heart failure with special emphasis on potential underlying mechanisms. While reduction of excessive extracellular matrix turnover leading to decreased fibrosis appears to be the most important effect of mineralocorticoid receptor antagonism in heart failure, other mechanisms such as regression of hypertrophy, improvement of endothelial function, reduction of superoxide formation, and enhanced renal sodium excretion may contribute. Recent data showed that in rats with left ventricular dysfunction after extensive myocardial infarction, eplerenone on top of ACE inhibition more effectively improved cardiac remodeling and molecular alterations than ACE inhibition alone.
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PMID:Mineralocorticoid receptor antagonism and cardiac remodeling in ischemic heart failure. 1532 Jul 79

Several case series published after the Randomized Aldactone Evaluation Study (RALES) have focused on the adverse effects of spironolactone when prescribed to participants not in a trial and the appropriateness of these prescribing practices; however, there is a paucity of data on potential benefits in patients not in a trial. Therefore, we examined data from a prospective cohort study of 1,037 patients with heart failure seen at the University of Alberta Heart Function Clinic. Median age was 69 years, 66% were men, 75% had systolic dysfunction, and mean ejection fraction was 33%. Only 40% of the 136 patients prescribed spironolactone had New York Heart Association class III or IV symptoms, and <25% fulfilled all of the RALES eligibility criteria. Mean daily dose of spironolactone was 23.9 mg; 25% of patients had spironolactone withdrawn after initiation, mostly due to increases in potassium and/or creatinine (9%), gynecomastia (5%), or dehydration/hyponatremia (6%). Only 1 of our spironolactone-treated patients developed serum potassium >6 mmol/L. Cox's proportional hazards analysis confirmed the association between use of spironolactone and increased survival rate (relative risk 0.09, 95% confidence interval 0.02 to 0.39), even though 78% of our patients did not fulfill the RALES eligibility criteria. Thus, although the complication rate was higher, the benefits of spironolactone seen in RALES extended to participants not in a trial who were treated with similar doses and followed closely in a clinic specializing in heart failure.
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PMID:Usefulness of spironolactone in a specialized heart failure clinic. 1532 26

Aldosterone plays a key role in the pathophysiology of heart failure. Angiotensin converting enzyme inhibitors and angiotensin II receptor blockers may not suppress aldosterone production in the long term. This allows aldosterone to exert its effects on myocardial fibrosis and cardiac remodelling, endothelial function, electrolytes and baroreceptor response. The Randomized Aldactone Evaluation Study (RALES) tested spironolactone against placebo in patients with severe heart failure. The study found a 30% reduction in the risk of death among patients treated with spironolactone and a 31% reduction in the risk of death from cardiac causes. Patients in the spironolactone group had significantly lower risks of death from progression of heart failure and sudden cardiac death. The Eplerenone Post-Acute Myocardial Infarction Heart Failure Efficacy and Survival Study (EPHESUS) investigated the effects of eplerenone against placebo in patients with myocardial infarction complicated by left ventricular dysfunction. Compared to placebo, the relative risk of death from any cause was 0.85 in eplerenone-treated patients, and the relative risk of death or hospitalisation for cardiovascular events was 0.87. The reduction in the risk of sudden death from cardiac causes was statistically significant. In conclusion, aldosterone blockade should form part of optimal therapy for patients with heart failure.
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PMID:Aldosterone blockade in heart failure. 1552 39

The two major outcome trials on the combination of angiotensin-converting enzyme (ACE) inhibitors and mineralocorticoid receptor (MR) antagonists in heart failure are RALES (Randomized Aldactone Evaluation Study) and EPHESUS (Eplerenone Post-Acute Myocardial Infarction Heart Failure Efficacy and Survival Study). There have also been studies in essential hypertension, and in diabetic hypertensive patients, on the cardiac and renal effects of ACE inhibitors and MR antagonists, individually and in combination. In the clinical studies on heart failure, in outcome trials and the smaller studies using surrogate end points, a combination of ACE inhibition and MR blockade is superior to ACE inhibition alone, and in the hypertension studies to either agent alone. Some insight into their distinct sites of protective action may be gained from studies on experimental animal preparations. The principal caveat in the use of combination therapy is the possibility of hyperkalemia, which should be minimal in patients with creatine clearance greater than 30 mL/min and with the low doses of MR antagonist shown to be effective in outcome trials.
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PMID:ACE inhibitors and mineralocorticoid receptor blockade in patients with congestive heart failure. 1566 15

1. Mineralocorticoid receptor (MR) antagonism with spironolactone reduces mortality in heart failure on top of ACE inhibition. To investigate the underlying mechanism, we compared the actions of both aldosterone and spironolactone to those of angiotensin (Ang) II in the rat heart. 2. Hearts of male Wistar rats were perfused according to Langendorff. Ang II and aldosterone increased left ventricular pressure (LVP) by maximally 11+/-4 and 9+/-2%, and decreased coronary flow (CF) by maximally 36+/-7 and 20+/-4%, respectively. Spironolactone did not significantly affect LVP or CF. 3. In hearts that were exposed to a 45-min coronary artery occlusion and 3 h of reperfusion, a 15-min exposure to spironolactone prior to occlusion reduced infarct size (% of risk area) from 68+/-2 to 45+/-3%, similar to the reduction (34+/-2%) observed following 'preconditioning' (15 min occlusion followed by 10 min reperfusion) prior to the 45-min occlusion. Aldosterone exposure did not affect infarct size (71+/-5%). 4. In cardiomyocytes, aldosterone decreased [(3)H]thymidine incorporation maximally by 73+/-3%, whereas in cardiac fibroblasts it decreased [(3)H]proline incorporation by 33+/-7%. Spironolactone inhibited both effects. Ang II increased DNA and collagen synthesis, and these effects were reversed by aldosterone. 5. In conclusion, aldosterone induces positive inotropic and vasoconstrictor effects in a nongenomic manner, and these effects are comparable to those of Ang II. Aldosterone reduces DNA and collagen synthesis via MR activation, and counteracts the Ang II-induced increases in these parameters. MR blockade reduces infarct size and increases LVP recovery following coronary artery occlusion. The MR-related phenomena may underlie, at least in part, the beneficial actions of spironolactone in heart failure.
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PMID:Genomic and nongenomic effects of aldosterone in the rat heart: why is spironolactone cardioprotective? 1583 44


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