Role of vasopressin in experimental congestive cardiac failure

The historical evolution of knowledge of the involvement of neurohormonal systems in the pathophysiology and treatment of heart failure

Our knowledge of the pathophysiology of heart failure (HF) underwent profound changes during the 1980s. Once thought to be of exclusively structural origin, HF began to be seen as the consequence of hormonal imbalance. A number of seminal studies were published in that decade focusing on the impact of neurohormonal activation in HF. Presently, eight neurohormonal systems are known to have a key role in HF development: four stimulate vasoconstriction and sodium/water retention (the sympathetic nervous system, the renin-angiotensin-aldosterone system [RAAS], endothelin, and the vasopressin-arginine system), while the other four stimulate vasodilation and natriuresis (the prostaglandin system, nitric oxide, the dopaminergic system, and the natriuretic peptide system [NPS]). These systems are strongly interconnected and are subject to intricate regulation, functioning together in a delicate homeostasis. Disruption of this homeostasis is characteristic of HF. This review explores the historical development of knowledge on the impact of the neurohormonal systems on HF pathophysiology, from the first studies to current understanding. In addition, the therapeutic potential of each of these systems is discussed, and currently used neurohormonal antagonists are characterized. Special emphasis is given to the latest drug approved for use in HF with reduced ejection fraction, sacubitril/valsartan. This drug combines two different molecules, acting on two different systems (RAAS and NPS) simultaneously.

Renal Sympathetic Denervation Improves Cardiac Dysfunction in Rats With Chronic Pressure Overload

Varied causative and risk factors can lead to cardiac dysfunction. Cardiac dysfunction often evolves into heart failure by cardiac remodeling due to autonomic nervous system disturbance and neurohumoral abnormalities, even if the detriment factors are removed. Renal sympathetic nerve activity plays a pivotal regulatory role in neurohumoral mechanisms. The present study was designed to determine the therapeutic effects of renal sympathetic denervation (RSD) on cardiac dysfunction, fibrosis, and neurohumoral response in transverse aortic constriction (TAC) rats with chronic pressure overload. The present study demonstrated that RSD attenuated myocardial fibrosis and hypertrophy, and structural remodeling of the left atrium and ventricle, up-regulated cardiac β adrenoceptor (β-AR, including β1AR and β2AR) and sarco-endoplasmic reticulum Ca2+-ATPase (SERCA) while down-regulated angiotensin II type 1 receptor (AT1R), and decreased plasma B-type natriuretic peptide (BNP), norepinephrine (NE), angiotensin II (Ang II), and arginine vasopressin (AVP) levels in TAC rats with chronic pressure overload. We conclude that RSD attenuates myocardial fibrosis, the left atrial enlargement, and the left ventricular wall hypertrophy; inhibits the overdrive of the sympathetic nervous system (SNS), renin-angiotensin-aldosterone system (RAAS), and AVP system in TAC rats with chronic pressure overload. RSD could be a promising non-pharmacological approach to control the progression of cardiac dysfunction.

Novel Therapies for Heart Failure: Vasopressin and Selective Aldosterone Antagonists

Despite favorable improvements in mortality, heart failure (HF) remains a problematic illness due to the ever-present burden of hospitalization. Clearly, novel treatment strategies are needed. This review focuses on two newer pharmacologic targets: arginine vasopressin and aldosterone. Arginine vasopressin receptor antagonists will most likely serve as an adjunct to or replacement of standard diuretic therapy in selected patients. The safety and efficacy of chronic therapy with oral arginine vasopressin receptor antagonists in large groups of congestive HF patients is currently under investigation. Aldosterone antagonism is emerging as a treatment of severe congestive HF. Recent large-scale clinical trials using aldosterone antagonists have proven that those with HF or left ventricular dysfunction postmyocardial infarction derive a survival benefit from aldosterone antagonism. Whether aldosterone antagonism should be prescribed in all patients with HF is unclear; however, in carefully selected and managed patients, aldosterone antagonism is helpful.

Acute decompensated heart failure: a contemporary approach to pharmacotherapeutic management

Hospital admissions for acute decompensated heart failure (ADHF) have increased precipitously during the past few decades and are projected to continue to increase in the future. To optimize patient outcomes and reduce the costs associated with this disorder, evidenced-based pharmacotherapy is essential. Continuous infusions of loop diuretic therapy rather than bolus dosing may enhance efficacy and reduce the extent of diuretic resistance. Nesiritide is a pharmacologically novel preload and afterload reducer but based on clinical trial evidence should be reserved for those unable to take or with resistance to intravenous nitrate therapy. Catecholamine- and phosphodiesterase-based inotropic therapies are efficacious, but the increased risk of arrhythmogenesis and the potential for negative survival effects limit their use. The experimental agent levosimendan is a positive inotropic agent but does not increase myocyte calcium concentrations as do catecholamines or phosphodiesterase inhibitors. Clinical trial evidence demonstrates a positive survival benefit for levosimendan versus dobutamine.