Publication Committee for the VMAC Investigators (Vasodilatation in the Management of Acute CHF). Intravenous nesiritide vs nitroglycerin for treatment of decompensated congestive heart failure: a randomized controlled trial

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.

Science or fiction: use of nesiritide as a first-line agent?

Nesiritide is an effective agent for the treatment of decompensated CHF. However, the VMAC trial shows that the agent's efficacy and safety are actually more similar than dissimilar to those of nitroglycerin. Indeed, objective reviews have placed nesiritide as a second-line agent behind current standard drug therapy. Finally, nesiritide is approximately 40 times the purchase price of standard agents such as nitroglycerin. For these reasons, we feel that nesiritide should not be considered as first-line therapy. Reflecting this notion, one institution has implemented a protocol that recommends administration of nitroglycerin and intravenous diuretics (using > or = 2 times the usual daily diuretic dose) before using nesiritide. In light of the existing data, we feel that this approach appears to be an appropriate and prudent one for nesiritide's place in therapy.

Epidemiology, pathophysiology, prognosis, and treatment of systolic and diastolic heart failure in elderly patients

American College of Cardiology/American Heart Association class I recommendations for treating patients with heart failure (HF) and abnormal left ventricular ejection fraction are diuretics in patients with fluid retention, an angiotensin-converting enzyme (ACE) inhibitor unless contraindicated, a beta-blocker unless contraindicated, digoxin for the treatment of symptoms of HF, and withdrawal of drugs known to precipitate or aggravate HF such as nonsteroidal anti-inflammatory drugs, calcium channel blockers, and most antiarrhythmic drugs. Class II(a) recommendations for treating HF with abnormal left ventricular ejection fraction are spironolactone in patients with class IV symptoms, preserved renal function, and normal serum potassium; exercise training as an adjunctive approach to improve clinical status in ambulatory patients; an angiotensin receptor blocker in patients who cannot be given an ACE inhibitor because of cough, rash, altered taste sensation, or angioedema; and hydralazine plus nitrates in patients being treated with diuretics, a beta-blocker, and digoxin who cannot be given an ACE inhibitor or an angiotensin receptor blocker because of hypotension or renal insufficiency. Patients with diastolic HF should be treated with cautious use of diuretics and with a beta-blocker. An ACE inhibitor should be added if HF persists or an angiotensin receptor blocker if the patient cannot tolerate an ACE inhibitor because of cough, angioedema, rash, or altered taste sensation. Isosorbide dinitrate plus hydralazine should be added if HF persists. A calcium channel blocker should be added if HF persists. Digoxin should be avoided in diastolic HF if sinus rhythm is present.

B-type natriuretic peptide in ischemic heart disease

B-type natriuretic peptide (BNP) and the N-terminal fragment of its prohormone (N-proBNP) are released from the heart in response to increased wall stress. Assays for these peptides are now commercially available, and measurement of BNP and N-proBNP is becoming commonplace in patients with suspected heart failure. BNP and N-proBNP facilitate diagnosis and risk stratification in patients with heart failure, and may help guide response to therapy. This review focuses on the emerging role of BNP and N-proBNP measurement in patients with acute coronary syndromes (ACS). Although experimental studies demonstrate rapid BNP release in response to cardiac ischemia, it is unlikely that BNP will be used to diagnose cardiac ischemia, because many other conditions are also associated with modest BNP elevation. In contrast, BNP holds tremendous promise as a prognostic marker in patients with ACS. Studies to date have shown consistently that higher BNP levels are associated with worse clinical outcomes, and that BNP provides unique information to clinical variables, other biomarkers, and left ventricular ejection fraction. Future studies are needed to identify the therapeutic implications of BNP elevation in patients with ACS.

Nesiritide (BNP) in the management of postoperative cardiac patients

Recombinant human B-type natriuretic peptide (BNP) is a promising new agent in the management of heart failure. The pharmacologic properties of BNP make it desirable to use in a subset of patients after cardiac surgical operations. Among these therapeutic potentials is the effect on markedly reducing pulmonary vascular resistance and central venous pressure with mild systemic vasodilatation. In addition, BNP directly effects the kidneys to promote natriuresis. We believe this agent to be useful in the treatment of the postcardiac surgery patients with left ventricular dysfunction and mild to moderate renal insufficiency. This report summarizes our experience in 2 patients.

New therapies for the management of acute heart failure

The standard treatment for acute heart failure (synonymous with pulmonary edema) is an upright posture, oxygen, morphine (often accompanied by an antiemetic), and intravenous diuretics. This treatment has remained unchanged for many years, and the precise mechanism by which each of these methods alleviates symptoms in patients is unclear. Nitrates, oral or intravenous, are also used with benefit, and have some hemodynamic advantages over intravenous diuretics. Recently, three new forms of treatment have been investigated. The use of milrinone, a phosphodiesterase inhibitor, for exacerbation of heart failure in patients with a background of chronic heart failure was not advantageous. The trials of levosimendan, a calcium sensitizer, in patients with pulmonary edema hinted at benefit. Nesiritide, a formulation of brain natriuretic peptide, does bring about hemodynamic improvement in acute heart failure, and is at least as effective as nitroglycerin, easier to prescribe, but prone to cause hypotension. These are small but important advances that increase our knowledge of the pathophysiology of acute heart failure, and also provide an indication of which drugs are preferable for the treatment of this distressing condition.

Severely increased blood pressure in the emergency department

Patients with severely increased blood pressure often present to the emergency department. Emergency physicians evaluate and treat hypertension in various contexts, ranging from the compliant patient with well-controlled blood pressure to the asymptomatic patient with increased blood pressure to the critically ill patient with increased blood pressure and acute target-organ deterioration. Despite extensive study and national guidelines for the assessment and treatment of chronically increased blood pressure, there is no clear consensus on the acute management of patients with severely increased blood pressure. In this article, we examine the broad spectrum of disease, from the asymptomatic to critically ill patient, and the dilemma it creates for the emergency physician in deciding how and when in the process to intervene.

Evaluation of pulmonary hypertension in heart transplant candidates

Assessment of the pulmonary circulation and right ventricular function is a cornerstone in the evaluation of the patient as a potential heart transplant recipient. The importance of pulmonary hypertension is linked to outcomes in the posttransplant period. Preoperative pulmonary vascular resistance is an independent risk factor for early death after heart transplantation. Pulmonary hypertension can be classified as reversible, or irreversible if not rapidly responsive to pharmacologic maneuvers. However, in most patients, the major component is likely to reverse with vasodilators, because of the central role played by the endothelium in the control of pulmonary vascular tone. To discriminate between patients with reversible and irreversible pulmonary hypertension, provocative therapies are used, and baseline and the postprovocation hemodynamic parameters are measured. To date, there is no reliable hemodynamic threshold beyond which right ventricular failure is certain to occur, nor are there values below which right ventricular failure is always avoidable. Because of this uncertainty, it becomes clear that only through careful preoperative assessment can this life-threatening condition be recognized preoperatively and, hence, managed in the posttransplant recovery period.

Nesiritide (Natrecor): a new treatment for acutely decompensated congestive heart failure

The care of the patient experiencing acutely decompensated congestive heart failure requires therapies that promote vasodilation and increase cardiac output while decreasing symptomatic hypotension and dysrhythmias. Nesiritide (Natrecor) is a new type of drug, recombinant human B-type natriuretic peptide (hBNP), approved for use in acutely decompensated congestive heart failure. The neurohormonal effects of endogenous BNP are reproduced by nesiritide. Indications, dosing, administration, and review of clinical trials are presented in this article.

Effect of nesiritide (B-type natriuretic peptide) and dobutamine on ventricular arrhythmias in the treatment of patients with acutely decompensated congestive heart failure: the PRECEDENT study

BACKGROUND

Dobutamine is commonly used as a means of treating decompensated congestive heart failure (CHF). Although typically effective at improving short-term hemodynamics and symptomatology, the frequent occurrence of arrhythmias and tachycardia is undesirable. In this randomized, multicenter trial, we compared the safety and clinical effectiveness of the cardiac hormone nesiritide (human B-type natriuretic peptide) with dobutamine in hospitalized patients with decompensated CHF.

METHODS

The study population consisted of 255 patients who were randomized to 1 of 2 doses of intravenous nesiritide (0.015 or 0.03 microg/kg/min) or dobutamine (> or =5 microg/kg/min) and stratified by means of an earlier history of ventricular tachycardia. Patients were also assessed with 24 hour Holter recordings immediately before and during study drug therapy and by means of signs and symptoms of CHF.

RESULTS

Dobutamine significantly increased the mean (1) number of ventricular tachycardia events per 24 hours by 48 +/- 205 (P =.001), (2) repetitive ventricular beats per hour by 15 +/- 53 (P =.001), (3) premature ventricular beats per hour by 69 +/- 214 (P =.006), and (4) heart rate by 5.1 +/- 7.7 beats per minute (P <.001). These end points were significantly decreased or unchanged in the nesiritide groups. Nesiritide did not increase heart rate, despite a greater reduction of blood pressure. Both drugs were similarly effective means of improving signs and symptoms of CHF.

CONCLUSIONS

Dobutamine is associated with substantial proarrhythmic and chronotropic effects in patients with decompensated CHF, whereas nesiritide actually reduces ventricular ectopy or has a neutral effect. Compared with dobutamine, nesiritide may be a safer, short-term treatment for patients with decompensated CHF.

"BNP" for heart failure: role of nesiritide in cardiovascular therapeutics

B-type natriuretic peptide, or nesiritide, recently gained US Food and Drug Administration approval as the first new parenteral agent approved for heart failure therapy in more than a decade. Nesiritide refers to a peptide identical to endogenous B-type natriuretic peptide, currently manufactured by recombinant DNA technology. Nesiritide has been evaluated in clinical trials involving more than 700 subjects. The drug produces a prompt fall in systemic vascular resistance and pulmonary capillary wedge pressure, associated with rapid clinical improvement in decompensated heart failure. Nesiritide represents an attractive choice for first-line therapy of acutely decompensated heart failure patients. In this review, the authors summarize the currently available data regarding the use of nesiritide, and offer recommendations for its use based on our experience with the compound in clinical trials.