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Commencing Volume 19, Issue 1, MedReviews has ceased the publication of this journal. Reviews in Cardiovascular Medicine will continue to be published by IMRPress, Ltd. (www.imrpress.org)

Volume 3, Supplement 4, 2002

Volume 3, Supplement 4, 2002

Table of Contents

Acutely Decompensated Heart Failure: Opportunities to Improve Care and Outcomes in the Emergency Department
Each year about 550,000 new patients are diagnosed as having congestive heart failure, which for acutely symptomatic patients is also referred to as acutely decompensated heart failure. The incidence of congestive heart failure is approximately 10 per 1000 for Americans over the age of 65 years. Men and women are affected in equal numbers, and 5-year mortality has been reported to be as high as 50%. Increased longevity increases the likelihood that heart failure will develop as a consequence of pathophysiologic processes that gradually weaken the myocardium and the vascular system. Patients who present to the emergency department with complaints of shortness of breath, dyspnea on exertion, increasing lower extremity edema, and/or worsening fatigue should have heart failure included in the differential diagnosis. Heart failure patients experiencing symptoms consistent with cardiac ischemia, hypoxia, potentially lethal arrhythmias, marked hypertension, or hypotension should be immediately triaged to a critical care area. The approval of nesiritide by the U.S. Food and Drug Administration in 2001 has stimulated the development of revisions in strategies for the emergency department treatment of acute decompensated heart failure patients. The early use of nesiritide, along with topical nitroglycerin and a loop diuretic, may lead to more rapid resolution of these patients’ acute symptoms and hemodynamic dysfunction. [Rev Cardiovasc Med. 2002;3(suppl 4):S3–S9]
B-Type Natriuretic Peptide Measurements in Diagnosing Congestive Heart Failure in the Dyspneic Emergency Department Patient
For the acutely ill patient presenting to the emergency department with dyspnea, an incorrect diagnosis could place the patient at risk for both morbidity and mortality. The stimulus for B-type natriuretic peptide (BNP) release is a change in left-ventricular wall stretch and volume overload. A rapid, whole-blood BNP assay (Triage BNP Test, Biosite Inc, San Diego, CA) that allows quick evaluation of the dyspneic patient has recently been approved by the U.S. Food and Drug Administration. Preliminary research with this test set the stage for the recently completed “Breathing Not Properly” BNP Multinational Study, a seven-center, prospective study of 1586 patients who presented to the emergency department with acute dyspnea and had BNP measured with a point-of-care assay upon arrival. BNP was accurate in making the diagnosis of congestive heart failure (CHF), and levels correlated to severity of disease. Knowledge of BNP levels could have reduced clinical indecision by 74%. Algorithms are being developed for use in the emergency department that take into account other illnesses that might raise BNP levels. BNP levels should be extremely important in ruling out and diagnosing decompensated CHF, as long as baseline “euvolemic” BNP values are known. Finally, in addition to helping assess whether a dyspneic patient has heart failure, BNP levels may also be useful in making both triage and management decisions. [Rev Cardiovasc Med. 2002;3(suppl 4):S10–S17]
Pharmacologic Therapies for Acutely Decompensated Heart Failure
The management of acutely decompensated heart failure in the emergency medical setting poses a major clinical challenge. Acutely decompensated heart failure is characterized by hemodynamic abnormalities and neuroendocrine activation that contribute to heart failure symptoms, end-organ dysfunction, arrhythmias, and progressive cardiac failure. The therapeutic goals in patients presenting with acutely decompensated heart failure are to stabilize the patient, reverse acute hemodynamic abnormalities, rapidly reverse dyspnea and/or hypoxemia caused by pulmonary edema, and initiate treatments that will decrease disease progression and improve survival. Pharmacologic therapies to impact the hemodynamic abnormalities and symptoms in patients with acutely decompensated heart failure include diuretics, inotropic agents, vasodilators, and natriuretic peptides. In patients with acutely decompensated heart failure, it has recently been demonstrated that elevation in left ventricular filling pressure is the hemodynamic abnormality that most directly impacts heart failure symptoms and is highly predictive of increased risk of fatal decompensation and sudden death. Measures of systemic perfusion, arterial pressure, and vascular resistance have not been predictive of symptoms or clinical outcomes. An ideal agent for acute decompensated heart failure would be one that rapidly reduces pulmonary wedge pressure, results in balanced arterial and venous dilation, promotes natriuresis, lacks direct positive inotropic effects, and does not result in reflex neuroendocrine activation. [Rev Cardiovasc Med. 2002;3(suppl 4):S18–S27]
Safety and Efficacy of Nesiritide for the Treatment of Decompensated Heart Failure
Nesiritide, the commercially available form of B-type natriuretic hormone, improved the overall clinical status of patients with acutely decompensated congestive heart failure and several indicators of cardiovascular function in randomized trials. In a trial comparing it to a variety of other agents, efficacy was similar, but fewer patients receiving nesiritide required intravenous diuretics. Nesiritide was associated with significantly lower 6-month mortality than dobutamine, which was found to be more proarrhythmic in an open-label trial. Nesiritide also caused a faster and greater improvement in pulmonary capillary wedge pressure than intravenous nitroglycerin. Adverse effects for nesiritide are generally lower than for other vasoactive agents used for heart failure. The primary adverse effect, hypotension, is dose related and causes symptoms in only about 4% of patients at the current recommended dose. Other side effects are minor or occur infrequently. [Rev Cardiovasc Med. 2002;3(suppl 4):S28–S34]
Role of Noninvasive Ventilation in the Management of Acutely Decompensated Heart Failure
Over the past decade, there have been a number of studies of the use of noninvasive ventilation (NIV) in patients with respiratory failure, including that associated with acute congestive heart failure (CHF). Many of these studies have focused on using NIV in an effort to avoid endotracheal intubation, with its associated complications and costs. Most studies have been small, retrospective, and not well focused on the CHF population. As a result, clinical use of NIV in a setting of severe CHF has been controversial and recommendations mixed; however, most studies support a beneficial role for NIV in patients with acute cardiogenic pulmonary edema. Its use is associated with lower endotracheal intubation rates and possibly lower mortality. This article describes two NIV modalities, continuous positive airway pressure (CPAP) and bi-level positive airway pressure (BLPAP), and compares their efficacy. Though BLPAP has theoretical advantages over CPAP, there are questions regarding its safety in a setting of CHF. The key to success in using NIV to treat severe CHF is proper patient selection, close patient monitoring, proper application of the technology, and objective therapeutic goals. When used appropriately, NIV can be a useful adjunct in the treatment of a subset of patients with acute CHF at risk for endotracheal intubation. [Rev Cardiovasc Med. 2002;3(suppl 4):S35–S40]
Rapid Optimization: Strategies for Optimal Care of Decompensated Congestive Heart-Failure Patients in the Emergency Department
Sooner or later all heart failure patients will present to the emergency department for medical attention. The American demographic trend of a skyrocketing elderly population coupled with the current heart-failure epidemic means that strategies optimizing emergency department care of heart failure are needed. Safe and effective management has the potential to decrease hospitalizations and intensive care unit admissions, prevent readmissions, and improve the quality of life in the heart-failure patient, as well as relieving some of the economic burden of heart-failure management from the U.S. medical care system. The emergency department observation unit provides a successful venue for the management of decompensated heart failure, and nesiritide offers the promise of shorter hospitalizations, improved quality of life, and better symptom resolution than standard therapy. [Rev Cardiovasc Med. 2002;3(suppl 4):S41–S48]