Withdrawal of digoxin from patients with chronic heart failure treated with angiotensin-converting-enzyme inhibitors. RADIANCE Study

Effect of aging on the incidence of digoxin toxicity

OBJECTIVE

To evaluate the relationship of the therapeutic serum digoxin concentration (SDC) range (0.5-2 ng/mL, as recommended in previous clinical studies) with the incidence of digoxin toxicity during digoxin maintenance therapy.

METHODS

Subjects included all inpatients (n = 462) and outpatients (n = 437) receiving digoxin oral maintenance therapy for heart failure and/or atrial fibrillation with tachycardia at Kosei Hospital, Anjo, Japan. SDC and blood chemistry analysis were determined, and a 24-hour Holter electrocardiographic recording was performed when the SDC was at the presumed steady-state concentration.

RESULTS

Analysis of clinical data showed that there was an overlapping (toxic and nontoxic) range of SDCs in which the incidence of digoxin toxicity was patient-dependent (1.4-2.9 ng/mL). No patient exhibited signs or symptoms of digoxin toxicity when the SDC was <1.4 ng/mL; all patients had evidence of toxicity when the SDC was >3 ng/mL. Additionally, it was shown that the concentration range of this overlapping range tended to broaden and shift to lower concentrations with increasing age. Patients with signs of toxicity when their SDCs were in the overlapping range had normal serum creatinine, blood urea nitrogen, digoxin clearance, creatinine clearance, and potassium concentrations, except for a significantly higher mean age than patients without toxicity. The incidence of digoxin toxicity was dependent on increasing age in patients whose SDCs were within the recommended therapeutic range. Moreover, clinical evidence of digoxin toxicity in patients >71 years old was 26.5%, despite their SDCs falling between 1.4 and 2 ng/mL.

CONCLUSIONS

Increased age is most likely associated with enhanced susceptibility to digoxin toxicity, possibly due to unknown pharmacodynamic changes. This raises the possibility that patients >71 years show clinical evidence of digoxin toxicity despite having SDCs within the recommended therapeutic range.

Defibrillators in nonischemic cardiomyopathy treatment evaluation

The Defibrillators in Nonischemic Cardiomyopathy Treatment Evaluation (DEFINITE) is a multicenter randomized trial. Patients will have nonischemic cardiomyopathy (LVEF < or = 35%), a history of symptomatic heart failure and spontaneous arrhythmia (> 10 PVCs/hour or nonsustained ventricular tachycardia defined as 3-15 beats at a rate of > 120 beats/min) on Holter monitor or telemetry within the past 6 months. Patients will be randomized to an implantable cardioverter defibrillator (ICD) versus no ICD. All patients will receive standard oral medical therapy for heart failure including angiotensin converting enzyme inhibitors and beta-blockers (if tolerated). Patients will be followed for 2-3 years. The primary endpoint will be total mortality. Quality-of-life and pharmacoeconomics analyses will also be performed. A registry will track patients who meet basic inclusion criteria but are not randomized. We estimate an annual total mortality of 15% at 2 years in the treatment arm that does not receive an ICD. The ICD is expected to reduce mortality by 50%. Approximately 204 patients will be required in each treatment group. Twenty-five centers will be included in a trial designed to last an estimated 4 years.

Optimising management of patients with advanced heart failure: the importance of preventing progression

Heart failure is a highly complex, progressive and deadly disease. When incorrectly treated, it results in irreversible structural damage to the myocardium and resists any conventional treatment. This stage has been arbitrarily termed refractory heart failure. However, with timely and sufficiently applied neurohumoral antagonists, progression can be prevented, or at least delayed. In contrast, as soon as heart failure has become moderate or severe due to advanced left ventricular dysfunction, polypharmacy is the rule. Physicians should make every effort to maintain or reconsider optimal neurohumoral antagonist therapy in such patients, even if symptomatic improvement from these agents may be slow. Proper use of diuretics is essential not only for symptom relief but also to achieve full benefit from angiotensin converting enzyme inhibitors and beta-blockers. Digitalis may be particularly indicated in severe heart failure, irrespective of rhythm. Adjunctive regimens can be helpful in specific patients, but evidence of their salutary effects to prolong life is lacking. In the decompensated state, tailoring intravenous therapy to haemodynamic goals followed by (re-)institution of optimal oral therapy is an option. Only if these strategies fail is heart transplantation justified. While waiting for a donor, patients have been bridged with various intravenous agents, most often inotropes, but symptom relief is associated with risk of increased mortality due to these drugs. New hope emerges from drugs interfering with endothelin and the cytokines, and from research into increasing contractility with calcium sensitising agents. Even though these developments follow established routes, they may enable a more effective approach to prevent worsening heart failure in every single patient.

Cardiac afferents and neurohormonal activation in congestive heart failure

Cardiac chambers have afferent connections to the brainstem and to the spinal cord. Vagal afferents mediate depressor responses and become activated by volume expansion, increased myocardial contractility and atrial natriuretic factor. Sympathetic afferents, on the contrary, are activated by metabolic mediators, myocardial ischemia and cardiac enlargement. These opposite behaviors may lead to activation or suppression of the sympathetic nervous system and of the renin-angiotensin-aldosterone system. As cardiac diseases progress, the heart dilates, plasma norepinephrine increases, atrial natriuretic factor is released and the renin-angiotensin-aldosterone system is suppressed to maintain water and sodium excretion. This dissociation of the neurohormonal profile of cardiac patients, may be explained by coactivation of sympathetic afferents, by cardiac dilatation, and of vagal afferents by atrial natriuretic factor. In more advanced stages, atrial natriuretic factor suppression of the renin-angiotensin-aldosterone system is overridden by overt sympathetic activation and sodium and water retention ensues. Digitalis, angiotensin-converting enzyme inhibitors and beta-blockers selectively decrease cardiac adrenergic drive. A common mechanism of action, to all three groups of drugs, would be attenuation of sympathetic afferents and partial normalization of vagal afferents. Consequently, heart size and cardiac afferents emerge as the key factors to understand the pathophysiology and treatment of the syndrome of congestive heart failure.

New advances in the pharmacological management of chronic heart failure

The management of heart failure has evolved in parallel with advances in the understanding of the disease process. Inotropes and diuretics are used to combat pump failure and fluid overload. While no convincing data has emerged regarding the long-term safety of inotropes, new exciting data concerning the role of diuretics, especially aldactone, has led to a renewed interest in this class of drug therapy. Angiotensin converting enzyme inhibitors (ACE inhibitors) were noted to not only affect symptomatology but also decrease mortality by interfering with the renin-angiotensin-aldosterone system. Recent research has focused on more complete blockade of the renin-angiotensin system than that achieved with ACE inhibitors alone with the addition of direct angiotensin II receptor blockers. This new class of drugs may become not only a reasonable alternative to ACE inhibitors in patients intolerant of the drug but also a possible addition to ACE inhibitors in the battle to prevent progression of remodelling and disease. beta-blockers are the most exciting new class of drugs used to combat heart failure. They appear not only to combat the remodelling process that occurs in the progression of disease but also other pathological events such as apoptosis and cellular oxidation. New medical therapies currently being investigated include novel agents such as endothelin antagonists, natriuretic peptides, vasopressin antagonists and anticytokine agents--all part of a new era in drug management of heart failure that has evolved with continued advances in the understanding of chronic heart failure (CHF).

Surviving heart failure: Robert L. Frye lecture

Heart failure is increasing in both incidence and prevalence and is associated with a high mortality. In patients with heart failure, coronary artery disease is the cause for about two thirds. Pathophysiologic changes have been linked to altered muscle function and hemodynamics, elevated neurohormones, and, more recently, cellular mechanisms, including apoptosis. Standard triple therapy for symptomatic heart failure consists of an angiotensin-converting enzyme (ACE) inhibitor, digoxin, and a diuretic. In patients with severe heart failure, spironolactone should be added. In large clinical trials, ACE inhibitors, spironolactone, and beta-blockers have reduced mortality. Other drugs may be helpful in the treatment of heart failure. Amiodarone is the antiarrhythmic drug of choice in patients with symptomatic arrhythmias and also has a role in the treatment of dilated cardiomyopathy. Angiotensin II receptor blockers are being compared with ACE inhibitors and appear promising. Newer agents being tested include antagonists to endothelin and tumor necrosis factor. Overall, it is clear that polypharmacy is the standard of care for patients with heart failure. A future challenge will be to prevent heart failure from occurring.

Therapeutic range of digoxin's efficacy in heart failure: what is the evidence?

Clinical studies have solidified the utility of digoxin in patients with left ventricular dysfunction and normal sinus rhythm. No definitive data have been published to clarify the range of serum digoxin concentrations associated with clinical benefit. The traditional therapeutic range of 0.8-2.0 ng/ml was developed originally to classify digoxin toxicity, not efficacy. In addition, this reference range was used before publication of the Digitalis Investigators Group trial. Clinical and neurohormonal studies have attempted to characterize serum concentrations that are associated with clinical efficacy.

Chronic Heart Failure

Physicians must aggressively treat heart failure in the early stages to prevent disease progression and improve survival. Early treatment implies early diagnosis of left ventricular (LV) dysfunction, before the onset of symptoms. Patients with risk factors for the development of heart failure, especially coronary disease or hypertension, should undergo echocardiography to evaluate LV function. Patients with LV systolic dysfunction should be further evaluated to determine the type of cardiac dysfunction, uncover correctable etiologic factors, determine prognosis, and guide treatment. Angiotensin-converting enzyme (ACE) inhibitors and beta-adrenergic blocking drugs improve survival and are integral to the treatment plan. Physicians should prescribe an ACE inhibitor as initial therapy for all patients with LV systolic dysfunction unless there are specific contraindications. The combination of hydralazine and isosorbide dinitrate is an acceptable alternative therapy for patients who cannot take ACE inhibitors. Diuretics should be used if there are signs or symptoms of volume overload. Beta-adrenergic blocking drugs should be added to therapy in stable patients with mild to moderate heart failure after optimal treatment with ACE inhibitors, diuretics, or other vasodilators. Digoxin should be used routinely in patients with severe heart failure and should be added to therapy in patients with mild to moderate heart failure who remain symptomatic despite optimal doses of ACE inhibitors and diuretics. Spironolactone should be added, but electrolytes should be closely monitored. Warfarin anticoagulation should be considered in patients with a left ventricular ejection fraction (LVEF) of 35% or less. Until survival data exist, angiotensin receptor blockers (ARBs) should not be used as initial therapy or as sole therapy but can be used for ACE-intolerant patients or can be added to standard heart failure therapy. Outpatient use of intravenous inotropic therapy should be avoided. Patients with severe heart failure should have peak oxygen consumption measured to quantify functional impairment, determine prognosis, and identify the need for advanced heart failure therapy. Patients who remain symptomatic while receiving optimal standard therapy should be referred early to a specialized heart failure center.

Nonischemic heart failure: epidemiology, pathophysiology, and progression of disease

The prevalence of nonischemic heart failure including idiopathic dilative cardiomyopathy is not well known. It may vary considerably in different population sub-groups and geographic areas. In ambulatory and hospitalized patients with clinically manifest heart failure primary cardiomyopathy is diagnosed in 2-15%, while in recent large scale therapeutic trials the proportion of patients with nonischemic heart failure ranged from 18% to 53%. There is a relation between sex, age and etiology of chronic heart failure, nonischemic cardiomyopathy being more frequent in women and in younger individuals. In contrast to ischemic heart failure, where the severity usually correlates with the extent of coronary artery lesions, the pathophysiology of cardiomyopathy is less clear. Genetic factors, myocarditis from infectious agents, auto-immune mechanisms, cytokine activation, hormonal and metabolic influences can play a role. The functional consequences of myocardial damage in nonischemic heart failure is a global instead of localized abnormality of ventricular contractility. There is epidemiological evidence that in general the prognosis of nonischemic heart failure is better than in ischemic heart failure. The mortality of patients with ischemic heart failure was usually higher in the placebo groups of recent heart failure trials than in patients with nonischemic etiology. Furthermore, therapeutic responses to angiotensin-converting enzyme (ACE) inhibitors, beta-blockers, amlodipine and amiodarone were also different in some studies. The outcome of nonischemic heart failure is better even in transplant candidates with the most advanced stages of heart failure, they survive longer and respond better to intensified drug regimens than patients with similar clinical severity of ischemic heart failure. Thus, an early and precise diagnosis of the etiology of heart failure should be encouraged not only in clinical trials but also in every day patient management. As more therapeutic options are developed, individualized drug selection for patients with various etiologies of heart failure may become possible.

Heart failure due to ischaemic heart disease: epidemiology, pathophysiology and progression

Ischaemic heart disease is the most common underlying cause of heart failure in industrialised countries. Its manifestations are protean with myocardial infarction being only one important facet. The prognosis of patients with heart failure due to ischaemic heart disease also appears to be worse than that associated with many other aetiologies. The presence of ischaemic heart disease may influence both the efficacy and choice of treatment. Agents such as digoxin and amlodipine appear less effective in patients with ischaemic heart disease while ACE inhibitors and beta-blockers appear as or more effective in patients with ischaemic heart disease. Many have expressed an opinion about how coronary disease should be managed in the patient with heart failure supported by little or no evidence. There are major theoretical and practical concerns about the use of anti-coagulant, anti-platelet and statin therapy in patients with heart failure as well as major theoretical benefits. Only randomised controlled trials will resolve these issues. The same may be said of revascularisation. Fortunately trials addressing all these areas are under way. This should put the management of coronary disease in patients with heart failure on a firm evidence-based footing.

Long-term results of the Spanish trial on treatment and survival of patients with predominantly mild heart failure

A randomized open-label clinical trial was conducted to determine whether mortality, readmission, or quality of life differed between heart failure patients managed with captopril plus diuretics and those with digoxin plus diuretics. A total of 345 heart failure patients in New York Heart Association functional classes 2 and 3 without atrial fibrillation, dyspnea of bronchopulmonary origin, or hypertension not controlled with diuretics was randomized for digoxin (n = 175) or captopril (n = 170) treatment and followed up for a median of 4.5 years. Socioeconomic, demographic, electrocardiographic, echocardiographic, spirometric, and chest radiograph data were obtained at the initial examination. In a random sample of half the patients, ergometric, echocardiographic, and Holter records were obtained at entry and at 3 and 18 months. Patients were followed up for > or = 3 years. The end points were mortality, hospitalization for cardiac events, deterioration in quality of life, worsening of functional class, and need for digoxin or captopril in the captopril and digoxin groups, respectively. The trial had to be terminated prematurely owing to the difficulty in finding candidates free of angiotensin-converting enzyme (ACE)-inhibitor treatment. Baseline patient characteristics were similar in both groups. From the clinical point of view, only the 48-month mortality was relevantly lower (20.9 vs. 31.9%, respectively) among patients treated with captopril than that in those receiving digoxin (log rank test, p = 0.07). No statistically or clinically relevant differences were found in other end points or adverse effects. The results suggest but do not confirm the hypothesis that captopril treatment in mild to moderate heart failure might provide better long-term survival than digoxin.

Symptomatic systolic ventricular failure

Over the past 20 to 30 years there have been significant advances in the management of heart failure related to improved understanding of pathophysiology, better methods of assessment, and improved drug treatments. The aims of treatment have broadened, with increased emphasis on earlier intervention. Clinical research activity in this area has been considerable, increasingly allowing an evidence-based approach to management. Most earlier trials of treatment were relatively short-term, small-group studies with various clinical end points, including severity of symptoms, exercise performance, and left ventricular function assessment; however, increasingly a higher standard of evidence has been required, including a provision of reliable, large-scale mortality trial data. This has been further encouraged, if not mandated, by the relatively recent appreciation that some agents may demonstrate dissociation of treatment effects, possibly dose related, with improved short-term outcomes but adverse effects on survival with prolonged treatment. The general principles of management of congestive heart failure encompass patient evaluation and confirmation of the diagnosis, consideration, and correction of underlying remediable causes and precipitating factors, pharmacological treatment, patient education and counseling, and planned follow-up, as summarized in recently published guidelines. This review focuses primarily on the available randomized controlled clinical trial evidence related to the pharmacological treatment of the clinical congestive heart failure syndrome. Other aspects of management, such as patient education, counseling, and planned follow-up, should be regarded as complementary to pharmacological treatment and important to ensure compliance and optimal long-term outcomes.

Potential benefit of biventricular pacing in patients with congestive heart failure and ventricular tachyarrhythmia

Treatment of congestive heart failure (CHF) aims for symptomatic relief and reduction of mortality both from sudden death and pump failure. The implantable cardioverter defibrillator (ICD) is highly effective in the prevention of sudden death, but no mortality benefit in advanced CHF has yet been shown. Biventricular pacing may lead to functional improvement in selected patients with CHF. Thus, a biventricular pacemaker with defibrillation capabilities may be ideal for patients with advanced CHF. We retrospectively analyzed the data from 384 patients (age 59 +/- 12 years, 322 male and 62 female) with regard to New York Heart Association (NYHA) CHF class, mean QRS duration, mean PR interval, presence of a QRS > 120 msec and incidence of atrial fibrillation at the time of ICD implantation. Based on eligibility criteria from studies in biventricular pacing, we analyzed how many patients may benefit from biventricular pacing. Patients with CHF were older (NYHA class III: 60.9 +/- 9.7, class II: 61.3 +/- 10 versus class I: 50.8 +/- 13.6 years, p < 0.001 each) and mean QRS duration was longer with advanced CHF (NYHA class III 127.8 +/- 30 msec; class II 119.4 +/- 27.7 msec; class 0-1: 103.9 +/- 17.7 msec, p < 0.001, analysis of variance) as was the mean PR interval (NYHA class III 189.9 +/- 33.5 msec; class II 176.1 +/- 29.3 msec; class 0-1 162.7 +/- 45.9 msec, p < 0.001, analysis of variance). The incidence of atrial fibrillation was higher in class III (25.5%) compared with class 0-1 (16.9%) and class II patients (14.1%, p = 0.043, chi-square test). A total of 28 patients (7.3%) fulfilled eligibility criteria for biventricular pacing if NYHA class III patients were considered candidates and 48 (12.5%) if patients with NYHA II CHF and ejection fraction < or = 30% were included. Thus, biventricular pacing may offer a promising therapeutic approach for a significant proportion of patients with CHF at risk for ventricular tachyarrhythmia.

Digitalis

Cardiac glycosides have played a prominent role in the therapy of congestive heart failure since William Withering codified their use in his late 18th century monograph on the efficacy of the leaves of the common foxglove plant (Digitalis purpurea). Despite their widespread acceptance into medical practice in the ensuing 200 years, both the efficacy and the safety of this class of drugs continue to be a topic of debate. Moreover, despite the fact that the molecular target for the cardiac glycosides, the alpha-subunit of sarcolemmal Na+K+-ATPase (or sodium pump) found on most eukaryotic cell membranes, has been known for several decades, it remains controversial whether the sympatholytic or positive inotropic effects of these agents is the mechanism most relevant to relief of heart failure symptoms in humans with systolic ventricular dysfunction. Herein, we review the molecular and clinical pharmacology of this venerable class of drugs, as well as the manifestations of digitalis toxicity and their treatment. We also review in some detail recent clinical trials designed to examine the efficacy of these drugs in heart failure, with a focus on the Digoxin Investigation Group data set. Although, in our opinion, the data on balance warrant the continued use of these drugs for the treatment of symptoms of heart failure in patients already receiving contemporary multidrug therapy for this disease, the use of digitalis preparations will inevitably decline with the maturation of newer pharmacotherapies.

Inappropriate use of digoxin in the elderly: how widespread is the problem and how can it be solved?

Cardiovascular disease is ubiquitous within the elderly population and requires treatment with multiple types of medications. As with any cardiovascular pharmaceutical regimen, the risk versus the benefit of each medication must be strongly considered. This is particularly true where, for various reasons, adverse effects are more often prevalent and pronounced. Over the years, it has been documented that digoxin is a frequently prescribed medication in elderly populations. Although this drug can be beneficial when used in the appropriate setting, recent data would suggest that inappropriate administration of digoxin is common and not without potentially serious consequences. Currently, the use of digoxin can be advocated to control heart failure in atrial fibrillation and when added to ACE inhibitors and diuretics in those patients with symptomatic heart failure related to systolic left ventricular dysfunction. It is likely that the excessive use of digoxin in elderly populations as discussed in this review is perhaps based on the prevalence of diastolic heart failure in the elderly as well as other co-morbid conditions that may mimic heart failure signs and symptoms. Since the elderly appear to be at high risk for digoxin toxicity, the inappropriate use of this medication to treat these conditions could result in significant and unnecessary morbidity. It is proposed that echocardiography should be performed in most elderly patients when congestive heart failure is suspected. This simple diagnostic tool, along with a careful history and medical examination, would hopefully prevent the misinterpretation of confusing clinical findings and would help to identify the patients with normal systolic function or valvular disease such as critical aortic stenosis, where digoxin treatment would not be warranted. If it is necessary to administer digoxin, then the likelihood of significant toxicity can be greatly reduced by using an algorithm to calculate the appropriate dosage, which takes into consideration the patient's gender, bodyweight and creatinine clearance. Although it is probable that the indications for digoxin use to treat congestive heart failure will continue to evolve, at the present time most would recommend using this agent in symptomatic heart failure related to a reduction in left ventricular systolic function or when associated with atrial fibrillation.

Cost of hospitalizations for heart failure: sodium retention versus other decompensating factors

OBJECTIVE

To determine the cost of heart failure-related hospital admissions and to compare the cost of admissions for sodium retention with the cost of admissions for other decompensating factors.

DESIGN

Retrospective, non-experimental, cost analysis.

SETTING

Midwestern university-affiliated, tertiary care, medical center.

SAMPLE

Two hundred seven heart failure-related admissions, 117 (57%) of which were for sodium retention leading to volume overload.

OUTCOME MEASURES

Cost of hospitalization.

PROCEDURE

Data obtained from the patient and financial records of patients hospitalized for heart failure in 1992 were analyzed using the ratio of cost-to-charge accounting procedure.

RESULTS

The total cost was $2,442,720 for the 207 heart failure-related admissions; the average cost was $12,400 per admission. Approximately half of the cost of the hospitalizations was expended in the 4 cost centers comprising routine and critical care services, which incorporate room charges and nursing care. Another one third of the cost was for supplies, medications, and laboratory tests. Admissions as a result of sodium retention had lower costs than admissions as a result of other factors.

CONCLUSION

The cost of hospitalization for heart failure is high. Routine services, supplies, medications, and laboratory tests used by these patients contribute to the high cost of care. Improved outpatient management strategies are necessary to reduce hospital admissions as a result of sodium retention.

Advanced Cancer and Comorbid Conditions: Prognosis and Treatment

BACKGROUND: Nonmalignant comorbid medical conditions, such as heart failure and emphysema, may complicate cancer treatment. METHODS: Guidelines from the National Hospice Organization for cancer and selected nonmalignant diseases are outlined, and treatment principles for end-stage heart failure and emphysema are reviewed. RESULTS: Estimates by clinicians of survivability in advanced cancer and nonmalignant disease are important in order to allow patients and family members to begin realistic advance planning. As disease progresses through its end stages to death, optimal management may include both disease-modifying and symptom-relieving interventions. CONCLUSIONS: A well-managed end of life is an important therapeutic option in informed consent discussions with seriously ill patients and their families.

Cardiovascular pharmacology of aging

Despite the relative paucity of drug trials in the old and especially the very old (> 85 years), some general principles of pharmacology in the aging patient can be taken from available data and clinical experience. The pharmacokinetic changes most consistently seen with aging occur in the volume of distribution, clearance, and half-life of a drug. Renal drug clearance is consistently diminished with aging. Hepatic metabolism is more variably affected, and in contrast to renal clearance, no reliable formula exists to estimate hepatic drug clearance. Pharmacodynamic changes, although present, are less well studied or described in the elderly. Drug interactions and adverse drug reactions increase with increasing numbers of medications prescribed and represent a complex interplay of age, underlying disease, and number and types of medications. The clinical caveats that apply to drug prescription in the very old include reduced starting doses with slow incremental increases; elimination of unnecessary medications; and anticipating and monitoring for drug interactions and ADRs, especially when prescribing warfarin, digoxin, and amiodarone. Future studies that look at the aging patient in the presence of effects of age, physiology, gender, comorbid illness, and multiple drug therapies may help evolve a new set of paradigms for geriatric drug prescribing.

Medication use in residential care facilities for the elderly

OBJECTIVE

To describe medication use by residents of residential care facilities for the elderly (RCFEs).

DESIGN

A cross-sectional survey of medication use.

SETTING

Licensed, private RCFEs recruited from a roster of all licensed RCFEs in the Los Angeles area.

SUBJECTS

Residents who were > or =60 years of age and whose medications were centrally stored in the facility.

MEASURES

Age, gender, race, health insurance coverage, dietary restrictions, ambulation status, medical diagnoses, and medication profile.

RESULTS

A total of 818 residents were surveyed. Residents were primarily white women who were >80 years. The average number of medications per resident was five; 94% of the sample took at least one medication. Cardiovascular drugs, central nervous system drugs, analgesics, diuretics, and potassium supplements were most commonly used. Use of multiple drugs within a therapeutic class was also common, with means ranging from 1.46 to 1.81 per resident for the most commonly prescribed classes. Diagnoses supporting the use of many medications were not documented in the residents' health records.

CONCLUSIONS

This RCFE sample was medically frail and took many medications. The frequent use of cardiovascular medication reflected the prevalence of cardiac disease in the elderly. The frequency of psychotropic drug use without a corresponding indication suggested prescribing for symptoms rather than documented medical conditions. Lack of recorded diagnoses limited the ability to evaluate drug therapy. Improved record keeping; periodic medication review; and resident, staff, and prescriber education are necessary to ensure appropriate medication use in this setting.

Cardiac glycosides in the next millennium

Despite the documented efficacy of cardiac glycosides in improving symptoms in patients with heart failure caused by systolic ventricular dysfunction, considerable debate continues as to whether the use of this class of drugs should continue into the next millennium. In this review, the authors briefly examine the basic pharmacology of these drugs relevant to the treatment of heart failure, emphasizing their role in reducing sympathetic nervous system activity in patients with advanced heart failure. Next, withdrawal trials and the Digoxin Investigation Group dataset are reviewed in some detail. Despite these important additional data on the safety and efficacy of digitalis use in heart failure that became available in the 1990s, considerable controversy remains. Perhaps most importantly, if the mechanism by which these drugs improve symptoms in patients with heart failure is principally mediated by sympatholytic activity, do they remain relevant as beta-adrenergic antagonists become standard therapy for this disease?

Current Concepts in the Management of Heart Failure

Objective:

To give an overview of the epidemiology, etiology, and symptoms and signs of heart failure (HF), and the role of various therapeutic modalities that influence functional status, morbidity, and mortality in HF.

Data Sources:

Computerized search of the MEDLINE database (1976–1998) and review chapters from medical textbooks.

Data Extraction:

Clinical trials evaluating the effect of drugs on morbidity and mortality of patients with HF.

Data Synthesis:

HF is a clinical syndrome with high prevalence and mortality. The treatment approach varies depending on the etiology and type of HF. Several large-scale clinical trials with angiotensin-converting enzyme (ACE) inhibitors demonstrate improved survival and reduced hospitalization in patients with all degrees of HF. Several other trials report similar benefits in postmyocardial infarction patients with HF. Angiotensin II type 1 receptor blocking agents have also been shown to reduce morbidity and mortality in elderly patients with HF and may be used in patients who cannot tolerate ACE inhibitors. Therapy with hydralazine and isosorbide dinitrate also improves exercise tolerance as well as survival in patients with HF. The combination of these agents with ACE inhibitors may be useful in patients who remain symptomatic while taking ACE inhibitors. Such second-generation dihydropyridine calcium-channel blockers as amlodipine have also been shown to improve symptoms, exercise tolerance, and survival in nonischemic patients. Diuretics are effective in reducing the symptoms of HF resulting from fluid overload. Inotropic drugs such as digoxin may improve symptoms and reduce hospitalization for patients with HF but do not reduce overall mortality. Long-term, continuous use of inotropic agents, such as amrinone, milrinone, dobutamine, and high-dose vesnarinone, may improve quality of life but increase mortality in HF. Beta-blockers, particularly Carvedilol, with vasodilating properties demonstrate positive survival results in patients with mild-to-moderate HF.

Conclusions:

ACE inhibitors are the initial drug of choice in the treatment of HF; however, angiotensin II receptor antagonists may be used in patients who are intolerant to ACE inhibitors. Diuretics are useful mainly to control the fluid overload in HF. Digoxin is helpful in patients with atrial fibrillation and rapid ventricular response and in patients who are resistant to ACE inhibitors and diuretics. Hydralazine and isosorbide dinitrate therapy is valuable in patients whose symptoms cannot be controlled with optimal doses of diuretics, digoxin, and ACE inhibitors. Careful use of newer beta-blockers, with optimal titration of diuretics, in mild-to-moderate HF may help prolong life. Newer dihydropyridine calcium-channel blockers may be beneficial in nonischemic patients with HF.

Management issues for women with epilepsy: a review of the literature

OBJECTIVE

A review of literature referable to management issues for women with epilepsy (WWE) was undertaken for the development of a practice parameter.

BACKGROUND

Epilepsy is a common neurologic condition with gender-related management implications. Although reviews of this topic often focus on pregnancy-related issues for WWE, specific health concerns for WWE are present throughout all phases of reproductive life.

METHODS

An OVID MEDLINE literature search was conducted for 1965 to 1997 using the following key words/phrases and cross referencing: epilepsy/ seizures and pregnancy, anticonvulsants, antiepileptic drugs (AEDs), teratogenesis, oral contraceptives, birth defects, folate/folic acid, vitamin K, metabolic bone disease, and breast-feeding.

RESULTS

Pregnancy outcome literature for WWE spans several decades. Methodology varies and interpretation is complicated by modern management strategies. Contributions of socioeconomic factors, AEDs, maternal epilepsy, and seizures during pregnancy to adverse pregnancy outcomes have not been clearly delineated. There is a biologic basis for recommendations concerning contraception, folate supplementation, vitamin K use in pregnancy, breast-feeding, metabolic bone disease, catamenial epilepsy, and reproductive endocrine disorders, but no outcome studies afford a strong evidence base for practice recommendation.

CONCLUSIONS

WWE face health issues for which there is no available outcome literature to guide decision making. The urgent need for studies in many of these areas is highlighted by expanded treatment options with new AEDs and epilepsy surgery.

Diastolic effects of chronic digitalization in systolic heart failure

BACKGROUND

The efficacy of short-term digitalization on exercise tolerance may, in part, reflect enhanced diastolic performance. However, cardiac glycosides can impair ventricular relaxation from cytosolic Ca++ overload. To detect any time-dependent adverse effect, we assessed the diastolic function after long-term use of digitalis in patients with mild to moderate systolic left ventricular failure.

METHODS AND RESULTS

From a cohort of 80 patients who received long-term, randomized, double-blind treatment with digitalis versus placebo at the WJB Dorn Veterans Affairs Medical Center, 38 survivors were evaluated at the end of follow-up (mean 48.4 months) with evaluators blinded to treatment used. Each survivor underwent equilibrium scintigraphic and echocardiographic assessment of diastolic function. Peak and mean filling rates normalized with filling volume (FV), diastolic phase durations normalized with duration of diastole, and filling fractions were measured from the time-activity curve. The isovolumic relaxation period and ventricular dimensions were computed echocardiographically. By actual-treatment-received analysis, treated versus untreated patients manifested a trend toward longer isovolumic relaxation (80.76 ms vs 61.54 ms, P = .06) but a markedly lower peak rapid filling rate (6.39 FV/sec vs 10.56 FV/sec, P = .02) despite comparable loading conditions. In addition, treated patients exhibited a lower mean rate of rapid filling (2.75 FV/sec vs 3.78 FV/sec, P = .05) in the absence of a longer rapid filling duration. However, the end-diastolic ventricular dimension did not differ between the 2 groups. Similar results were obtained by intention-to-treat analysis. Importantly, the mortality rate from worsening heart failure in the inception cohort was lower in the digitalis group versus the placebo group (P = .05) with no difference in total cardiac or all-cause mortality.

CONCLUSIONS

After long-term digitalization for systolic left ventricular failure, cross-sectional comparison with a control group from the same inception cohort shows a decrease in the rate and degree of ventricular relaxation. This effect did not interfere with the overall ventricular filling or with a favorable impact on outcome from worsening heart failure.

Reproducibility and responsiveness of quality of life assessment and six minute walk test in elderly heart failure patients

OBJECTIVE

To examine the reproducibility and responsiveness to change of a six minute walk test and a quality of life measure in elderly patients with heart failure.

DESIGN

Longitudinal within patient study.

SUBJECTS

60 patients with heart failure (mean age 82 years) attending a geriatric outpatient clinic, 45 of whom underwent a repeat assessment three to eight weeks later.

MAIN OUTCOME MEASURES

Subjects underwent a standardised six minute walk test and completed the chronic heart failure questionnaire (CHQ), a heart failure specific quality of life questionnaire. Intraclass correlation coefficients (ICC) were calculated using a random effects one way analysis of variance as a measure of reproducibility. Guyatt's responsiveness coefficient and effect sizes were calculated as measures of responsiveness to change.

RESULTS

24 patients reported no major change in cardiac status, while seven had deteriorated and 14 had improved between the two clinic visits. Reproducibility was satisfactory (ICC > 0.75) for the six minute walk test, for the total CHQ score, and for the dyspnoea, fatigue, and emotion domains of the CHQ. Effect sizes for all measures were large (> 0.8), and responsiveness coefficients were very satisfactory (> 0.7). Effect sizes for detecting deterioration were greater than those for detecting improvement.

CONCLUSIONS

Quality of life assessment and a six minute walk test are reproducible and responsive measures of cardiac status in frail, very elderly patients with heart failure.

Effect of Digoxin on Ventricular Remodeling and Responsiveness of beta-Adrenoceptors in Chronic Volume Overload

BACKGROUND: Digoxin improves baroreflex function and reduces neurohumoral activation in severe heart failure, but it is uncertain how digoxin affects ventricular remodeling and progression to left ventricular dysfunction. In addition, the effect of digoxin in in vitro beta-adrenoceptor density and function, and contractile reserve in vivo is not well understood. METHODS AND RESULTS: To study this, we compared digoxin with placebo treatment in rats with chronic volume overload induced by aortocaval fistula and in sham-operated control animals. Left ventricular end-diastolic cavity dimensions (LVDd) and wall thickness were measured weekly by in vivo transthoracic echocardiography, and left ventricular mass (LVM) and percent fractional shortening (%FS) were calculated. Six weeks after fistula creation, simultaneous echocardiographic and invasive hemodynamic evaluation at rest and in response to incremental dobutamine (1-10 µg/kg/min intravenously) were measured. Myocardial plasma membrane beta-adrenoceptor density and maximal adenylate cyclase responses (V(max)) to isoproterenol, 5'-guanylylimi dodiphosphate, and forskolin were measured in vitro. Volume overload induced progressive increases in LVDd and LVM over the 6-week study period. Percent fractional shortening at rest, and the change in %FS in response to dobutamine stress were dramatically reduced 6 weeks after fistula creation. Although 6-week fistula animals had unchanged beta-adrenoceptor density (B(max)) and binding affinity (K(d)) as compared with controls, maximal adenylate cyclase responses to stimulation in vitro (V(max)) were markedly reduced. Digoxin treatment prevented this loss of responsiveness of adenylate cyclase but did not affect beta-adrenoceptor density or affinity in vitro. Digoxin had no effect on LVDd, LVM, %FS, or the response to dobutamine infusion in vivo. CONCLUSIONS: Although digoxin prevented beta-adrenoceptor desensitization and improved in vitro myocardial adenylate cyclase response, the cardiac response to adrenergic stimulation in vivo was not significantly improved. These results suggest that the role of beta-adrenoceptor desensitization in the progression from volume overload hypertrophy to left ventricular dysfunction and heart failure may be less important than previously thought. Furthermore, although digoxin treatment did produce modest hemodynamic benefits, it did not prevent progressive remodeling in this model.

Superiority of "triple" drug therapy in heart failure: insights from the PROVED and RADIANCE trials. Prospective Randomized Study of Ventricular Function and Efficacy of Digoxin. Randomized Assessment of Digoxin and Inhibitors of Angiotensin-Converting Enzyme

OBJECTIVES

We sought to study the efficacy of "triple" therapy with digoxin, diuretic and angiotensin-converting enzyme inhibitor (ACEI) compared to other combinations of these drugs in patients with symptomatic left ventricular systolic dysfunction.

BACKGROUND

Controversy continues concerning the role of combining digoxin with diuretic and ACEI in the initial management of patients with heart failure.

METHODS

The study utilized data from two studies of digoxin efficacy: Prospective Randomized Study of Ventricular Function and Efficacy of Digoxin (PROVED) and Randomized Assessment of Digoxin and Inhibitors of Angiotensin-Converting Enzyme (RADIANCE). Worsening heart failure defined as augmentation of heart failure therapy or an emergency room visit or hospitalization for increased heart failure was the main outcome measure.

RESULTS

A total of 266 patients comprising the four treatment groups of the combined PROVED (diuretic alone or digoxin and diuretic) and RADIANCE (ACEI and diuretic, or digoxin, diuretic and ACEI) trials were analyzed. Worsening heart failure occurred in only 4 of the 85 patients who continued digoxin, diuretic and ACEI therapy (4.7%) compared to 18 of the 42 patients (19%) on digoxin and diuretic therapy (p=0.009), to 23 of the 93 patients (25%) on ACEI and diuretic therapy (p=0.001) and to 18 of the 46 patients (39%) on diuretic alone (p < 0.001). Life table and multivariate analysis also demonstrated that worsening heart failure was least likely in patients treated with triple therapy (p < 0.01 vs. all other groups).

CONCLUSION

Pending definitive, prospective clinical trials, our results argue for triple therapy as the initial management of patients with symptomatic heart failure due to systolic dysfunction.

The short-term effects of digoxin in patients with right ventricular dysfunction from pulmonary hypertension

OBJECTIVE

Studies on the effects of digoxin in patients with right ventricular failure and normal left ventricular function have not been performed. We evaluated the short-term effects of digoxin administration in patients with primary pulmonary hypertension on hemodynamics, neurohormones, and baroreceptor responsiveness.

DESIGN

This was a prospective study with patients serving as their own controls.

SETTING

University Hospital Intensive Care Unit with central monitoring.

PATIENTS

Seventeen patients with primary pulmonary hypertension and symptomatic heart failure were enrolled.

INTERVENTIONS

Following baseline hemodynamics, neurohormonal samples were drawn and the heart rate response to change in blood pressure following a challenge of phenylephrine and nitroprusside were recorded. One mg of intravenous digoxin was given and the measurements repeated after 2 hours.

RESULTS

Following digoxin there was a significant increase in cardiac output (3.49+/-1.2 to 3.81+/-1.2 L/min., p=0.028), a significant fall in norepinephrine (680+/-89 to 580+/-85 pg/ml, p=.013), and a significant increase in atrial natriuretic peptide (311+/-44 to 421+/-9 pg/ml, p=0.01). All of the patients had changes in heart rate and blood pressure following phenylephrine and nitroprusside challenge, but there was no significant difference in the change in heart rate response to change in blood pressure when rechallenged after digoxin treatment.

CONCLUSION

Digoxin produces a modest increase in cardiac output in patients with pulmonary hypertension and right ventricular failure, as well as a significant reduction in circulating norepinephrine. No detectable effects of digoxin on baroreceptor responsiveness were apparent. The use of digoxin in pulmonary hypertension is warranted.

Impact of angiotensin-converting enzyme inhibitor underdosing on rehospitalization rates in congestive heart failure

In a retrospective, cohort design, clinical usage of digoxin, diuretic, and angiotensin-converting enzyme (ACE) inhibitor was assessed in all patients readmitted over a 36-month period for congestive heart failure (CHF) diagnostic-related group (DRG) 127. ACE inhibitor dose-response analysis used the discharge dose of ACE inhibitor, converted to enalapril-equivalent doses and adjusted for renal function. Principal end points were time-to-readmission and 90-day readmission rate. Of 314 total patients, digoxin was used in 72%, diuretic in 86%, and 67% received an ACE inhibitor. Only 22% of those on an ACE inhibitor received currently recommended doses of enalapril > or = 20 mg/day or equivalent, whereas 41% received enalapril < or = 5 mg/day. Time-to-readmission was increased by an ACE inhibitor (p = 0.002) but not digoxin or diuretic. An ACE inhibitor was the principal covariate of 90-day readmission rate (p <0.05). The readmission rate was not reduced with daily ACE inhibitor doses of < or = 5 mg enalapril, whereas daily doses of > or = 10 mg enalapril reduced 90-day readmission rates by 28% compared to those receiving diuretic or digoxin therapy (p <0.05). Using a dynamic model, the dose required to achieve 90% to 95% of the theoretical maximum ACE inhibitor effect exceeded 100 mg enalapril daily. Thus, CHF readmission rates are lower when daily ACE inhibitor doses exceed 5 mg enalapril or the equivalent daily, but are unaffected by digoxin or diuretic. Modeled maximum ACE inhibitor benefits require doses 8- to 10-fold higher than current usage patterns.

Pregnancy outcome following first trimester exposure to sumatriptan

We prospectively compared pregnancy outcome after exposure to sumatriptan with that of disease-matched controls and nonteratogen controls. There were no differences in the rates of live births, spontaneous abortions, therapeutic abortions, or major birth defects among the three groups. This first prospective report suggests that the use of sumatriptan during organogenesis is not associated with an apparent increased risk of major birth defects.

A case series of hospitalized patients with elevated digoxin levels

PURPOSE

Although there is renewed enthusiasm for the use of digoxin in patients with heart failure, current dosing guidelines are based on a nomogram published in 1974. We studied the incidence of and risk factors for elevated digoxin levels in patients admitted to a community hospital, and compared their dosage regimens to published guidelines.

SUBJECTS AND METHODS

We reviewed the charts of all patients who had serum digoxin levels greater than 2.4 ng/mL during a 6-month period. We collected demographic and clinical data, indications for digoxin use, digoxin dosage, concurrent medications, laboratory data, and clinical and electrocardiographic features of digoxin toxicity.

RESULTS

Of the 1,433 patients with digoxin assays, 115 (8%) patients had elevated levels. Of the 82 patients with complete records and correctly timed digoxin levels, 59 (72%) had electrocardiographic or clinical features of digoxin toxicity. Patients with serum digoxin levels >2.4 ng/mL were slightly older (78 +/- 8 versus 73 +/- 9 years of age; P = 0.12) and had greater serum creatinine levels (3.1 +/- 7.3 versus 1.4 +/- 0.3 mg/dL; P = 0.01) than those with levels < or =2.4 ng/mL. Forty-seven patients had elevated digoxin levels on admission, including 21 patients admitted for digoxin toxicity. Impaired or worsening renal function contributed to high levels in 37 patients, and a drug interaction was a contributory factor in 10 cases. Twenty (43%) of these patients were taking the recommended maintenance dose based on the scheme employed in the Digitalis Investigation Group study. Thirty-five patients developed high digoxin levels while in hospital. In 26 patients, this followed a loading dose of digoxin for the control of rapid atrial fibrillation. Impaired renal function was implicated in all of these patients. Despite the elevated digoxin level, rate control was achieved in only 11 patients of these patients.

CONCLUSIONS

Elevated digoxin levels and clinical toxicity remains a common adverse drug reaction. Elderly patients, particularly those with impaired renal function and low body weights, are at the greatest risk. As published digoxin nomograms often result in toxicity, clinical variables need to be monitored. In patients with congestive heart failure and normal sinus rhythm the potential benefit of digoxin is small; thus, patients should receive a dose that minimizes the risk of toxicity. For patients with new onset atrial fibrillation, other agents may be preferable for rate control.

Double-blind, randomized, placebo-controlled study of oral, high-dose methylprednisolone in attacks of MS

OBJECTIVE

There is only limited evidence from adequately controlled clinical trials to support high-dose methylprednisolone therapy for attacks of multiple sclerosis (MS) and none supporting oral administration. We assessed the effect of oral high-dose methylprednisolone therapy in attacks of MS.

METHODS

Twenty-five patients with an attack of MS lasting less than 4 weeks were randomized to placebo treatment. Twenty-six patients received oral methylprednisolone (500 mg once a day for 5 days with a 10-day tapering period). The patients received scores on the Scripps Neurological Rating Scale (NRS) and Kurtzke Expanded Disability Status Scale. The symptoms were scored on a visual analog scale (VAS) before treatment and after 1, 3, and 8 weeks of treatment. Primary efficacy measures were NRS and VAS scores in the first 3 weeks and changes in NRS score and answers to an efficacy questionnaire administered after 8 weeks of treatment.

RESULTS

Changes in NRS scores among methylprednisolone- and placebo-treated patients differed significantly in the first 3 weeks and after 8 weeks (p = 0.005 and p = 0.0007). VAS scores the first 3 weeks and treatment efficacy after 8 weeks also favored a beneficial effect of methylprednisolone treatment (p = 0.02 and p = 0.05). After 1, 3, and 8 weeks, 4%, 24%, and 32% in the placebo group and 31%, 54%, and 65% in the methylprednisolone group had improved one point on the Expanded Disability Status Scale score (all p < 0.05). No serious adverse events were seen.

CONCLUSION

Oral high-dose methylprednisolone is recommended for managing attacks of MS.

A decade of clinical trial developments in postmyocardial infarction, congestive heart failure, and sustained ventricular tachyarrhythmia patients: from CAST to AVID and beyond. Cardiac Arrhythmic Suppression Trial. Antiarrhythmic Versus Implantable Defibrillators

Multiple trials using antiarrhythmic drugs, pharmacologic therapy, and implantable cardioverter defibrillators have been performed in an attempt to improve survival in patients: (1) postmyocardial infarction; (2) with congestive heart failure, with and without nonsustained ventricular tachycardia; and (3) with sustained ventricular tachycardia and those who have survived an out-of-hospital cardiac arrest. This article reviews some of the key findings and limitations of completed and ongoing trials. We also make recommendations for the current treatment of such patients based on the results of these trials.

Are symptoms the most important target for therapy in chronic heart failure?

Symptoms combined with a loss of quality of life can be considered part of the morbidity of heart failure. Patients with chronic heart failure (CHF) have a poorer quality of life than do those with other chronic conditions including arthritis and lung disease. Although there is no evidence to show a mortality benefit, diuretics are frequently used for symptomatic relief in CHF patients. Angiotensin converting enzyme (ACE) inhibitors have been shown both to improve symptoms and to reduce mortality; however, ACE inhibitors have yet to show any conclusive benefit in improving quality of life. Digoxin is widely used and offers symptomatic relief, but it has been shown to have no overall effect on mortality. More recently, certain beta-blockers have been shown to impact both morbidity and mortality in patients already receiving standard therapy including an ACE inhibitor and diuretics. This article reviews these and additional therapies currently used in the management of CHF in the context of their impact on the joint goals of reducing both morbidity and mortality.

Treatment guidelines in heart failure

The risk of heart failure increases with age. Prognosis is poor, with 82% of patients dying within 6 years of diagnosis. As the population ages, heart failure is becoming an increasing problem. Heart failure is a complex disease that may be managed in a variety of ways depending on its severity and cause. A wide range of pharmacological and nonpharmacological therapeutic measures are available to relieve symptoms and prolong life. These have changed considerably in the last decade. Cardiology experts in the United States and Europe have developed guidelines for the diagnosis and management of heart failure. These are intended to help physicians to keep up with therapeutic developments and to encourage more appropriate and cost-effective management of patients with heart failure. The European guidelines were updated more recently than their US counterparts and consequently contain certain new developments, such as the inclusion of the latest data on beta-blockers, including carvedilol, that have shown morbidity and mortality rate benefits in patients with mild-to-moderate heart failure. As the management of heart failure is changing rapidly, regular schemes for updating of guidelines are being considered.