Serum digoxin concentration and outcomes in women with heart failure: A bi-directional effect and a possible effect modification by ejection fraction

When cardiovascular medicines should be discontinued

An integral component of the practice of medicine is focused on the initiation of medications, based on clinical practice guidelines and underlying trial evidence, which usually test the addition of novel medications intended for life-long use in short-term clinical trials. Much less attention is given to the question of medication discontinuation, especially after a lengthy period of treatment, during which patients age gets older and diseases may either progress or new diseases may emerge. Given the paucity of data, clinical practice guidelines offer little to no guidance on when and how to deprescribe cardiovascular medications. Such decisions are often left to the discretion of clinicians, who, together with their patients, express concern of potential adverse effects of medication discontinuation. Even in the absence of adverse effects, the continuation of medications without any proven effect may cause harm due to drug-drug interactions, the emergence of polypharmacy, and additional preventable spending to already strained health systems. Herein, several cardiovascular medications or medication classes are discussed that in the opinion of this author group should generally be discontinued, either for the prevention of potential harm, for a lack of benefit, or for the availability of better alternatives.

Adverse Drug Reactions to Guideline-Recommended Heart Failure Drugs in Women: A Systematic Review of the Literature

OBJECTIVES

This study sought to summarize all available evidence on sex differences in adverse drug reactions (ADRs) to heart failure (HF) medication.

BACKGROUND

Women are more likely to experience ADRs than men, and these reactions may negatively affect women's immediate and long-term health. HF in particular is associated with increased ADR risk because of the high number of comorbidities and older age. However, little is known about ADRs in women with HF who are treated with guideline-recommended drugs.

METHODS

A systematic search of PubMed and EMBASE was performed to collect all available information on ADRs to angiotensin-converting enzyme inhibitors, β-blockers, angiotensin II receptor blockers, mineralocorticoid receptor antagonists, ivabradine, and digoxin in both women and men with HF.

RESULTS

The search identified 155 eligible records, of which only 11 (7%) reported ADR data for women and men separately. Sex-stratified reporting of ADRs did not increase over the last decades. Six of the 11 studies did not report sex differences. Three studies reported a higher risk of angiotensin-converting enzyme inhibitor-related ADRs in women, 1 study showed higher digoxin-related mortality risk for women, and 1 study reported a higher risk of mineralocorticoid receptor antagonist-related ADRs in men. No sex differences in ADRs were reported for angiotensin II receptor blockers and β-blockers. Sex-stratified data were not available for ivabradine.

CONCLUSIONS

These results underline the scarcity of ADR data stratified by sex. The study investigators call for a change in standard scientific practice toward reporting of ADR data for women and men separately.

Treatment of Heart Failure with Abnormal Left Ventricular Systolic Function in Older Adults

Heart failure (HF) with abnormal left ventricular (LV) ejection fraction should be identified and treated. Treat hypertension with diuretics, angiotensin-converting enzyme (ACE) inhibitors, and β-blockers. Treat myocardial ischemia with nitrates and β-blockers. Treat volume overload and HF with diuretics. Treat HF with ACE inhibitors and β-blockers. Sacubitril/valsartan may be used instead of an ACE inhibitor or ARB in chronic symptomatic HF and abnormal LV ejection fraction. Add isosorbide dinitrate/hydralazine in African Americans with class II to IV HF treated with diuretics, ACE inhibitors, and β-blockers. Exercise training is recommended. Indications for implantable cardioverter-defibrillator and cardiac resynchronization therapy are discussed.

The Role of Positive Inotropic Drugs in the Treatment of Older Adults with Heart Failure and Reduced Ejection Fraction

Positive inotropic drugs have long been studied for their potential benefits in patients with heart failure and reduced ejection fraction (HFrEF). Although there has been an extensive amount of research about the clinical effects of these drugs in general, few studies examined their effect in older patients. Therefore, there is little or no evidence to guide the use of positive inotropes in older patients with HFrEF. However, recommendations from national heart failure guidelines may be generalized to older HFrEF patients on an individual basis, taking into consideration the basic geriatric principles of pharmacotherapy: start low and go slow.

Digoxin and 30-Day All-Cause Readmission in Long-Term Care Residents Hospitalized for Heart Failure

BACKGROUND

Digoxin use has been shown to be associated with a lower risk of 30-day all-cause hospital readmissions in older patients with heart failure (HF). In the current study, we examined this association among long-term care (LTC) residents hospitalized for HF.

METHODS

Of the 8049 Medicare beneficiaries discharged alive after hospitalization for HF from 106 Alabama hospitals, 545 (7%) were LTC residents, of which 227 (42%) received discharge prescriptions for digoxin. Propensity scores for digoxin use, estimated for each of the 545 patients, were used to assemble a matched cohort of 158 pairs of patients receiving and not receiving digoxin who were balanced on 29 baseline characteristics. Hazard ratios (HRs) and 95% confidence intervals (CIs) for outcomes associated with digoxin among matched patients were estimated using Cox regression models.

RESULTS

Matched patients (n = 316) had a mean age of 83 years, 74% were women, and 18% African American. Thirty-day all-cause readmission occurred in 21% and 20% of patients receiving and not receiving digoxin, respectively (HR, 1.02; 95% CI, 0.63-1.66). Digoxin had no association with all-cause mortality (HR, 0.90; 95% CI, 0.48-1.70), HF readmission (HR, 0.90; 95% CI, 0.38-2.12), or a combined endpoint of all-cause readmission or all-cause mortality (HR, 0.97; 95% CI, 0.65-1.45) at 30 days. These associations remained unchanged at 1 year postdischarge.

CONCLUSIONS

The lack of an association between digoxin and 30-day all-cause readmission in older nursing home residents hospitalized for HF is intriguing and needs to be interpreted with caution given the small sample size.

Heart Failure Complicating Acute Mtyocardial Infarction

Factors predisposing the older person with acute myocardial infarction (MI) to develop heart failure (HF) include an increased prevalence of MI, multivessel coronary artery disease, decreased left ventricular (LV) contractile reserve, impairment of LV diastolic relaxation, increased hypertension, LV hypertrophy, diabetes mellitus, valvular heart disease, and renal insufficiency. HF associated with acute MI should be treated with a loop diuretic. The use of nitrates, angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, aldosterone antagonists, beta-blockers, digoxin, and positive inotropic drugs; treatment of arrhythmias and mechanical complications; and indications for use of implantable cardioverter-defibrillators and cardiac resynchronization is discussed.

Update of treatment of heart failure with reduction of left ventricular ejection fraction

Underlying and precipitating causes of heart failure (HF) with reduced left ventricular ejection fraction (HFrEF) should be identified and treated when possible. Hypertension should be treated with diuretics, angiotensin-converting enzyme (ACE) inhibitors, and β-blockers. Diuretics are the first-line drugs in the treatment of patients with HFrEF and volume overload. Angiotensin-converting enzyme inhibitors and β-blockers (carvedilol, sustained-release metoprolol succinate, or bisoprolol) should be used in treatment of HFrEF. Use an angiotensin II receptor blocker (ARB) (candesartan or valsartan) if intolerant to ACE inhibitors because of cough or angioneurotic edema. Sacubitril/valsartan may be used instead of an ACE inhibitor or ARB in patients with chronic symptomatic HFrEF class II or III to further reduce morbidity and mortality. Add an aldosterone antagonist (spironolactone or eplerenone) in selected patients with class II-IV HF who can be carefully monitored for renal function and potassium concentration. (Serum creatinine should be ≤ 2.5 mg/dl in men and ≤ 2.0 mg/dl in women. Serum potassium should be < 5.0 mEq/l). Add isosorbide dinitrate plus hydralazine in patients self-described as African Americans with class II-IV HF being treated with diuretics, ACE inhibitors, and β-blockers. Ivabradine can be used in selected patients with HFrEF.

Use of Inotropic Agents in Treatment of Systolic Heart Failure

The most common use of inotropes is among hospitalized patients with acute decompensated heart failure, with reduced left ventricular ejection fraction and with signs of end-organ dysfunction in the setting of a low cardiac output. Inotropes can be used in patients with severe systolic heart failure awaiting heart transplant to maintain hemodynamic stability or as a bridge to decision. In cases where patients are unable to be weaned off inotropes, these agents can be used until a definite or escalated supportive therapy is planned, which can include coronary revascularization or mechanical circulatory support (intra-aortic balloon pump, extracorporeal membrane oxygenation, impella, left ventricular assist device, etc.). Use of inotropic drugs is associated with risks and adverse events. This review will discuss the use of the inotropes digoxin, dopamine, dobutamine, norepinephrine, milrinone, levosimendan, and omecamtiv mecarbil. Long-term inotropic therapy should be offered in selected patients. A detailed conversation with the patient and family shall be held, including a discussion on the risks and benefits of use of inotropes. Chronic heart failure patients awaiting heart transplants are candidates for intravenous inotropic support until the donor heart becomes available. This helps to maintain hemodynamic stability and keep the fluid status and pulmonary pressures optimized prior to the surgery. On the other hand, in patients with severe heart failure who are not candidates for advanced heart failure therapies, such as transplant and mechanical circulatory support, inotropic agents can be used for palliative therapy. Inotropes can help reduce frequency of hospitalizations and improve symptoms in these patients.

Safety and efficacy of digoxin: systematic review and meta-analysis of observational and controlled trial data

OBJECTIVE

To clarify the impact of digoxin on death and clinical outcomes across all observational and randomised controlled trials, accounting for study designs and methods.

DATA SOURCES AND STUDY SELECTION

Comprehensive literature search of Medline, Embase, the Cochrane Library, reference lists, and ongoing studies according to a prospectively registered design (

PROSPERO

CRD42014010783), including all studies published from 1960 to July 2014 that examined treatment with digoxin compared with control (placebo or no treatment).

DATA EXTRACTION AND SYNTHESIS

Unadjusted and adjusted data pooled according to study design, analysis method, and risk of bias.

MAIN OUTCOME MEASURES

Primary outcome (all cause mortality) and secondary outcomes (including admission to hospital) were meta-analysed with random effects modelling.

RESULTS

52 studies were systematically reviewed, comprising 621,845 patients. Digoxin users were 2.4 years older than control (weighted difference 95% confidence interval 1.3 to 3.6), with lower ejection fraction (33% v 42%), more diabetes, and greater use of diuretics and anti-arrhythmic drugs. Meta-analysis included 75 study analyses, with a combined total of 4,006,210 patient years of follow-up. Compared with control, the pooled risk ratio for death with digoxin was 1.76 in unadjusted analyses (1.57 to 1.97), 1.61 in adjusted analyses (1.31 to 1.97), 1.18 in propensity matched studies (1.09 to 1.26), and 0.99 in randomised controlled trials (0.93 to 1.05). Meta-regression confirmed that baseline differences between treatment groups had a significant impact on mortality associated with digoxin, including markers of heart failure severity such as use of diuretics (P=0.004). Studies with better methods and lower risk of bias were more likely to report a neutral association of digoxin with mortality (P<0.001). Across all study types, digoxin led to a small but significant reduction in all cause hospital admission (risk ratio 0.92, 0.89 to 0.95; P<0.001; n=29,525).

CONCLUSIONS

Digoxin is associated with a neutral effect on mortality in randomised trials and a lower rate of admissions to hospital across all study types. Regardless of statistical analysis, prescription biases limit the value of observational data.

Use of a simplified nomogram to individualize digoxin dosing versus standard dosing practices in patients with heart failure

STUDY OBJECTIVES

To compare the frequency of achieving a therapeutic serum digoxin concentration (SDC), defined as 0.5-0.9 ng/ml, by using a simplified nomogram to individualize digoxin dosing with standard dosing practices in patients with heart failure, and to characterize the relationship between genetic polymorphisms of the ABCB1 gene and SDC.

DESIGN

Prospective study with a historical control group.

SETTING

Outpatient care center of an urban academic medical center.

PATIENTS

A total of 131 adults with heart failure due to left ventricular dysfunction who were treated with digoxin.

INTERVENTION

Digoxin doses were determined either by the dosing nomogram (65 patients) or standard care (SC; 66 patients) by using historical controls who were randomly selected from a list of SDCs obtained from laboratory records and who had their digoxin doses determined by standard dosing practices.

MEASUREMENTS AND MAIN RESULTS

The primary end point was the proportion of patients achieving a steady-state SDC of 0.5-0.9 ng/ml; secondary end points were mean SDC and proportion of patients achieving a steady-state SDC lower than 1.0 ng/ml. Postdistributive steady-state SDCs were measured 2-4 weeks after digoxin dosage adjustment or initiation. Therapeutic SDCs were achieved with similar frequency in both groups (38.7% in the nomogram group vs 34.5% in the SC group, p=0.65); however, more patients in the nomogram group had SDCs lower than 1.0 ng/ml than in the SC group (85.0% vs 44.9%, p<0.001). Mean daily digoxin doses were lower in the nomogram group (149 ± 67 μg vs 177 ± 74 μg, p=0.02), resulting in lower mean SDCs compared with those in the SC group (0.52 ± 0.30 ng/ml vs 1.12 ± 0.58 ng/ml, p<0.001). Patients in the pharmacogenetic substudy provided blood samples for genotyping of three common ABCB1 single nucleotide polymorphisms: C1236T (rs1128503), G2677T/A (rs2032582), and C3435T (rs1045642). SDCs were not significantly associated with ABCB1 genotypes.

CONCLUSION

Our simplified digoxin dosing nomogram resulted in lower SDCs compared with standard dosing practices but achieved therapeutic SDCs with similar frequency. A greater proportion of patients dosed according to our nomogram had SDCs lower than 1.0 ng/ml, consistent with consensus guidelines. Genetic polymorphisms of the ABCB1 gene were not associated with SDC.

Digoxin-associated decrease in parathyroid hormone (PTH) concentrations in patients with atrial fibrillation

BACKGROUND

Parathyroid hormone (PTH) secretion is regulated mainly by the calcium sensor receptor. Recently, other components of calcium homoeostasis have been revealed, namely the effect of Klotho on stimulation of PTH secretion by the recruitment of Na-K-ATPase and by its being a cofactor in the inhibitory effect of FGF 23 on PTH secretion. It seems that ouabain, a Na-K-ATPase inhibitor, prevents the increase in PTH secretion in a hypocalcemic environment, as observed in mouse and bovine tissues. We hypothesized that digoxin, which is similar to ouabain in its effect on the sodium pump, might decrease PTH levels in humans.

METHODS

Twenty patients with atrial fibrillation were studied. Ten patients were treated with digoxin and the other ten patients with verapamil. Baseline chemistry parameters were determined and 0·25 mg digoxin injected. Plasma PTH concentrations, ionized calcium concentrations and digoxin levels were recorded at 30 min, 1 h, 2 h and 4 h postinjection.

RESULTS

Baseline blood parameters were similar in both groups. In the control group plasma PTH concentrations increased, whereas in the digoxin group, they decreased. Ionized calcium concentrations did not change over time in either groups. There seemed to be blunting of the circadian rhythm of PTH levels in the morning hours.

CONCLUSIONS

Although the patients were normocalcemic, plasma PTH concentrations decreased with digoxin treatment. The effect of the sodium pump on PTH secretion might be important in human PTH homoeostasis and might be a potential target for the treatment of disturbances in calcium homoeostasis.

Comparison of women versus men hospitalized with heart failure (from a 20-year registry in a middle-eastern country 1991-2010)

The aim of the present study was to compare the clinical characteristics, treatment, and outcomes of women and men hospitalized with heart failure (HF) in a Middle-Eastern country. A retrospective analysis of all patients hospitalized with HF in the State of Qatar from 1991 through 2010 was made. The clinical characteristics, management, and outcomes of the patients with HF were compared according to gender. A subset analysis according to ethnicity was also done (Middle Eastern Arabs vs South Asians). During the 20-year period, 2,379 women and 4,689 men were hospitalized for HF. The women were older and more likely to have diabetes mellitus, hypertension, and chronic renal impairment compared to the male patients. The women were less likely to be current smokers and to have ischemic heart disease compared to the men. Impaired left ventricular function was more common among men. The in-hospital mortality rates were comparable between the 2 groups (7.7% in women vs 8.2% in men; p = 0.4) and significantly improved with time in the 2 groups (p = 0.001). The mortality rates were comparable among the women, regardless of the ethnicity. In conclusion, overall improvement occurred in survival in patients hospitalized with HF in a Middle-Eastern country, regardless of gender. Women hospitalized with HF had mortality rates comparable to those of men.

Influence of sex on treatment and outcome in chronic heart failure

The population is aging, the prevalence of heart failure increases with age, and on average women live longer than men. There is evidence for sex-specific effects of individual, guideline-recommended drugs used for treatment of chronic heart failure. Women are underrepresented in most clinical trials and only a minority of drug applications to regulatory authorities have included sex analyses. The present review focuses on the potential female survival benefit in heart failure, the influence of sex on medical treatment in a broader sense, and the potential benefit to be derived from guideline recommended treatment and common adjunctive heart failure medication.

Cardiovascular drug therapy in the elderly

Pharmacokinetic considerations in the elderly include absorption, bioavailablility, drug distribution, half-life, drug metabolism, and drug excretion. There are numerous physiologic changes with aging that affect pharmacodynamics with alterations in end-organ responsiveness. This article discusses use of cardiovascular drugs in the elderly including digoxin, diuretics, beta-adrenergic blockers, angiotensin-converting enzyme inhibitors, angiotensin-II receptor blockers, nitrates, calcium channel blockers, alpha-adrenergic blockers, antiarrhythmic drugs, lipid-lowering drugs, and anticoagulants. This article also discusses the adverse effects of cardiovascular drugs in the elderly, medications best to avoid in the elderly, and the prudent use of medications in the elderly.

Treatment of heart failure with decreased left ventricular ejection fraction

Class I recommendations for treating patients with current or prior symptoms of heart failure with reduced left ventricular ejection fraction (LVEF) include using diuretics and salt restriction in individuals with fluid retention. Use angiotensin-converting enzyme (ACE) inhibitors, beta blockers, and angiotensin II receptor blockers if intolerant to ACE inhibitors because of cough or angioneurotic edema. Nonsteroidal anti-inflammatory drugs, most antiarrhythmic drugs, and calcium channel blockers should be avoided or withdrawn. Exercise training is recommended. Implant cardioverter-defibrillator (ICD) is recommended in individuals with a history of cardiac arrest, ventricular fibrillation, or hemodynamically unstable ventricular tachycardia. ICD is indicated in patients with ischemic heart disease for at least 40 d post-myocardial infarction or nonischemic cardiomyopathy, an LVEF of 30% or less, New York Heart Association (NYHA) class II or III symptoms on optimal medical therapy, and an expectation of survival of at least 1 yr. Cardiac resynchronization therapy should be used in individuals with an LVEF of 35% or below, NYHA class III or IV symptoms despite optimal therapy, and a QRS duration greater than 120 ms. An aldosterone antagonist can be added in selected patients with moderately severe to severe symptoms of heart failure who can be carefully monitored for renal function and potassium concentration (serum creatinine should be <or=2.5 mg/dL in men and <or=2.0 mg/dL in women; serum potassium should be <5.0 mEq/L).