Rationale and design of the DIGIT-HF trial (DIGitoxin to Improve ouTcomes in patients with advanced chronic Heart Failure): a randomized, double-blind, placebo-controlled study

AIMS

Despite recent advances in the treatment of chronic heart failure (HF), mortality and hospitalizations still remain high. Additional therapies to improve mortality and morbidity are urgently needed. The efficacy of cardiac glycosides - although regularly used for HF treatment - remains unclear. DIGIT-HF was designed to demonstrate that digitoxin on top of standard of care treatment improves mortality and morbidity in patients with HF and a reduced ejection fraction (HFrEF).

METHODS

Patients with chronic HF, New York Heart Association (NYHA) functional class III-IV and left ventricular ejection fraction (LVEF) ≤ 40%, or patients in NYHA functional class II and LVEF ≤ 30% are randomized 1:1 in a double-blind fashion to treatment with digitoxin (target serum concentration 8-18 ng/mL) or matching placebo. Randomization is stratified by centre, sex, NYHA functional class (II, III, or IV), atrial fibrillation, and treatment with cardiac glycosides at baseline. A total of 2190 eligible patients will be included in this clinical trial (1095 per group). All patients receive standard of care treatment recommended by expert guidelines upon discretion of the treating physician. The primary outcome is a composite of all-cause mortality or hospital admission for worsening HF (whatever occurs first). Key secondary endpoints are all-cause mortality, hospital admission for worsening HF, and recurrent hospital admission for worsening HF.

CONCLUSION

The DIGIT-HF trial will provide important evidence, whether the cardiac glycoside digitoxin reduces the risk for all-cause mortality and/or hospital admission for worsening HF in patients with advanced chronic HFrEF on top of standard of care treatment.

Epidemiology of overdose episodes from the period prior to hospitalization for drug poisoning until discharge in Japan: An exploratory descriptive study using a nationwide claims database

Background

Little is known about the nationwide epidemiology of the annual rate, causative substance, and clinical course of overdose-related admission. We aimed to describe the epidemiology of overdose episodes from the period prior to hospitalization for drug poisoning until discharge to home.

Methods

We assessed all cases of admission due to overdose (21,663 episodes) in Japan from October 2012 through September 2013 using the National Database of Health Insurance Claims and Specific Health Checkups of Japan.

Results

The annual rate of overdose admission was 17.0 per 100,000 population. Women exhibited two peaks in admission rates at 19–34 years (40.9 per 100,000) and ≥75 years (27.8 per 100,000). Men exhibited one peak in the admission rate at ≥75 years (23.7 per 100,000). Within 90 days prior to overdose, ≥60% and ≥9% of patients aged 19–49 years received a prescription for benzodiazepines and barbiturates, respectively. In addition, 59% of patients aged ≥75 years received a prescription for benzodiazepines prior to overdose, 47% had a history of congestive heart failure, and 24% had a diagnosis of poisoning by cardiovascular drugs. The proportion of patients with recent psychiatric treatments decreased with age (65.1% in those aged 35–49 years and 13.9% in those aged ≥75 years).

Conclusions

The findings emphasize the need for overdose prevention programs that focus on psychiatric patients aged 19–49 years who are prescribed benzodiazepines or barbiturates and on non-psychiatric patients aged ≥75 years who are prescribed benzodiazepines or digitalis.

•

Benzodiazepines were prescribed to ≥59% of overdose patients aged ≥19 years.

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Cardiovascular drugs were frequently ingested among overdose patients aged ≥75 years.

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The proportions of patients with recent psychiatric treatments decreased with age.

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Overdose prevention should be optimized according to the age-related differences.

Prospecting endophytic fungal assemblage of Digitalis lanata Ehrh. (foxglove) as a novel source of digoxin: a cardiac glycoside

Endophytes, the chemical synthesizers inside plants, are the microorganisms having mutualistic relationship with the host plant. They can be used by plants for defense in addition to the production of a wide variety of beneficial bioactive secondary metabolites. There are reports that microbial endophytes mimic the bioactive compounds as produced by the plant itself thus making them a promising source of novel compounds. During the present study, endophytes were isolated from the symptomless leaves and stem of the angiosperm, Digitalis lanata (foxglove). Digitalis lanata belongs to the family Plantaginaceae and is an important medicinal plant known for the production of an important glycoside, digoxin having valuable medicinal importance. Glycosides from Digitalis have been reported to be cardiotonic and are widely used in the treatment of various heart conditions namely atrial fibrillation, atrial flutter, heart failure, etc. Endophytic fungi were isolated from Digitalis to screen them for such glycosides as have been found in the plant itself. A total of 35 fungal endophytes were isolated and screened for the production of secondary metabolites. After preliminary analysis by thin layer chromatography for the presence of bioactive compounds, crude extracts of five fungal cultures were selected for HPLC. HPLC chromatograms revealed the production of glycoside digoxin from the five selected endophytic cultures, thus providing a novel, alternative and eco-friendly source for the production of such a pharmaceutically important and valuable drug.

Ouabain prevents pathological cardiac hypertrophy and heart failure through activation of phosphoinositide 3-kinase α in mouse

Background

Use of low doses of digitalis to prevent the development of heart failure was advocated decades ago, but conflicting results of early animal studies dissuaded further research on this issue. Recent discoveries of digitalis effects on cell signal pathways prompted us to reexamine the possibility of this prophylactic action of digitalis. The specific aim of the present study was to determine if subinotropic doses of ouabain would prevent pressure overload-induced cardiac remodeling in the mouse by activating phosphoinositide 3-kinase α (PI3Kα).

Results

Studies were done on an existing transgenic mouse deficient in cardiac PI3Kα (p85-KO) but with normal cardiac contractility, a control mouse (Con), and on cultured adult cardiomyocytes. In Con myocytes, but not in p85-KO myocytes, ouabain activated PI3Kα and Akt, and caused cell growth. This occurred at low ouabain concentrations that did not activate the EGFR-Src/Ras/Raf/ERK cascade. Con and p85-KO mice were subjected to transverse aortic constriction (TAC) for 8 weeks. A subinotropic dose of ouabain (50 µg/kg/day) was constantly administrated by osmotic mini-pumps for the first 4 weeks. All mice were monitored by echocardiography throughout. Ouabain early treatment attenuated TAC-induced cardiac hypertrophy and fibrosis, and improved cardiac function in TAC-operated Con mice but not in TAC-operated p85-KO mice. TAC downregulated α2-isoform of Na⁺/K⁺-ATPase but not its α1-isoform in Con hearts, and ouabain treatment prevented the downregulation of α2-isoform. TAC-induced reduction of α2-isoform did not occur in p85-KO hearts.

Conclusions

Our results show that (a) safe doses of ouabain prevent or delay cardiac remodeling of pressure overloaded mouse heart; and (b) these prophylactic effects are due to ouabain binding to α2-isoform resulting in the selective activation of PI3Kα. Our findings also suggest that potential prophylactic use of digitalis for prevention of heart failure in man deserves serious consideration.

Electronic supplementary material

The online version of this article (doi:10.1186/s13578-015-0053-7) contains supplementary material, which is available to authorized users.

Digoxin intoxication: An old enemy in modern era

Objectives

Although development of new treatment modalities limited digoxin usage, digoxin intoxication is still an important issue which could be easily overlooked. In this report, we analyzed a case series definitively diagnosed as digoxin intoxication in the modern era.

Methods

We analyzed 71 patients hospitalized with digoxin intoxication confirmed by history, complaints, clinical and electrocardiograph (ECG) findings, and serum digoxin levels > 2.0 ng/mL, during a five year period. The demographic and clinical data, indications for digoxin use, digoxin dosage, concurrent medications, laboratory data, hospital monitoring, and ECG findings were obtained from all patients.

Results

Thirty-eight of 71 patients (53.5%) had symptoms of heart failure during admission or later. Sixty-four percent of patients were older than 75 years. The percentage of females was 67%. Atrial fibrillation, hypertension and gastrointestinal complaints were more frequent in the females (64% in females, 30% in males, P = 0.007; 81% in female, 52% in males, P = 0.01; 50% in female, 17.3% in males, P = 0.008, respectively). The mortality rate during the hospital course was 7%.

Conclusions

This report demonstrated the reduced mortality rates in patients with digoxin intoxication over the study period. Gastrointestinal complaints are the most common symptoms in this population.

Cardioprotective effects of garcinol following myocardial infarction in rats with isoproterenol-induced heart failure

Myocardial infarction is a clinical form of necrosis in the myocardium caused by an imbalance between the coronary blood supply and myocardial demand. Garcinol is a polyisoprenylated benzophenone found in the fruit of Garcinia indica, which is abundant in tropical regions. This fruit contains high levels of garcinol, isoxanthochymol, isogarcinol, hydroxycitric acid and xanthochymol. Garcinol and hydroxycitric acid have been shown to have antioxidant effects. In this study, rats were assigned to sham, control, low-dose, high-dose and positive control groups. Hemodynamic and apoptotic markers were evaluated, and histopathological analysis was conducted. The mRNA and protein levels of caspase-3, Bax, Bcl-2 and cleaved caspase-3 were quantified. Garcinol treatment increased the heart rate and improved the maximum rate of increase in left-ventricle (LV) pressure (+dp/dt_max), maximum rate of decrease in LV pressure (–dp/dt_max), LV ejection fraction and LV systolic pressure in rats with induced heart failure. Garcinol treatment reversed body, liver and heart weight changes, resulting in returns to near-normal levels. In the garcinol treatment group, the number of broken fibers, extent of inflammatory cell infiltration and rate of apoptosis remained within normal ranges. Garcinol reduced the cross-sectional areas of cardiomyocytes, and reduced interstitial fibrosis to a normal level. The mRNA and protein levels of cleaved caspase-3, caspase-3 and Bax were reduced, whereas those of Bcl-2 were increased, following high-dose (100 mg/kg) garcinol treatment. These findings suggest that garcinol effectively prevents apoptosis in rats with isoproterenol-induced heart failure and in cardiac H9C2 cells.

An Overview of Cardenolides in Digitalis - More Than a Cardiotonic Compound

The genus Digitalis L. containing species, commonly known as the "foxglove", is the main source of cardenolides, which have various pharmacological properties effective against certain pathological conditions including myocardial infarction, arterial hypertension, cardiac dysfunction, angina, and hypertrophy. Togehter with a prime effect of controlling the heart rhythm, many workers demonstrated that lanatoside C and some other cardiac glycosides are effective in several cancer treatments such as prostate and breast cancers. Due to digoxigenin derivatives of cardenolides, which are mainly used for medicinal purposes, such as digoxigenin, D. lanata as a main source is of great interest for commercial scale production of cardenolides in Europe. Phytochemical studies on cardenolides, naturally occurring plant secondary metabolites, have mainly focused on the species of the genus Digitalis L., as the members of this family have a high level and diverse content of cardenolides. During the last few decades, plant tissue culture techniques have been optimised for many plant species including Digitalis, however, the production capacity of cardenolides somehow failed to reach a commercially desired extent. In this review paper, the genus Digitalis is evaluated in terms of its main botanical and physiological features, traditional uses, molecular genetics and metabolomics, cellular mechanism of action, medicinal uses, clinical pharmacology, drug interactions, therapy in the management of cardiovascular disorders, potential utility of therapy in extracardiac conditions, and toxicity.

Association of digitalis treatment with outcomes following myocardial infarction in patients with heart failure or evidence of left ventricular dysfunction: an analysis from the High-Risk Myocardial Infarction Database Initiative

BACKGROUND

Contradictory findings have been reported regarding the safety and efficacy of digitalis in patients recovering from acute myocardial infarction (MI). We studied the association of digitalis use with long-term and short-term prognosis in patients presenting with an acute MI complicated with heart failure (HF), left ventricular dysfunction, or both.

METHODS AND RESULTS

Using the High-Risk MI Database Initiative combining data from 4 major clinical trials, totaling 27,673 patients, we investigated the association between digitalis use at baseline (3093 patients with digitalis and 24,580 without) with the rate of all-cause death, sudden cardiac death, cardiovascular death, HF hospitalization and the combination of the latter two, over a mean follow-up time of 2.7 years. Patients with and without atrial fibrillation (AF) were studied separately. After a propensity score-based analysis, among patients without AF, those receiving digitalis experienced a higher rate of all-cause [hazard ratio (HR) 1.54, 95% confidence interval (CI) 1.42-1.67] and sudden cardiac death (HR 1.65, 95% CI 1.44-1.89), compared to those not receiving digitalis; similar results were found for the other 3 endpoints (all HR around 1.6). In contrast, in AF patients, digitalis had a milder effect on all outcomes (all HR ≤ 1.12), with significant association only for the composite endpoint (HR 1.10, 95% CI 1.00-1.21, p = 0.049); comparable results were obtained at 30 days. Finally, the detrimental effect associated with digitalis use appeared to be more pronounced in patients with ejection fraction ≥ 40%.

CONCLUSIONS

In MI survivors with HF and/or systolic dysfunction, digitalis was associated with a significant increased risk of death in patients without AF with mild to neutral associations for patients with AF. These findings raise concerns regarding the safety of digitalis in MI survivors with HF, especially for those without AF.

Combined amiodarone and digitalis therapy before heart transplantation is associated with increased post-transplant mortality

Aims

Amiodarone and digitalis are frequently used drugs in patients with heart failure. Both have separately been linked to reduced post‐transplant survival, but their combined impact on mortality after HTX remains uncertain. This study investigated the effects of combined amiodarone and digitalis use before HTX on post‐transplant outcomes.

Methods and results

This registry study analysed 600 patients receiving HTX at Heidelberg Heart Center between 1989 and 2016. Patients were stratified by amiodarone and digitalis use before HTX. Analysis included patient characteristics, medication, echocardiographic features, heart rates, permanent pacemaker implantation, atrial fibrillation, and post‐transplant survival including causes of death. One hundred eighteen patients received amiodarone before HTX (19.7%), hereof 67 patients with digitalis (56.8%) and 51 patients without digitalis before HTX (43.2%). Patients with and without amiodarone before HTX showed a similar 1 year post‐transplant survival (72.0% vs. 78.4%, P = 0.11), but patients with combined amiodarone and digitalis before HTX had a worse 1 year post‐transplant survival (64.2%, P = 0.01), along with a higher percentage of death due to transplant failure (P = 0.03). Echocardiographic analysis of these patients showed a higher percentage of an enlarged right ventricle (P = 0.02), left atrium (P = 0.02), left ventricle (P = 0.03), and a higher rate of reduced left ventricular ejection fraction (P = 0.03). Multivariate analysis indicated combined amiodarone and digitalis use before HTX as a significant risk factor for 1 year mortality after HTX (hazard ratio: 1.69; 95% confidence interval: 1.02–2.77; P = 0.04).

Conclusions

Combined pre‐transplant amiodarone and digitalis therapy is associated with increased post‐transplant mortality.

Impact of Digitalis Use on Mortality in Japanese Patients With Non-Valvular Atrial Fibrillation - A Subanalysis of the J-RHYTHM Registry

BACKGROUND

Because the influence of digitalis use on the death of patients with non-valvular atrial fibrillation (NVAF) remains controversial, a subanalysis of the J-RHYTHM Registry was performed.

METHODS AND RESULTS

A consecutive series of outpatients with AF from 158 institutions was enrolled and followed for 2 years or until the occurrence of an event. Among 7,406 patients with NVAF, 7,018 (age, 69.7±10.0 years; men, 71.1%) with information on antiarrhythmic drug and digitalis use at baseline were divided into 2 groups based on digitalis use. The influence of digitalis on death was investigated using a propensity score-matching model. In 802 patients treated with digitalis, all-cause death was significantly higher than in 6,216 patients with no digitalis use during the 2-year follow-up period (4.4% vs. 2.4%, unadjusted P<0.001). Digitalis use was significantly associated with all-cause death in the crude model (hazard ratio [HR] 1.85, 95% confidence interval [CI] 1.28-2.68, P=0.001). However, after propensity score-matching, the association was not significant (HR 1.31, 95% CI 0.70-2.46, P=0.405). Older age, male sex, heart failure, coronary artery disease, and lower body mass index were significantly associated with all-cause death in NVAF patients treated with digitalis.

CONCLUSIONS

Digitalis use was not independently associated with all-cause death, and several clinical confounding factors might contribute to increased mortality in NVAF patients treated with digitalis.

Non-β-Blocking Carvedilol Analog, VK-II-86, Prevents Ouabain-Induced Cardiotoxicity

BACKGROUND

It has been shown that carvedilol and its non β-blocking analog, VK-II-86, inhibit spontaneous Ca2+ release from the sarcoplasmic reticulum (SR). The aim of this study is to determine whether carvedilol and VK-II-86 suppress ouabain-induced arrhythmogenic Ca2+ waves and apoptosis in cardiac myocytes.

METHODS AND RESULTS

Rat cardiac myocytes were exposed to toxic doses of ouabain (50 µmol/L). Cell length (contraction) was monitored in electrically stimulated and non-stimulated conditions. Ouabain treatment increased contractility, frequency of spontaneous contractions and apoptosis compared to control cells. Carvedilol (1 µmol/L) or VK-II-86 (1 µmol/L) did not affect ouabain-induced inotropy, but significantly reduced the frequency of Ca2+ waves, spontaneous contractions and cell death evoked by ouabain treatment. This antiarrhythmic effect was not associated with a reduction in Ca2+ calmodulin-dependent protein kinase II (CaMKII) activity, phospholamban and ryanodine receptor phosphorylation or SR Ca2+ load. Similar results could be replicated in human cardiomyocytes derived from stem cells and in a mathematical model of human myocytes.

CONCLUSIONS

Carvedilol and VK-II-86 are effective to prevent ouabain-induced apoptosis and spontaneous contractions indicative of arrhythmogenic activity without affecting inotropy and demonstrated to be effective in human models, thus emerging as a therapeutic tool for the prevention of digitalis-induced arrhythmias and cardiac toxicity.

Designing and construction of genetically encoded FRET-based nanosensor for qualitative analysis of digoxin

Nanobiotechnological improvements defined on the utilization of biological materials and principles have enormously partaken to revolutionize physical, chemical, and biological sciences. However, the exploration of plant nanobiotechnology is still in its outset. The search for novel tools to monitor plant biomolecules is an emerging issue for the nanobiotechnologists. Given this, a genetically encoded FRET-based nanobiosensor has been developed to monitor the popular plant cardiac glycoside - digoxin, which is used as the most common prescription drug for heart-related illnesses across the world. Digoxin is sourced from the leaves of the foxglove plant (Digitalis purpurea L.) and has a significant demand in the medical sector. Moreover, with the rising popularity of the herbal formulations in the global market, attention towards the authentication and quality control of the herbal drugs is important. Furthermore, digoxin has a very narrow therapeutic range, i.e., 0.6 nM - 2.6 nM. Therefore, strict monitoring of blood digoxin levels is necessary. Besides, previously used techniques for drug authentication and quantification of small-molecule drugs in blood samples are not the best choice available. The nanobiosensor is based on the FRET (Fluorescence Resonance Energy Transfer) mechanism, and it is constructed in such a way that it gives a changed FRET output in the presence of digoxin. Two fluorophores, enhanced cyan fluorescent protein (ECFP) and Venus, were attached on either end of the sensory domain - human nuclear receptor ROR-gamma (RORγt). The developed nanobiosensor was named as fluorescent indicator protein for digoxin, (FLIP-digoxin). The ligand binding affinity of FLIP-digoxin was calculated as 425 μM. Affinity mutants of the FLIP-digoxin were also generated to measure digoxin in wide concentration ranges. This sensor offers high-throughput qualitative analysis of digoxin in Digitalis preparations procured from local drug stores. It confirms the authenticity of the preparations through the detection of digoxin. The FLIP-1n was also able to monitor digoxin concentration in serum samples in lesser than 5 min. The nanobiosensor was found pH stable, digoxin-specific, non- interfered by the biological serum species and can perform high throughput screening of the Digitalis powder, infusion and tincture preparations.

Effect of digitalis level on readmission and mortality rate among heart failure reduced ejection fraction patients

INTRODUCTION

Digitalis has been used for over 200 years to treat patients with heart failure, and evidence supports its use to improve clinical symptoms and quality of life, but not survival. The objective of this retrospective study was to evaluate the effects of digitalis on readmission and mortality in patients with heart failure with reduced ejection fraction (HFrEF) who were receiving current guideline recommended medical therapy.

METHODS

We reviewed medical record data from a retrospective cohort study of 1047 patients admitted to the hospital from 2005 to 2014 with decompensated HFrEF. 244 received digitalis, at some point during patient trajectory, and 803 never received digitalis. The primary outcomes of interest were the length of stay in hospital, readmission rates after discharge at 1, 6, 12, and 24 months and the overall mortality rate, at the same time points.

RESULTS

We studied the effects of digitalis after adjusting for age, sex, race, potentially confounding comorbidities, and prescription medications. Digitalis treatment is associated with decreases in EF in patients with HFrEF (OR = -2.83, P < 0.001) and was associated with an increased readmission rate for any reason after discharge from the hospital at 6, 12, and 24 months, 53%, 34%, and 35%, respectively. No statistically significant difference was found between patients who received digitalis and those who did not (referent group) for the length of hospital stay and overall mortality rate.

CONCLUSION

Digitalis use is associated with increased re-admission rates for any reason following discharge from the hospital at 6, 12, and 24 months.

Unusual digoxin toxicity with myocardial injury

A 38-year-old healthy male presented with vomiting and profuse diarrhea, associated with blurry and yellow coloration of the vision (xanthopsia). Laboratory workup was unremarkable, except for hyperkalemia (K 5.2 mEq/L) and mildly elevated troponin level 0.11 ng/mL (cut-off value 0.08). An electrocardiogram showed sinus bradycardia with deep scooping of the T waves. Although the patient denied intake of any drugs, herbs, consumption of plants, a digoxin level was drawn and was significantly elevated >5ng/mL (therapeutic range 0.8-2.0). Further questioning revealed that the patient was a pharmacist mixing raw material to fabricate medication, and that he could have incidentally ingested contaminated water. His symptoms improved with parallel improvement in the electrocardiogram T wave abnormalities. An echocardiogram was normal. The positive troponin was felt to be secondary to severe digoxin toxicity. Review of the literature however showed no report of elevated troponin in the setting of digoxin toxicity.

Predicting the physiological response of Tivela stultorum hearts with digoxin from cardiac parameters using artificial neural networks

Multi-layer perceptron artificial neural networks (MLP-ANNs) were used to predict the concentration of digoxin needed to obtain a cardio-activity of specific biophysical parameters in Tivela stultorum hearts. The inputs of the neural networks were the minimum and maximum values of heart contraction force, the time of ventricular filling, the volume used for dilution, heart rate and weight, volume, length and width of the heart, while the output was the digoxin concentration in dilution necessary to obtain a desired physiological response. ANNs were trained, validated and tested with the dataset of the in vivo experiment results. To select the optimal network, predictions for all the dataset for each configuration of ANNs were made, a maximum 5% relative error for the digoxin concentration was set and the diagnostic accuracy of the predictions made was evaluated. The double-layer perceptron had a barely higher performance than the single-layer perceptron; therefore, both had a good predictive ability. The double-layer perceptron was able to obtain the most accurate predictions of digoxin concentration required in the hearts of T. stultorum using MLP-ANNs.

Digitalis therapy is associated with higher comorbidities and poorer prognosis in patients undergoing ablation of atrial arrhythmias: data from the German Ablation Registry

BACKGROUND

Digitalis glycosides are employed for rate control of atrial fibrillation. Recent studies suggested potential harmful effects of digitalis monotherapy and combination with antiarrhythmic drugs. The aim of the present study was to assess the prevalence and potential impact of digitalis therapy on outcome in patients undergoing catheter ablation of supraventricular arrhythmias.

METHODS AND RESULTS

The German Ablation Registry is a nationwide, prospective registry with a 1-year follow-up investigating 12,566 patients receiving catheter ablations of supraventricular arrhythmias in 52 German centres. The present analysis focussed on pharmacotherapy in 8608 patients undergoing catheter ablation of atrial tachycardia, atrial fibrillation, or atrial flutter. Patients receiving digitalis therapy (n = 417) were older and presented a significantly increased prevalence of comorbidities including coronary artery disease, heart failure, diabetes, and pulmonary disease. One-year mortality was significantly higher in digitalis-treated patients (4.7% vs. 1.3%, p < 0.001), most strikingly in patients undergoing ablation of atrial flutter. This effect was maintained after adjustment for important risk factors. Similar results were obtained for as the combined endpoint of death, myocardial infarction, stroke and major bleeding (6.6% vs. 2.7%, p < 0.001), and non-fatal rehospitalisations (54.1% vs. 45.1%, p = 0.001).

CONCLUSION

In the present study of patients undergoing catheter ablation of supraventricular arrhythmias, an association of digitalis therapy with increased mortality and an increased rate of other severe adverse events were observed. The results from this 'real-life' registry are consistent with previously published studies. However, whether digitalis therapy promotes a poorer prognosis or may just serve as a marker for this aspect cannot be thoroughly interpreted.

General Anesthetic Management of a Patient With Hypertrophic Cardiomyopathy for Oral Surgery: Did Digitalis Contribute to Bradycardia?

Stabilization of circulatory dynamics is a critical issue in the anesthetic management of patients with hypertrophic cardiomyopathy (HCM). In this report, we managed general anesthesia for a 74-year-old male patient with nonobstructive HCM who developed circulatory instability intraoperatively. Severe bradycardia measuring 35 beats/min and hypotension measuring 78 mm Hg systolic were observed during surgery. Using stroke volume variation and stroke volume from the FloTrac as indices, successful circulatory management was performed with dopamine. The hypotension and bradycardia were thought to be the result of methyldigoxin and possibly associated with our perioperative management. Cardiology consult should have been obtained. We demonstrated that the FloTrac can be beneficial in diagnosing and managing cardiovascular instability and administration of dopamine in the anesthetic management of nonobstructive HCM patients.

Comparative Therapeutic Potential of Cardioactive Glycosides in Doxorubicin Model of Heart Failure

In the present study, we investigated the cardioactive glycosides oleandrin and ouabain, and compared them to digoxin in a model of cardiotoxicity induced by doxorubicin. Adult rats were distributed into four experimental groups. Each group was challenged with a single intraperitoneal application of doxorubicin at a dose of 12 mg/kg. Then, they were treated with saline solution and the glycosides oleandrin, ouabain, and digoxin at a dose of 50 µg/kg, for 7 days. They underwent echocardiography, electrocardiography, hematologic, biochemical tests, and microscopic evaluation of the heart. All animals presented congestive heart failure, which was verified by a reduction in the ejection fraction. Oleandrin and digoxin were able to significantly reduce (p < 0.05) the eccentric remodeling caused by doxorubicin. Oleandrin and digoxin were significantly lower (p < 0.05) than the control group in maintaining systolic volume and left ventricular volume in diastole. Other parameters evaluated did not show significant statistical differences. All animals showed an increase in erythrocyte count, and an increase in the duration of the QRS complex on the ECG and myocardial necrosis at the histopathological analysis. It is concluded that the glycosides oleandrin, ouabain, and digoxin in the used dosage do not present therapeutic potential for the treatment of congestive heart failure caused by doxorubicin.

[Not Available]

Zusammenfassung. Wir präsentieren den Fall einer 23-jährigen Patientin, die in suizidaler Absicht Blätter des Roten Fingerhutes sammelte und einnahm. Trotz Einnahme einer relevanten Dosis hatte sie jedoch nur geringe Symptome. Intoxikationen mit Herzglykosiden sind selten, können aber relevante Herzrhythmusstörungen verursachen. Die einzige wirksame Behandlung stellt die frühzeitige und ggf. prophylaktische Gabe von digitalisspezifischen Fab-Antikörpern dar.

Digitalis Therapy and Risk of Recurrent Ventricular Tachyarrhythmias and ICD Therapies in Atrial Fibrillation and Heart Failure

OBJECTIVE

This study sought to assess the impact of treatment with digitalis on recurrences of ventricular tachyarrhythmias in implantable cardioverter defibrillator (ICD) recipients with atrial fibrillation (AF) and heart failure (HF).

BACKGROUND

The data regarding outcomes of digitalis therapy in ICD recipients are limited.

METHODS

A large retrospective registry was used, including consecutive ICD recipients with episodes of ventricular tachyarrhythmia between 2002 and 2016. Patients treated with digitalis were compared to patients without digitalis treatment. The primary prognostic outcome was first recurrence of ventricular tachyarrhythmia at 5 years. Kaplan-Meier and multivariable Cox regression analyses were applied.

RESULTS

A total of 394 ICD recipients with AF and/or HF was included (26% with digitalis treatment and 74% without). Digitalis treatment was associated with decreased freedom from recurrent ventricular tachy-arrhythmias (HR = 1.423; 95% CI 1.047-1.934; p = 0.023). Accordingly, digitalis treatment was associated with decreased freedom from appropriate ICD therapies (HR = 1.622; 95% CI 1.166-2.256; p = 0.004) and, moreover, higher rates of rehospitalization (38 vs. 21%; p = 0.001) and all-cause mortality (33 vs. 20%; p = 0.011).

CONCLUSION

Among ICD recipients suffering from AF and HF, treatment with digitalis was associated with increased rates of recurrent ventricular tachyarrhythmias and ICD therapies. However, the endpoints may also have been driven by interactions between digitalis, AF, and HF.

Utilizing Big Data to Identify Tiny Toxic Components: Digitalis

The botanical genus Digitalis is equal parts colorful, toxic, and medicinal, and its bioactive compounds have a long history of therapeutic use. However, with an extremely narrow therapeutic range, even trace amounts of Digitalis can cause adverse effects. Using chemical methods, the United States Food and Drug Administration traced a 1997 case of Digitalis toxicity to a shipment of Plantago (a common ingredient in dietary supplements marketed to improve digestion) contaminated with Digitalis lanata. With increased accessibility to next generation sequencing technology, here we ask whether this case could have been cracked rapidly using shallow genome sequencing strategies (e.g., genome skims). Using a modified implementation of the Site Identification from Short Read Sequences (SISRS) bioinformatics pipeline with whole-genome sequence data, we generated over 2 M genus-level single nucleotide polymorphisms in addition to species-informative single nucleotide polymorphisms. We simulated dietary supplement contamination by spiking low quantities (0-10%) of Digitalis whole-genome sequence data into a background of commonly used ingredients in products marketed for "digestive cleansing" and reliably detected Digitalis at the genus level while also discriminating between Digitalis species. This work serves as a roadmap for the development of novel DNA-based assays to quickly and reliably detect the presence of toxic species such as Digitalis in food products or dietary supplements using genomic methods and highlights the power of harnessing the entire genome to identify botanical species.

Repurposing cardiac glycosides for anticancer treatment: a review of clinical studies

Cardiac glycosides (CGs), which are traditionally used for heart disease, show promise for cancer therapy. However, there is a lack of a comprehensive review of clinical studies in this area, and so far, CGs have not been widely integrated into clinical cancer treatment. This review covers clinical studies from the past five years, highlighting the potential of CGs to reduce cancer risk, enhance chemotherapy effectiveness, mitigate chemotherapy-induced side effects and improve quality of life. Future clinical trials should personalize the dosage of CGs, integrate molecular testing and investigate immunogenic cell death induction and the potential of CGs for treating bone cancer and metastasis. Optimizing the repurposing of CGs for anticancer treatment requires consideration of specific CGs, cancer types and concurrent medications.

Differential expression of 3β-HSD and mlncRNAs in response to abiotic stresses in Digitalis nervosa

Digitalis nervosa is an important medicinal plant species belonging to the family of Scrophulariaceae that has the potential to be used for heart failure. 3β-hydroxysteroid dehydrogenase (3β-HSD) is a key gene in the biosynthesis of cardenolides for making digitalis effective compounds, hence identification of this gene is important for genetic engineering purposes towards increasing the yield of cardiac glycosides. In addition, mRNA-like non-coding RNAs (mlncRNAs), a class of long non coding RNAs, play key roles in various biological processes and may affect cardenolides pathway in digitalis plants.  In the present work, full sequence of 3β-HSD was isolated from Digitalis nervosa. Gene expression patterns of 3β-HSD along with three mlncRNAs including mlncRNA23, mlncRNA28 and mlncRNA30 were studied and the results indicated that they are differentially expressed in different tissues including roots, stems and leaves, with the highest expression levels in leaves.  Moreover, the transcript levels of these genes affected by the cold and drought stresses. The results obtained from the present study is important in order to understand the potential role of mlncRNAs in digitalis plants, especially in response to abiotic stresses.