A comparison of oral milrinone, digoxin, and their combination in the treatment of patients with chronic heart failure

The drug risks of cilostazol: A pharmacovigilance study of FDA Adverse Event Reporting System database

OBJECTIVE

Cilostazol is indicated for alleviating intermittent claudication (IC) in stable-phase peripheral arterial disease (PAD) patients. Conducting data mining on adverse events (AEs) of cilostazol in the U.S. Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) database to explore its potential medication risks and advance more rational and secure clinical medication practices.

METHODS

This study utilized the Open Vigil 2.1-MedDRA tool to retrieve and extract AE reporting data related to cilostazol from the FAERS database spanning the first quarter of 2004 to the first quarter of 2024. The primary methodology employed was the application of the reporting odds ratio (ROR) method to detect risk signals associated with AEs of cilostazol.

RESULTS

A total of 2,130 AE reports involving cilostazol were identified as the primary suspect drug, with a total of 7,134 AEs reported. These reports were predominantly concentrated among patients aged 60 and above, with a higher occurrence in males compared to females. Japan ranked first among the reporting countries, and the majority of reports were submitted by healthcare professionals. Through the screening of cilostazol, a total of 323 positive risk signals for AEs were identified, encompassing 23 system organ classes (SOCs). A comparison with the existing cilostazol product label revealed 8 AEs that were not included based on the number of AE reports, and 19 AEs that were not included based on the strength of the risk signals. Cilostazol exhibited positive risk signals for AEs primarily affecting 8 organ systems based on the SOC classification. Among these, cardiac disorders ranked highest, with a total of 53 positive risk signals for cardiovascular-related AEs identified. In terms of the number of reports, cardiac failure ranked first, aligning with the black box warning issued by the FDA regarding cilostazol. The occurrence of adverse reactions related to cilostazol is primarily concentrated within the first month of treatment. However, a certain proportion of adverse reactions have been reported to occur after long-term use (exceeding 360 days) of cilostazol therapy.

CONCLUSION

Our results have further enriched the observations from existing clinical and real-world studies, uncovering new AE signals for cilostazol, including fall, cerebral infarction, pneumonia, loss of consciousness, acute kidney injury, renal impairment, renal failure, cardiac vein perforation, basal ganglia haematoma, cerebral hyperperfusion syndrome, et al. This study also highlights the significant impact of cilostazol on the cardiovascular system, necessitating close attention to potential cardiovascular toxicities. In addition to focusing on the short-term adverse reactions following cilostazol administration, thorough research into its long-term safety profile is also imperative. This study provides recommendations and guidance for the rational and safe clinical use of cilostazol. In the future, prospective studies are needed to explore the occurrence of related AEs further.

Consequences of Discontinuing Long-Term Drug Treatment in Patients With Heart Failure and Reduced Ejection Fraction

There is uncertainty regarding the clinical effects of discontinuation of drugs for heart failure after long-term use. The withdrawal of long-term treatment can follow 1 of 4 distinct patterns: 1) loss of on-treatment effect with no observed changes following discontinuation (eg, prazosin); 2) attenuation or loss of on-treatment effect with rebound clinical worsening following discontinuation (eg, nitroprusside); 3) persistence of deleterious on-treatment effect followed by clinical worsening after discontinuation (eg, milrinone and flosequinan); and 4) persistence of favorable on-treatment effect followed by clinical worsening after discontinuation (eg, digoxin and sodium-glucose cotransporter 2 inhibitors). Persuasive evidence for persistence of efficacy has been demonstrated for the use of digoxin, diuretic agents, sodium-glucose cotransporter 2 inhibitors, and (to a limited extent) for angiotensin-converting enzyme inhibitors. Available evidence for worsening of clinical status following the withdrawal of neurohormonal antagonists largely consists of observational studies. However, their findings are difficult to interpret because of considerable confounding related to the fact that drugs were withdrawn for clinical reasons, which represented a more important contributor to the poor outcome of these patients than the withdrawal of an effective drug. Nevertheless, the totality of available evidence points to a meaningful clinical deterioration within a few weeks following the withdrawal for most drugs that have been evaluated for the treatment of heart failure. These findings suggests that that our current emphasis on the implementation of foundational drugs needs to include an equally important emphasis to avoid even short-term gaps in treatment.

Comparative Effectiveness and Safety of Intermittent, Repeated, or Continuous Use of Levosimendan, Milrinone, or Dobutamine in Patients With Advanced Heart Failure: A Network and Single-Arm Meta-analysis

ABSTRACT

The aim of this study was to synthesize the available evidence regarding differences in the long-term safety and efficacy of intermittent, repeated, or continuous palliative inotropic therapy among patients with advanced heart failure. We systematically searched the PubMed, Embase, and Cochrane Library electronic databases, with a cutoff date of November 23, 2023, for studies reporting outcomes in adult patients with advanced heart failure treated with intermittent, repeated, or continuous levosimendan, milrinone, or dobutamine. Forty-one studies (18 randomized controlled trials and 23 cohort studies) comprising 5137 patients met the inclusion criteria. The results of the network meta-analysis of randomized controlled trials showed that levosimendan had significant advantages over milrinone or dobutamine in reducing mortality and improving left ventricular ejection fraction. A single-arm meta-analysis also indicated that levosimendan had the lowest mortality and significantly improved B-type brain natriuretic peptide and left ventricular ejection fraction. Regarding safety, hypotension events were observed more frequently in the levosimendan and milrinone groups. However, the current evidence is limited by the heterogeneity and relatively small sample size of the studies.

Abnormal phosphorylation / dephosphorylation and Ca2+ dysfunction in heart failure

Heart failure (HF) can be caused by a variety of causes characterized by abnormal myocardial systole and diastole. Ca2+ current through the L-type calcium channel (LTCC) on the membrane is the initial trigger signal for a cardiac cycle. Declined systole and diastole in HF are associated with dysfunction of myocardial Ca2+ function. This disorder can be correlated with unbalanced levels of phosphorylation / dephosphorylation of LTCC, endoplasmic reticulum (ER), and myofilament. Kinase and phosphatase activity changes along with HF progress, resulting in phased changes in the degree of phosphorylation / dephosphorylation. It is important to realize the phosphorylation / dephosphorylation differences between a normal and a failing heart. This review focuses on phosphorylation / dephosphorylation changes in the progression of HF and summarizes the effects of phosphorylation / dephosphorylation of LTCC, ER function, and myofilament function in normal conditions and HF based on previous experiments and clinical research. Also, we summarize current therapeutic methods based on abnormal phosphorylation / dephosphorylation and clarify potential therapeutic directions.

Phosphodiesterase in heart and vessels: from physiology to diseases

Phosphodiesterases (PDEs) are a superfamily of enzymes that hydrolyze cyclic nucleotides, including cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). Both cyclic nucleotides are critical secondary messengers in the neurohormonal regulation in the cardiovascular system. PDEs precisely control spatiotemporal subcellular distribution of cyclic nucleotides in a cell- and tissue-specific manner, playing critical roles in physiological responses to hormone stimulation in the heart and vessels. Dysregulation of PDEs has been linked to the development of several cardiovascular diseases, such as hypertension, aneurysm, atherosclerosis, arrhythmia, and heart failure. Targeting these enzymes has been proven effective in treating cardiovascular diseases and is an attractive and promising strategy for the development of new drugs. In this review, we discuss the current understanding of the complex regulation of PDE isoforms in cardiovascular function, highlighting the divergent and even opposing roles of PDE isoforms in different pathogenesis.

Use of Inotropic Agents in Advanced Heart Failure: Pros and Cons

BACKGROUND

Use of inotropic agents in advanced heart failure (HF) has over time been evaluated in several randomized, controlled clinical trials (RCTs). However, the evidence for both efficacy and safety is conflicting.

SUMMARY

In this narrative review, the evidence for and role of inotropes in advanced HF are outlined. Readers are provided with a comprehensive overview of key-findings from 23 important RCTs comparing orally or intravenously administered inotropes. Clinically relevant pros and cons of inotropic regimens are summarized to guide the clinician in the management of advanced HF patients in different settings (e.g., out-patient, in-patient, and intensive care unit). Finally, future perspectives and potential new agents are discussed.

KEY MESSAGES

Long-term use of inotropes in advanced HF is controversial and should only be considered in selected patients (e.g., as palliative or bridging strategy). However, short-term use continues to play a large role in hospitalized patients with cardiogenic shock or severe decompensated acute HF.

Engineered cardiac tissue model of restrictive cardiomyopathy for drug discovery

Restrictive cardiomyopathy (RCM) is defined as increased myocardial stiffness and impaired diastolic relaxation leading to elevated ventricular filling pressures. Human variants in filamin C (FLNC) are linked to a variety of cardiomyopathies, and in this study, we investigate an in-frame deletion (c.7416_7418delGAA, p.Glu2472_Asn2473delinAsp) in a patient with RCM. Induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) with this variant display impaired relaxation and reduced calcium kinetics in 2D culture when compared with a CRISPR-Cas9-corrected isogenic control line. Similarly, mutant engineered cardiac tissues (ECTs) demonstrate increased passive tension and impaired relaxation velocity compared with isogenic controls. High-throughput small-molecule screening identifies phosphodiesterase 3 (PDE3) inhibition by trequinsin as a potential therapy to improve cardiomyocyte relaxation in this genotype. Together, these data demonstrate an engineered cardiac tissue model of RCM and establish the translational potential of this precision medicine approach to identify therapeutics targeting myocardial relaxation.

Cyclic nucleotide phosphodiesterases as therapeutic targets in cardiac hypertrophy and heart failure

Cyclic nucleotide phosphodiesterases (PDEs) modulate the neurohormonal regulation of cardiac function by degrading cAMP and cGMP. In cardiomyocytes, multiple PDE isozymes with different enzymatic properties and subcellular localization regulate local pools of cyclic nucleotides and specific functions. This organization is heavily perturbed during cardiac hypertrophy and heart failure (HF), which can contribute to disease progression. Clinically, PDE inhibition has been considered a promising approach to compensate for the catecholamine desensitization that accompanies HF. Although PDE3 inhibitors, such as milrinone or enoximone, have been used clinically to improve systolic function and alleviate the symptoms of acute HF, their chronic use has proved to be detrimental. Other PDEs, such as PDE1, PDE2, PDE4, PDE5, PDE9 and PDE10, have emerged as new potential targets to treat HF, each having a unique role in local cyclic nucleotide signalling pathways. In this Review, we describe cAMP and cGMP signalling in cardiomyocytes and present the various PDE families expressed in the heart as well as their modifications in pathological cardiac hypertrophy and HF. We also appraise the evidence from preclinical models as well as clinical data pointing to the use of inhibitors or activators of specific PDEs that could have therapeutic potential in HF.

Palliative Inotropes in Advanced Heart Failure: Comparing Outcomes Between Milrinone and Dobutamine

BACKGROUND

We sought to describe and compare outcomes among advanced patients with heart failure (not candidates for orthotopic heart transplant/left ventricular assist device) on long-term milrinone or dobutamine, which are not well-studied in the contemporary era.

METHODS AND RESULTS

We included adults with refractory stage D heart failure who were not candidates for orthotopic heart transplant or left ventricular assist device and discharged on palliative dobutamine or milrinone. The primary outcome was 1-year survival. A 6-month predictor of survival analysis was conducted. A total of 248 patients (133 on milrinone, 115 on dobutamine) were included. There were no differences in baseline comorbidities between milrinone and dobutamine cohorts, except for the prevalence of chronic kidney disease, which was higher in the dobutamine group. On discharge, the proportion of patients on beta-blockers and mineralocorticoid antagonists was higher in milrinone group. Overall, the 1-year mortality rate was 70%. The dobutamine cohort had a significantly higher 1-year mortality rate (84% vs 58%, P <0.001). The type of inotrope did not predict survival at 6 months when adjusted for discharge medications and comorbidities. Beta-blockers and angiotensin-converting enzyme/angiotensin receptor blocker/angiotensin receptor neprilysin inhibitor continued at discharge predicted survival at 6 months.

CONCLUSIONS

The 1-year mortality from palliative inotropes remains high. Compared with dobutamine, use of milrinone was associated with improved survival owing to better optimization of guideline-directed medical therapy, primarily beta-blocker therapy.

Phosphodiesterases and Compartmentation of cAMP and cGMP Signaling in Regulation of Cardiac Contractility in Normal and Failing Hearts

Cardiac contractility is regulated by several neural, hormonal, paracrine, and autocrine factors. Amongst these, signaling through β-adrenergic and serotonin receptors generates the second messenger cyclic AMP (cAMP), whereas activation of natriuretic peptide receptors and soluble guanylyl cyclases generates cyclic GMP (cGMP). Both cyclic nucleotides regulate cardiac contractility through several mechanisms. Phosphodiesterases (PDEs) are enzymes that degrade cAMP and cGMP and therefore determine the dynamics of their downstream effects. In addition, the intracellular localization of the different PDEs may contribute to regulation of compartmented signaling of cAMP and cGMP. In this review, we will focus on the role of PDEs in regulating contractility and evaluate changes in heart failure.

Nitric oxide — soluble guanylate cyclase — cyclic guanosine monophosphate signaling pathway in the pathogenesis of heart failure and search for novel therapeutic targets

Heart failure is a severe disease with an unfavorable prognosis, which requires intensification of therapy and the search for novel approaches to treatment. In this review, the physiological significance of soluble guanylate cyclase-related signaling pathway, reasons for decrease in its activity in heart failure and possible consequences are discussed. Pharmacological methods of stimulating the production of cyclic guanosine monophosphate using drugs with different mechanisms of action are considered. Data from clinical studies regarding their effectiveness and safety are presented. A promising approach is stimulation of soluble guanylate cyclase, which showed beneficial effects in preclinical studies, as well as in the recently completed phase III VICTORIA study.

Targeting Cyclic Guanosine Monophosphate to Treat Heart Failure: JACC Review Topic of the Week

The significant morbidity and mortality associated with heart failure with reduced ejection fraction (HFrEF) or heart failure with preserved ejection fraction (HFpEF) justify the search for novel therapeutic agents. Reduced cyclic guanosine monophosphate levels contribute to HF progression. Among molecules modulating the nitric oxide (NO)-GMP-phosphodiesterase (PDE) pathway, the evaluation of nitrates, synthetic natriuretic peptides (NP), and NP analogs has yielded mixed results. Conversely, sacubitril/valsartan, combining NP degradation inhibition through neprilysin and angiotensin receptor blockade, has led to groundbreaking findings in HFrEF. Other strategies to increase tissue cyclic guanosine monophosphate have been attempted, such as PDE-3 or PDE-5 inhibition (with negative or neutral results), NO-independent soluble guanylate cyclase (sGC) activation, or enhancement of sGC sensitivity to endogenous NO. Following the positive results of the phase 3 VICTORIA (A Study of Vericiguat in Participants With Heart Failure With Reduced Ejection Fraction) trial on the sGC stimulator vericiguat in HFrEF, the main open questions are the efficacy of the sacubitril/valsartan-vericiguat combination in HFrEF and of vericiguat in HFpEF.

Digoxin Combined with Aerobic Interval Training Improved Cardiomyocyte Contractility

Digoxin is a cardiotonic that increases the cardiac output without causing deleterious effects on heart, as well as improves the left ventricular performance during physical exercise. We tested whether the association between chronic digoxin administration and aerobic interval training (AIT) promotes beneficial cardiovascular adaptations by improving the myocardial contractility and calcium (Ca²⁺⁾ handling. Male Wistar rats were randomly assigned to sedentary control (C), interval training (T), sedentary digoxin (DIGO) and T associated to digoxin (TDIGO). AIT was performed on a treadmill (1h/day, 5 days/week) for 60 days, consisting of successive 8-min periods at 80% and 20% of VO₂máx for 2 min. Digoxin was administered by orogastric gavage for 60 days. Left ventricle samples were collected to analysis of Ca²⁺ handling proteins; contractility and Ca²⁺ handling were performed on isolated cardiomyocytes. TDIGO group had a greater elevation in fractional shortening (44%) than DIGO, suggesting a cardiomyocyte contractile improvement. In addition, T or TDIGO groups showed no change in cardiomyocytes properties after Fura2-acetoxymethyl ester, as well as in sarcoplasmic reticulum Ca^2+-ATPase (SERCA2a), phospholamban and calcineurin expressions. The main findings indicate that association of digoxin and aerobic interval training improved the cardiomyocyte contractile function, but these effects seem to be unrelated to Ca²⁺ handling.

Cardiac Cyclic Nucleotide Phosphodiesterases: Roles and Therapeutic Potential in Heart Failure

The cyclic nucleotides cyclic adenosine-3′,5′-monophosphate (cAMP) and cyclic guanosine-3′,5′-monophosphate (cGMP) maintain physiological cardiac contractility and integrity. Cyclic nucleotide–hydrolysing phosphodiesterases (PDEs) are the prime regulators of cAMP and cGMP signalling in the heart. During heart failure (HF), the expression and activity of multiple PDEs are altered, which disrupt cyclic nucleotide levels and promote cardiac dysfunction. Given that the morbidity and mortality associated with HF are extremely high, novel therapies are urgently needed. Herein, the role of PDEs in HF pathophysiology and their therapeutic potential is reviewed. Attention is given to PDEs 1–5, and other PDEs are briefly considered. After assessing the role of each PDE in cardiac physiology, the evidence from pre-clinical models and patients that altered PDE signalling contributes to the HF phenotype is examined. The potential of pharmacologically harnessing PDEs for therapeutic gain is considered.

The Role of Digoxin in the Treatment of Chronic Congestive Heart Failure

It is now well established that digoxin is an effective drug for the treatment of heart failure. Since treatment with angiotensin-converting enzyme (ACE) inhibitors reduces mortality in congestive heart failure, digoxin should be added to ACE inhibitors in patients with moderate or severe heart failure. The beneficial effects of digoxin may be due, in part, to its well-documented sympathoinhibitory effects that can avert the adverse effects of long-term excessive sympathetic adrenergic stimulation in heart failure.

Heart Failure: A Palliative Medicine Review of Disease, Therapies, and Medications With a Focus on Symptoms, Function, and Quality of Life

Despite significant advances in heart failure (HF) treatment, HF remains a progressive, extremely symptomatic, and terminal disease with a median survival of 2.1 years after diagnosis. HF often leads to a constellation of symptoms, including dyspnea, fatigue, depression, anxiety, insomnia, pain, and worsened cognitive function. Palliative care is an approach that improves the quality of life of patients and their caregivers facing the problems associated with life-threatening illness and therefore is well suited to support these patients. However, historically, palliative care has often focused on supporting patients with malignant disease, rather than a progressive chronic disease such as HF. Predicting mortality in patients with HF is challenging. The lack of obvious transition points in disease progression also raises challenges to primary care providers and specialists to know at what point to integrate palliative care during a patient's disease trajectory. Although therapies for HF often result in functional and symptomatic improvements including health-related quality of life (HRQL), some patients with HF do not demonstrate these benefits, including those patients with a preserved ejection fraction. Provision of palliative care for patients with HF requires an understanding of HF pathogenesis and common medications used for these patients, as well as an approach to balancing life-prolonging and HRQL care strategies. This review describes HF and current targeted therapies and their effects on symptoms, hospital admission rates, exercise performance, HRQL, and survival. Pharmacological interactions with and precautions related to commonly used palliative care medications are reviewed. The goal of this review is to equip palliative care clinicians with information to make evidence-based decisions while managing the balance between optimal disease management and patient quality of life.

Digoxin is associated with worse outcomes in patients with heart failure with reduced ejection fraction

AIMS

The aim of this study was to investigate the impact of digoxin use on the outcomes of patients with heart failure with reduced ejection fraction (HFrEF) and its possible interaction with atrial fibrillation or use of currently guideline-recommended treatments in the real world in China.

METHODS AND RESULTS

Patients hospitalized with HFrEF from 45 hospitals participating in the China National Heart Failure Registration Study (CN-HF) were enrolled to assess the all-cause mortality, HF mortality, all-cause re-hospitalization, and HF re-hospitalization associated with digoxin use. Eight hundred eighty-two eligible HFrEF patients in the CN-HF registry were included: 372 patients with digoxin and 510 patients without digoxin. Among them, 794 (90.0%) patients were followed up for the endpoint events, with a median follow-up of 28.6 months. Kaplan-Meier survival analysis showed that the all-cause mortality (P < 0.001) and all-cause re-hospitalization (P = 0.020) were significantly higher in digoxin group than non-digoxin group, while HF mortality (P = 0.232) and HF re-hospitalization (P = 0.098) were similar between the two groups. The adjusted Cox proportional-hazards regression analysis demonstrated that digoxin use remained as an independent risk factor for increased all-cause mortality [hazard ratio (HR) 1.76; 95% confidence interval (CI) 1.27-2.44; P = 0.001] and all-cause re-hospitalization (HR 1.27; 95% CI 1.03-1.57; P = 0.029) in HFrEF patients and the predictive value of digoxin for all-cause mortality irrespective of rhythm or in combination with other guideline-recommended therapies.

CONCLUSIONS

Digoxin use is independently associated with increased risk of all-cause mortality and all-cause re-hospitalization in HFrEF patients.

Milrinone-Induced Postconditioning Requires Activation of Mitochondrial Ca2+-sensitive Potassium (mBKCa) Channels

OBJECTIVES

Cardioprotection by postconditioning requires activation of mitochondrial large-conductance Ca2+-sensitive potassium (mBKCa) channels. The involvement of these channels in milrinone-induced postconditioning is unknown. The authors determined whether cardioprotection by milrinone-induced postconditioning involves activation of mBKCa channels in the rat heart in vitro.

DESIGN

Randomized, prospective, blinded laboratory investigation.

SETTING

Experimental laboratory.

PARTICIPANTS

Male Wistar rats.

INTERVENTIONS

Hearts of male Wistar rats were randomized, placed on a Langendorff system, and perfused with Krebs-Henseleit buffer at a constant pressure of 80 mmHg. All hearts were subjected to 33 minutes of global ischemia and 60 minutes of reperfusion. At the onset of reperfusion, hearts were perfused with different concentrations of milrinone (0.3-100 μM) for determination of a dose-effect curve. In a second set of experiments, 3 μM milrinone was administered in combination with the mBKCa channel inhibitor paxilline (1 μM). Infarct size was determined by triphenyltetrazoliumchloride staining.

MEASUREMENTS AND MAIN RESULTS

In control animals, infarct size was 37 ± 7%. Milrinone at a concentration of 3 μM reduced infarct size to 22 ± 7% (p < 0.05 v control). Higher milrinone concentrations did not confer stronger protection. Paxilline completely blocked milrinone-induced cardioprotection whereas paxilline alone had no effect on infarct size.

CONCLUSIONS

This study shows that activation of mBKCa channels plays a pivotal role in milrinone-induced postconditioning.

Acute isoproterenol leads to age-dependent arrhythmogenesis in guinea pigs

Sudden cardiac death from ventricular arrhythmias is more common in adult patients with with heart failure compared with pediatric patients with heart failure. We identified age-specific differences in arrhythmogenesis using a guinea pig model of acute β-adrenergic stimulation. Young and adult guinea pigs were exposed to the β-adrenergic agonist isoproterenol (ISO; 0.7 mg/kg) for 30 min in the absence or presence of flecainide (20 mg/kg), an antiarrhythmic that blocks Na⁺ and ryanodine channels. Implanted cardiac monitors (Reveal LINQ, Medtronic) were used to monitor heart rhythm. Alterations in phosphorylation and oxidation of ryanodine receptor 2 (RyR2) were measured in left ventricular tissue. There were age-specific differences in arrhythmogenesis and sudden death associated with acute β-adrenergic stimulation in guinea pigs. Young and adult guinea pigs developed arrhythmias in response to ISO; however, adult animals developed significantly more premature ventricular contractions and experienced higher arrhythmia-related mortality than young guinea pigs treated with ISO. Although there were no significant differences in the phosphorylation of left ventricular RyR2 between young and adult guinea pigs, adult guinea pigs exposed to acute ISO had significantly more oxidation of RyR2. Flecainide treatment significantly improved survival and decreased the number of premature ventricular contractions in young and adult animals in association with lower RyR2 oxidation. Adult guinea pigs had a greater propensity to develop arrhythmias and suffer sudden death than young guinea pigs when acutely exposed to ISO. This was associated with higher oxidation of RyR2. The incidence of sudden death can be rescued with flecainide treatment, which decreases RyR2 oxidation. NEW & NOTEWORTHY Clinically, adult patients with heart failure are more likely to develop arrhythmias and sudden death than pediatric patients with heart failure. In the present study, older guinea pigs also showed a greater propensity to arrhythmias and sudden death than young guinea pigs when acutely exposed to isoproterenol. Although there are well-described age-related cardiac structural changes that predispose patients to arrhythmogenesis, the present data suggest contributions from dynamic changes in cellular signaling also play an important role in arrhythmogenesis.

Left ventricular ejection fraction as therapeutic target: is it the ideal marker?

Heart failure (HF) consists the fastest growing clinical cardiac disease. HF patients are categorized on the basis of underlying left ventricular ejection fraction (LVEF) into HF with preserved EF (HFpEF), reduced LVEF (HFrEF), and mid-range LVEF (HFmrEF). While LVEF is the most commonly used surrogate marker of left ventricular (LV) systolic function, the implementation of two-dimensional echocardiography in estimating this parameter imposes certain caveats on current HF classification. Most importantly, LVEF could fluctuate in repeated measurements or even recover after treatment, thus blunting the borders between proposed categories of HF and enabling upward classification of patients. Under this prism, we sought to summarize possible procedures to improve systolic function in patients with HFrEF either naturally or by the means of pharmacologic and non-pharmacologic treatment and devices. Therefore, we reviewed established pharmacotherapy, including beta-blockers, inhibitors of renin-angiotensin-aldosterone axis, statins, and digoxin as well as novel treatments like sacubitril-valsartan, ranolazine, and ivabradine. In addition, we assessed evidence in favor of cardiac resynchronization therapy and exercise training programs. Finally, innovative therapeutic strategies, including stem cells, xanthine oxidase inhibitors, antibiotic regimens, and omega-3 polyunsaturated fatty acids, were also taken into consideration. We concluded that LVEF is subject to changes in HF after intervention and besides the aforementioned HFrEF, HFpEF, and HFmrEF categories, a new entity of HF patients with recovered LVEF should be acknowledged. An improved global and refined LV function assessment by sophisticated imaging modalities and circulating biomarkers is expected to render HF classification more accurate and indicate patients with viable-yet dysfunctional-myocardium and favorable characteristics as the ideal candidates for LVEF recovery by individualized HF therapy.

Design of a Phase 3 trial of intracoronary administration of human adenovirus 5 encoding human adenylyl cyclase type 6 (RT-100) gene transfer in patients with heart failure with reduced left ventricular ejection fraction: The FLOURISH Clinical Trial

The prognosis of patients with HFrEF remains poor despite the use of current medical and device therapies. Preclinical studies of HFrEF using IC delivery of RT-100, a replication deficient, E1/E3-deleted human adenovirus 5 encoding human AC6 was associated with favorable effects on LV function and remodeling. A recent multicenter, double-blind, placebo-controlled, phase 2 study demonstrated the safety of IC delivery of RT-100 in HFrEF patients and potential efficacy at the higher doses. This phase 2 dose finding study, which included doses not expected to be effective, identified a potential reduction in congestive heart failure admissions in the AC6-treated group one year after randomization. The FLOURISH study is designed to investigate the prospect of reduction of heart failure hospitalization and other clinical adverse events and improvement in EF. The FLOURISH study is a double-blind, placebo-controlled, multicenter Phase 3 clinical trial that will randomize 536 patients to a one-time IC administration of RT-100 (10¹² vp) or placebo in a 1:1 ratio. Subjects will be 18-80 years of age, on optimal standard of care HF therapy with LVEF ≥10% and ≤35% by echocardiogram, and will undergo IC administration of RT-100 vs. placebo on Day 1. Follow-up study visits will be performed at Weeks 1 and 4, and Months 3, 6, and 12. Patients will be followed for an additional 36 months for safety assessments with telephone contact at Months 24, 36, and 48. The primary objective is to determine the efficacy of IC RT-100 vs. placebo in reducing the event rate of all (first and repeat) HF hospitalizations occurring from baseline to 12 months. The secondary objectives are to determine the efficacy of IC RT-100 on CV death, all cause death, and all HF events and in improving NYHA functional classification. Exploratory endpoints will include echocardiographic parameters of left ventricular systolic and diastolic function, HF symptoms and physical limitations, 6-minute walking distance, Borg dyspnea score, and NT-proBNP levels. The FLOURISH study, which received fast track designation from the Food and Drug Administration in December 2017, will further investigate the role of a one-time intracoronary injection of RT-100 in reducing HF hospitalizations and will serve as a registration trial (potentially pivotal investigation) for RT-100 as a treatment for HFrEF.

Functions of PDE3 Isoforms in Cardiac Muscle

Isoforms in the PDE3 family of cyclic nucleotide phosphodiesterases have important roles in cyclic nucleotide-mediated signalling in cardiac myocytes. These enzymes are targeted by inhibitors used to increase contractility in patients with heart failure, with a combination of beneficial and adverse effects on clinical outcomes. This review covers relevant aspects of the molecular biology of the isoforms that have been identified in cardiac myocytes; the roles of these enzymes in modulating cAMP-mediated signalling and the processes mediated thereby; and the potential for targeting these enzymes to improve the profile of clinical responses.

Developing Drugs for Heart Failure With Reduced Ejection Fraction: What Have We Learned From Clinical Trials?

There remains a large unmet need for new therapies in the treatment of heart failure with reduced ejection fraction (HFrEF). In the early drug development phase, the therapeutic potential of a drug is not yet fully understood and trial endpoints other than mortality are needed to guide drug development decisions. While a true surrogate marker for mortality in heart failure (HF) remains elusive, the successes and failures of previous trials can reveal markers that support clinical Go/NoGo decisions.

Cardiac Phosphodiesterases and Their Modulation for Treating Heart Disease

An important hallmark of cardiac failure is abnormal second messenger signaling due to impaired synthesis and catabolism of cyclic adenosine 3',5'- monophosphate (cAMP) and cyclic guanosine 3',5'- monophosphate (cGMP). Their dysregulation, altered intracellular targeting, and blunted responsiveness to stimulating pathways all contribute to pathological remodeling, muscle dysfunction, reduced cell survival and metabolism, and other abnormalities. Therapeutic enhancement of either cyclic nucleotides can be achieved by stimulating their synthesis and/or by suppressing members of the family of cyclic nucleotide phosphodiesterases (PDEs). The heart expresses seven of the eleven major PDE subtypes - PDE1, 2, 3, 4, 5, 8, and 9. Their differential control over cAMP and cGMP signaling in various cell types, including cardiomyocytes, provides intriguing therapeutic opportunities to counter heart disease. This review examines the roles of these PDEs in the failing and hypertrophied heart and summarizes experimental and clinical data that have explored the utility of targeted PDE inhibition.

Korean Guidelines for Diagnosis and Management of Chronic Heart Failure

The prevalence of heart failure (HF) is skyrocketing worldwide, and is closely associated with serious morbidity and mortality. In particular, HF is one of the main causes for the hospitalization and mortality in elderly individuals. Korea also has these epidemiological problems, and HF is responsible for huge socioeconomic burden. However, there has been no clinical guideline for HF management in Korea. 
The present guideline provides the first set of practical guidelines for the management of HF in Korea and was developed using the guideline adaptation process while including as many data from Korean studies as possible. The scope of the present guideline includes the definition, diagnosis, and treatment of chronic HF with reduced/preserved ejection fraction of various etiologies.

Long-Term Effects of Flosequinan on the Morbidity and Mortality of Patients With Severe Chronic Heart Failure: Primary Results of the PROFILE Trial After 24 Years

OBJECTIVES

The purpose of this clinical trial was to evaluate the long-term effects of flosequinan on the morbidity and mortality of patients with severe chronic heart failure.

BACKGROUND

Flosequinan was the first oral vasodilator to be used in the clinic to augment the effects of digitalis, diuretics, and angiotensin-converting enzyme inhibitors in heart failure. However, the drug activated neurohormonal systems and exerted both positive inotropic and chronotropic effects, raising concerns about its safety during long-term use.

METHODS

Following a run-in period designed to minimize the risk of tachycardia, we randomly assigned 2,354 patients in New York Heart Association functional class III to IV heart failure and with an ejection fraction ≤35% to receive long-term treatment with placebo or flosequinan (75 or 100 mg/day) in addition to their usual therapy. The primary outcome was all-cause mortality.

RESULTS

The trial was terminated after a recommendation of the Data and Safety Monitoring Board, because during an average of 10 months of follow-up, 192 patients died in the placebo group and 255 patients died in the flosequinan group (hazard ratio: 1.39, 95% confidence interval: 1.15 to 1.67; p = 0.0006). Flosequinan also increased the risk of disease progression, which was paralleled by drug-related increases in heart rate and neurohormonal activation. However, during the first month, patients in the flosequinan group were more likely to report an improvement in well-being and less likely to experience worsening heart failure. Similarly, during the month following drug withdrawal at the end of the trial, patients withdrawn from flosequinan were more likely than those withdrawn from placebo to report symptoms of or to require treatment for worsening heart failure.

CONCLUSIONS

Although flosequinan produced meaningful symptomatic benefits during short- and long-term treatment, the drug increased the risk of death in patients with severe chronic heart failure.

Perioperative Inotrope Therapy and Atrial Fibrillation Following Coronary Artery Bypass Graft Surgery: Evidence of a Racial Disparity

BACKGROUND AND OBJECTIVE

Following coronary artery bypass graft (CABG) surgery, mortality rates are significantly higher among black patients who experience postoperative atrial fibrillation (POAF). Perioperative inotropic therapy (PINOT) was associated with POAF in previous reports, but the extent to which race influences this association is unknown. In the present study, the relationship between PINOT, race, and POAF was examined in patients undergoing CABG surgery.

METHODS AND SETTING

Clinical records were examined from a prospectively maintained cohort of 11,855 patients (median age 64 yrs; 70% male; 16% black) undergoing primary isolated CABG at a large cardiovascular institute in the southeastern region of the United States. Relative risk (RR) and 95% confidence intervals (CIs) were computed using log-binomial regression.

MAIN RESULTS

The association between PINOT and POAF was significantly increased among black patients (adjusted RR 1.7, CI 1.4-2.0) compared with white patients (adjusted RR 1.3, CI 1.2-1.4) (p_interaction  = 0.013).

CONCLUSIONS

These findings suggest that PINOT may be disproportionately associated with POAF among black patients undergoing CABG surgery. Additional studies are needed to examine further the potential underlying mechanisms of this association.

Effect of Levosimendan and Milrinone on Regional Myocardial Ischemia/Reperfusion-Induced Arrhythmias in Dogs

Phosphodiesterase inhibitors as inodilators in heart failure are associated with promotion of arrhythmias. Calcium sensitizers have been proposed for the treatment of severe decompensated heart failure. The effect of levosimendan, a calcium sensitizer, and milrinone, a phosphodiesterase inhibitor, on ventricular arrhythmias was compared in a model of acute regional myocardial ischemia and reperfusion. The left anterior descending coronary artery in dogs was occluded for 25 minutes, followed by reperfusion. The 2 drugs were administered in a hemodynamically equieffective dose (0.1 μmol/kg) 10 minutes before coronary occlusion. Levosimendan, but not milrinone, significantly attenuated the pronounced increase in the number of ventricular premature beats (-63%), tachycardia (-50%), fibrillation (-70%), and inhomogeneity of ventricular electrical activation. Levosimendan significantly improved the overall survival rate. Levosimendan has a more beneficial profile than milrinone regarding the development of ventricular arrhythmias during and after regional myocardial ischemia

Intracoronary Gene Transfer of Adenylyl Cyclase 6 in Patients With Heart Failure: A Randomized Clinical Trial

IMPORTANCE

Gene transfer has rarely been tested in randomized clinical trials.

OBJECTIVE

To evaluate the safety and efficacy of intracoronary delivery of adenovirus 5 encoding adenylyl cyclase 6 (Ad5.hAC6) in heart failure.

DESIGN, SETTING, AND PARTICIPANTS

A randomized, double-blind, placebo-controlled, phase 2 clinical trial was conducted in US medical centers (randomization occurred from July 19, 2010, to October 30, 2014). Participants 18 to 80 years with symptomatic heart failure (ischemic and nonischemic) and an ejection fraction (EF) of 40% or less were screened; 86 individuals were enrolled, and 56 were randomized. Data analysis was of the intention-to-treat population. Participants underwent exercise testing and measurement of left ventricular EF (echocardiography) and then cardiac catheterization, where left ventricular pressure development (+dP/dt) and decline (-dP/dt) were recorded. Participants were randomized (3:1 ratio) to receive 1 of 5 doses of intracoronary Ad5.hAC6 or placebo. Participants underwent a second catheterization 4 weeks later for measurement of dP/dt. Exercise testing and EF were assessed 4 and 12 weeks after randomization.

INTERVENTIONS

Intracoronary administration of Ad5.hAC6 (3.2 × 109 to 1012 virus particles) or placebo.

MAIN OUTCOMES AND MEASURES

Primary end points included exercise duration and EF before and 4 and 12 weeks after randomization and peak rates of +dP/dt and -dP/dt before and 4 weeks after randomization. Fourteen placebo participants were compared (intention to treat) with 24 Ad5.hAC6 participants receiving the highest 2 doses (D4 + 5).

RESULTS

Fifty-six individuals were randomized and monitored for up to 1 year. Forty-two participants (75%) received Ad5.hAC6 (mean [SE] age, 63 [1] years; EF, 30% [1%]), and 14 individuals (25%) received placebo (age, 62 [1] years; EF, 30% [2%]). Exercise duration showed no significant group differences (4 weeks, P = .27; 12 weeks, P = .47, respectively). The D4 + 5 participants had increased EF at 4 weeks (+6.0 [1.7] EF units; n = 21; P < .004), but not 12 weeks (+3.0 [2.4] EF units; n = 21; P = .16). Placebo participants showed no increase in EF at 4 weeks or 12 weeks. Exercise duration showed no between-group differences (4-week change from baseline: placebo, 27 [36] seconds; D4 + 5, 44 [25] seconds; P = .27; 12-week change from baseline: placebo, 44 [28] seconds; D4 + 5, 58 [29 seconds, P = .47). AC6 gene transfer increased basal left ventricular peak -dP/dt (4-week change from baseline: placebo, +93 [51] mm Hg/s; D4 + 5, -39 [33] mm Hg/s; placebo [n = 21]; P < .03); AC6 did not increase arrhythmias. The admission rate for patients with heart failure was 9.5% (4 of 42) in the AC6 group and 28.6% (4 of 14) in the placebo group (relative risk, 0.33 [95% CI, 0.08-1.36]; P = .10).

CONCLUSIONS AND RELEVANCE

AC6 gene transfer safely increased LV function beyond standard heart failure therapy, attainable with one-time administration. Larger trials are warranted.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00787059.

Pediatric Cardiac Intensive Care Society 2014 Consensus Statement: Pharmacotherapies in Cardiac Critical Care Treatment of Acute Heart Failure

OBJECTIVES

To provide an evidence-based review of pharmacotherapies to treat acute heart failure. To accomplish this objective, we will discuss circulatory physiology, vasoactive agents, and their indications in the management of acute heart failure.

DATA SOURCE

A MEDLINE-baseline review of the literature.

CONCLUSIONS

The optimal selection of vasoactive agents requires a consideration of circulatory physiology and the tailored application of pharmacotherapies to treat patients with acute heart failure.

Clinical Characteristics and Treatment of Cardiomyopathies in Children

Cardiomyopathies are diseases of the heart muscle, a term introduced in 1957 to identify a group of myocardial diseases not attributable to coronary artery disease. The definition has since been modified to refer to structural and or functional abnormalities of the myocardium where other known causes of myocardial dysfunction, such as systemic hypertension, valvular disease and ischemic heart disease, have been excluded. In this review, we discuss the pathophysiology, clinical assessment and therapeutic strategies for hypertrophic, dilated and hypertrophic cardiomyopathies, with a particular focus on aspects unique to children.

Characteristics, Treatments, and Outcomes of Hospitalized Heart Failure Patients Stratified by Etiologies of Cardiomyopathy

OBJECTIVES

The authors sought to describe characteristics, treatments, and in-hospital outcomes of hospitalized heart failure (HF) patients stratified by etiology.

BACKGROUND

Whether characteristics and outcomes of HF patients differ by cardiomyopathy etiology is unknown.

METHODS

The authors analyzed data on 156,013 hospitalized HF patients from 319 U.S. hospitals participating in Get With The Guidelines-HF between 2005 and 2013. Characteristics, treatments, and in-hospital outcomes were assessed by HF etiology. Standard regression techniques adjusted for site and patient-level characteristics were used to examine association between HF etiology and in-hospital outcomes.

RESULTS

Median age was 75 years, 69.2% were white, and 49.5% were women. Overall, 92,361 patients (59.2%) had ischemic cardiomyopathy and 63,652 patients (40.8%) had nonischemic cardiomyopathy (NICM). Hypertensive (n = 28,141; 48.5%) and idiopathic (n = 17,808; 30.7%) cardiomyopathies accounted for the vast majority of NICM patients. Post-partum (n = 209; 0.4%), viral (n = 447; 0.8%), chemotherapy (n = 721; 1.2%), substance abuse (n = 2,653; 4.6%), familial (n = 556; 1.0%), and other (n = 7,523; 13.0%) etiologies were far less frequent. There were significant differences in baseline characteristics between those with ischemic cardiomyopathy compared with NICM with respect to age (76 years vs. 72 years), sex (44.4% vs. 56.9% women), and ejection fraction (38% vs. 45%). Risk-adjusted quality of care provided to eligible patients varied minimally by etiology. Similarly, in-hospital mortality did not differ among ischemic compared with NICM patients. However, among NICM patients, only hypertensive cardiomyopathy had a lower mortality rate compared with idiopathic NICM (adjusted odds ratio: 0.83; 95% confidence interval: 0.71 to 0.97).

CONCLUSIONS

Characteristics of hospitalized HF patients vary by etiology. Both risk-adjusted quality of care and in-hospital outcomes did not differ by etiology.

New medical therapies for heart failure

Heart failure (HF) can rightfully be called the epidemic of the 21(st) century. Historically, the only available medical treatment options for HF have been diuretics and digoxin, but the capacity of these agents to alter outcomes has been brought into question by the scrutiny of modern clinical trials. In the past 4 decades, neurohormonal blockers have been introduced into clinical practice, leading to marked reductions in morbidity and mortality in chronic HF with reduced left ventricular ejection fraction (LVEF). Despite these major advances in pharmacotherapy, our understanding of the underlying disease mechanisms of HF from epidemiological, clinical, pathophysiological, molecular, and genetic standpoints remains incomplete. This knowledge gap is particularly evident with respect to acute decompensated HF and HF with normal (preserved) LVEF. For these clinical phenotypes, no drug has been shown to reduce long-term clinical event rates substantially. Ongoing developments in the pharmacotherapy of HF are likely to challenge our current best-practice algorithms. Novel agents for HF therapy include dual-acting neurohormonal modulators, contractility-enhancing agents, vasoactive and anti-inflammatory peptides, and myocardial protectants. These novel compounds have the potential to enhance our armamentarium of HF therapeutics.

Enhanced external counterpulsation improves endothelial function and exercise capacity in patients with ischaemic left ventricular dysfunction

Enhanced external counterpulsation (EECP) therapy decreases angina episodes and improves quality of life in patients with left ventricular (LV) dysfunction (LVD). However, studies have not elucidated the mechanisms of action and overall effects of EECP in patients with LVD. The purpose of the present study was to investigate the effects of EECP on endothelial function in peripheral conduit arteries and exercise capacity (peak Vo2 ) in patients with LVD. Patients with ischaemic LVD (ejection fraction (EF) 34.5 ± 4.2%; n = 9) and patients with symptomatic coronary artery disease (CAD) and preserved LV function (EF 53.5 ± 6.6%; n = 15) were studied before and after 35 sessions (1 h) of EECP. Brachial and femoral artery flow-mediated dilation (bFMD and fFMD, respectively) were evaluated using high-resolution ultrasound. Enhanced external counterpulsation elicited similar significant improvements in the following FMD parameters in the CAD and LVD groups (P ≥ 0.05 between groups for all): absolute bFMD (+53% and +70%, respectively), relative bFMD (+50% and +74%, respectively), bFMD normalized for shear rate (+70% and +61%, respectively), absolute fFMD (+33% and +21%, respectively) and relative fFMD (+32% and +17%, respectively). In addition, EECP significantly improved plasma levels of nitrate/nitrite (+55% and +28%) and prostacyclin (+50% and +70%), as well as peak Vo2 (+36% and +21%), similarly in both the CAD and LVD groups (P ≥ 0.05 between groups for all). Despite reduced LV function, EECP therapy significantly improves peripheral vascular function and functional capacity in CAD patients with ischaemic LVD to a similar degree to that seen in CAD patients with preserved LV function.

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.

Is there a role for digitalis in chronic heart failure?--First update

This Living FRISBEE (Living FRIendly Summary of the Body of Evidence using Epistemonikos) is an update of the summary published in April 2015, based on a new systematic review published in May 2015. The main clinical guidelines recommend the use of digitalis for chronic heart failure when moderate to severe symptoms persist after standard therapy, even though there is controversy about its efficacy and security. Searching in Epistemonikos database, which is maintained by screening 30 databases, we identified four systematic reviews including 13 randomized trials. We combined the evidence using meta-analysis and generated a summary of findings table following the GRADE approach. We concluded the use of digitalis for chronic heart failure probably leads to little or no decrease in mortality, but they might reduce hospitalizations and clinical deterioration. However, the certainty of the evidence is low.

Effect of pimobendan on the incidence of arrhythmias in small breed dogs with myxomatous mitral valve degeneration

OBJECTIVE

To determine if pimobendan, a phosphodiesterase III inhibitor and calcium sensitizer with positive survival benefits, has an effect on incidence of arrhythmias compared to placebo in small breed dogs with congestive heart failure (CHF) due to myxomatous mitral valve degeneration (MMVD).

ANIMALS

Eight client-owned small breed dogs (<15 kg) with CHF due to MMVD.

METHODS

A prospective double-blind randomized placebo-controlled crossover study design was used. Data were recorded at baseline and 2 weeks post-administration of placebo or pimobendan. Average heart rate and incidence of arrhythmia were determined from 24 h Holter analysis. Owners completed a quality of life (QOL) questionnaire at each time point and recorded sleeping respiratory rates (SRR). Mixed effects analysis of variance, with dog as the random variable was used to compare values obtained between baseline, placebo, and pimobendan.

RESULTS

Compared to baseline, QOL scores were significantly improved following administration of either placebo or pimobendan (p = 0.021 and p < 0.001, respectively). No significant differences in type or incidence of supraventricular or ventricular arrhythmia were identified. Average heart rate with pimobendan was significantly lower than baseline (p < 0.001). Compared to baseline, SRR was significantly lower with pimobendan (p = 0.004), and significantly different from placebo (p = 0.045).

CONCLUSIONS

No significant difference between pimobendan and placebo was found on incidence of supraventricular or ventricular arrhythmia. The decrease in average heart rate and SRR may be reflective of superior heart failure control achieved with pimobendan therapy.

Outcomes of a contemporary sample of patients with atrial fibrillation taking digoxin: results from the AFBAR study

INTRODUCTION AND OBJECTIVES

We aimed to assess and compare the effect of digoxin on clinical outcomes in patients with atrial fibrillation vs those under beta-blockers or none of these drugs.

METHODS

AFBAR is a prospective registry study carried out by a team of primary care physicians (n=777 patients). Primary endpoints were survival, survival free of admission due to any cause, and survival free of admission due to cardiovascular causes. The mean follow up was 2.9 years. Four groups were analyzed: patients receiving digoxin, beta-blockers, or digoxin plus beta-blockers, and patients receiving none of these drugs.

RESULTS

Overall, 212 patients (27.28%) received digoxin as the only heart control strategy, 184 received beta-blockers (23.68%), 58 (7.46%) were administered both, and 323 (41.57%) received none of these drugs. Digoxin was not associated with all-cause mortality (estimated hazard ratio=1.42; 95% confidence interval, 0.77-2.60; P=.2), admission due to any cause (estimated hazard ratio=1.03; 95% confidence interval, 0.710-1.498; P=.8), or admission due to cardiovascular causes (estimated hazard ratio=1.193; 95% confidence interval, 0.725-1.965; P=.4). No association was found between digoxin use and all-cause mortality, admission due to any cause, or admission due to cardiovascular causes in patients without heart failure. There was no interaction between digoxin use and sex in all-cause mortality or in survival free of admission due to any cause. However, an association was found between sex and admission due to cardiovascular causes.

CONCLUSIONS

Digoxin was not associated with increased all-cause mortality, survival free of admission due to any cause, or admission due to cardiovascular causes, regardless of underlying heart failure.

Management of ACCF/AHA Stage C heart failure

ACC Stage C heart failure includes those patients with prior or current symptoms of heart failure in the context of an underlying structural heart problem who are primarily managed with medical therapy. Although there is guideline-based medical therapy for those with heart failure with reduced ejection fraction (HFrEF), therapies in heart failure with preserved ejection fraction (HFpEF) have thus far proven elusive. Emerging therapies such as serelaxin are currently under investigation and may prove beneficial. The role of advanced surgical therapies, such as mechanical circulatory support, in this population is not well defined. Further investigation is warranted for these therapies in patients with Stage C heart failure.

Outcomes of a contemporary sample of patients with atrial fibrillation taking digoxin: results from the AFBAR study

INTRODUCTION AND OBJECTIVES

We aimed to assess and compare the effect of digoxin on clinical outcomes in patients with atrial fibrillation vs those under beta-blockers or none of these drugs.

METHODS

AFBAR is a prospective registry study carried out by a team of primary care physicians (n=777 patients). Primary endpoints were survival, survival free of admission due to any cause, and survival free of admission due to cardiovascular causes. The mean follow up was 2.9 years. Four groups were analyzed: patients receiving digoxin, beta-blockers, or digoxin plus beta-blockers, and patients receiving none of these drugs.

RESULTS

Overall, 212 patients (27.28%) received digoxin as the only heart control strategy, 184 received beta-blockers (23.68%), 58 (7.46%) were administered both, and 323 (41.57%) received none of these drugs. Digoxin was not associated with all-cause mortality (estimated hazard ratio=1.42; 95% confidence interval, 0.77-2.60; P=.2), admission due to any cause (estimated hazard ratio=1.03; 95% confidence interval, 0.710-1.498; P=.8), or admission due to cardiovascular causes (estimated hazard ratio=1.193; 95% confidence interval, 0.725-1.965; P=.4). No association was found between digoxin use and all-cause mortality, admission due to any cause, or admission due to cardiovascular causes in patients without heart failure. There was no interaction between digoxin use and sex in all-cause mortality or in survival free of admission due to any cause. However, an association was found between sex and admission due to cardiovascular causes.

CONCLUSIONS

Digoxin was not associated with increased all-cause mortality, survival free of admission due to any cause, or admission due to cardiovascular causes, regardless of underlying heart failure.

Digitalis for treatment of heart failure in patients in sinus rhythm

BACKGROUND

Digitalis glycosides have been in clinical use for the treatment of heart failure (HF) for longer than 200 years. In recent years, several trials have been conducted to address concerns about their efficacy and toxicity.

OBJECTIVES

To examine the effectiveness of digitalis glycosides in treating HF in patients with normal sinus rhythm. To examine the effects of digitalis in patients taking diuretics and angiotensin-converting enzyme inhibitors; in patients with varying severity and duration of disease; in patients with prior exposure to digitalis versus no prior exposure; and in patients with "HF due to systolic dysfunction" versus "HF with preserved ejection fraction."

SEARCH METHODS

Searches on the following databases were updated in May 2013: The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and Dissertation Abstracts. Annual meeting abstracts of the American Heart Association, the American College of Cardiology, and the European Society of Cardiology were searched from 1996 to March 2013. In addition, reference lists provided by the pharmaceutical industry (GlaxoSmithKline and Covis Pharma) were searched.

SELECTION CRITERIA

Included were randomized placebo-controlled trials of 20 or more adult participants of either sex with symptomatic HF who were studied for seven weeks or longer. Excluded were trials in which the prevalence of atrial fibrillation was 2% or greater, or in which any arrhythmia that might compromise cardiac function or any potentially reversible cause of HF such as acute ischemic heart disease or myocarditis was present.

DATA COLLECTION AND ANALYSIS

Articles selected from the searches described above were evaluated in a joint effort of the review authors. The staff of the Cochrane Heart Group ran searches on the Cochrane Central Register of Controlled Trials, MEDLINE, and EMBASE.

MAIN RESULTS

No new studies were identified in the updated searches. Thirteen studies (7896 participants) are included, and major endpoints of mortality, hospitalization, and clinical status, based respectively on 8, 4, and 12 of these selected studies, were recorded and analyzed. The data show no evidence of a difference in mortality between treatment and control groups, whereas digitalis therapy is associated with lower rates of both hospitalization and clinical deterioration. The largest study, in which most participants were taking angiotensin-converting enzyme inhibitors, showed a significant rise in "other cardiac" deaths, possibly due to arrhythmias. However collectively, these findings were based on studies done before beta-blockers, as well as angiotensin receptor blockers and aldosterone antagonists, became widely used to treat HF.

AUTHORS' CONCLUSIONS

The literature indicates that digitalis may have a useful role in the treatment of patients with HF who are in normal sinus rhythm. New trials are needed to elucidate the importance of the dosage of digitalis and its usefulness in the era of beta-blockers and other agents shown to be effective in treating HF.

Cyclic nucleotide phosphodiesterase 3A1 protects the heart against ischemia-reperfusion injury

Phosphodiesterase 3A (PDE3A) is a major regulator of cAMP in cardiomyocytes. PDE3 inhibitors are used for acute treatment of congestive heart failure, but are associated with increased incidence of arrhythmias and sudden death with long-term use. We previously reported that chronic PDE3A downregulation or inhibition induced myocyte apoptosis in vitro. However, the cardiac protective effect of PDE3A has not been demonstrated in vivo in disease models. In this study, we examined the role of PDE3A in regulating myocardial function and survival in vivo using genetically engineered transgenic mice with myocardial overexpression of the PDE3A1 isozyme (TG). TG mice have reduced cardiac function characterized by reduced heart rate and ejection fraction (52.5±7.8% vs. 83.9±4.7%) as well as compensatory expansion of left ventricular diameter (4.19±0.19mm vs. 3.10±0.18mm). However, there was no maladaptive increase of fibrosis and apoptosis in TG hearts compared to wild type (WT) hearts, and the survival rates also remained the same. The diminution of cardiac contractile function is very likely attributed to a decrease in beta-adrenergic receptor (β-AR) response in TG mice. Importantly, the myocardial infarct size (4.0±1.8% vs. 24.6±3.8%) and apoptotic cell number (1.3±1.0% vs. 5.6±1.5%) induced by ischemia/reperfusion (I/R) injury were significantly attenuated in TG mice. This was associated with decreased expression of inducible cAMP early repressor (ICER) and increased expression of anti-apoptotic protein BCL-2. To further verify the anti-apoptotic effects of PDE3A1, we performed in vitro apoptosis study in isolated adult TG and WT cardiomyocytes. We found that the apoptotic rates stimulated by hypoxia/reoxygenation or H2O2 were indeed significantly reduced in TG myocytes, and the differences between TG and WT myocytes were completely reversed in the presence of the PDE3 inhibitor milrinone. These together indicate that PDE3A1 negatively regulates β-AR signaling and protects against I/R injury by inhibiting cardiomyocyte apoptosis.