Digoxin use and lower risk of 30-day all-cause readmission in older patients with heart failure and reduced ejection fraction receiving β-blockers

Successful conservative management of left ventricular assist device candidates

AIMS

Clinical trials comparing LVADs vs. conservative therapy were performed before the availability of novel medications or used suboptimal medical therapy. This study aimed to report that long-term stabilization of patients entering a left ventricular assist device (LVAD) programme is possible with the use of aggressive conservative therapy. This is important because the excellent clinical stabilization provided by LVADs comes at the expense of significant complications.

METHODS AND RESULTS

This study was a single-centre prospective evaluation of consecutive patients with advanced heart failure (HF) fulfilling criteria for LVAD implantation based on clinical and echocardiographic characteristics, cardiopulmonary exercise test, and right heart catheterization results. Their initial therapy included inotropes, thiamine, beta-blockers, digoxin, spironolactone, hydralazine, and nitrates followed by the introduction of novel HF therapies. Coronary revascularization and cardiac resynchronization therapy were performed when indicated, and all patients were closely followed at our outpatient clinic. During the study period, 28 patients were considered suitable for LVAD implantation (mean age 63 ± 10.8 years, 92% men, 78% ischaemic, median HF duration 4 years). Clinical stabilization was achieved and maintained in 21 patients (median follow-up 20 months, range 9-38 months). Compared with baseline evaluation, cardiac index increased from 2.05 (1.73-2.28) to 2.88 (2.63-3.55) L/min/m² , left ventricular end-diastolic diameter decreased from 65.5 (62.4-66) to 58.3 (53.8-62.5) mm, and maximal oxygen consumption increased from 10.1 (9.2-11.3) to 16.1 (15.3-19) mL/kg/min. Three patients died and only four ultimately required LVAD implantation.

CONCLUSIONS

Notwithstanding the small size of our cohort, our results suggest that LVAD implantation could be safely deferred in the majority of LVAD candidates.

Research Progress in Pharmacological Activities and Applications of Cardiotonic Steroids

Cardiotonic steroids (CTS) are a group of compounds existing in animals and plants. CTS are commonly referred to cardiac glycosides (CGs) which are composed of sugar residues, unsaturated lactone rings and steroid cores. Their traditional mechanism of action is to inhibit sodium-potassium ATPase to strengthen the heart and regulate heart rate, so it is currently widely used in the treatment of cardiovascular diseases such as heart failure and tachyarrhythmia. It is worth noticing that recent studies have found an avalanche of inestimable values of CTS applications in many fields such as anti-tumor, anti-virus, neuroprotection, and immune regulation through multi-molecular mechanisms. Thus, the pharmacological activities and applications of CTS have extensive prospects, which would provide a direction for new drug research and development. Here, we review the potential applications of CTS in cardiovascular system and other systems. We also provide suggestions for new clinical practical strategies of CTS, for many diseases. Four main themes will be discussed, in relation to the impact of CTS, on 1) tumors, 2) viral infections, 3) nervous system diseases and 4) immune-inflammation-related diseases.

Utilization of Digoxin among Hospitalized Older Patients with Heart Failure and Atrial Fibrillation in Thailand: Prevalence, Associated Factors, and Clinical Outcomes

Background

Digoxin is used to control heart rate in patients with heart failure (HF) and atrial fibrillation (AF). However, its use is often limited in older patients, as they are prone to digoxin toxicity. This study aimed to determine the prevalence of digoxin use, investigate the factors associated with digoxin use, and explore the association between digoxin use and clinical outcomes in older Thai patients with HF and AF.

Methods

This cross-sectional study used data obtained from an electronic medical records database. We performed logistic regression analysis to determine the prevalence of digoxin use at index discharge and the factors associated with its use. The Cox proportional hazard model was used to determine the association of all-cause mortality and HF rehospitalization with digoxin use.

Results

Of the 640 patients assessed, 107 (16.72%) were prescribed digoxin before discharge. The factors negatively associated with digoxin use included high serum creatinine level (adjusted odds ratio [AOR]=0.38; 95% confidence interval [CI], 0.22–0.65) and ischemic heart disease (IHD) (AOR=0.52; 95% CI, 0.30–0.88). The factors positively associated with digoxin use were the use of diuretics (AOR=2.65; 95% CI, 1.60–4.38) and mineralocorticoid receptor antagonists (MRAs) (AOR=2.24; 95% CI, 1.18–4.27). We observed no significant association between digoxin use and clinical outcomes (adjusted hazard ratio=1.00; 95% CI, 0.77–1.30).

Conclusion

Digoxin use was prevalent among older patients with HF and AF. Patients with high serum creatinine or IHD were less likely to be prescribed digoxin, whereas those using diuretics or MRAs were more likely to be prescribed digoxin. Although digoxin use was not uncommon among older patients, it was prescribed with caution among Thai patients hospitalized with HF and AF.

Digoxin Initiation and Outcomes in Patients with Heart Failure (HFrEF and HFpEF) and Atrial Fibrillation

BACKGROUND

Digoxin reduces the risk of heart failure hospitalization but has no effect on mortality in patients with heart failure without atrial fibrillation in the randomized controlled trial setting. Observational studies of digoxin use in patients with atrial fibrillation have suggested a higher risk for poor outcomes. Less is known about this association in patients with heart failure and atrial fibrillation, the examination of which was the objective of the current study.

METHODS

We conducted an observational propensity score-matched study of predischarge digoxin initiation in 1768 hospitalized patients with heart failure and atrial fibrillation in the Medicare-linked Organized Program to Initiate Lifesaving Treatment in Hospitalized Patients with Heart Failure (OPTIMIZE-HF) registry, balanced on 56 baseline characteristics (mean age, 79 years; 55% women; 7% African American). Hazard ratios (HRs) and 95% confidence intervals (CIs) for outcomes were estimated for the 884 patients initiated on digoxin compared with 884 not initiated on digoxin.

RESULTS

HRs (95% CIs) for 30-day, 2-year, and 4-year all-cause mortality were 0.80 (0.55-1.18; P = .261), 0.94 (0.87-1.16; P = .936), and 1.01 (0.90-1.14; P = .729), respectively. Respective HRs (95% CIs) for heart failure readmission were 0.67 (0.49-0.92; P = .014), 0.81 (0.69-0.94; P = .005), and 0.85 (0.74-0.97; P = .022), and those for all-cause readmission were 0.78 (0.64-0.96; P = .016), 0.90 (0.81-1.00; P = .057), and 0.91 (0.83-1.01; P = .603). These associations were homogeneous between patients with left ventricular ejection fraction ≤45% vs >45%.

CONCLUSIONS

Among hospitalized older patients with heart failure (HFrEF and HFpEF) and atrial fibrillation, initiation of digoxin was associated with a lower risk of heart failure readmission but had no association with mortality.

Digoxin Initiation and Outcomes in Patients with Heart Failure with Preserved Ejection Fraction

BACKGROUND

Digoxin reduces the risk of heart failure hospitalization in patients with heart failure with reduced ejection fraction. Less is known about this association in patients with heart failure with preserved ejection fraction (HFpEF), the examination of which was the objective of the current study.

METHODS

In the Medicare-linked OPTIMIZE-HF registry, 7374 patients hospitalized for HF had ejection fraction ≥50% and were not receiving digoxin prior to admission. Of these, 5675 had a heart rate ≥50 beats per minute, an estimated glomerular filtration rate ≥30 mL/min/1.73 m2 or did not receive inpatient dialysis, and digoxin was initiated in 524 of these patients. Using propensity scores for digoxin initiation, calculated for each of the 5675 patients, we assembled a matched cohort of 513 pairs of patients initiated and not initiated on digoxin, balanced on 58 baseline characteristics (mean age, 80 years; 66% women; 8% African American). Hazard ratios (HRs) and 95% confidence intervals (CIs) for outcomes associated with digoxin initiation were estimated in the matched cohort.

RESULTS

Among the 1026 matched patients with HFpEF, 30-day heart failure readmission occurred in 6% and 9% of patients initiated and not initiated on digoxin, respectively (HR 0.70; 95% CI, 0.45-1.10; P = .124). HRs (95% CIs) for 30-day all-cause readmission and all-cause mortality associated with digoxin initiation were 0.95 (0.73-1.23; P = .689) and 0.93 (0.55-1.56; P = .773), respectively. Digoxin initiation had no association with 6-year outcomes.

CONCLUSION

Digoxin initiation prior to hospital discharge was not associated with 30-day or 6-year outcomes in older hospitalized patients with HFpEF.

Development of Indirect Competitive Enzyme-Linked Immunosorbent Assay and Lateral-Flow Immunochromatographic Strip for the Detection of Digoxin in Human Blood

Mouse-mouse hybridoma cell lines producing stable, highly specific monoclonal antibodies with good affinity for the cardiac glycoside digoxin (DIG) were established to construct an indirect enzyme-linked immunosorbent assay and lateral-flow immunochromatographic strip to detect DIG in human blood. The hapten DIG was coupled to bovine serum albumin or chicken ovalbumin by sodium periodate oxidation. The highest sensitivity and specificity antibody had a median inhibitory concentration (IC₅₀) of 0.45 ng/mL, a linear range of detection of 0.293-0.7 ng/mL, and low cross-reactivity with several DIG analogues. The cut-off value of the lateral-flow immunochromatographic strip was 5 ng/mL when the strip was tested with human blood. The immunochromatographic lateral flow strip test provides a quick and convenient method for determining DIG in plasma which can be visually observed in only 5 min to promote rational drug use.

Digoxin Use and Outcomes in Patients With Heart Failure With Reduced Ejection Fraction

BACKGROUND

Heart failure is a leading cause for hospital readmission. Digoxin use may lower this risk in patients with heart failure with reduced ejection fraction (HFrEF), but data on contemporary patients receiving other evidence-based therapies are lacking.

METHODS

Of the 11,900 patients with HFrEF (ejection fraction ≤45%) in Medicare-linked OPTIMIZE-HF, 8401 were not on digoxin, of whom 1571 received discharge prescriptions for digoxin. We matched 1531 of these patients with 1531 not receiving digoxin by propensity scores for digoxin use. The matched cohort (n = 3062; mean age, 76 years; 44% women; 14% African American) was balanced on 52 baseline characteristics. We assembled a second matched cohort of 2850 patients after excluding those with estimated glomerular filtration rate <15 mL/min/1.73 m2 and heart rate <60 beats/min. Hazard ratios (HRs) and 95% confidence intervals (CIs) for digoxin-associated outcomes were estimated in the matched cohorts.

RESULTS

Among the 3062 matched patients, digoxin use was associated with a significantly lower risk of heart failure readmission at 30 days (HR, 0.74; 95% CI, 0.59-0.93), 1 year (HR, 0.81; 95% CI, 0.72-0.92), and 6 years (HR, 0.90; 95% CI 0.81-0.99). The association with all-cause readmission was significant at 1 and 6 years but not 30 days. There was no association with mortality. Similar associations were observed among the 2850 matched patients without bradycardia or renal insufficiency.

CONCLUSIONS

Among hospitalized older patients with HFrEF receiving contemporary treatments for heart failure, digoxin use is associated with a lower risk of hospital readmission but not all-cause mortality.

Digoxin Discontinuation and Outcomes in Patients With Heart Failure With Reduced Ejection Fraction

BACKGROUND

The deleterious effects of discontinuation of digoxin on outcomes in ambulatory patients with chronic heart failure (HF) with reduced ejection fraction (HFrEF) receiving angiotensin-converting enzyme inhibitors are well-documented.

OBJECTIVES

The authors sought to determine the relationship between digoxin discontinuation and outcomes in hospitalized patients with HFrEF receiving more contemporary guideline-directed medical therapies including beta-blockers and mineralocorticoid receptor antagonists.

METHODS

Of the 11,900 hospitalized patients with HFrEF (EF ≤45%) in the Medicare-linked OPTIMIZE-HF (Organized Program to Initiate Lifesaving Treatment in Hospitalized Patients with Heart Failure) registry, 3,499 received pre-admission digoxin, which was discontinued in 721 patients. Using propensity scores for digoxin discontinuation, estimated for each of the 3,499 patients, a matched cohort of 698 pairs of patients, balanced on 50 baseline characteristics (mean age 76 years; mean EF 28%; 41% women; 13% African American; 65% on beta-blockers) was assembled.

RESULTS

Four-year post-discharge, digoxin discontinuation was associated with significantly higher risks of HF readmission (hazard ratio [HR]: 1.21; 95% confidence interval [CI]: 1.05 to 1.39; p = 0.007), all-cause readmission (HR: 1.16; 95% CI: 1.04 to 1.31; p = 0.010), and the combined endpoint of HF readmission or all-cause mortality (HR: 1.20; 95% CI: 1.07 to 1.34; p = 0.002), but not all-cause mortality (HR: 1.09; 95% CI: 0.97 to 1.24; p = 0.163). Discontinuation of digoxin was associated with a significantly higher risk of all 4 outcomes at 6 months and 1 year post-discharge. At 30 days, digoxin discontinuation was associated with higher risks of all-cause mortality (HR: 1.80; 95% CI: 1.26 to 2.57; p = 0.001) and the combined endpoint (HR: 1.36; 95% CI: 1.09 to 1.71; p = 0.007), but not of HF readmission (HR: 1.19; 95% CI: 0.90 to 1.59; p = 0.226) or all-cause readmission (HR: 1.03; 95% CI: 0.84 to 1.26; p = 0.778).

CONCLUSIONS

Among hospitalized older patients with HFrEF on more contemporary guideline-directed medical therapies, discontinuation of pre-admission digoxin therapy was associated with poor outcomes.

Therapeutic Advances in the Management of Acute Decompensated Heart Failure

BACKGROUND

Acute decompensated heart failure (ADHF) is the most common presenting phenotype of acute heart failure (AHF). The main goal of this article was to review the contemporary management strategies in these patients and to describe how future clinical trials may address unmet clinical needs.

AREAS OF UNCERTAINTY

The current pathophysiologic understanding of AHF is incomplete. The guideline recommendations for the management of ADHF are based only on algorithms provided by expert consensus guided by blood pressure and/or clinical signs of congestion or hypoperfusion. The lack of adequately conducted trials to address the unmet need for evidence therapy in AHF has not yet been surpassed, and at this time, there is no evidence-based strategy for targeted decongestive therapy to improve outcomes. The precise time point for initiation of guideline-directed medical therapies (GDMTs), as respect to moment of decompensation, is also unknown.

DATA SOURCES

The available data informing current management of patients with ADHF are based on randomized controlled trials, observational studies, and administrative databases.

THERAPEUTIC ADVANCES

A major step-forward in the management of ADHF patients is recognizing congestion, either clinical or hemodynamic, as a major trigger for heart failure (HF) hospitalization and most important target for therapy. However, a strategy based exclusively on congestion is not sufficient, and at present, comprehensive assessment during hospitalization of cardiac and noncardiovascular substrate with identification of potential therapeutic targets represents "the corner-stone" of ADHF management. In the last years, substantial data have emerged to support the continuation of GDMTs during hospitalization for HF decompensation. Recently, several clinical trials raised hypothesis of "moving to the left" concept that argues for very early implementation of GDMTs as potential strategy to improve outcomes.

CONCLUSIONS

The management of ADHF is still based on expert consensus documents. Further research is required to identify novel therapeutic targets, to establish the precise time point to initiate GDMTs, and to identify patients at risk of recurrent hospitalization.

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.

One- to 10-Day Versus 11- to 30-Day All-Cause Readmission and Mortality in Older Patients With Heart Failure

Heart failure (HF) is the leading cause for 30-day all-cause readmission in older Medicare beneficiaries and 30-day all-cause readmission is associated with a higher risk of mortality. In the current analysis, we examined if that association varied by timing of 30-day all-cause readmission. Of the 8,049 Medicare beneficiaries hospitalized for HF, 1,688 had 30-day all-cause readmissions, of whom 1,519 were alive at 30 days. Of these, 626 (41%) had early (first 10 days) 30-day readmission. Propensity scores for early 30-day readmission, estimated for all 1,519 patients, were used to assemble a matched cohort of 596 pairs of patients with early versus late (11 to 30 days) all-cause readmission balanced on 34 baseline characteristics. Two-year all-cause mortality occurred in 51% and 57% of matched patients with early versus late 30-day all-cause readmissions, respectively (hazard ratio [HR] associated with late 30-day readmission, 1.22; 95% confidence interval [CI], 1.04 to 1.42; p = 0.014). This association was not observed in the subset of 436 patients whose 30-day all-cause readmission was due to HF (HR, 1.01; 95% CI, 0.79 to 1.28; p = 0.963), but was observed in the subset of 756 patients whose 30-day all-cause readmission was not due to HF (HR, 1.37; 95% CI, 1.12 to 1.67; p = 0.002; p for interaction, 0.057). In conclusion, in a high-risk subset of older hospitalized HF patients readmitted within 30 days, readmission during 11 to 30 (vs 1 to 10) days was associated with a higher risk of death and this association appeared to be more pronounced in those readmitted for non-HF-related reasons.

Digoxin use and lower risk of 30-day all-cause readmission in older patients with heart failure and reduced ejection fraction receiving β-blockers

BACKGROUND

Digoxin use has been associated with a lower risk of 30-day all-cause admission and readmission in patients with heart failure and reduced ejection fraction (HFrEF).

HYPOTHESIS

Digoxin use will be associated with improved outcomes in patients with HFrEF receiving β-blockers.

METHODS

Of the 3076 hospitalized Medicare beneficiaries with HFrEF (EF <45%), 1046 received a discharge prescription for β-blockers, of which 634 were not on digoxin. Of the 634, 204 received a new discharge prescription for digoxin. Propensity scores for digoxin use, estimated for each of the 634 patients, were used to assemble a matched cohort of 167 pairs of patients receiving and not receiving digoxin, balanced on 30 baseline characteristics. Matched patients (n = 334) had a mean age of 74 years and were 46% female and 30% African American.

RESULTS

30-day all-cause readmission occurred in 15% and 27% of those receiving and not receiving digoxin, respectively (hazard ratio [HR]: 0.51, 95% confidence interval [CI]: 0.31-0.83, P = 0.007). This beneficial association persisted during 4 years of follow-up (HR: 0.72, 95% CI: 0.57-0.92, P = 0.008). Digoxin use was also associated with a lower risk of the combined endpoint of all-cause readmission or all-cause mortality at 30 days (HR: 0.54, 95% CI: 0.34-0.86, P = 0.009) and at 4 years (HR: 0.76, 95% CI: 0.61-0.96, P = 0.020).

CONCLUSIONS

In hospitalized patients with HFrEF receiving β-blockers, digoxin use was associated with a lower risk of 30-day all-cause readmission but not mortality, which persisted during longer follow-up.