Markers of Iron Metabolism and Outcomes in Patients with Heart Failure: A Systematic Review.

Iron deficiency (ID) in conjunction with heart failure (HF) poses a challenge for clinicians and is associated with worse HF outcomes. Treatment of ID with IV iron supplementation for patients with HF has demonstrated benefits in quality of life (QoL) and HF-related hospitalizations. The aim of this systematic review was to summarize the evidence linking iron metabolism biomarkers with outcomes in patients with HF to assist in the optimal use of these biomarkers for patient selection. A systematic review of observational studies in English from 2010 to 2022 was conducted using PubMed, with keywords of "Heart Failure" and respective iron metabolism biomarkers ("Ferritin", "Hepcidin", "TSAT", "Serum Iron", and "Soluble Transferrin Receptor"). Studies pertaining to HF patients, with available quantitative data on serum iron metabolism biomarkers, and report of specific outcomes (mortality, hospitalization rates, functional capacity, QoL, and cardiovascular events) were included, irrespective of left ventricular ejection fraction (LVEF) or other HF characteristics. Clinical trials of iron supplementation and anemia treatment were removed. This systematic review was conducive to formal assessment of risk of bias via Newcastle-Ottawa Scale. Results were synthesized based on their respective adverse outcomes and iron metabolism biomarker(s). Initial and updated searches identified 508 unique titles once duplicates were removed. The final analysis included 26 studies: 58% focused on reduced LVEF; age range was 53-79 years; males composed 41-100% of the reported population. Statistically significant associations of ID were observed with all-cause mortality, HF hospitalization rates, functional capacity, and QoL. Increased risk for cerebrovascular events and acute renal injury have also been reported, but these findings were not consistent. Varying definitions of ID were utilized among the studies; however, most studies employed the current European Society of Cardiology criteria: serum ferritin < 100 ng/mL or the combination of ferritin between 100-299 ng/mL and transferrin saturation (TSAT) < 20%. Despite several iron metabolism biomarkers demonstrating strong association with several outcomes, TSAT better predicted all-cause mortality, as well as long-term risk for HF hospitalizations. Low ferritin was associated with short-term risk for HF hospitalizations, worsening functional capacity, poor QoL, and development of acute renal injury in acute HF. Elevated soluble transferrin receptor (sTfR) levels were associated with worse functional capacity and QoL. Finally, low serum iron was significantly associated with increased risk for cardiovascular events. Considering the lack of consistency among the iron metabolism biomarkers for association with adverse outcomes, it is important to incorporate additional biomarker data, beyond ferritin and TSAT, when assessing for ID in HF patients. These inconsistent associations question how best to define ID to ensure proper treatment. Further research, potentially tailored to specific HF phenotypes, is required to optimize patient selection for iron supplementation therapy and appropriate targets for iron stores replenishment.

Spironolactone metabolite concentrations in decompensated heart failure: insights from the ATHENA-HF trial.

AIMS: In Aldosterone Targeted Neurohormonal Combined with Natriuresis Therapy in Heart Failure (ATHENA-HF), high-dose spironolactone (100 mg daily) did not improve efficacy endpoints over usual care [placebo or continued low-dose spironolactone (25 mg daily) in patients already receiving spironolactone] in the treatment of acute heart failure (HF). We hypothesized that low concentrations of the long-acting active metabolites of spironolactone [canrenone and 7α-thiomethylspironolactone (7α-TMS)] in the high-dose group could have contributed to these neutral results. METHODS AND RESULTS: In patients randomized to high-dose spironolactone not previously treated with spironolactone (high-dose-naïve, n = 112), concentrations of canrenone and 7α-TMS increased at 48 and 96 h compared to baseline, and between 48 and 96 h (all P < 0.005), indicating that steady-state concentrations had not been reached by 48 h. In patients previously on low-dose, high-dose spironolactone (high-dose-previous, n = 37), concentrations of canrenone increased at 48 and 96 h compared to baseline (both P < 0.0005), with a marginal increase between 48 and 96 h (P = 0.0507). At 48 h, both high-dose groups had higher concentrations of both metabolites than the low-dose spironolactone group (P < 0.0001). Moreover, concentrations of both metabolites were higher in high-dose-previous vs. high-dose-naïve patients (P < 0.01), indicating that previous spironolactone use was significant, and that steady-state has not been reached in high-dose-naïve patients at 48 h. We found limited and inconsistent evidence of correlation between metabolite concentrations and endpoints. CONCLUSIONS: Lower-than-anticipated concentrations of spironolactone active metabolites were observed for at least 48 h in the high-dose spironolactone group and may have contributed to the absence of pharmacological effects of spironolactone in the ATHENA-HF trial.

Spironolactone in Acute Heart Failure Patients With Renal Dysfunction and Risk Factors for Diuretic Resistance: From the ATHENA-HF Trial.

BACKGROUND: Acute heart failure (HF) patients with renal insufficiency and risk factors for diuretic resistance may be most likely to derive incremental improvement in congestion with the addition of spironolactone. METHODS: The Aldosterone Targeted Neurohormonal Combined with Natriuresis Therapy in Heart Failure (ATHENA-HF) trial randomized 360 acute HF patients with reduced or preserved ejection fraction to spironolactone 100 mg daily or usual care for 96 hours. The current analysis assessed the effects of study therapy within tertiles of baseline estimated glomerular filtration rate (eGFR) and subgroups at heightened risk for diuretic resistance. RESULTS: Across eGFR tertiles, there was no incremental benefit of high-dose spironolactone on any efficacy endpoint, including changes in log N-terminal pro-B-type natriuretic peptide and signs and symptoms of congestion (all P for interaction ≥ 0.06). High-dose spironolactone had no significant effect on N-terminal pro-B-type natriuretic peptide reduction regardless of blood pressure, diabetes mellitus status, and loop diuretic dose (all P for interaction ≥ 0.38). In-hospital changes in serum potassium and creatinine were similar between treatment groups for all GFR tertiles (all P for interaction ≥ 0.18). Rates of inpatient worsening HF, 30-day worsening HF, and 60-day all-cause mortality were numerically higher among patients with lower baseline eGFR, but relative effects of study treatment did not differ with renal function (all P for interaction ≥ 0.27). CONCLUSIONS: High-dose spironolactone did not improve congestion over usual care among patients with acute HF, irrespective of renal function and risk factors for diuretic resistance. In-hospital initiation or continuation of spironolactone was safe during the inpatient stay, even when administered at high doses to patients with moderate renal dysfunction.

Efficacy and Safety of Spironolactone in Acute Heart Failure: The ATHENA-HF Randomized Clinical Trial.

Importance: Persistent congestion is associated with worse outcomes in acute heart failure (AHF). Mineralocorticoid receptor antagonists administered at high doses may relieve congestion, overcome diuretic resistance, and mitigate the effects of adverse neurohormonal activation in AHF. Objective: To assess the effect of high-dose spironolactone and usual care on N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels compared with usual care alone. Design, Setting, and Participants: This double-blind and placebo (or low-dose)-controlled randomized clinical trial was conducted in 22 US acute care hospitals among patients with AHF who were previously receiving no or low-dose (12.5 mg or 25 mg daily) spironolactone and had NT-proBNP levels of 1000 pg/mL or more or B-type natriuretic peptide levels of 250 pg/mL or more, regardless of ejection fraction. Interventions: High-dose spironolactone (100 mg) vs placebo or 25 mg spironolactone (usual care) daily for 96 hours. Main Outcomes and Measures: The primary end point was the change in NT-proBNP levels from baseline to 96 hours. Secondary end points included the clinical congestion score, dyspnea assessment, net urine output, and net weight change. Safety end points included hyperkalemia and changes in renal function. Results: A total of 360 patients were randomized, of whom the median age was 65 years, 129 (36%) were women, 200 (55.5%) were white, 151 (42%) were black, 8 (2%) were Hispanic or Latino, 9 (2.5%) were of other race/ethnicity, and the median left ventricular ejection fraction was 34%. Baseline median (interquartile range) NT-proBNP levels were 4601 (2697-9596) pg/mL among the group treated with high-dose spironolactone and 3753 (1968-7633) pg/mL among the group who received usual care. There was no significant difference in the log NT-proBNP reduction between the 2 groups (-0.55 [95% CI, -0.92 to -0.18] with high-dose spironolactone and -0.49 [95% CI, -0.98 to -0.14] with usual care, P = .57). None of the secondary end point or day-30 all-cause mortality or heart failure hospitalization rate differed between the 2 groups. The changes in serum potassium and estimated glomerular filtration rate at 24, 48, 72, and 96 hours. were similar between the 2 groups. Conclusions and Relevance: Adding treatment with high-dose spironolactone to usual care for patients with AHF for 96 hours was well tolerated but did not improve the primary or secondary efficacy end points. Trial Registration: clinicaltrials.gov Identifier: NCT02235077.

Cardiac mortality in {beta}-thalassemia major: resting but not dobutamine stress echocardiography predicts mortality among initially cardiac disease-free patients in a prospective 12-year study.

AIMS: Cardiac death remains the principal cause of mortality in beta-thalassemia major (beta-TM). Echocardiography may provide additional information, incremental to haematological profile, both for guiding chelation therapy and to assess prognosis. METHODS AND RESULTS: Between 1993 and 1995, 36 patients with beta-TM and normal cardiac function and 25 normal volunteers underwent evaluation using resting and dobutamine stress echocardiography (DSE). Dobutamine stress echocardiography was performed at baseline and repeated after 2 years. The primary endpoint was cardiac mortality. During a 12-year observation period, seven patients (19%) died from heart failure. All seven deaths occurred among the cohort of 12 patients with median ferritin concentrations >or= 2800 ng/mg. In addition, a resting left ventricular ejection fraction (LVEF) < 60% was also associated with increased late mortality. In multivariate analysis, increased serum ferritin levels and reduced LVEF but not DSE or other haematological variables were independent survival determinants. CONCLUSION: Resting LVEF provides prognostic information that is additional to ferritin levels among patients with beta-TM.

Global vasomotor dysfunction and accelerated vascular aging in beta-thalassemia major.

BACKGROUND: Patients with beta-thalassemia major (beta-TM) demonstrate an increased incidence of vascular complications, which are thought to result from a procoagulant/proinflammatory environment. We investigated the arterial vasorelaxing capacity and sought for early carotid atherosclerosis and underlying pathophysiological correlates in these transfusion-dependent patients. METHODS AND RESULTS: The vasodilatory properties of the brachial artery and the carotid intima-media thickness (IMT) were examined with ultrasonography in 35 non-diabetic young adults with beta-TM (patient group) and 35 control subjects (control group). Among thalassemic patients, both endothelium-dependent (FMD) and -independent dilatation (FID) as well as their ratio was impaired, whereas IMT was increased (p<0.01). Patients on optimal, as compared with those on non-optimal chelation treatment had a non-significantly lower IMT. Vasodilatory capacity in the patient group was inversely correlated with IMT and independently associated either with the quality of chelation therapy (FMD) or serum ferritin levels (FID). Plasma concentrations of D-dimers, circulating markers of endothelial activation, inflammation and apoptosis were higher, while plasma cholesterol and fibrinogen levels were lower-than-normal in the patient group. Independent predictors of IMT among thalassemic patients were tumor necrosis factor-alpha levels and age. CONCLUSIONS: Young adults with beta-TM exhibit both a global impairment of arterial vasorelaxation and early carotid atherosclerosis. A procoagulant/proinflammatory state in these transfusion-dependent patients may overwhelm atheroprotective mechanisms, including an optimal chelation regimen, and promote vascular injury and atherogenesis.