The effects of serum iron level without anemia on long-term prognosis of patients with coronary heart disease complicated with chronic heart failure: a retrospective cohort study

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.

Iron metabolism and cardiovascular disease: Basic to translational purviews and therapeutical approach

Iron interactions with the cardiovascular system were proposed about half a century ago, yet a clear-cut understanding of this micronutrient and its intricacies with acute and chronic events is still lacking. In chronic heart failure, patients with decreased iron stores appear to benefit from intravenous administration of metallic formulations, whereas acute diseases (e.g., myocardial infarction, stroke) are barely studied in randomized controlled trials in humans. However, proof-of-concept studies have indicated that the dual redox characteristics of iron could be involved in atherosclerosis, necrosis, and ferroptosis. To this end, we sought to review the currently available body of literature pertaining to these temporal profiles of heart diseases, as well as the pathophysiologic mechanism by which iron enacts, underlining key points related to treatment options.

Beneficial effect of the short-chain fatty acid propionate on vascular calcification through intestinal microbiota remodelling

BACKGROUND

Vascular calcification is a major cause of the high morbidity and mortality of cardiovascular diseases and is closely associated with the intestinal microbiota. Short-chain fatty acids (SCFAs) are derived from the intestinal microbiota and can also regulate intestinal microbiota homeostasis. However, it remains unclear whether exogenous supplementation with propionate, a SCFA, can ameliorate vascular calcification by regulating the intestinal microbiota. This study was conducted to explore the roles of propionate and the intestinal microbiota in the process of vascular calcification.

METHODS

In total, 92 patients were enrolled consecutively as the observational cohort to analyse the relationship between SCFAs and vascular calcification in both blood and faecal samples. A rat model of vascular calcification was induced by vitamin D3 and nicotine (VDN) to validate the effect of propionate. Differences in the intestinal microbiota were analysed by 16S ribosomal RNA gene sequencing. Faecal microbiota transplantation and Akkermansia muciniphila transplantation experiments were performed to evaluate the functions of the intestinal microbiota.

RESULTS

The results of the observational cohort study revealed that the levels of SCFAs (particularly propionate) in both blood and faecal samples independently correlated negatively with calcification scores (P < 0.01). To verify the activities of propionate, it was provided to VDN-treated rats, and oral or rectal propionate delivery reshaped the intestinal microbiota, resulted in elevated SCFA production, improved intestinal barrier function and alleviated inflammation, ultimately ameliorating vascular calcification. Furthermore, we demonstrated that transplantation of the propionate-modulated intestinal microbiota induced beneficial outcomes similar to those with oral or rectal propionate administration. Interestingly, linear discriminant analysis (LDA) effect size (LEfSe) revealed that oral or rectal propionate administration and propionate-modulated intestinal microbiota transplantation both enriched primarily Akkermansia. Subsequently, we demonstrated that Akkermansia supplementation could ameliorate VDN-induced vascular calcification in rats.

CONCLUSIONS

Propionate can significantly ameliorate vascular calcification in VDN-treated rats, and this effect is mediated by intestinal microbiota remodelling. The findings in our study indicate that the intestinal tract-vessel axis is a promising target for alleviating vascular calcification. Video Abstract.

Relation of Iron Status to Prognosis After Acute Coronary Syndrome

Iron deficiency has been extensively researched and is associated with adverse outcomes in heart failure. However, to our knowledge, the temporal evolution of iron status has not been previously investigated in patients with acute coronary syndrome (ACS). Therefore, we aimed to explore the temporal pattern of repeatedly measured iron, ferritin, transferrin, and transferrin saturation (TSAT) in relation to prognosis post-ACS. BIOMArCS (BIOMarker study to identify the Acute risk of a Coronary Syndrome) is a prospective, multicenter, observational cohort study conducted in The Netherlands between 2008 and 2015. A total of 844 patients with post-ACS were enrolled and underwent high-frequency (median 17) blood sampling during 1 year follow-up. Biomarkers of iron status were measured batchwise in a central laboratory. We analyzed 3 patient subsets, including the case-cohort (n = 187). The primary endpoint (PE) was a composite of cardiovascular mortality and repeat nonfatal ACS, including unstable angina pectoris requiring revascularization. The association between iron status and the PE was analyzed using multivariable joint models. Mean age was 63 years; 78% were men, and >50% had iron deficiency at first sample in the case-cohort. After adjustment for a broad range of clinical variables, 1 SD decrease in log-iron was associated with a 2.2-fold greater risk of the PE (hazard ratio 2.19, 95% confidence interval 1.34 to 3.54, p = 0.002). Similarly, 1 SD decrease in log-TSAT was associated with a 78% increased risk of the PE (hazard ratio 1.78, 95% confidence interval 1.17 to 2.65, p = 0.006). Ferritin and transferrin were not associated with the PE. Repeated measurements of iron and TSAT predict risk of adverse outcomes in patients with post-ACS during 1 year follow-up. Trial Registration: The Netherlands Trial Register. Unique identifiers: NTR1698 and NTR1106. Registered at https://www.trialregister.nl/trial/1614 and https://www.trialregister.nl/trial/1073.

Differences in needs for community collaboration for heart failure between medical and nursing care staff

The increased numbers of older and frail patients with heart failure (HF) means there is an urgent need to establish regional collaborative systems for medical and nursing care. However, expectations related to collaborative HF care among medical and care staff remain unclear. We conducted a questionnaire survey with staff in hospitals, clinics, and nursing care facilities (NCFs) who had experienced collaboration through the common HF collaborative pathway in the western region of Tottori Prefecture, Japan, from July 2019 to July 2020. We received 150 responses from hospitals and 41 responses from clinics and NCFs. Following introduction of the collaborative pathway, 57% of respondents from hospitals, 35% from clinics, and 71% from NCFs rated collaboration as improved. Staff from hospitals and clinics were most satisfied with improved education interventions following implementation of the collaborative pathway, and NCF staff were most satisfied with improved information sharing. Staff from hospitals and NCFs placed the highest importance on improving information sharing through collaboration, and clinic staff placed the highest importance on improving efficiency. The needs for collaborative HF care differ between hospitals, clinics, and NCFs. A collaboration program should be designed to meet the different needs of diverse staff in the community.

Dysregulation of iron metabolism in cardiovascular diseases: From iron deficiency to iron overload

Iron deficiency and iron overload are the most prevalent and opposite forms of dysregulated iron metabolism that affect approximately 30 percent of the world population, in particularly, elderly and patients with chronic diseases. Both iron deficiency and overload are frequently observed in a wide range of cardiovascular diseases, contributing to the onset and progression of these diseases. One of the devastating seqeulae for iron overload is the induction of ferroptosis, a newly defined form of regulated cell death which heavily impacts cardiac function through ferroptotic cell death in cardiomyocytes. In this review, we will aim to evaluate iron deficiency and iron overload in cardiovascular diseases. We will summarize current therapeutic strategies to tackle iron deficiency and iron overload, major pitfalls of current studies, and future perspectives.