Association of anemia with clinical outcomes in stable coronary artery disease

Prognostic Impact of Anemia and Hemoglobin Levels in Unselected Patients Undergoing Coronary Angiography

Background/Objectives: This study investigates the prevalence and prognostic impact of concomitant anemia in unselected patients undergoing invasive coronary angiography (CA). The spectrum of patients undergoing CA has significantly changed during the past decades, related to ongoing demographic changes and improved treatment strategies for patients with cardiovascular disease. Methods: Consecutive patients undergoing invasive CA from 2016 to 2022 were retrospectively included at one institution. Patients with anemia (i.e., hemoglobin < 13.0 g/dL for males and <12.0 g/dL for females) were compared with patients without anemia (i.e., nonanemics). The primary endpoint was rehospitalization for heart failure (HF) at 36 months. Secondary endpoints comprised the risk of rehospitalization for acute myocardial infarction (AMI) and coronary revascularization. Statistical analyses included Kaplan-Meier, multivariable Cox proportional regression analyses, and propensity score matching. Results: From 2016 to 2022, 7645 patients undergoing CA were included with a median hemoglobin level of 13.2 g/dL. Anemics had a higher prevalence of coronary artery disease (CAD) (76.3% vs. 74.8%; p = 0.001), alongside an increased need for percutaneous coronary intervention (PCI) (45.3% vs. 41.5%; p = 0.001). At 36 months, the risk of rehospitalization for HF was higher in anemic patients (27.4% vs. 18.4%; p = 0.001; HR = 1.583; 95% CI 1.432-1.750; p = 0.001), which was still evident after multivariable adjustment (HR = 1.164; 95% CI 1.039-1.304; p = 0.009) and propensity score matching (HR = 1.137; 95% CI 1.006-1.286; p = 0.040). However, neither the risk of AMI (8.4% vs. 7.4%, p = 0.091) nor the risk of coronary revascularization at 36 months (8.0% vs. 8.5%, p = 0.447) was higher in anemic compared with nonanemic patients. Conclusions: In consecutive patients undergoing CA, concomitant anemia was independently associated with an increased risk of rehospitalization for HF, but not AMI or coronary revascularization. Patients with LVEF ≥ 35% and multivessel disease were especially susceptible to anemia-induced HF-related rehospitalization.

Impact of anemia on in-stent restenosis after percutaneous coronary intervention

Background

Anemia is a common risk factor for post-percutaneous coronary intervention (PCI) adverse events; however, data on its association with in-stent restenosis (ISR) is limited.

Methods

538 patients who underwent PCI between January 2017 and September 2019 and follow-up angiography 9–12 months after the initial PCI were enrolled in this study. Baseline clinical and procedural characteristics were compared between the ISR and non-ISR groups, and independent predictors of ISR were determined using propensity score matching.

Results

The incidence of anemia was 53.5% in patients with ISR and 19.0% in those without ISR. Univariable logistic regression analyses showed that anemia (OR, 4.283; 95% CI, 1.949–9.410; P < 0.001), diabetes mellitus (OR, 2.588; 95% CI, 1.176–5.696; P = 0.018), chronic kidney disease (OR, 3.058; 95% CI, 1.289–7.252; P = 0.011), multiple stenting (OR, 2.592; 95% CI, 1.205–5.573; P = 0.015), bifurcation lesion (OR, 2.669; 95% CI, 1.236–5.763; P = 0.012), and calcification (OR, 3.529; 95% CI, 1.131–11.014; P = 0.030) were closely associated with ISR. Low-density lipoprotein cholesterol (LDL-c) levels and stent diameter were also significantly linked to ISR, as was anemia (P = 0.009) after propensity score matching.

Conclusion

Anemia is closely associated with post-PCI ISR, and patients with lower hemoglobin levels are at a higher risk of ISR.

Trends and Inpatient Outcomes of Primary Atrial Fibrillation Hospitalizations with Underlying Iron Deficiency Anemia: An Analysis of The National Inpatient Sample Database from 2004 -2018

Atrial fibrillation (AF) is the most prevalent arrhythmia in the United States. However, studies evaluating the impact of iron deficiency anemia on AF outcomes are limited. Therefore, we aimed to evaluate the association of iron deficiency anemia (IDA) on clinical outcomes in patients hospitalized with AF. A retrospective analysis of adult hospital discharges from the National Inpatient Sample (NIS) between 2004 and 2018 was conducted. Multivariable logistic regression was used to assess the association of IDA and other clinical outcomes ie inpatient mortality, acute myocardial infarction, cardiogenic shock, acute kidney injury, vasopressors use, length of stay, and other resource utilization. These models were adjusted for patient and hospital-level characteristics. A total of 5,975,241 weighted primary AF hospitalizations were identified. Out of these, 152,059 (2.5%) had diagnosis of IDA. After adjustment of variables, admissions with IDA were associated with higher rates of acute myocardial infarction (adjusted odds ratio [aOR] = 1.10, 95% CI 1.01-1.19 P = 0.026), use of vasopressors (aOR = 1.30, CI 1.27-1.32, P <0.001), invasive mechanical ventilation (aOR = 1.26, CI 1.14-1.40 P <0.001) and acute kidney injury (aOR = 1.72, CI 1.66-1.79 P <0.001). There was no significant difference in all-cause mortality (aOR = 0.97, CI 0.87-1.07, P = 0.513), cardiogenic shock, in-hospital cardiac arrest or use of mechanical circulatory support. Adjusted mortality in patients with AF and IDA decreased from 1.09% to 0.54% from 2004 to2018 (P -trend < 0.001). Among hospitalized patients with AF, our study did not show any difference in all-cause mortality between those with and without IDA.

Anemia is a novel predictor for clinical ISR following PCI

Background

Conflicting data were found regarding the anemia’s effect on percutaneous coronary intervention (PCI) outcomes. We directed our study to investigate anemia’s effect on clinical in-stent restenosis (ISR) following PCI.

Results

A prospective multi-center cohort study was performed on 470 consecutive participants undergoing elective PCI. We classified the participants into two groups: group 1 who were anemic and group 2 who were non-anemic as a control group. At 1, 3, 6, and 12 months by clinic visits, we followed up with the patients to assess anemia’s clinical ISR effect. We found that 20% of the patients undergoing PCI had anemia. Anemic patients showed a statistically significant higher rate of impaired renal function and diabetes and a higher percentage of the female gender. Multivariate regression analysis for major adverse cardiovascular events (MACEs) after adjusting for confounding factors revealed that anemia represents a more risk on MACE (adjusted hazard ratio (HR) was 4.13; 95% CI 2.35–7.94; p value < 0.001) and carries a higher risk upon clinical ISR (adjusted HR was 3.51; 95% CI 1.88–7.16; p value < 0.001) over 12 months of follow-up.

Conclusion

Anemic patients going through PCI are generally females, diabetics, and have renal impairment. Anemia might be considered another indicator for clinical ISR and is fundamentally associated with an increased MACE incidence.

Long-term Pattern of Red Cell Distribution Width in Patients With ST-Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

Red cell distribution width (RDW) is an indirect marker of inflammation and an independent predictor of long-term mortality. The aim of this study was to determine RDW values in patients with ST-elevation acute myocardial infarction (STEMI) submitted to primary percutaneous coronary intervention (PCI) and evaluate its association with adverse outcomes. We measured RDW in STEMI patients before undergoing primary PCI and divided into low and high RDW. Patients were followed up to 3 years after their discharge for the occurrence of in-hospital, 30-days, and long-term major adverse cardiovascular events (MACEs) and mortality. We included 485 patients with a mean age of 61.1(±12.5) years, 62.9% were male. In multivariate analysis, RDW remained independent predictor of long-term mortality and MACE [relative risk (RR) 1.51; 95% confidence interval (95% CI) = 1.11-2.05; P = 0.007 and RR = 1.42; 95% CI = 1.30-1.82; P = 0.004. Area under the curve for long-term mortality was 0.65 (95% CI = 0.61-0.69; P < 0.0001). RDW < 13.4 had a negative predictive value of 87.4% for all-cause mortality. Patients who had worse outcomes remained with higher values of RDW during the follow-up. In conclusion, high RDW is an independent predictor of long-term mortality and MACE in patients with STEMI undergoing primary PCI. A low RDW has an excellent negative predictive value for long-term mortality. Patients with sustained elevated levels of RDW have worse outcomes at long-term follow-up.

Mechanisms responsible for reduced erythropoiesis during androgen deprivation therapy in men with prostate cancer

Androgen deprivation therapy (ADT) is a mainstay of treatment for prostate cancer (PCa). As androgens stimulate erythropoiesis, ADT is associated with a reduction in hematocrit, which in turn contributes to fatigue and related morbidity. However, the mechanisms involved in ADT-induced reduction in erythropoiesis remain unclear. We conducted a 6-mo prospective cohort study and enrolled men with PCa about to undergo ADT (ADT-Group) and a control group of men who had previously undergone prostatectomy for localized PCa and were in remission (Non-ADT Group). All participants had normal testosterone levels at baseline. Fasting blood samples were collected at baseline, 12 wk, and 24 wk after initiation of ADT; samples were obtained at the same intervals from enrollment in the Non-ADT group. Blood count, iron studies, erythropoietin, erythroferrone, and hepcidin levels were measured. Seventy participants formed the analytical sample (31 ADT, 39 Non-ADT). ADT was associated with a significant reduction in erythrocyte count (estimated mean difference = -0.2×10⁶ cells/µl, 95%CI = -0.3 to -0.1×10⁶ cells/µl, P < 0.001), hematocrit (-1.9%, 95%CI = -2.7 to -1.1%, P < 0.001), and hemoglobin (-0.6 g/dl, 95%CI = -0.8 to -0.3 g/dl, P < 0.001). Serum hepcidin concentration increased in the ADT-group (18 ng/ml, P < 0.001); however, iron concentrations did not change (-1.1 µg/dl, P = 0.837). Ferritin levels increased in men on ADT (60 ng/ml, P < 0.001). Iron binding capacity, transferrin saturation, erythroferrone, and erythropoietin did not change. Nine men undergoing ADT developed new-onset anemia. In conclusion, reduced proliferation of marrow erythroid progenitors leads to ADT-induced reduction in erythropoiesis. Future studies should evaluate the role of selective androgen receptor modulators in the treatment of ADT-induced anemia.

Management standards for stable coronary artery disease in India

Coronary artery disease (CAD) is one of the important causes of cardiovascular morbidity and mortality globally, giving rise to more than 7 million deaths annually. An increasing burden of CAD in India is a major cause of concern with angina being the leading manifestation. Stable coronary artery disease (SCAD) is characterised by episodes of transient central chest pain (angina pectoris), often triggered by exercise, emotion or other forms of stress, generally triggered by a reversible mismatch between myocardial oxygen demand and supply resulting in myocardial ischemia or hypoxia. A stabilised, frequently asymptomatic phase following an acute coronary syndrome (ACS) is also classified as SCAD. This definition of SCAD also encompasses vasospastic and microvascular angina under the common umbrella.

Bridging therapy in antiphospholipid syndrome and antiphospholipid antibodies carriers: case series and review of the literature

Peri-operative management of patients on warfarin involves assessing and balancing individual risks for thromboembolism and bleeding. The timing of warfarin withdrawal and a tailored pre/postoperative management (including the substitution of heparin in place of warfarin, the so-called bridging therapy) is critical in patients with prothrombotic conditions. The antiphospholipid syndrome (APS) is the most common cause of acquired thrombophilia. In this particular subset of patients, as the risk of thrombosis is higher than in general population, bridging therapy can represent a real challenge for treating physicians. Only few studies have been designed to address this topic. We aim to report our experience and to review the available literature in the peri-procedural management of APS and antiphospholipid antibody-positive patients, reporting adverse events and attempting to identify potential risk factor associated with thrombosis or bleeding complications.

Temporary is not always benign: similarities and differences between transient ischemic attack and angina

The introduction of the tissue-based definition of transient ischemic attack (TIA), according to which TIA may be diagnosed only in the absence of an infarction on brain neuroimaging, prompts reflections about similarities and differences between TIA and angina. Both share transitory symptoms in the absence of tissue damage, whereas stroke and myocardial infarction are associated with tissue necrosis. Apart from this, TIA and angina are widely different with respect to pathophysiology, natural history, prognosis, and response to specific medical treatments. In general terms, it could be argued that TIA differs from angina as the brain differs from the heart in structure, physiology, metabolism, and performance. Most importantly, in TIA and angina, the reversible nature of symptoms cannot be assumed as a favorable prognostic indicator. In fact, reversibility of stable angina denotes a low-risk condition, whereas in TIA and unstable angina reversibility may suggest plaque instability and relevant risk of ischemic recurrences.

Therapy for hepatitis C virus infection increases survival of patients with pretreatment anemia

BACKGROUND & AIMS

Individuals with chronic hepatitis C virus (HCV) infection and pretreatment anemia are less likely to begin and complete a full course of treatment for HCV. However, among those who are treated for HCV infection, the effect of treatment on mortality is not clear.

METHODS

We performed a retrospective analysis of 200,139 HCV-infected veterans using data from the Electronically Retrieved Cohort of Hepatitis C-Infected veterans (2001-2008). The effects of treatment and treatment duration on survival were compared based on data from 1820 treated and 27,690 untreated anemic HCV-infected veterans. The association between HCV treatment and mortality was estimated using the Cox proportional hazard models, with adjustments for potential confounders. The main outcome was all-cause mortality.

RESULTS

In multivariable analysis, pretreatment anemia was associated significantly with African American race (odds ratio [OR], 2.03; 95% confidence interval [CI], 1.95-2.11), chronic kidney disease (OR, 3.36; 95% CI, 3.23-3.51), and decompensated liver disease (OR, 3.69; 95% CI, 3.53-3.86). All-cause mortality for treated, anemic, HCV-infected veterans was lower (54.2 per 1000 person-years; 95% CI, 49.2-59.7 per 1000 person years) than for untreated, anemic HCV-infected veterans (146.8 per 1000 person-years; 95% CI, 144.2-149.4 per 1000 person-years). The adjusted hazard ratio for treatment of HCV in anemic veterans was 0.45 (95% CI, 0.39-0.51), which was reduced after exclusion of comorbidities (hazard ratio, 0.28; 95% CI, 0.22-0.37).

CONCLUSIONS

Based on a retrospective analysis of a veterans database, HCV therapy increases survival rates of individuals with pretreatment anemia. Additional studies are needed to determine strategies to increase rates of HCV therapy for this group.

Anemia and mortality in older persons: does the type of anemia affect survival?

Anemia is a common condition among community-dwelling older adults. The present study investigates the effect of type of anemia on subsequent mortality. We analyzed data from participants of the Third National Health and Nutrition Survey who were aged ≥50 and had valid hemoglobin levels determined by laboratory measurement. Anemia was defined by World Health Organization criteria. 7,171 subjects met our inclusion criterion. Of those with anemia (n = 862, deaths = 491), 24% had nutritional anemia, 11% had anemia of chronic renal disease, 26% had anemia of chronic inflammation, and 39% had unexplained anemia. We found an overall relative risk (RR) for mortality of 1.8 (p < 0.001) comparing those with anemia to those without, after adjusting for age, sex, and race. After we controlled for a number of chronic medical conditions, the overall RR was 1.6. Compared to persons without anemia, we found the following RRs for the type of anemia: nutritional (2.34, p < 0.0001), chronic renal disease (1.70, p < 0.0001), chronic inflammation (1.48, p < 0.0001), and unexplained (1.26, p < 0.01). Anemia is common although not severe in older non-institutionalized adults. When compared with non-anemic older adults, those with nutritional anemia or anemia due to chronic renal disease have the highest mortality risk.

Anemia and dementia among the elderly: the São Paulo Ageing & Health Study

BACKGROUND

Anemia and dementia are common diseases among the elderly, but conflicting data are available regarding an association between these two conditions. We analyzed data from the São Paulo Ageing & Health Study to address the relationship between anemia and dementia.

METHODS

This cross-sectional observational study included participants aged 65 years and older from a deprived area of the borough of Butantan, São Paulo, Brazil. Data about demographics, education, income, and cognitive and daily life function were collected, as well as blood samples. Anemia and dementia were defined according to WHO and DSM-IV criteria, respectively.

RESULTS

Of the 2267 subjects meeting the inclusion criteria, 2072 agreed to participate in the study; of whom 1948 had a valid total blood count and were included in the analysis. Anemia was diagnosed in 203 (10.2%) participants and dementia in 99 (5.1%). The frequency of anemia was higher in patients with dementia according to univariate analysis (odds ratio (OR) = 2.00, 95% confidence interval (CI) = 1.17-3.41, p = 0.01), but this association was not present after adjusting for age (OR = 1.33, 95% CI = 0.76-2.33, p = 0.32). Further multivariate adjustment did not change the results.

CONCLUSION

Although anemia and dementia are frequent disorders in older people, we found their relationship to be mediated exclusively by aging in this low-income population from São Paulo.

Threshold haemoglobin levels and the prognosis of stable coronary disease: two new cohorts and a systematic review and meta-analysis

BACKGROUND

Low haemoglobin concentration has been associated with adverse prognosis in patients with angina and myocardial infarction (MI), but the strength and shape of the association and the presence of any threshold has not been precisely evaluated.

METHODS AND FINDINGS

A retrospective cohort study was carried out using the UK General Practice Research Database. 20,131 people with a new diagnosis of stable angina and no previous acute coronary syndrome, and 14,171 people with first MI who survived for at least 7 days were followed up for a mean of 3.2 years. Using semi-parametric Cox regression and multiple adjustment, there was evidence of threshold haemoglobin values below which mortality increased in a graded continuous fashion. For men with MI, the threshold value was 13.5 g/dl (95% confidence interval [CI] 13.2-13.9); the 29.5% of patients with haemoglobin below this threshold had an associated hazard ratio for mortality of 2.00 (95% CI 1.76-2.29) compared to those with haemoglobin values in the lowest risk range. Women tended to have lower threshold haemoglobin values (e.g, for MI 12.8 g/dl; 95% CI 12.1-13.5) but the shape and strength of association did not differ between the genders, nor between patients with angina and MI. We did a systematic review and meta-analysis that identified ten previously published studies, reporting a total of only 1,127 endpoints, but none evaluated thresholds of risk.

CONCLUSIONS

There is an association between low haemoglobin concentration and increased mortality. A large proportion of patients with coronary disease have haemoglobin concentrations below the thresholds of risk defined here. Intervention trials would clarify whether increasing the haemoglobin concentration reduces mortality.

Assessment and treatment of preoperative anemia: Continuing Professional Development

PURPOSE

The purpose of this continuing professional development (CPD) module is to review the risk of anemia and transfusion in perioperative patients and to propose an approach for the diagnosis and treatment of preoperative anemia.

PRINCIPAL FINDINGS

Preoperative anemia has been associated with increased transfusion of red blood cells, organ injury, and mortality. Postoperative anemia has also been associated with impaired recovery from surgery. Transfusion also increases the risk of infection, organ injury, and mortality. Preoperatively, iron deficiency anemia can be corrected with oral or intravenous iron; certain types of patients might respond to administration of erythrocyte stimulating agents (ESAs). With ESAs, the increased risk of thrombosis should be balanced against the expected benefit.

CONCLUSIONS

Preoperative diagnosis and treatment of anemia may reduce the risk of morbidity and mortality associated with both anemia and transfusion.

Hematologic parameters, atherosclerotic progression, and prognosis in patients with previous coronary artery bypass grafting (from the Post CABG Trial)

Although inflammatory markers and anemia have both been associated with prognosis in patients with cardiovascular disease, their relation with atherosclerotic progression in patients with previous coronary artery bypass grafting (CABG) is unknown. A total of 1,273 patients enrolled in the Post CABG Trial who had undergone CABG 1 to 11 years before entry were studied. Subjects were randomly assigned to lovastatin in low or high doses and low-dose warfarin or placebo in a factorial design. Subjects underwent coronary angiography at baseline and after a mean follow-up of 4.3 years. White blood cells (WBCs), hemoglobin, and platelets were measured at baseline in all subjects. Graft progression was defined as a decrease > or =0.6 mm in lumen diameter at the site of greatest change at follow-up. During follow-up, 195 subjects sustained a clinical event and 857 grafts developed significant worsening. Risk of clinical events tended to be greater with higher WBC counts, with hazard ratios for ascending quartiles of 1.4 (95% confidence interval [CI] 0.9 to 2.2), 1.6 (95% CI 1.0 to 2.6), and 1.6 (95% CI 1.0 to 2.7). WBC count also tended to be associated with significant atherosclerotic progression, particularly in subjects assigned to placebo rather than warfarin (p interaction = 0.04). There was no association of hemoglobin or platelet count with risk of clinical events or graft progression, but few trial subjects were anemic. In conclusion, WBC count is associated with a graded increase in cardiovascular events in patients with coronary artery bypass grafts.

Anemia and cerebral outcomes: many questions, fewer answers

A number of clinical studies have associated acute anemia with cerebral injury in perioperative patients. Evidence of such injury has been observed near the currently accepted transfusion threshold (hemoglobin [Hb] concentration, 7-8 g/dL), and well above the threshold for cerebral tissue hypoxia (Hb 3-4 g/dL). However, hypoxic and nonhypoxic mechanisms of anemia-induced cerebral injury have not been clearly elucidated. In addition, protective mechanisms which may minimize cerebral injury during acute anemia have not been well defined. Vasodilatory mechanisms, including nitric oxide (NO), may help to maintain cerebral oxygen delivery during anemia as all three NO synthase (NOS) isoforms (neuronal, endothelial, and inducible NOS) have been shown to be up-regulated in different experimental models of acute hemodilutional anemia. Recent experimental evidence has also demonstrated an increase in an important transcription factor, hypoxia inducible factor (HIF)-1alpha, in the cerebral cortex of anemic rodents at clinically relevant Hb concentrations (Hb 6-7 g/dL). This suggests that cerebral oxygen homeostasis may be in jeopardy during acute anemia. Under hypoxic conditions, cytoplasmic HIF-1alpha degradation is inhibited, thereby allowing it to accumulate, dimerize, and translocate into the nucleus to promote transcription of a number of hypoxic molecules. Many of these molecules, including erythropoietin, vascular endothelial growth factor, and inducible NOS have also been shown to be up-regulated in the anemic brain. In addition, HIF-1alpha transcription can be increased by nonhypoxic mediators including cytokines and vascular hormones. Furthermore, NOS-derived NO may also stabilize HIF-1alpha in the absence of tissue hypoxia. Thus, during anemia, HIF-1alpha has the potential to regulate cerebral cellular responses under both hypoxic and normoxic conditions. Experimental studies have demonstrated that HIF-1alpha may have either neuroprotective or neurotoxic capacity depending on the cell type in which it is up-regulated. In the current review, we characterize these cellular processes to promote a clearer understanding of anemia-induced cerebral injury and protection. Potential mechanisms of anemia-induced injury include cerebral emboli, tissue hypoxia, inflammation, reactive oxygen species generation, and excitotoxicity. Potential mechanisms of cerebral protection include NOS/NO-dependent optimization of cerebral oxygen delivery and cytoprotective mechanisms including HIF-1alpha, erythropoietin, and vascular endothelial growth factor. The overall balance of these activated cellular mechanisms may dictate whether or not their up-regulation leads to cytoprotection or cellular injury during anemia. A clearer understanding of these mechanisms may help us target therapies that will minimize anemia-induced cerebral injury in perioperative patients.