Proinflammatory, immunomodulating, and prothrombotic properties of anemia and red blood cell transfusions

Risk Factors Associated with Thromboembolic Complications After total Hip Arthroplasty: An Analysis of 1,129 Pulmonary Emboli

INTRODUCTION

Venous thromboembolism (VTE) remains a dangerous complication after total hip arthroplasty (THA), despite advances in chemoprophylactic measures. This study aimed to identify risk factors of developing pulmonary embolism (PE) and deep vein thrombosis (DVT) after THA using a modern cohort of patients reflecting contemporary practices.

METHODS

The Premier Healthcare Database was queried for primary, elective THAs from January 1st, 2015, to December 31st, 2021. Patients who developed PE or DVT within 90 days of THA were compared with patients who did not develop any postoperative VTE. Differences in patient demographics, comorbidities, hospital factors, perioperative medications, chemoprophylactic agents, and allogeneic blood transfusion were compared between cohorts. Multivariable logistic regression models were used to identify independent risk factors of PE and DVT. In total, 544,298 THAs were identified, of which 1,129 (0.21%) developed a PE and 1,799 (0.33%) developed a DVT.

RESULTS

Patients diagnosed with a PE had significantly higher rates of in-hospital death (2.6% vs 0.1%, P < 0.001) compared with those without a PE. Age (adjusted odds ratio: 1.02 per year, 95% confidence interval [CI]: 1.01 to 1.03) and Black race (aOR: 1.52, 95% CI: 1.24 to 1.87) were associated with an increased risk of PE. Comorbidities associated with increased risk of PE included chronic pulmonary disease (aOR: 1.58, 95% CI: 1.36 to 1.84), pulmonary hypertension (aOR: 2.06, 95% CI: 1.39 to 3.04), and history of VTE (aOR: 2.38, 95% CI: 1.98 to 2.86). Allogeneic blood transfusion (aOR: 2.40, 95% CI: 1.88 to 3.06) was also associated with an increased risk of PE while dexamethasone utilization was associated with a reduced risk (aOR: 0.83, 95% CI: 0.73 to 0.95).

DISCUSSION

Increasing age; Black race; allogeneic blood transfusion; and comorbidities, including chronic pulmonary disease, pulmonary hypertension, and history of VTE, were independent risk factors of PE after THA. Given the increased mortality associated with PE, patients should be carefully evaluated for these factors and managed with an appropriate chemoprophylactic regimen.

Increased Risk of Venous Thromboembolism in Patients with Postoperative Anemia After Total Joint Arthroplasty: Are Transfusions to Blame?

BACKGROUND

The relationship between anemia and the risk of venous thromboembolism (VTE) following total knee arthroplasty (TKA) and total hip arthroplasty (THA) remains unclear. Red blood cell (RBC) transfusions, which have been shown to have thrombogenic effects, may explain conflicting data. This study sought to elucidate the relationship between anemia, RBC transfusions, and VTE following total joint arthroplasty (TJA).

METHODS

Using the International Classification of Diseases, Tenth Revision (ICD-10) and Current Procedural Terminology (CPT) codes, the Premier Healthcare Database was queried for all adults who underwent primary elective THA or TKA from January 2015 to December 2020. Patients were classified into 3 cohorts: those who did not have a diagnosis of anemia and did not receive an RBC transfusion (the control group), those with acute blood loss anemia who did not receive a transfusion (the anemia without transfusion group), and those with acute blood loss anemia who did receive a transfusion (the anemia with transfusion group). The primary outcomes assessed were the 90-day rate and risk of deep vein thrombosis (DVT), pulmonary embolism (PE), and aggregate VTE. Analysis of variance and pairwise comparisons were used to compare groups. Multivariable analyses were performed to account for confounding factors.

RESULTS

The 1,290,815 patients identified as having undergone TJA included 1,078,507 control patients (83.6%), 198,233 patients who had anemia without transfusion (15.4%), and 14,075 patients who had anemia and transfusion (1.1%). Age, sex, race, length of hospital stay, and hospital costs were significantly different between the 3 groups. After adjusting for confounding factors, there was no difference between the anemia without transfusion group and the control group with regard to DVT (adjusted odds ratio [OR], 0.97 [95% confidence interval (CI), 0.89 to 1.06]; p = 0.500), PE (adjusted OR, 1.04 [95% CI, 0.92 to 1.18]; p = 0.543), and VTE (adjusted OR, 0.99 [95% CI, 0.92 to 1.06]; p = 0.697). However, patients with anemia and transfusion had an increased risk of PE (adjusted OR, 1.83 [95% CI, 1.34 to 2.51]; p < 0.001) and VTE (adjusted OR, 1.39 [95% CI, 1.14 to 1.70]; p = 0.001) compared with patients in the control group.

CONCLUSIONS

Patients with acute blood loss anemia who received a transfusion were at increased risk for developing VTE following TJA, whereas patients with anemia who did not receive a transfusion were not. Orthopaedic surgeons need to be aware of the risks of transfusion and individualize the use of transfusions in their patients.

LEVEL OF EVIDENCE

Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Relationship between Hemoglobin Concentration at Admission with the Incidence of No-Reflow Phenomenon and In-Hospital Mortality in Acute Myocardial Infarction with Elevation of ST Segments in Patients who underwent Primary Percutaneous Coronary Intervention

Anemia in acute ST-segment elevation myocardial infarction (STEMI) is associated with a pro-coagulant state, contributing to the incidence of no-reflow phenomenon and increased mortality following primary percutaneous coronary intervention (PPCI). However, clinical data remain contradictory. The objective of our study was to evaluate the association of admission hemoglobin (Hb) concentration and in-hospital mortality of STEMI patients' post-PPCI, as well as final thrombolysis in myocardial infarction (TIMI) flow. A cross-sectional study was performed from the database of Jakarta Acute Coronary Syndrome Registry, consisting of 3,071 STEMI patients who underwent PPCI between January 2014 and December 2019. No-reflow phenomenon was defined as final TIMI flow <3 of the infarct-related artery. Outcome measures were the occurrence of no-reflow and in-hospital mortality. Anemia criteria were based on the World Health Organization. Anemia was found in 550 patients (17.9%). Patients with anemia were older (60 ± 10 years, p < 0.001), predominantly women (20.7 vs. 11.2%, p < 0.001), TIMI risk score >4 (45.8 vs. 30.4%, p < 0.00), and Killip classification >1 (25.8 vs. 20.8%, p < 0.009). Anemia at admission was not associated with no-reflow phenomenon (odds ratio [OR] = 0.889; 95% confidence interval [CI] = 0.654–1.209, p = 0.455). Multivariate regression models showed that anemia was not associated with in-hospital mortality (OR = 0.963; 95% CI = 0.635–1.459, p = 0.857) and with no-reflow phenomenon (OR = 0.939; 95% CI = 0.361–2.437, p = 0.896). Anemia upon admission was not related to the no-reflow phenomena or in-hospital mortality in STEMI patients undergoing PPCI.

Association of thrombocytopenia and infection in patients with ST-elevation myocardial infarction undergoing percutaneous coronary intervention

Background

The impact of thrombocytopenia on infection in patients with ST-elevation myocardial infarction (STEMI) remains poorly understood.

Aims

To evaluate the association between thrombocytopenia and infection in patients with STEMI.

Methods

Patients diagnosed with STEMI were identified from January 2010 to June 2016. The primary endpoint was in-hospital infection, and major adverse clinical events (MACE) and all-cause death were considered as secondary endpoints.

Results

A total of 1401 STEMI patients were enrolled and divided into two groups according to the presence (n = 186) or absence (n = 1215) of thrombocytopenia. The prevalence of in-hospital infection was significantly higher in the thrombocytopenic group (30.6% (57/186) vs. 16.2% (197/1215), p < 0.001). Prevalence of in-hospital MACE (30.1% (56/186) vs. 16.4% (199/1215), p < 0.001) and all-cause death (8.1% (15/186) vs. 3.8% (46/1215), p = 0.008) revealed an increasing trend. Multivariate analysis indicated that thrombocytopenia was independently associated with increased in-hospital infection (OR, 2.09; 95%CI 1.32–3.27; p = 0.001) and MACE (1.92; 1.27–2.87; p = 0.002), but not all-cause death (1.87; 0.88–3.78; p = 0.091). After a median follow-up of 2.85 years, thrombocytopenia was not associated with all-cause death at multivariable analysis (adjusted hazard ratio, 1.19; 95%CI 0.80–1.77; p = 0.383).

Conclusions

Thrombocytopenia is significantly correlated with in-hospital infection and MACE, and might be used as a prognostic tool in patients with STEMI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02210-3.

Association Between Radial Versus Femoral Access for Percutaneous Coronary Intervention and Long-Term Mortality

Background

Percutaneous coronary intervention with radial arterial access has been associated with fewer occurrences of major bleeding. However, published data on the long‐term mortality and major adverse cardiac events after percutaneous coronary intervention with radial or femoral arterial access are inconclusive.

Method and Results

This was a territory‐wide retrospective cohort study including 26 022 patients who underwent first‐ever percutaneous coronary intervention between January 1, 2010 and December 31, 2017 in Hong Kong. Among the 14 614 patients matched by propensity score (7307 patients in each group), 558 (7.6%) and 787 (10.8%) patients died during the observation period in the radial group and femoral group, respectively, resulting in annualized all‐cause mortality rates of 2.69% and 3.87%, respectively. The radial group had a lower risk of all‐cause mortality compared with the femoral group up to 3 years after percutaneous coronary intervention (hazard ratio [HR], 0.70; 95% CI, 0.63–0.78; P<0.001). Radial access was associated with a lower risk of major adverse cardiac events (HR, 0.78; 95% CI, 0.73–0.83, P<0.001), myocardial infarction after hospital discharge (HR, 0.78; 95% CI, 0.70–0.87, P<0.001), and unplanned revascularization (HR, 0.76; 95% CI, 0.68–0.85, P<0.001). The risks of stroke were similar across the 2 groups (HR, 0.96; 95% CI, 0.82–1.13, P=0.655).

Conclusions

Radial access was associated with a significant reduction in all‐cause mortality at 3 years compared with femoral access. Radial access was associated with reduced risks of myocardial infarction and unplanned revascularization, but not stroke. The benefits were sustained beyond the early postoperative period.

RBC Transfusion Induced ST Segment Variability Following the Norwood Procedure

Supplemental Digital Content is available in the text.

Objectives:

The transfusion of stored RBCs decreases nitric oxide bioavailability, which may have an adverse effect on vascular function. We assessed the effects of RBC transfusion on coronary vascular function by evaluating the relationship between myocardial oxygen delivery and demand as evidenced by ST segment variability.

Design:

Retrospective case-control study.

Setting:

Nine-hundred seventy-three–bed pediatric hospital with a 54-bed cardiovascular ICU.

Patients:

Seventy-three neonates with hypoplastic left heart syndrome following the Norwood procedure, 38 with a Blalock-Taussig shunt and 35 with a right ventricle to pulmonary artery shunt.

Interventions:

RBC transfusion.

Materials and Main Results:

High-frequency physiologic data were captured 30 minutes prior to the initiation of (baseline) and during the 120 minutes of the transfusion. A rate pressure product was calculated for each subject and used as an indicator of myocardial oxygen demand. Electrocardiogram leads (aVL, V1, II) were used to construct a 3D ST segment vector to assess ST segment variability and functioned as a surrogate indicator of myocardial ischemia. One-hundred thirty-eight transfusions occurred in the Blalock-Taussig shunt group and 139 in the right ventricle to pulmonary artery shunt group. There was no significant change in the rate pressure product for either group; however, ST segment variability progressively increased for the entire cohort during the transfusion, becoming statistically significant by the end of the transfusion. Upon subgroup analysis, this finding was noted with statistical significance in the Blalock-Taussig shunt group and trending toward significance in the right ventricle to pulmonary artery shunt group.

Conclusions:

We found a significant increase in the ST segment variability and evidence of myocardial ischemia temporally associated with RBC transfusions in neonates following the Norwood procedure, specifically among those in the Blalock-Taussig shunt group, which may impact immediate and long-term outcomes.

The Impact of Baseline Thrombocytopenia on Late Bleeding and Mortality After Transcatheter Aortic Valve Implantation (From the Japanese Multicenter OCEAN-TAVI Registry)

Baseline thrombocytopenia was reported as a risk factor for bleeding or mortality in several medical areas, particularly in the cardiovascular field. This study aimed to assess the prognostic value of baseline thrombocytopenia in patients who had transcatheter aortic valve implantation. This study included 2,588 patients from the Optimized Catheter valvular intervention Japanese multicenter registry. Thrombocytopenia was defined as platelet count of <150 × 10⁹/L and was classified into moderate/severe (<100 × 10⁹/L) and mild (≧100-<150 × 10⁹/L). At 3 years after index procedure, the moderate/severe thrombocytopenia group had a significantly higher cumulative composite late bleeding than the no thrombocytopenia group (log-rank test, p < 0.0001). Moreover, the moderate/severe thrombocytopenia group had a significantly higher cumulative all-cause, cardiovascular, and noncardiovascular mortality rates than the no thrombocytopenia group (log-rank test, p < 0.0001, p = 0.0014, p < 0.0001, respectively). After adjusting for confounders, the excess risk of moderate/severe and mild thrombocytopenia relative to no thrombocytopenia for the composite bleeding remained significant (hazard ratio 2.66: [95% confidence interval: 1.35 to 4.88], p = 0.006 and hazard ratio 2.10: [95% confidence interval: 1.36 to 3.21], p = 0.001, respectively). In conclusion, baseline thrombocytopenia was associated with an increased risk of late bleeding and poor prognosis. Baseline platelet level could be a prognostic marker for risk stratification.

A retrospective analysis of venous thromboembolism trends in chemotherapy‐induced anemia: Red blood cell transfusion versus erythrocyte stimulating agent administration

Background

Patients receiving a variety of chemotherapy regimens often develop chemotherapy‐induced anemia (CIA), which contributes to poor outcomes including increased mortality. Prompt and effective treatment of CIA is essential to prevent fewer chemotherapy dose delays and reductions. Optimal therapy of CIA is controversial and involves the solitary and combined use of intravenous iron, red blood cell (RBC) transfusions, and erythropoietin stimulating agents (ESAs). Despite the baseline coagulopathies present in patients with malignancy, administration of both RBC transfusions and ESAs is associated with venous thromboembolism (VTE). It remains unknown whether the risk of VTE in patients with CIA is greater among patients who receive RBC transfusions or ESAs.

Methods

A retrospective study analyzed 10,269 University of Pennsylvania Health System patients with malignancies of various type, stage, and histopathology who developed CIA between 2008 and 2017. Using multivariate Cox regression, we determined adjusted hazard ratios (and corresponding 95% confidence intervals) of VTE development after adjusting for RBC and ESA intervention (all during the 90 days following CIA diagnosis).

Results

Among the 10,269 patients with CIA, 2,642 (25.7%) developed a VTE within the 90‐day period. VTE risk following RBC transfusion (HR = 1.37, 95% CI 1.24‐1.50, P < .001) was more than twice as common as VTE risk following ESA administration (HR = 0.53, 95% CI 0.40‐0.69, P < .001).

Conclusion

While both RBC transfusion and ESA are independently associated with VTE, our data suggest a greater risk of VTE development with RBC transfusion as compared with ESA.

Blood transfusion and ischaemic outcomes according to anemia and bleeding in patients with non-ST-segment elevation acute coronary syndromes: Insights from the TAO randomized clinical trial

BACKGROUND

The benefits and risks of blood transfusion in patients with acute myocardial infarction who are anemic or who experience bleeding are debated. We sought to study the association between blood transfusion and ischemic outcomes according to haemoglobin nadir and bleeding status in patients with NST-elevation myocardial infarction (NSTEMI).

METHODS

The TAO trial randomized patients with NSTEMI and coronary angiogram scheduled within 72h to heparin plus eptifibatide versus otamixaban. After exclusion of patients who underwent coronary artery bypass surgery, patients were categorized according to transfusion status considering transfusion as a time-varying covariate. The primary ischemic outcome was the composite of all-cause death or MI within 180 days of randomization. Subgroup analyses were performed according to pre-transfusion hemoglobin nadir and bleeding status.

RESULTS

12,547 patients were enrolled. Among these, blood transfusion was used in 489 (3.9%) patients. Patients who received transfusion had a higher rate of death or MI (29.9% vs. 8.1%, p<0.01). This excess risk persisted after adjustment on GRACE score and nadir of hemoglobin (HR 3.36 95%CI 2.63-4.29 p<0.01). Subgroup analyses showed that blood transfusion was associated with a higher risk in patients without overt bleeding (adjusted HR 6.25 vs. 2.85; p-interaction 0.001) as well as in those with hemoglobin nadir > 9.0 g/dl (HR 4.01; p-interaction<0.0001).

CONCLUSION

In patients with NSTEMI, blood transfusion was associated with an overall increased risk of ischaemic events. However, this was mainly driven by patients without overt bleeding and those hemoglobin nadir > 9.0g/dl. This suggests possible harm of transfusion in those groups.

Unstable intertrochanteric fractures are associated with a greater hemoglobin drop during the perioperative period: a retrospective case control study

Background

With an increase in the elderly population, the occurrence of hip fractures, femoral neck fractures, and intertrochanteric fractures (ITFs) is also increasing. It is important to establish effective perioperative methods that would help reduce the morbidity and mortality rates associated with ITFs. The purpose of this study was to determine the effects of ITFs according to the AO classification for perioperative hemoglobin drop.

Methods

Seventy-six patients with ITFs classified as AO 31-A1 or A2 and fixated with intramedullary nails participated in this retrospective cohort study. Medical records of these patients were retrospectively reviewed from September 2016 to August 2018. The perioperative hemoglobin drop was chosen as the main outcome measure and calculated as the difference between pre- and postoperative hemoglobin levels. Multivariate linear regression analysis was performed and included the following variables: AO classification (A1.1-A2.1 [stable] vs. A2.2-A2.3 [unstable]), time interval between injury and surgery, age, body mass index, and the use of anticoagulants.

Results

Among the 76 patients who met the inclusion criteria, a significantly higher hemoglobin drop was observed in the AO 31 A2.2-A2.3 (unstable) group than in the AO 31 A1.1-A2.1 (stable) group (p = 0.04). The multivariate analysis also showed a greater hemoglobin drop in the unstable group (p < 0.05).

Conclusions

Patients with unstable ITFs exhibited a greater hemoglobin drop and a hidden blood loss was suspected around the fracture site. We believe that this should be taken into consideration when presurgical blood transfusion is being planned for patients with unstable ITFs, to reduce associated postoperative complications, especially in patients with severe anemia or high risk of mortality.

The effect of red blood cell transfusion on platelet function in critically ill patients

INTRODUCTION

Red blood cell (RBC) transfusion is associated with an increased risk of pro-thrombotic events, but the underlying mechanism is poorly understood. We hypothesized that RBC transfusion modulates platelet activity in critically ill patients with and without sepsis.

METHODS

In a prospective cohort study, 37 critically ill patients receiving a single RBC unit to correct for anemia were sampled prior to and 1 h after transfusion. Platelet exposure of P-selectin, CD63 and binding of PAC-1 as well as formation of platelet-leukocyte complexes were measured by flow cytometry. The ability of plasma from critically ill patients to induce ex vivo platelet aggregation was assessed by flow cytometry after incubation with platelets from a healthy donor.

RESULTS

RBC transfusion neither triggered the expression of platelet activation markers nor the formation of platelet-leukocyte complexes. Plasma from critically ill patients induced more spontaneous platelet aggregation prior to RBC transfusion compared to healthy controls, which was further augmented following RBC transfusion. Also collagen-induced platelet aggregation was already increased prior to RBC transfusion compared to healthy controls, and this response was unaffected by RBC transfusion. In contrast, ristocetin-induced platelet agglutination was decreased when compared to controls, suggesting impaired vWF-dependent platelet agglutination, even in the presence of high vWF levels. Following RBC transfusion, ristocetin-induced platelet agglutination further decreased. There were no differences between septic and non-septic recipients in all assays.

CONCLUSION

Ex vivo platelet aggregation is disturbed in the critically ill. Transfusion of a RBC unit may further increase the spontaneous platelet aggregatory response.

Relation of hemoglobin level to no-reflow in patients with ST-segment elevation myocardial infarction undergoing primary coronary intervention

Introduction

The primary goal in the management of acute ST segment elevation myocardial infarction (STEMI) is to open the occluded artery at an early stage. The development of no-reflow is multifactorial, and the etiology is not fully understood. There is accumulating evidence that anemia is related to a series of severe complications in cardiovascular disease (CVD) such as thromboembolic events, bleeding complications, uncontrolled hypertension, and inflammation characterized by elevated levels of inflammatory cytokines.

Aim

We investigated the relationship between hemoglobin level and the no-reflow of infarct-related artery (IRA) in patients with STEMI undergoing primary percutaneous coronary intervention (PPCI).

Material and methods

A total of 3804 patients with acute STEMI who underwent PPCI were enrolled. The patients were divided into two groups according to thrombolysis in myocardial infarction (TIMI) flow grades after PPCI. Hematological parameters were measured on admission. Univariate and multivariate logistic regression analyses were conducted to assess the association between hemoglobin level and no-reflow.

Results

In the current study, 471 (12.4%) patients presented with no-reflow after PPCI. The patients in the no-reflow group had a significantly lower hemoglobin level (12.1 ±1.9 g/dl vs. 13.8 ±1.8 g/dl, p < 0.001). The multivariate logistic regression models revealed that hemoglobin level (OR = 0.564, 95% CI: 0.526–0.605; p < 0.001) was an independent predictor of development of no-reflow. The cutoff value for hemoglobin level was 11.5 g/dl with sensitivity of 83.0% and specificity of 80.0% (AUC = 0.844, 95% CI: 0.821–0.867; p < 0.001).

Conclusions

Our results suggest that hemoglobin level showed a moderate diagnostic performance regarding the prediction of no-reflow in patients with STEMI undergoing PPCI.

Mortality and cardiorespiratory complications in trochanteric femoral fractures: a ten year retrospective analysis

PURPOSE

Despite intense research and innovations in peri-operative management, a high mortality rate and frequent systemic complications in trochanteric femoral fractures persist. The aim of the present study was to identify predictive factors for mortality and cardio-respiratory complications after different treatment methods in a ten year period at a level I trauma centre.

METHODS

Retrospectively, all patients above 60 years of age with trochanteric femoral fracture between January 2000 and May 2011 were analyzed at a level I trauma centre. Demographic variables, comorbidities, and data regarding the surgical procedures, including required transfusions and post-operative complications, were evaluated, and the in-hospital mortality was recorded. The grade of osteoporosis was classified radiographically using the Singh index.

RESULTS

The in-hospital mortality rate was 8.2% among 437 patients (male/female ratio = 110/327, mean age = 81 years) with extramedullary open (n = 144), intramedullary (n = 166), and extramedullary minimally invasive (n = 125) procedures. Significant influential factors on in-hospital mortality were identified with binary logistic regression analysis: an age of ≥90 years (P = 0.011), male sex (P = 0.003), a high American Society of Anesthesiologists (ASA) grade (3-5, P = 0.042), and a high osteoporosis grade (Singh index 3-1, P = 0.011). A total of 21.5% of the study population suffered cardio-respiratory complications post-operatively. The specific mortality was 28.7% (P < 0.001), which was influenced by a high ASA grade (3-5, P = 0.002) and a high transfusion rate (P = 0.004). Minimally invasive locked plating was associated with increased cardio-respiratory complications (P = 0.031).

CONCLUSIONS

This study identified high patient age, distinctive comorbidities, male sex, and high osteoporosis grade as significant risk factors for increased in-hospital mortality in the treatment of trochanteric femoral fractures. Furthermore, high ASA grade and a liberal transfusion regime led to an increased incidence of cardio-respiratory complications. Patient-specific characteristics, especially osteoporosis grade and pre-existing medical conditions, may assist in the identification of high-risk patients and allow a patient-specific geriatric co-management plan.

Clinical outcomes of various continued antiplatelet therapies in patients who were administered DAPT following the implantation of drug-eluting stents and developed gastrointestinal hemorrhage

Although an increasing number of patients accept dual antiplatelet therapy (DAPT) following implantation of drug-eluting stents (DES) for coronary heart disease (CHD), the proportion of patients with DAPT who subsequently develop gastrointestinal hemorrhage continues to increase. To ensure the clinical outcomes from DES, it is important to formulate a novel continued antiplatelet therapy for patients who were administered DAPT and subsequently develop gastrointestinal hemorrhage following DES implantation. The present study aimed to evaluate the effects of continued aspirin, clopidogrel or DAPT use on the incidence of clinical adverse events and gastrointestinal rebleeding in patients who received DAPT and subsequently developed gastrointestinal hemorrhage following implantation of DES for CHD. Between 2004 and 2010, 108 consecutive patients receiving DAPT developed gastrointestinal hemorrhage following DES implantation for CHD at Liuzhou General Hospital (Liuzhou, Guangxi). These patients were divided into three groups according to the novel antiplatelet therapy. The occurrence of major adverse cardiac events (MACE), including cardiac death, non-fatal myocardial infarction, heart failure or target vessel revascularization, net adverse clinical events (NACE), including major bleeding, stroke or MACE, and gastrointestinal rebleeding during clinical follow-up following the initial procedure were compared among these three groups. The results of this analysis demonstrated that the occurrence rate of MACE, NECE and gastrointestinal rebleeding was not significantly different among these groups (P>0.05). Furthermore, survival analysis was performed and although the survival curves of MACE and NECE were not significantly different among these groups, gastrointestinal rebleeding was demonstrated to be significantly different among the three groups (P<0.05), and continued aspirin or clopidogrel use was superior to continued DAPT. In conclusion, the results of the present study indicated that there were no significant differences in the clinical effectiveness and safety of continuing antiplatelet monotherapy or DAPT in patients who are administered DAPT and experience gastrointestinal hemorrhage following DES implantation. As for the prevention of recurrent bleeding, antiplatelet monotherapy was demonstrated to be superior to DAPT. Moreover, the treatment of patients who are administered DAPT and experience gastrointestinal hemorrhage following DES implantation must involve an evaluation of the risk of complications, including stent thrombosis, continuous bleeding and recurrent hemorrhage.

Transfusion of Blood and Blood Products

In transfusion medicine, several blood products can be prepared and used as replacement therapy; however, four of these products are more commonly used in general practice: RBCs, fresh frozen plasma (FFP), platelets and cryoprecipitate. RBC transfusions are mainly administered to improve tissue oxygenation in cases of anaemia or acute blood loss due to trauma or surgery. FFP, platelets and cryoprecipitate are used for the prevention and treatment of bleeding.

Impact of major bleeding on long-term mortality in anemic versus nonanemic patients undergoing percutaneous coronary intervention using bivalirudin

Bleeding complications after percutaneous coronary intervention (PCI) have been associated with higher short and long-term mortality. Bivalirudin has been shown to reduce bleeding complications in patients who underwent PCI; however, the impact of anemia on bleeding complications and long-term mortality has not been studied. A total of 11,991 patients who underwent PCI over a period of 8 years with bivalirudin as the primary antithrombotic agent were included. Anemia was defined according to the World Health Organization definition. Bleeding complications were prospectively collected. Survival analysis was performed using multivariable Cox proportional hazards models. Of the 11,991 patients, 4,815 patients (40%) had baseline anemia. Major bleeding occurred in 3.3% of patients with anemia compared with 0.7% of patients without anemia (p <0.001) driven largely by transfusion events. In the overall study population, major bleeding was a significant predictor of mortality (hazard ratio [HR] 1.4, 95% confidence interval [CI] 1.04 to 1.8, p = 0.027) at a mean follow-up of 2.6 years (interquartile range 1.4 to 3.5). In patients with anemia, major bleeding remained an independent predictor of mortality (HR 1.5, 95% CI 1.1 to 2.0, p = 0.008); however, in patients without anemia, it did not (HR 1.25, 95% CI 0.52 to 3.03, p = 0.62). In patients who underwent PCI with bivalirudin therapy, major bleeding is associated with early and long-term mortality, which is more pronounced in patients with baseline anemia.

Risk factors for in-hospital mortality and prolonged length of stay in older patients with solid tumor malignancies

OBJECTIVE

Hospitalized adult patients with cancer and with major comorbidities have higher mortality rates and longer duration of hospitalization. There is limited understanding of risk factors that contribute to prolonged hospitalization and mortality in older patients with solid tumors.

MATERIALS AND METHODS

Risk factors associated with in-hospital mortality and prolonged length of stay (LOS) in older patients with cancer were investigated in a retrospective cohort study. Data from the University HealthSystem Consortium database included 386,377 patients age ≥ 65 years with solid tumors hospitalized between 1995 and 2003 at 133 U.S. academic medical centers.

RESULTS

The overall mortality rate was 7.3%. Mortality in older patients with cancer was strongly associated with longer LOS. Almost twice as many deaths were observed among those with LOS ≥ 10 days (p<0.0001). Nearly 38% of older cancer patients who died in hospital had potentially curable disease. Primary central nervous system malignancies were most strongly associated with in-hospital mortality (OR=1.81; 1.59-2.07), followed by esophageal (OR=1.74; 1.54-1.97) and lung cancer (OR=1.57; 1.43-1.72). Male gender, African-American race, and Hispanic and Asian race/ethnicity were associated with increased risk of mortality (p<0.0001). Additional risk factors included metastatic disease, infection, neutropenia, renal, lung, hepatic, cerebrovascular disease, arterial/venous thromboembolism, heart failure, and red blood cell transfusion. Risk factors for prolonged LOS included gastric cancer, infection, venous thromboembolism and red blood cell transfusion.

CONCLUSIONS

Prolonged LOS was strongly associated with mortality. Risk factors such as infection, neutropenia and red blood cell transfusion, when modified, could potentially reduce rates of prolonged LOS and mortality in older patients with cancer.

Characteristics and in-hospital outcomes of patients with non-ST-segment elevation myocardial infarction undergoing an invasive strategy according to hemoglobin levels

The benefit of an invasive strategy in non-ST-segment elevation myocardial infarction (NSTEMI) was established from randomized trials that included few anemic patients. The aim of this study was to describe the characteristics, therapies, and mortality of patients with NSTEMIs who undergo an invasive strategy in relation to their admission hemoglobin levels. Data from 73,067 patients with NSTEMIs who underwent cardiac catheterization and who were captured by the Acute Coronary Treatment and Intervention Outcomes Network Registry-Get With the Guidelines (ACTION-GWTG) were examined. Patients were divided into 3 hemoglobin groups on the basis of initial hemoglobin level: (1) <10 g/dl, (2) 10 to 12 g/dl, or (3) >12 g/dl. Patients with hemoglobin <10 g/dl had more co-morbidities and more 3-vessel coronary artery disease at catheterization compared with those with hemoglobin >12 g/dl (46.2% vs 33.9%, all p values <0.0001). They received fewer acute antithrombotic therapies, less often underwent revascularization (57.4% vs 74.1%), and had higher rates of red blood cell transfusion before catheterization (32.1% vs 0.3%, all p values <0.0001). After adjustment, in-hospital mortality was inversely associated with initial hemoglobin, with a 7% increase for each 1 g/dl decrease in hemoglobin lower than 15 g/dl (odds ratio 1.07, 95% confidence interval 1.02 to 1.11). In conclusion, in patients presenting with NSTEMIs and managed with an invasive strategy, a lower hemoglobin level is associated with more extensive coronary artery disease, less use of revascularization and evidence-based therapies, and increased mortality.

Clinical and economic outcomes associated with blood transfusions among elderly Americans following coronary artery bypass graft surgery requiring cardiopulmonary bypass

BACKGROUND

Blood transfusion occurring during hospitalisation for heart surgery has been shown to be associated with increased morbidity and mortality and with increased time spent in hospital, use of healthcare services, and costs. The objective of this study was to assess how perioperative blood transfusion among adults 65 years and older who underwent coronary artery bypass graft surgery requiring cardiopulmonary bypass in the United States is associated with immediate and longer term clinical and economic outcomes.

MATERIALS AND METHODS

Using data from a 5% random sample of Medicare patients who underwent their first (within 2 years) coronary artery bypass graft requiring cardiopulmonary bypass procedure in 2005 or 2006, this study estimated associations (hazard ratios and regression coefficients) between transfusion status (received or not) and complications after surgery, serious adverse events, death, and costs using Cox proportional hazard and generalised linear models adjusting for patients' demographic and clinical characteristics.

RESULTS

Adjusted hazard ratios were statistically significant (P<0.05) for risks of complications (1.20), serious adverse events (1.58), and death (1.49). There was also a statistically significantly (P≤0.01) and strong relationship between receiving transfused blood and Medicare payments over the subsequent 45 months following discharge ($5,778 per calendar quarter for those receiving transfusion vs $5,197; all costs are measured in 2011 USD).

CONCLUSION

Blood transfusion during hospitalisation for coronary artery bypass graft requiring cardiopulmonary bypass was significantly associated with increased long-term post-operative morbidity, mortality, and overall healthcare costs. This study contributes to the evidence demonstrating an association between transfusion and adverse clinical and economic outcomes by using a nationally representative longitudinal cost and utilisation database.

Red blood cell microparticles and blood group antigens: an analysis by flow cytometry

BACKGROUND

The storage of blood induces the formation of erythrocytes-derived microparticles. Their pathogenic role in blood transfusion is not known so far, especially the risk to trigger alloantibody production in the recipient. This work aims to study the expression of clinically significant blood group antigens on the surface of red blood cells microparticles.

MATERIAL AND METHODS

Red blood cells contained in erythrocyte concentrates were stained with specific antibodies directed against blood group antigens and routinely used in immunohematology practice. After inducing erythrocytes vesiculation with calcium ionophore, the presence of blood group antigens was analysed by flow cytometry.

RESULTS

The expression of several blood group antigens from the RH, KEL, JK, FY, MNS, LE and LU systems was detected on erythrocyte microparticles. The presence of M (MNS1), N (MNS2) and s (MNS4) antigens could not be demonstrated by flow cytometry, despite that glycophorin A and B were identified on microparticles using anti-CD235a and anti-MNS3.

DISCUSSION

We conclude that blood group antigens are localized on erythrocytes-derived microparticles and probably keep their immunogenicity because of their capacity to bind specific antibody. Selective segregation process during vesiculation or their ability to elicit an immune response in vivo has to be tested by further studies.

Discontinuation of long-term clopidogrel therapy is associated with death and myocardial infarction after saphenous vein graft percutaneous coronary intervention

OBJECTIVES

This study sought to examine the pattern of death and myocardial infarction (MI) after clopidogrel cessation in patients undergoing percutaneous coronary intervention (PCI) of the saphenous vein graft (SVG).

BACKGROUND

The timing and incidence of adverse events by different durations of clopidogrel therapy after SVG PCI remain unknown.

METHODS

This is a cohort study of patients undergoing SVG PCI between 2000 and 2009, followed for all-cause mortality or MI after stopping clopidogrel. Incidence rates were calculated across different time periods after clopidogrel cessation. Adjusted incidence rate ratios (IRR) were calculated with multivariable regression (piecewise exponential and Poisson).

RESULTS

There were 603 patients who underwent SVG PCI, of which 411 were event-free at the time of clopidogrel cessation. The incidence rate (95% confidence interval: [CI])/1,000 person-days of death or MI after stopping clopidogrel in the time intervals of 0 to 90 days, 91 to 365 days, and 1 to 2 years were 1.26 (95% CI: 0.93 to 1.70), 0.41 (95% CI: 0.30 to 0.56), and 0.41 (95% CI: 0.30 to 0.55), respectively. In multivariable analyses, the overall IRR (95% CI) for death or MI in the 0- to 90-day interval after stopping clopidogrel compared with the 91- to 365-day interval was 2.58 (95% CI: 1.64 to 4.07). Similar results were observed over a broad range of clopidogrel treatment durations (<6 months, 6 months to 1 year, 1 to 2 years, or >2 years). The results were also consistent across subgroups, including sex, stent type, stent diameter, PCI period, and diabetes status. When death alone was evaluated, there remained a significant increase in the event rate in the 0- to 90-day interval compared with the 91- to 365-day interval (IRR: 2.33; 95% CI: 1.32 to 4.11).

CONCLUSIONS

A clustering of events was observed in the initial 0 to 90 days after clopidogrel cessation in all treatment durations of clopidogrel investigated after SVG PCI. These results might have important implications in high-risk cohorts undergoing PCI. Additional studies are needed to elucidate the mechanisms underlying the early clustering of events after clopidogrel cessation.

Acute gastrointestinal bleeding after percutaneous coronary intervention

Bleeding from the GI tract is a commonly encountered clinical problem after percutaneous coronary intervention. The GI tract is likely to become the most commonly encountered site of bleeding as cardiologists adopt smaller access sheath sizes, percutaneous closure devices and a radial artery approach, further reducing access-site bleeding. To appropriately manage gastrointestinal bleeding in this setting, the clinician must strike a balance between arresting hemorrhage and preventing ischemic coronary complications. To do so, an appreciation of both cardiovascular and gastrointestinal issues is required. This review aims to provide the required knowledge, as well as a series of recommendations from our practice, to assist in the management of this potentially fatal complication.

Association between bleeding severity and long-term mortality in patients experiencing vascular complications after percutaneous coronary intervention

Vascular complications (VCs) occur in 3% to 8% of percutaneous coronary interventions (PCIs). However, only a portion of patients who experience VCs bleed significantly. The aim of this study was to assess the covariates associated with the amount of blood loss in patients experiencing postprocedural VCs as well as the effect of the degree of blood loss on long-term mortality. Overall, 7,718 unselected patients who underwent PCI through femoral access were evaluated. Those experiencing VCs were identified and stratified with regard to the degree of hematocrit (HCT) decrease after the procedure. In total, 444 patients (5.8%) had VCs. Compared to those without VCs, patients with VCs were older and had more extensive co-morbidities. Severe blood loss was most frequent in those who had vascular perforation requiring surgical repair or in those who had retroperitoneal bleeding. Overall, <25% of patients with hematoma had severe blood loss. The raw 1-year mortality was doubled in patients with minimal or moderate HCT decrease and was tripled in those with severe decreases in HCT. Similarly, the rate of definite stent thrombosis was tripled in patients with VCs and moderate or severe decreases in HCT. After adjustment, only patients with VCs and the greater HCT decreases had an increased risk for death at 1 year (hazard ratio 1.80, 95% confidence interval 1.03 to 3.14). Independent predictors of severe HCT decrease included age, female gender, glycoprotein IIb/IIIa inhibitor use, and activated clotting time peak. Bivalirudin and closure devices were independently associated with less frequent severe HCT decrease. In conclusion, VCs do not entail an increased risk for death at 1 year unless associated with severe blood loss. The use of bivalirudin and closure devices seems to reduce the risk for such complications.

Retroperitoneal hemorrhage after percutaneous coronary intervention in the current practice era: clinical outcomes and prognostic value of abdominal/pelvic computed tomography

BACKGROUND

Retroperitoneal hemorrhage (RPH) is a serious but infrequent complication of percutaneous coronary intervention (PCI). This study aimed to describe the clinical outcomes of patients who developed RPH following PCI in the current practice era, with particular focus on treatment strategies and the related prognostic value of abdominal/pelvic computed tomography (CT).

METHODS

Among 20,904 patients undergoing PCI, we identified 93 RPH (0.45%) confirmed by CT or by unequivocal surgical findings. We identified three groups with RPH for comparison: patients who developed refractory shock (systolic blood pressure <80 mm Hg for ≥30 min despite fluids and vasopressors, n = 16 [17.2%]); patients with transient hypotension (<30 min, n = 34 [36.6%]); and patients without hypotension (n = 43 [46.2%]). The primary endpoint was a composite of in-hospital mortality, myocardial infarction, and cerebral vascular accident (CVA).

RESULTS

Baseline clinical, angiographic, and procedural characteristics were similar among the three groups. Patients who developed refractory shock had significantly more bleeding quantified by abdominal/pelvic CT (P < 0.001), had a higher rate and amount of red blood cell transfusion (P < 0.001), and were managed invasively more frequently (68.7%) than the rest of the population. The primary endpoint trended higher in patients presenting with refractory shock; however, this difference was not statistically significant. The volume of bleeding quantified by CT and the timing of imaging diagnosis did not correlate with the primary endpoint. Red blood cell transfusion, but not clopidogrel discontinuation, was associated with the primary endpoint.

CONCLUSIONS

RPH remains as a serious complication of PCI and is associated with high rates of mortality and morbidity independently of the therapeutic strategy. In patients who were hemodynamically stable, RPH volume as quantified by non-contrast abdominal/pelvic CT did not contribute to prognosis.

Plasma levels of sphingosine 1-phosphate are strongly correlated with haematocrit, but variably restored by red blood cell transfusions

Anaemia and RBC (red blood cell) transfusion may be associated with worse clinical outcomes, especially with longer blood storage duration prior to transfusion. The mechanisms underlying these harmful effects are unknown. RBCs have been proposed to buffer plasma S1P (sphingosine 1-phosphate), a lysophospholipid essential for the maintenance of endothelial integrity and important in the regulation of haematopoietic cell trafficking. The present study examined the effect of anaemia, RBC transfusion and RBC storage duration on plasma S1P levels. Plasma S1P from 30 individuals demonstrated a linear correlation with Hct (haematocrit; R²=0.51, P<0.001) with no evidence for a plateau at Hct values as low as 19%. RBC transfusion in 23 anaemic patients with baseline mean Hct of 22.2±0.34% (value is the mean±S.D.) increased Hct to 28.3±0.6% at 72 h. Despite an Hct increase, RBC transfusion failed to elevate plasma S1P consistently. A trend towards an inverse correlation was observed between RBC storage duration and the post-transfusion increase in plasma S1P. After 30 days of storage, RBC S1P decreased to 19% of that observed in fresh (3–7-day-old) RBC segments. RBC membranes contain low levels of both S1P phosphatase and S1P lyase activities that may account for the decline in S1P levels with storage. Our results support a role for RBCs in buffering plasma S1P and identify a disturbance in the capacity after transfusion. Changes in S1P content may contribute to an RBC storage lesion. Further studies should investigate the clinical significance of alterations in circulating S1P levels and the potential value of enriching stored RBCs with S1P.

In-hospital prognostic value of hemoglobin levels on admission in patients with acute ST segment elevation myocardial infarction undergoing primary angioplasty

PURPOSE

Anemia is a common comorbidity in patients presenting with ST-elevation myocardial infarction (STEMI). The aim of this study was to investigate the in-hospital prognostic value of admission hemoglobin (Hb) levels in patients with acute STEMI undergoing primary percutaneous coronary intervention (p-PCI).

METHODS

This is a retrospective study of 1,625 patients with STEMI stratified by quartiles of admission Hb concentration (Q1 ≤12.5 g/dl, Q2 12.6-13.8 g/dl, Q3 13.9-15.0 g/dl, Q4 ≥15.1 g/dl). Main outcome measures were in-hospital rates of all cause mortality, re-infarction, target vessel revascularization, stroke, heart failure (HF) and bleeding complications.

RESULTS

The incidences of in-hospital mortality according to quartiles from Q1 to Q4 were 8.6, 3.9, 2.4 and 2.6%, respectively (p < 0.001). The incidences of major hemorrhage and HF were significantly higher in Q1, compared to the other quartiles (7.4, 1.9, 3.1, 2.8%, p < 0.001; 16.3, 8.5, 7.7, 9.8%, p < 0.001, respectively). Multiple logistic-regression analysis showed that low admission Hb level (Q1) is an independent and a potent predictor for in-hospital mortality [unadjusted odds ratio (OR): 3.84, 95% confidence interval (CI): 1.78-7.82; p < 0.001].

CONCLUSION

Lower concentrations of Hb on admission are associated with higher rates of in-hospital mortality, heart failure and major bleeding after p-PCI.

Association of red blood cell transfusion and postoperative outcomes after endovascular aortic repair

BACKGROUND

Several studies have documented worse postoperative outcomes in patients who received red blood cell (RBC) transfusion perioperatively during cardiac surgery or in critical care settings. These findings were attributed to activation of the inflammatory response with the release of cytokines and immune suppression. The aim of this study was to evaluate the association of RBC transfusion on the day of surgery and postoperative outcomes following endovascular aortic repair (EVAR).

METHODS

A total of 510 patients who underwent EVAR from April 2005 to March 2007 were considered for analysis. The exposure of interest was whether or not patients receive RBC transfusion on the day of surgery. The primary outcome was a composite in-hospital morbidity/mortality outcome. The authors assessed the association between RBC transfusion and our composite outcome using logistic regression after adjusting for the available potential confounders using propensity score matching.

RESULTS

Propensity scores were estimated for 418 out of the 510 patients; 92 patients were not included because of missing data. Propensity matching resulted in 42 successfully matched pairs. Median (quartiles) propensity score was 0.46 (0.28, 0.66) for the matched patients with transfusion and 0.46 (0.29, 0.61) for the matched patients without transfusion (P = .75, Wilcoxon rank sum test). Results of the multivariable model developed after propensity score matching suggest that RBC transfusion was not significantly associated with experiencing a postoperative complication; estimated odds ratio (95% confidence interval) of 2.7 (0.8, 9.0), P = .11.

CONCLUSION

In this study, RBC transfusion was not independently associated with an increased incidence of in-hospital morbidity and mortality after EVAR.

Heparin plus a glycoprotein IIb/IIIa inhibitor versus bivalirudin monotherapy and paclitaxel-eluting stents versus bare-metal stents in acute myocardial infarction (HORIZONS-AMI): final 3-year results from a multicentre, randomised controlled trial

BACKGROUND

Primary results of the HORIZONS-AMI trial have been previously reported. In this final report, we aimed to assess 3-year outcomes.

METHODS

HORIZONS-AMI was a prospective, open-label, randomised trial undertaken at 123 institutions in 11 countries. Patients aged 18 years or older were eligible for enrolment if they had ST-segment elevation myocardial infarction (STEMI), presented within 12 h after onset of symptoms, and were undergoing primary percutaneous coronary intervention. By use of a computerised interactive voice response system, we randomly allocated patients 1:1 to receive bivalirudin or heparin plus a glycoprotein IIb/IIIa inhibitor (GPI; pharmacological randomisation; stratified by previous and expected drug use and study site) and, if eligible, randomly allocated 3:1 to receive a paclitaxel-eluting stent or a bare metal stent (stent randomisation; stratified by pharmacological group assignment, diabetes mellitus status, lesion length, and study site). We produced Kaplan-Meier estimates of major adverse cardiovascular events at 3 years by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00433966.

FINDINGS

Compared with 1802 patients allocated to receive heparin plus a GPI, 1800 patients allocated to bivalirudin monotherapy had lower rates of all-cause mortality (5·9%vs 7·7%, difference -1·9% [-3·5 to -0·2], HR 0·75 [0·58-0·97]; p=0·03), cardiac mortality (2·9%vs 5·1%, -2·2% [-3·5 to -0·9], 0·56 [0·40-0·80]; p=0·001), reinfarction (6·2%vs 8·2%, -1·9% [-3·7 to -0·2], 0·76 [0·59-0·99]; p=0·04), and major bleeding not related to bypass graft surgery (6·9%vs 10·5%, -3·6% [-5·5 to -1·7], 0·64 [0·51-0·80]; p=0·0001) at 3 years, with no significant differences in ischaemia-driven target vessel revascularisation, stent thrombosis, or composite adverse events. Compared with 749 patients who received a bare-metal stent, 2257 patients who received a paclitaxel-eluting stent had lower rates of ischaemia-driven target lesion revascularisation (9·4%vs 15·1%, -5·7% [-8·6 to -2·7], 0·60 [0·48-0·76]; p<0·0001) after 3 years, with no significant differences in the rates of death, reinfarction, stroke or stent thrombosis. Stent thrombosis was high (≥4·5%) in both groups.

INTERPRETATION

The effectiveness and safety of bivalirudin monotherapy and paclitaxel-eluting stenting are sustained at 3 years for patients with STEMI undergoing primary percutaneous coronary intervention.

FUNDING

Boston Scientific and The Medicines Company.

[The effect of aspirin alone or aspirin plus additional antiplatelets therapy on upper gastrointestinal hemorrhage]

BACKGROUND/AIMS

The increasing incidence of cardiovascular disease has led to an increase in the frequency of upper gastrointestinal (GI) hemorrhage due to the use of antiplatelet agents. This study examined the clinical characteristics of patients with upper GI hemorrhage who were administered aspirin alone or a combination treatment of antiplatelet agents.

METHODS

A 656 patients who underwent drug-eluting coronary stenting at Ewha Mokdong Hospital in 2008 were divided into three groups according to the antiplatetlet agents used after the intervention; groups of aspirin alone, aspirin plus clopidogrel, and aspirin, and clopidogrel plus another antiplatelet agent, respectively. Patients admitted with GI hemorrhage in the same period without a medication history of antiplatelet or nonsteroidal anti-inflammatory drugs were used as the control hemorrhage group. The medical records were reviewed.

RESULTS

Significant GI symptoms were observed in 21.1% of total patients, of whom 48.2% had ulcers. The upper GI hemorrhage rate was 3.8%. There was no significant difference in the hemorrhage rate between three groups. Compared to the control hemorrhage group, the endoscopic variables of the antiplatelet-related hemorrhage group were not significantly different. However, the Helicobacter pylori infection rate was lower, the admission period was longer, and the mortality rate was higher in the antiplatelet-related hemorrhage group (p<0.05, respectively). There was no direct association between restarting or discontinuance of antiplatelets after the hemorrhage event and mortality.

CONCLUSIONS

Adding other antiplatelet agents to aspirin did not increase the hemorrhage rate. However, active diagnostic and therapeutic efforts are recommended in patients with GI symptoms during antiplatelet therapy.

Emerging Role for Use of Liposomes in the Biopreservation of Red Blood Cells

SUMMARY: Biopreservation is the process of maintaining the integrity and functionality of cells held outside the native environment for extended storage times. The development of red blood cell (RBC) biopreservation techniques that maintain in vitro RBC viability and function represents the foundation of modern blood banking. The biopreservation of RBCs for clinical use can be categorized based on the techniques used to achieve biologic stability, including hypothermic storage and cryopreservation. This review will examine the emerging role of liposomes in the RBC biopreservation, including the incorporation of liposomes into RBC membranes as an effective approach for minimizing RBC hypothermic storage membrane lesion and use of liposomes as a permeabilization strategy for the intracellular accumulation of novel intracellular cryoprotectants. Integration of current biopreservation research with blood banking practices offers enormous potential for future improvements of safety and efficacy of RBC transfusion.

Analysis and clinical relevance of microparticles from red blood cells

PURPOSE OF REVIEW

The mechanisms involved in the formation of red blood cell (RBC) microparticles in vivo as well as during erythrocyte storage are reviewed, and the potential role of microparticles in transfusion medicine is described.

RECENT FINDINGS

Microparticles release is an integral part of the erythrocyte ageing process, preventing early removal of RBCs. Proteomics analyses have outlined the key role of band 3-ankyrin anchoring complex and the occurrence of selective RBC membrane remodelling mechanisms in microparticles formation. The presence of several RBC antigens, expressed on microparticles, has been demonstrated. The potential deleterious effects of RBC microparticles in transfused recipients, including hypercoagulability, microcirculation impairment and immunosuppression, are discussed.

SUMMARY

Formation and role of RBC microparticles are far from being completely understood. Combining various approaches to elucidate these mechanisms could improve blood product quality and transfusion safety. Implementation of RBC microparticles as biomarkers in the laboratory routine needs to overcome technical barriers involved in their analysis.

Platelet-white blood cell (WBC) interaction, WBC apoptosis, and procoagulant activity in stored red blood cells

BACKGROUND

Nonleukoreduced units of red blood cells (RBCs) contain activated platelets (PLTs) that interact with white blood cells (WBCs) and may promote inflammation and thrombosis in the recipient. The aim of this study was to characterize PLT-WBC interactions (PLT-WBC aggregates [PLAs]), WBC apoptosis, WBC death, and the development of procoagulant activity in RBCs during storage.

STUDY DESIGN AND METHODS

RBCs were prepared from volunteer donor blood and stored. Samples were analyzed with flow cytometry between Days 1 and 15 to measure PLT-monocyte aggregate (PMA) and PLT-neutrophil aggregate (PNA) formation, WBC apoptosis (annexin V binding), and cell death (binding of 7-aminoactinomycin D). Procoagulant activity in the supernatant of four RBC preparations was assessed between Days 1 and 39 using a clotting assay with and without the addition of an inhibitory anti-tissue factor (TF) antibody, αTF-5.

RESULTS

PLA formation was extensive and maximal on Day 3 of storage (PNA, 23 ± 13%; PMA, 93 ± 4%; n = 6). Apoptosis was progressive throughout storage, with 95 ± 4% of neutrophils and 73 ± 19% of monocytes binding annexin V on Day 15. Cell death became measurable after apoptosis. Procoagulant activity was observed in all RBCs but with varying temporal patterns. It was partially TF dependent and removed with high-speed centrifugation, suggestive of an association with microparticles.

CONCLUSION

The activation of PLTs during the storage of RBCs induces PLA formation that precedes WBC apoptosis and death. Procoagulant activity, likely associated with microparticles derived from apoptotic WBCs, may contribute to adverse effects of stored, nonleukoreduced RBCs.

Relation between hemoglobin level and recurrent myocardial ischemia in acute coronary syndromes detected by continuous electrocardiographic monitoring

Anemia has been associated with adverse outcomes in patients with acute coronary syndromes (ACS). However, the underlying pathophysiologic mechanisms have not been well elucidated. We sought to determine the independent relation between the hemoglobin level and recurrent ischemia in patients with non-ST-segment elevation ACS using continuous electrocardiographic monitoring. In the Integrilin and Enoxaparin Randomized Assessment of Acute Coronary Syndrome Treatment (INTERACT) trial, 746 patients presenting with non-ST-segment elevation ACS underwent continuous ST-segment monitoring for 48 hours. The data were analyzed independently at a core laboratory. We stratified the study population according to their hemoglobin level on presentation. The primary outcome of the study was recurrent ischemia, defined as ST-segment shifts on continuous electrocardiographic monitoring. Of the 705 patients with analyzable data, 64 had a baseline hemoglobin level <120 g/L, 259 had a level of 120 to 139 g/L, 315 had a level of 140 to 159 g/L, and 67 had a level >160 g/L. The corresponding rates of recurrent ischemia were 39.1%, 22.0%, 15.6%, and 11.9% (p for trend <0.001). A lower hemoglobin level was associated with advanced age, co-morbidities, and a higher GRACE risk score. In multivariable analysis adjusting for these confounders, lower hemoglobin levels retained a significant independent association with recurrent ischemia (p for trend = 0.004). In conclusion, a lower hemoglobin level at presentation was independently associated with recurrent ischemia detected by continuous electrocardiographic monitoring in the setting of non-ST-segment elevation ACS. This suggests that anemia might predispose patients to recurrent ischemia, which could be an important underlying mediator of worse outcomes in patients with lower hemoglobin levels.

Impact of anemia on clinical outcomes of patients with ST-segment elevation myocardial infarction in relation to gender and adjunctive antithrombotic therapy (from the HORIZONS-AMI trial)

The aim of this study was to assess the impact of baseline anemia on the outcomes of patients with ST elevation myocardial infarctions who underwent primary percutaneous coronary intervention in relation to contemporary adjunctive antithrombotic therapy and gender. In the Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction (HORIZONS-AMI) trial, patients were randomized to bivalirudin alone or to unfractionated heparin plus a glycoprotein IIb/IIIa inhibitor before primary percutaneous coronary intervention. Outcomes were assessed at 30 days and 1 year according to anemia and gender. Baseline anemia was present in 331 of 3,153 patients (10.5%). Patients with versus without baseline anemia had a more than twofold increase in major bleeding at 30 days (13.5% vs 6.7%, p <0.0001) and at 1 year (14.8% vs 7.2%, p <0.0001), an association that on multivariate analysis was independent of gender. Mortality was significantly higher in men with versus without baseline anemia (4.6% vs 1.8% at 30 days, p = 0.003; 8.9% vs 3.0% at 1 year, p <0.0001) but not in women (5.3% vs 3.6% at 30 days, p = 0.42; 7.5% vs 5.9% at 1 year, p = 0.54). On multivariate analysis, anemia independently predicted 1-year all-cause mortality in men but not in women. Bivalirudin compared with unfractionated heparin plus a glycoprotein IIb/IIIa inhibitor resulted in twofold lower rates of all-cause and cardiac mortality and major bleeding in patients without but not in those with baseline anemia. In conclusion, baseline anemia was associated with increased major bleeding and death in patients with ST elevation myocardial infarctions who underwent primary PCI but was a stronger predictor of early and late mortality in men than in women. Paradoxically, in this post hoc analysis, the reductions in major bleeding and mortality in ST elevation myocardial infarction afforded by bivalirudin occurred primarily in patients without baseline anemia.

Early goal-directed therapy: on terminal life support?

Early goal-directed therapy (EGDT) has become regarded as the standard of care for the management of patients with severe sepsis and septic shock. The elements of EGDT have been bundled together as the "Sepsis Bundle," and compliance with the elements of the bundle is frequently used as an indicator of the quality of care delivered. The major elements of EGDT include fluid resuscitation to achieve a central venous pressure of 8 to 12 cm of water, followed by the transfusion of packed red cells or an inotropic agent to maintain the central venous oxygen saturation higher than 70%. Although the concept of early resuscitation is a scientifically sound concept, we believe that the major elements of the sepsis bundle are fatally flawed.