Association of blood transfusion with increased mortality in myocardial infarction: a meta-analysis and diversity-adjusted study sequential analysis

Blood

This chapter describes the role of blood in the transmission of viruses and recounts early efforts to ensure the safety of the US blood supply. A person of average weight has approximately 5 quarts of blood containing more than 20 trillion individual cells. The discovery of blood groups by Karl Landsteiner in 1901 enabled the safe transfusion of blood, and transfusion therapy came into widespread use after World War II. However, it was soon recognized that donor blood could transmit infectious agents, and this was more likely to occur if the person giving the blood was motivated by a monetary reward. The frequency of transfusion-transmitted disease has been greatly reduced since 1985, when the Red Cross, other blood collectors, and the Food and Drug Administration began to rigorously screen donors and extensively test the donated blood. The chapter concludes by describing several recent advances that have further improved transfusion safety.

Clinical factors influencing the decision to transfuse after percutaneous native kidney biopsy

Background

Transfusion of erythrocytes is the most common intervention after a complicated percutaneous renal biopsy (PRB). Anemia is considered to be a leading risk factor for bleeding following a PRB, and based on recent studies of transfusions in hospitalized patients, many institutions are restricting the threshold for erythrocyte transfusion to a lower hemoglobin concentration (Hgb). The purpose of this study is to analyze factors that influence the transfusion decision after a PRB, and to determine whether anemia is truly a risk factor for bleeding or anemic patients are simply more likely to receive a transfusion because of their already lower pre-PRB Hgb.

Methods

PRB of native kidneys was performed using real-time ultrasound with automated biopsy needles from January 1990 to April 2014. All patients were prospectively followed for bleeding with a 24-h inpatient observation. An intervention for a bleeding complication (BL-I) was defined by undergoing a procedure (cystoscopy, embolization), receiving a blood transfusion (BL-T), death and/or readmission related to the biopsy. To further define the effect of anemia, patients were divided into three pre-PRB Hgb groups: <9.0 g/dL (n = 79), 9.0–11.0 g/dL (n = 266) and >11.0 g/dL (n = 565).

Results

BL-I occurred in 71/910 (7.8%) of PRBs. The majority of these were BL-T (57/71, 80%; 57/910, 6.3% overall). Patients with BL-I had lower pre-PRB Hgb than those without BL-I (mean ± SD; 10.3 ± 2.0 versus 12.0 ± 2.1 g/dL, P < 0.0001) and a greater change (Δ) in Hgb (2.1 ± 1.6 versus 1.0 ± 0.8 g/dL, P < 0.0001). When compared with higher Hgb, patients with Hgb <9.0 g/dL had more traditional risk factors for bleeding (older age: 49 ± 18 versus 48 ± 18 versus 45 ± 16 years, P = 0.02; female: 72 versus 70 versus 56%, P < 0.0001; higher serum creatinine: 4.0 ± 2.9 versus 2.9 ± 2.6 versus 1.7 ± 1.4 mg/dL, P < 0.0001; higher systolic blood pressure: 138 ± 18 versus 133 ± 19 versus 133 ± 18 mmHg, P = 0.06; higher bleeding time: 7.6 ± 1.8 versus 7.4 ± 2.0 versus 6.7 ± 1.8 min, P < 0.0001). When BL-T was stratified by pre-PRB Hgb, there were more transfusions in those with lower pre-PRB Hgb (24 versus 9 versus 3%, P < 0.0001). However, these patients not only had fewer hematomas (58 versus 83 versus 87%, P = 0.04) but also demonstrated a smaller ΔHgb post-PRB (1.3 ± 1.0 versus 1.8 ± 0.8 versus 3.2 ± 1.6, P < 0.0001) compared with patients with higher pre-PRB Hgb, yet still received a transfusion.

Conclusions

While patients with lower pre-PRB Hgb have more of the traditional risk factors for a complication after PRB, there was actually less clinically evident bleeding in these patients who were transfused. Although anemia itself has been considered to be a risk factor for a complication in the past, it more accurately represents only a predictor of receiving an erythrocyte transfusion. In the setting of the PRB, the decision for transfusion is influenced more by the severity of anemia at baseline as opposed to clinically evident bleeding.

Implementing a blood utilization program to optimize transfusion practice

Blood utilization review programs educate clinicians on guidelines for appropriate transfusion, review local transfusion practice, and provide feedback on transfusion trends. To gather data on transfusion practice, modern blood utilization programs leverage electronic medical records and computerized physician order entry with automated decision support. Data may be collected and feedback may be given in real-time for individual transfusions or retrospectively with aggregated data. Important elements for a successful program include a multidisciplinary group that can champion the effort, adequate documentation and data capture for transfusions, and regular discussions about trends with ordering clinicians. Blood utilization programs are popular because they can lower transfusion risk, improve quality outcomes, and lower costs.

Ten Years Experiences With Preoperative Evaluation Clinic for Day Admission Cardiac and Major Vascular Surgical Patients: Model for "Perioperative Anesthesia and Surgical Home"

Admission on the day of surgery for elective cardiac and noncardiac surgery is the prevalent practice in North America and Canada. This approach realizes medical, psychological and logistical benefits, and its success is predicated on an effective outpatient preoperative evaluation. The establishment of a highly functional preoperative clinic with a comprehensive set up and efficient logistical pathways is invaluable. This notion in recent years has included the entire perioperative period, and the concept of a perioperative anesthesia/surgical home (PASH) is gaining popularity. The anesthesiologists as perioperative physicians can organize and lead the entire process from the preoperative evaluation, through the hosptial discharge. The functions of the PASH include preoperative optimization of medical conditions and psychological preparation of the patients and their support system; the care in the operating room and intensive care unit; pain management; respiratory therapy; cardiac rehabilitation; and specialized nutrition. Along with oversight of the medical issues, the preoperative visit is an opportune time for counseling, clarification of expectations and discussion of research, as well as for utilization of various informatics systems to consolidate the pertinent information and distribute it to relevant health care providers. We review the scientific foundation and practical applications of a preoperative visit and share our experience with the development of the preoperative evaluation clinic, designed specifically for cardiac and major vascular patients scheduled for day admission surgery. The ultimate goal of preoperative evaluation clinic is to ensure a safe, efficient, and cost-effective perioperative care for patients undergoing a complex type of surgery.

An evidence-based approach to red blood cell transfusions in asymptomatically anaemic patients

INTRODUCTION

Surgeons and physicians encounter blood transfusions on a daily basis but a robust evidence-based strategy on indications and timing of transfusion in asymptomatic anaemic patients is yet to be determined. For judicious use of blood products, the risks inherent to packed red blood cells, the patient's co-morbidities and haemoglobin (Hb)/haematocrit levels should be considered. This review critiques and summarises the latest available evidence on the indications for transfusions in healthy and cardiac disease patients as well as the timing of transfusions relative to surgery.

METHODS

An electronic literature search of the MEDLINE(®), Google Scholar™ and Trip databases was conducted for articles published in English between January 2006 and January 2015. Studies discussing timing and indications of transfusion in medical and surgical patients were retrieved. Bibliographies of studies were checked for other pertinent articles that were missed by the initial search.

FINDINGS

Six level 1 studies (randomised controlled trials or systematic reviews) and six professional society guidelines were included in this review. In healthy patients without cardiac disease, a restrictive transfusion trigger of Hb 70-80g/l is safe and appropriate whereas in cardiac patients, the trigger is Hb 80-100g/l. The literature on timing of transfusions relative to surgery is limited. For the studies available, preoperative transfusions were associated with a decreased incidence of subsequent transfusions and timing of transfusions did not affect the rates of colorectal cancer recurrence.

Red Cell Transfusion Triggers and Postoperative Outcomes After Major Surgery

BACKGROUND

The effect of packed red blood cell (PRBC) transfusion on postoperative outcomes of patients undergoing major surgery remains unclear. We sought to determine the impact of blood utilization, as well as transfusion practices, on perioperative outcomes of patients undergoing cardiothoracic-vascular (CT-V) and gastrointestinal (GI) procedures.

METHODS

Patients who underwent major surgical procedures at Johns Hopkins Hospital between 2009 and 2014 were identified. Data on perioperative hemoglobin (Hb) and blood utilization were obtained; transfusion strategy was categorized as liberal (Hb trigger ≥7 g/dL) vs. restrictive (Hb trigger <7 g/dL). Risk-adjusted logistic regression models and propensity score matching were used to assess the association between transfusion triggers and perioperative morbidity.

RESULTS

Among 10,163 patients undergoing either CT-V (50.9 %) or GI (49.1 %) surgery, 4401 (43.3 %) patients received PRBCs. Of the 4401 patients transfused, 71.2 % were transfused using a liberal trigger (≥7 g/dL hemoglobin), while 28.8 % had a restrictive trigger (<7 g/dL). The median number of PRBCs transfused was 3 (restrictive 5 vs. liberal 2 units). While ischemic adverse events were more common among patients undergoing CT-V surgery (17.3 %), infection was the more common complication among patients undergoing GI surgery (11.9 %). American Society of Anesthesiologist (ASA) class 3-4, Charlson score ≥3, and total units of transfused PRBCs were independently associated with overall complications (all P < 0.05). Patients in the restrictive transfusion group did not have increased risk of complications compared with the liberal transfusion group on multivariable analysis (odds ratio (OR) 1.16, 95 % confidence interval (CI) 0.98-1.38; P = 0.08) or after propensity score matching (OR 1.04, 95 % CI 0.88-1.22; P = 0.65).

CONCLUSIONS

Liberal transfusion triggers after major surgery were more common than restrictive practice. Patients with restrictive transfusion trigger did not have increased risk for complications compared with patients transfused with a liberal trigger.

Blood transfusion, bleeding, anemia, and survival in patients with acute myocardial infarction: FAST-MI registry

BACKGROUND

An association between transfusion during index hospitalization and increased subsequent mortality has been reported in acute myocardial infarction (AMI). Whether this reflects the prognostic role of transfusion per se, or the impact of the index event leading to transfusion, remains unclear. We sought to evaluate the impact of transfusion on mortality in patients with AMI.

METHODS

Using the nationwide FAST-MI 2005 AMI registry, we recorded anemia on admission, Thrombolysis in Myocardial Infarction major or minor bleeding, and transfusions during hospital stay. Multivariable analyses were performed to identify independent predictors of in-hospital and 5-year mortality. Cohorts of patients matched for propensity to receive transfusion were compared.

RESULTS

Among 3541 patients with AMI, 827 (23.4%) had anemia on admission, 114 (3.2%) had minor or major bleeding, and 151 (4.3%) underwent transfusion. After multivariable analysis, both anemia and bleeding were independently associated with 5-year mortality (hazard ratio [HR] 1.4, 95% CI 1.2-1.6 and HR 1.4, 95% CI 1.1-1.8, respectively), whereas transfusion did not appear to be an independent predictor (HR 1.1, 95% CI 0.8-1.5). Mortality at 5 years did not differ between cohorts matched for propensity to receive transfusion.

CONCLUSIONS

In this cohort, anemia on admission and bleeding during hospitalization were both associated with increased 5-year mortality in patients with myocardial infarction. Conversely, transfusion per se was not associated with lower survival. Further work is needed to clarify the optimal transfusion strategy in patients with bleeding or anemia and myocardial infarction.

Anemia in Intensive Cardiac Care Unit patients - An underestimated problem

The heterogeneous group of patients admitted to Intensive Cardiac Care Unit (ICCU) as well as nonspecific complaints associated with anemia might be the reason for underdiagnosing or minimization of this problem. Because of this heterogeneity, there are no clear guidelines to follow. It is known that anemia is impairing the outcome. Thus, it is crucial to keep alert in the diagnosis and treatment of anemia, especially in critically ill cardiac patients. The greatest groups of patients admitted to ICCU are those with acute coronary syndromes (ACS), acute decompensated heart failure (ADHF), severe arrhythmias as well as individuals after cardiac operations. However, patients suffering other critical cardiac illnesses quite often become anemic during hospitalization in ICCU. It is because anemia is typed in the clinical features of heavy diseases or may be the consequence of treatment. The current review focuses on the incidence, complex etiology and predictive role of anemia in a diverse group of ICCU patients. It discusses clinical aspects of anemia treatment in particular groups of critically ill cardiac patients because proper treatment increases chances for recovery and improves the outcome in this severe group of patients.

Forum for debate: Safety of allogeneic blood transfusion alternatives in the surgical/critically ill patient

In recent years, several safety alerts have questioned or restricted the use of some pharmacological alternatives to allogeneic blood transfusion in established indications. In contrast, there seems to be a promotion of other alternatives, based on blood products and/or antifibrinolytic drugs, which lack a solid scientific basis. The Multidisciplinary Autotransfusion Study Group and the Anemia Working Group España convened a multidisciplinary panel of 23 experts belonging to different healthcare areas in a forum for debate to: 1) analyze the different safety alerts referred to certain transfusion alternatives; 2) study the background leading to such alternatives, the evidence supporting them, and their consequences for everyday clinical practice, and 3) issue a weighted statement on the safety of each questioned transfusion alternative, according to its clinical use. The members of the forum maintained telematics contact for the exchange of information and the distribution of tasks, and a joint meeting was held where the conclusions on each of the items examined were presented and discussed. A first version of the document was drafted, and subjected to 4 rounds of review and updating until consensus was reached (unanimously in most cases). We present the final version of the document, approved by all panel members, and hope it will be useful for our colleagues.

Restrictive versus liberal transfusion strategy for red blood cell transfusion: systematic review of randomised trials with meta-analysis and trial sequential analysis

OBJECTIVE

To compare the benefit and harm of restrictive versus liberal transfusion strategies to guide red blood cell transfusions.

DESIGN

Systematic review with meta-analyses and trial sequential analyses of randomised clinical trials.

DATA SOURCES

Cochrane central register of controlled trials, SilverPlatter Medline (1950 to date), SilverPlatter Embase (1980 to date), and Science Citation Index Expanded (1900 to present). Reference lists of identified trials and other systematic reviews were assessed, and authors and experts in transfusion were contacted to identify additional trials.

TRIAL SELECTION

Published and unpublished randomised clinical trials that evaluated a restrictive compared with a liberal transfusion strategy in adults or children, irrespective of language, blinding procedure, publication status, or sample size.

DATA EXTRACTION

Two authors independently screened titles and abstracts of trials identified, and relevant trials were evaluated in full text for eligibility. Two reviewers then independently extracted data on methods, interventions, outcomes, and risk of bias from included trials. random effects models were used to estimate risk ratios and mean differences with 95% confidence intervals.

RESULTS

31 trials totalling 9813 randomised patients were included. The proportion of patients receiving red blood cells (relative risk 0.54, 95% confidence interval 0.47 to 0.63, 8923 patients, 24 trials) and the number of red blood cell units transfused (mean difference -1.43, 95% confidence interval -2.01 to -0.86) were lower with the restrictive compared with liberal transfusion strategies. Restrictive compared with liberal transfusion strategies were not associated with risk of death (0.86, 0.74 to 1.01, 5707 patients, nine lower risk of bias trials), overall morbidity (0.98, 0.85 to 1.12, 4517 patients, six lower risk of bias trials), or fatal or non-fatal myocardial infarction (1.28, 0.66 to 2.49, 4730 patients, seven lower risk of bias trials). Results were not affected by the inclusion of trials with unclear or high risk of bias. Using trial sequential analyses on mortality and myocardial infarction, the required information size was not reached, but a 15% relative risk reduction or increase in overall morbidity with restrictive transfusion strategies could be excluded.

CONCLUSIONS

Compared with liberal strategies, restrictive transfusion strategies were associated with a reduction in the number of red blood cell units transfused and number of patients being transfused, but mortality, overall morbidity, and myocardial infarction seemed to be unaltered. Restrictive transfusion strategies are safe in most clinical settings. Liberal transfusion strategies have not been shown to convey any benefit to patients.

TRIAL REGISTRATION

PROSPERO CRD42013004272.

Blood transfusion after percutaneous coronary intervention and risk of subsequent adverse outcomes: a systematic review and meta-analysis

OBJECTIVES

This study sought to define the prevalence and prognostic impact of blood transfusions in contemporary percutaneous coronary intervention (PCI) practice.

BACKGROUND

Although the presence of anemia is associated with adverse outcomes in patients undergoing PCI, the optimal use of blood products in patients undergoing PCI remains controversial.

METHODS

A search of EMBASE and MEDLINE was conducted to identify PCI studies that evaluated blood transfusions and their association with major adverse cardiac events (MACE) and mortality. Two independent reviewers screened the studies for inclusion, and data were extracted from relevant studies. Random effects meta-analysis was used to estimate the risk of adverse outcomes with blood transfusions. Statistical heterogeneity was assessed by considering the I(2) statistic.

RESULTS

Nineteen studies that included 2,258,711 patients with more than 54,000 transfusion events were identified (prevalence of blood transfusion 2.3%). Crude mortality rate was 6,435 of 50,979 (12.6%, 8 studies) in patients who received a blood transfusion and 27,061 of 2,266,111 (1.2%, 8 studies) in the remaining patients. Crude MACE rates were 17.4% (8,439 of 48,518) in patients who had a blood transfusion and 3.1% (68,062 of 2,212,730) in the remaining cohort. Meta-analysis demonstrated that blood transfusion was independently associated with an increase in mortality (odds ratio: 3.02, 95% confidence interval: 2.16 to 4.21, I(2) = 91%) and MACE (odds ratio: 3.15, 95% confidence interval: 2.59 to 3.82, I(2) = 81%). Similar observations were recorded in studies that adjusted for baseline hematocrit, anemia, and bleeding.

CONCLUSIONS

Blood transfusion is independently associated with increased risk of mortality and MACE events. Clinicians should minimize the risk for periprocedural transfusion by using available bleeding-avoidance strategies and avoiding liberal transfusion practices.

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.

Lower versus higher hemoglobin threshold for transfusion in septic shock

BACKGROUND

Blood transfusions are frequently given to patients with septic shock. However, the benefits and harms of different hemoglobin thresholds for transfusion have not been established.

METHODS

In this multicenter, parallel-group trial, we randomly assigned patients in the intensive care unit (ICU) who had septic shock and a hemoglobin concentration of 9 g per deciliter or less to receive 1 unit of leukoreduced red cells when the hemoglobin level was 7 g per deciliter or less (lower threshold) or when the level was 9 g per deciliter or less (higher threshold) during the ICU stay. The primary outcome measure was death by 90 days after randomization.

RESULTS

We analyzed data from 998 of 1005 patients (99.3%) who underwent randomization. The two intervention groups had similar baseline characteristics. In the ICU, the lower-threshold group received a median of 1 unit of blood (interquartile range, 0 to 3) and the higher-threshold group received a median of 4 units (interquartile range, 2 to 7). At 90 days after randomization, 216 of 502 patients (43.0%) assigned to the lower-threshold group, as compared with 223 of 496 (45.0%) assigned to the higher-threshold group, had died (relative risk, 0.94; 95% confidence interval, 0.78 to 1.09; P=0.44). The results were similar in analyses adjusted for risk factors at baseline and in analyses of the per-protocol populations. The numbers of patients who had ischemic events, who had severe adverse reactions, and who required life support were similar in the two intervention groups.

CONCLUSIONS

Among patients with septic shock, mortality at 90 days and rates of ischemic events and use of life support were similar among those assigned to blood transfusion at a higher hemoglobin threshold and those assigned to blood transfusion at a lower threshold; the latter group received fewer transfusions. (Funded by the Danish Strategic Research Council and others; TRISS ClinicalTrials.gov number, NCT01485315.).

Atrial fibrillation and coronary artery disease: which antithrombotic treatment strategy?

PURPOSE OF REVIEW

The optimal antithrombotic therapy in patients with atrial fibrillation and coronary artery disease is controversial. The benefit of the combination of antithrombotic therapies remains debatable, and, as the bleeding risk is substantial, this calls for knowledge of the duration, and which and how many agents should be used.

RECENT FINDINGS

The first randomized trial to challenge current recommendations of triple therapy (oral anticoagulation plus clopidogrel plus aspirin) examined patients on warfarin undergoing percutaneous coronary intervention with stent implantation. A reduced risk of any bleeding (hazard ratio 0.36) was found with combination of clopidogrel compared with triple therapy without increasing major cardiovascular events. In real-life patients, a nationwide Danish registry supported these findings, and, relative to triple therapy, no significant difference was found for recurrent myocardial infarction when adding only clopidogrel (hazard ratio 0.69) or aspirin (hazard ratio 0.96) to vitamin K antagonist. However, the latter regimen was associated with significantly increased risk of death.

SUMMARY

Within 1 year after myocardial infarction and/or percutaneous coronary intervention in patients with atrial fibrillation, current consensus papers endorse use of dual antiplatelet therapy on top of oral anticoagulation. A regimen consisting of oral anticoagulation and clopidogrel (without aspirin) could provide an alternative from a benefit and safety perspective.

Red blood cell and platelet microparticles in myocardial infarction patients treated with primary angioplasty

BACKGROUND

Red blood cell and platelet microparticles (RBCm and PLTm, respectively) have drawn research attention as to their potential prothrombotic and vasoconstrictive effects in experimental settings. However, the relevance of circulating microparticles in clinical settings is largely undetermined.

METHODS

Circulating microparticles were quantified with a flow cytometric method in blood samples from consecutive STEMI patients after primary PCI. A matched cohort of healthy volunteers was used to derive reference values for comparison. STEMI patients were followed for 6 months for a composite clinical endpoint.

RESULTS

Fifty-one STEMI patients (age 59.8 ± 8.8 years) and 50 controls (age 56.2 ± 9.2 years; p=0.155) were enrolled. RBCm concentration was 18,198 ± 6062/μl in the reference cohort versus 33,740 ± 21,169/μl in STEMI patients (p<0.001). RBCm count was not correlated to total RBCs (standardized beta 0.018; p=0.861). PLTm did not differ between groups (17,529 ± 16,292/μl in STEMI patients versus 14,372 ± 6211/μl in controls; p=0.203). RBCm c-statistic was 0.832 (95% confidence interval 0.720 to 0.944), while PLTm prognostic value was not statistically significant (c-statistic 0.614, 95% confidence interval 0.444 to 0.784). In the multivariate analysis, RBCm concentration was independently associated with the occurrence of the clinical endpoint, after adjustment for age, ejection fraction, serum creatinine and presence of diabetes (adjusted p=0.034).

CONCLUSIONS

The present study demonstrates for the first time that erythrocyte microparticles are elevated in patients with STEMI treated with primary PCI, with levels approximately double those measured in a reference population of healthy volunteers, and their concentrations appear to be positively associated with adverse clinical events.

Anemia and red blood cell transfusion in critically ill cardiac patients

Anemia and red blood cell (RBC) transfusion occur frequently in hospitalized patients with cardiac disease. In this narrative review, we report the epidemiology of anemia and RBC transfusion in hospitalized adults and children (excluding premature neonates) with cardiac disease, and on the outcome of anemic and transfused cardiac patients. Both anemia and RBC transfusion are common in cardiac patients, and both are associated with mortality. RBC transfusion is the only way to rapidly treat severe anemia, but is not completely safe. In addition to hemoglobin (Hb) concentration, the determinant(s) that should drive a practitioner to prescribe a RBC transfusion to cardiac patients are currently unclear. In stable acyanotic cardiac patients, Hb level above 70 g/L in children and above 70 to 80 g/L in adults appears safe. In cyanotic children, Hb level above 90 g/L appears safe. The appropriate threshold Hb level for unstable cardiac patients and for children younger than 28 days is unknown. The optimal transfusion strategy in cardiac patients is not well characterized. The threshold at which the risk of anemia outweighs the risk of transfusion is not known. More studies are needed to determine when RBC transfusion is indicated in hospitalized patients with cardiac disease.

Update: acute coronary syndromes (VI): treatment of acute coronary syndromes in the elderly and in patients with comorbidities

Acute coronary syndromes have a wide spectrum of clinical presentations and risk of adverse outcomes. A distinction should be made between treatable (extent of ischemia, severity of coronary disease and acute hemodynamic deterioration) and untreatable risk (advanced age, prior myocardial damage, chronic kidney dysfunction, other comorbidities). Most of the patients with "untreatable" risk have been excluded from the "guideline-generating" clinical trials. In recent years, despite the paucity of specific randomized trials, major advances have been completed in the management of elderly patients and patients with comorbidities: from therapeutic nihilism to careful titration of antithrombotic agents, a shift toward the radial approach to percutaneous coronary interventions, and also to less-invasive cardiac surgery. Further advances should be expected from the development of drug regimens suitable for use in the elderly and in patients with renal dysfunction, from a systematic multidisciplinary approach to the management of patents with diabetes mellitus and anemia, and from the courage to undertake randomized trials involving these high-risk populations.

Transradial versus transfemoral approach in patients undergoing percutaneous coronary intervention for acute coronary syndrome. A meta-analysis and trial sequential analysis of randomized controlled trials

Background

Transfemoral approach (TFA) remains the most common vascular access for percutaneous coronary intervention (PCI) in many countries. However, in the last years several randomized trials compared transradial approach (TRA) with TFA in patients with acute coronary syndrome (ACS), but only few studies were powered to estimate rare events. The aim of the current study was to clarify whether TRA is superior to TFA approach in patients with ACS undergoing percutaneous coronary intervention. A meta-analysis, meta-regression and trial sequential analysis of safety and efficacy of TRA in ACS setting was performed.

Methods and Results

Medline, the Cochrane Library, Scopus, scientific session abstracts and relevant websites were searched. Data concerning the study design, patient characteristics, risk of bias, and outcomes were extracted. The primary endpoint was death. Secondary endpoints were: major bleeding and vascular complications. Outcomes were assessed within 30 days. Eleven randomized trials involving 9,202 patients were included. Compared with TFA, TRA significantly reduced the risk of death (odds ratio [OR] 0.70; 95% confidence interval [CI], 0.53–0.94; p = 0.016), but this finding was not confirmed in trial sequential analysis, indicating that sufficient evidence had not been yet reached. Furthermore, TRA compared with TFA reduced the risk of major bleeding (OR 0.60; 95% CI, 0.41–0.88; p = 0.008) and vascular complications (OR 0.35; 95% CI, 0.28–0.46; p<0.001); these findings were supported by trial sequential analyses.

Conclusions

In patients with ACS undergoing PCI, a lower risk of death was observed with TRA. Nevertheless, the association between mortality and TRA in ACS setting should be interpreted with caution because it is based on insufficient evidence. However, because of the clinical relevance associated with major bleeding and vascular complications reduction, TRA should be recommended as first-choice vascular access in patients with ACS undergoing cardiac catheterization.

Red blood cell transfusion: what is the evidence when to transfuse?

PURPOSE OF REVIEW

This review provides a summary of the clinical trials evaluating transfusion thresholds and recommendations for red blood cell transfusion. We highlight the trial results in patients in the critical care setting, undergoing surgery, and patients with gastrointestinal bleed, acute coronary syndrome, and acute brain injury.

RECENT FINDINGS

Clinical trials in hip fracture patients with underlying cardiovascular disease or risk factors, and in cardiac surgery, support the findings from prior studies in intensive care unit patients that restrictive transfusion (7-8 g/dl) is well tolerated even in elderly high-risk patients. Restrictive transfusion strategy (7 g/dl) was further supported by the statistically lower mortality in patients with gastrointestinal bleeding compared with liberal transfusion (10 g/dl) strategy. Pilot trials in acute coronary syndrome raise the possibility that liberal transfusion improves outcome, but large trials are needed.

SUMMARY

A restrictive transfusion strategy of administering red blood cell transfusion in patients with hemoglobin concentration of 7-8 g/dl in most patients is supported by randomized clinical trials. Further randomized clinical trials are needed to establish the optimal transfusion threshold in patients with acute coronary syndrome and brain injury, and to elucidate physiological triggers.

Patterns and outcomes of red blood cell transfusion in patients undergoing percutaneous coronary intervention

IMPORTANCE

Studies have shown variation in the use of red blood cell transfusion among patients with acute coronary syndromes. There are no definitive data for the efficacy of transfusion in improving outcomes, and concerning data exist about possible association with harm. Current transfusion practices in patients undergoing percutaneous coronary intervention (PCI) are not well understood.

OBJECTIVE

To determine the current patterns of blood transfusion among patients undergoing PCI and the association of transfusion with adverse cardiac outcomes across hospitals in the United States.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study of all patient visits from the CathPCI Registry from July 2009 to March 2013 that included PCI, excluding those with missing data on bleeding complications or who underwent in-hospital coronary artery bypass graft surgery (N = 2,258,711 visits).

MAIN OUTCOMES AND MEASURES

Transfusion rates in the overall population and by hospital (N = 1431) were the primary outcomes. The association of transfusion with myocardial infarction, stroke, and death after accounting for a patient's propensity for transfusion was also measured.

RESULTS

The overall rate of transfusion was 2.14% (95% CI, 2.13%-2.16%) and quarterly transfusion rates slightly declined from July 2009 to March 2013 (from 2.11% [95% CI, 2.03%-2.19%] to 2.04% [95% CI, 1.97%-2.12%]; P < .001). Patients who were more likely to receive transfusion were older (mean, 70.5 vs 64.6 years), were women (56.3% vs 32.5%), and had hypertension (86.4% vs 82.0%), diabetes (44.8% vs 34.6%), advanced renal dysfunction (8.7% vs 2.3%), prior myocardial infarction (33.0% vs 30.2%), or prior heart failure (27.0% vs 11.8%). Overall, 96.3% of sites gave a transfusion to less than 5% of patients and 3.7% of sites gave a transfusion to 5% of patients or more. Variation in hospital risk-standardized rates of transfusion persisted after adjustment, and hospitals showed variability in their transfusion thresholds. Receipt of transfusion was associated with myocardial infarction (42,803 events; 4.5% vs 1.8%; odds ratio [OR], 2.60; 95% CI, 2.57-2.63), stroke (5011 events; 2.0% vs 0.2%; OR, 7.72; 95% CI, 7.47-7.98), and in-hospital death (31,885 events; 12.5% vs 1.2%; OR, 4.63; 95% CI, 4.57-4.69), irrespective of bleeding complications.

CONCLUSIONS AND RELEVANCE

Among patients undergoing PCI at US hospitals, there was considerable variation in blood transfusion practices, and receipt of transfusion was associated with increased risk of in-hospital adverse cardiac events. These observational findings may warrant a randomized trial of transfusion strategies for patients undergoing PCI.

Clinical pearls in perioperative medicine

At the 2001 annual meeting of the American College of Physicians (ACP), a new and innovative teaching format, the "Clinical Pearls" session, was introduced. Clinical Pearls sessions were designed to teach physicians using clinical cases. The session format involves specialty speakers presenting a number of short cases to a physician audience. Each case is followed by a multiple-choice question, answered by each attendee using an electronic audience-response system. After a summary of the answer distribution is shown, the correct answer is displayed and the speaker discusses important teaching points and clarifies why one answer is most clinically appropriate. Each case presentation ends with 1 or 2 "Clinical Pearls," defined as a practical teaching point, supported by the literature, and generally not well known to most internists. The Clinical Pearls sessions are consistently one the most popular and well attended sessions at the American College of Physicians' national meeting each year. Herein, we present the Clinical Pearls in Perioperative Medicine, presented at the ACP National Meeting in San Francisco, California, April 11-13, 2013.

Reduction in red blood cell transfusion associated with engagement of the ordering physician

BACKGROUND

Data on red blood cell (RBC) transfusion in the United States show variation in practice and overprescribing or overdosing is considered to be prevalent. Education or restrictive interventions could modify practice.

STUDY DESIGN AND METHODS

RBC transfusion and mortality rates were recorded in a single institution over a 15-year period. The first 3 years were used as a baseline. Education measures were used to influence practice for 3 years followed by a 9-year period when questionable RBC orders in nonbleeding inpatients resulted in prospective physician notification for potential modification. Physician notification was done by blood bank technologists with transfusion medicine physician support, if needed. Pretransfusion hemoglobin levels of more than 9 g/dL were recommended for cancellation and levels between 8 and 9 g/dL advised for a single unit, if 2 or more units were requested. RBC transfusion rates were described as inpatient units per 1000 discharges to allow for interyear comparison.

RESULTS

A downward trend in RBC transfusion was noted for the intervention period. Comparison of the baseline period with the past 3 years of the intervention period showed an approximate 33% decrease, which was highly significant (508 ± 66 vs. 341 ± 32, p < 0.01). Inpatient mortality rates declined over this period.

CONCLUSION

Physician education in appropriate transfusion practice is desirable but may not greatly impact RBC use. Engagement of physicians who prescribe RBCs that appear inappropriate for indication or dose was associated with a significant decline in RBC use without evidence of a change in mortality.

Evaluation and management of anemia in the elderly

Anemia is now recognized as a risk factor for a number of adverse outcomes in the elderly, including hospitalization, morbidity, and mortality. What constitutes appropriate evaluation and management for an elderly patient with anemia, and when to initiate a referral to a hematologist, are significant issues. Attempts to identify suggested hemoglobin levels for blood transfusion therapy have been confounded for elderly patients with their co-morbidities. Since no specific recommended hemoglobin threshold has stood the test of time, prudent transfusion practices to maintain hemoglobin thresholds of 9-10 g/dL in the elderly are indicated, unless or until evidence emerges to indicate otherwise.

Arginase regulates red blood cell nitric oxide synthase and export of cardioprotective nitric oxide bioactivity

The theory that red blood cells (RBCs) generate and release nitric oxide (NO)-like bioactivity has gained considerable interest. However, it remains unclear whether it can be produced by endothelial NO synthase (eNOS), which is present in RBCs, and whether NO can escape scavenging by hemoglobin. The aim of this study was to test the hypothesis that arginase reciprocally controls NO formation in RBCs by competition with eNOS for their common substrate arginine and that RBC-derived NO is functionally active following arginase blockade. We show that rodent and human RBCs contain functional arginase 1 and that pharmacological inhibition of arginase increases export of eNOS-derived nitrogen oxides from RBCs under basal conditions. The functional importance was tested in an ex vivo model of myocardial ischemia-reperfusion injury. Inhibitors of arginase significantly improved postischemic functional recovery in rat hearts if administered in whole blood or with RBCs in plasma. By contrast, arginase inhibition did not improve postischemic recovery when administered with buffer solution or plasma alone. The protective effect of arginase inhibition was lost in the presence of a NOS inhibitor. Moreover, hearts from eNOS(-/-) mice were protected when the arginase inhibitor was given with blood from wild-type donors. In contrast, when hearts from wild-type mice were given blood from eNOS(-/-) mice, the arginase inhibitor failed to protect against ischemia-reperfusion. These results strongly support the notion that RBCs contain functional eNOS and release NO-like bioactivity. This process is under tight control by arginase 1 and is of functional importance during ischemia-reperfusion.

Choosing wisely in adult hospital medicine: five opportunities for improved healthcare value

BACKGROUND

In an effort to lead physicians in addressing the problem of overuse of medical tests and treatments, the American Board of Internal Medicine Foundation developed the Choosing Wisely campaign. The Society of Hospital Medicine (SHM) joined the initiative to highlight the need to critically appraise resource utilization in hospitals.

METHODS

The SHM employed a staged methodology to develop the adult Choosing Wisely list. This included surveys of the organization's leaders and general membership, a review of the literature, and Delphi panel voting.

RESULTS

The 5 recommendations that were subsequently approved by the SHM Board are: (1) Do not place, or leave in place, urinary catheters for incontinence or convenience or monitoring of output for non-critically ill patients (acceptable indications: critical illness, obstruction, hospice, perioperatively for <2 days for urologic procedures; use weights instead to monitor diuresis). (2) Do not prescribe medications for stress ulcer prophylaxis to medical inpatients unless at high risk for gastrointestinal complications. (3) Avoid transfusions of red blood cells for arbitrary hemoglobin or hematocrit thresholds and in the absence of symptoms or active coronary disease, heart failure, or stroke. (4) Do not order continuous telemetry monitoring outside of the intensive care unit without using a protocol that governs continuation. (5) Do not perform repetitive complete blood count and chemistry testing in the face of clinical and lab stability.

CONCLUSIONS

Hospitalists have many opportunities to impact overutilization of care. The adult hospital medicine Choosing Wisely recommendations offer an explicit starting point for eliminating waste in the hospital.

Liberal versus restrictive transfusion thresholds for patients with symptomatic coronary artery disease

BACKGROUND

Prior trials suggest it is safe to defer transfusion at hemoglobin levels above 7 to 8 g/dL in most patients. Patients with acute coronary syndrome may benefit from higher hemoglobin levels.

METHODS

We performed a pilot trial in 110 patients with acute coronary syndrome or stable angina undergoing cardiac catheterization and a hemoglobin <10 g/dL. Patients in the liberal transfusion strategy received one or more units of blood to raise the hemoglobin level ≥10 g/dL. Patients in the restrictive transfusion strategy were permitted to receive blood for symptoms from anemia or for a hemoglobin <8 g/dL. The predefined primary outcome was the composite of death, myocardial infarction, or unscheduled revascularization 30 days post randomization.

RESULTS

Baseline characteristics were similar between groups except age (liberal, 67.3; restrictive, 74.3). The mean number of units transfused was 1.6 in the liberal group and 0.6 in the restrictive group. The primary outcome occurred in 6 patients (10.9%) in the liberal group and 14 (25.5%) in the restrictive group (risk difference = 15.0%; 95% confidence interval of difference 0.7% to 29.3%; P = .054 and adjusted for age P = .076). Death at 30 days was less frequent in liberal group (n = 1, 1.8%) compared to restrictive group (n = 7, 13.0%; P = .032).

CONCLUSIONS

The liberal transfusion strategy was associated with a trend for fewer major cardiac events and deaths than a more restrictive strategy. These results support the feasibility of and the need for a definitive trial.

Antiplatelet and anticoagulant strategies in acute coronary syndrome: where we are in 2013

Multiple antiplatelet and anticoagulant therapies are available for the treatment of acute coronary syndromes. The combination of agents should be tailored to the individual patient carefully considering the balance between ischemic and bleeding risk, as well as the planned revascularization strategy. Despite multiple large-scale, rigorously designed and conducted randomized controlled trials, it can be difficult to select the correct pharmacotherapy for each patient and many unanswered questions remain, such as the safety and optimal doses of differing combinations of antiplatelet/anticoagulant therapy, as well as the timing and duration of therapies. In addition, the headline results of many trials report improved efficacy outcomes at the cost of increased bleeding risk; however, very few show a clear mortality benefit. It is therefore difficult to weigh up the risk–benefit profile of emerging therapies.

Acute coronary syndromes: Blood transfusion in patients with acute MI and anaemia

In a meta-analysis of predominantly observational data, blood transfusion was independently associated with adverse outcomes in patients with myocardial infarction. These findings are consistent with previously published research, but clinical application of these data is hindered by the lack of prospective, randomized trials and the inherent bias in observational studies.