Secondary surgical-site infection after coronary artery bypass grafting: A multi-institutional prospective cohort study

The Relationship Between Transfusion in Cardiac Surgery Patients and Adverse Outcomes

OBJECTIVES

To understand if red blood cell (RBC) transfusions are independently associated with a risk of mortality, prolonged intubation, or infectious, cardiac, or renal morbid outcomes.

DESIGN

A retrospective review.

SETTING

A single-institution university hospital.

PARTICIPANTS

A total of 2,458 patients undergoing coronary bypass artery graft and/or valvular surgery from July 2014 through January 2018.

INTERVENTIONS

No interventions were done.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was the occurrence of an adverse event or prolonged intubation. Infectious, cardiac, and renal composite outcomes were also defined. These composites, along with mortality, were analyzed individually and then combined to form the "any adverse events" composite. Preoperative demographic and intraoperative parameters were analyzed as univariate risk factors for adverse outcomes. Logistic regression was used to screen variables, with a p value criterion of p < 0.05 for entry into the model selection procedure. A backward selection algorithm was used with variable entry and retention criteria of p < 0.05 to select the final multivariate model. Multivariate logistic regression models were used to determine whether there was an association between the volume of RBC transfusion and the defined adverse event after adjusting for covariates. A p value < 0.01 was considered statistically significant in the final model of each aim to adjust for multiple comparisons. The final logistic models for each of the following outcomes indicate an increased risk of that outcome per each additional unit of RBC transfused. For prolonged intubation, the odds ratio (OR) was 1.493 (p < 0.0001), OR = 1.358 (p < 0.0001) for infectious composite outcomes, OR = 1.247 (p < 0.0001) for adverse renal outcomes, and OR = 1.467 (p < 0.0001) for any adverse event.

CONCLUSIONS

The authors demonstrated a strong independent association between RBC transfusion volume and adverse outcomes after cardiac surgery. Efforts should be undertaken, such as preoperative anemia management and control of coagulopathy, in order to minimize the need for RBC transfusion.

Healthcare costs and outcomes associated with surgical site infections after coronary artery bypass grafting surgeries in Oman

BACKGROUND

Surgical site infection (SSI) after coronary artery bypass graft (CABG) surgeries is considered a key indicator of the quality of healthcare services.

OBJECTIVE

This study aimed to estimate the healthcare outcomes associated with SSIs after CABG surgeries in Oman in terms of mortality rate, case-fatality rate, LOS, readmission rate and healthcare costs.

METHODS

The nested case-control study design was used based on retrospective data, which was conducted from 2016 to 2017. The case group encompassed all CABG patients with confirmed SSIs within 30 days of the surgery (n = 104) while controls were CABG patients without SSIs (n = 404).

RESULTS

Forty-four (42.3%) of the SSI patients were readmitted to the hospital compared to eight (2%) of the control group (p < .001). Patients in the case group had a longer LOS (M = 24.4, SD = 44.6 days) compared to those in the control group (M = 11, SD = 21 days, p = .003). The mean healthcare costs of cases (M = Omani Rial [OMR] 3823, SD = OMR 2516) were significantly greater than controls (M = OMR 3154, SD = OMR 1415, p = .010).

CONCLUSION

Results from this study can be baseline data for formulating new hypotheses and testing the causal relationship between SSIs after CABG surgeries and the readmission rate, LOS and health care costs.Key messagesSurgical Site Infections (SSIs) are still a major complication after cardiac surgeries in Oman.SSIs after cardiac surgeries are associated with substantially increased healthcare costs and length of stay.SSIs after cardiac surgeries are associated with negative outcomes such as mortality and case-fatality rates.

Diagnosis of Early Bacterial Pneumonia and Sepsis After Cardiovascular Surgery: A Diagnostic Prediction Model Based on LASSO Logistic Regression

Background

Early postoperative bacterial pneumonia and sepsis (ePOPS), which occurs within the first 48 hours after cardiovascular surgery, is a serious life-threatening complication. Diagnosis of ePOPS is extremely challenging, and the existing diagnostic tools are insufficient. The purpose of this study was to construct a novel diagnostic prediction model for ePOPS.

Methods

Least Absolute Shrinkage and Selection Operator (LASSO) with logistic regression was used to construct a model to diagnose ePOPS based on patients' comorbidities, medical history, and laboratory findings. The area under the receiver operating characteristic curve (AUC) was used to evaluate the model discrimination.

Results

A total of 1203 patients were recruited and randomly split into a training and validation set in a 7:3 ratio. By early morning on the 3rd postoperative day (POD3), 103 patients had experienced 133 episodes of bacterial pneumonia or sepsis (15 patients had both). LASSO logistic regression model showed that duration of mechanical ventilation (P=0.015), NYHA class ≥ III (P=0.001), diabetes (P<0.001), exudation on chest radiograph (P=0.011) and IL-6 on POD3 (P<0.001) were independent risk factors. Based on these factors, we created a nomogram named DICS-I with an AUC of 0.787 in the training set and 0.739 in the validation set.

Conclusion

The DICS-I model may be used to predict the risk of ePOPS after cardiovascular surgery, and is also especially suitable for predicting the risk of IRAO. The DICS-I model could help clinicians to adjust antibiotics on the POD3.

Incidence and risk factors of surgical site infections after coronary artery bypass grafting surgery in Oman

Background

There is limited information about the incidence and risk factors of surgical site infections (SSIs) after coronary artery bypass (CABG) surgeries in the Omani population.

Aim

To estimate the prevalence and describe possible risk factors of SSIs after CABG surgeries in Oman.

Method

A retrospective nested case-control design was used to screen 596 patients who underwent CABG surgeries over 2 years (2016-2017) in two tertiary hospitals in Oman. The CDC definition for SSIs was used to identify the infected cases.

Results

Prevalence rate of SSIs was 17.4% and 17.5% in 2016 and 2017, respectively. The most isolated microorganism was Gram-positive bacteria (45.2%). Risk factors of SSIs include female gender (OR = 3.2, p < 0.001), diabetes (OR = 5.83, p < 0.001), overweight or obese (OR = 2.14, p < 0.05) and shaving technique [using razor shaving] (OR = 8.4, p < 0.001). Readmission rate for the case group was 44.2%.

Conclusion

The infection rate of SSIs after CABG surgeries in developing countries, such as Oman, is considerably high. There is an urgent need to establish SSIs preventive program at the national level. Frequent and systematic assessment of infection control practices before and after CABG surgeries is fundamental and priority strategy to prevent SSIs.

Polymeric nanoparticles in the diagnosis and treatment of myocardial infarction: Challenges and future prospects

Myocardial infarction (MI) is the leading cause of morbidity and mortality worldwide. Despite extensive efforts to provide early diagnosis and adequate treatment regimens, detection of MI still faces major limitations and pathological MI complications continue to threaten the recovery of survivors. Polymeric nanoparticles (NPs) represent novel noninvasive drug delivery systems for the diagnosis and treatment of MI and subsequent prevention of fatal heart failure. In this review, we cover the recent advances in polymeric NP-based diagnostic and therapeutic approaches for MI and their application as multifunctional theranostic tools. We also discuss the in vivo behavior and toxicity profile of polymeric NPs, their application in noninvasive imaging, passive, and active drug delivery, and use in cardiac regenerative therapy. We conclude with the challenges faced with polymeric nanosystems and suggest future efforts needed for clinical translation.

Iron supplementation for patients undergoing cardiac surgery: a systematic review and meta-analysis of randomized controlled trials

PURPOSE

Iron supplementation has been evaluated in several randomized controlled trials (RCTs) for its potential to increase baseline hemoglobin and decrease red blood cell transfusion during cardiac surgery. This study's main objective was to evaluate the current evidence for iron administration in cardiac surgery patients.

METHODS

We searched MEDLINE, EMBASE, CENTRAL, Web of Science databases, and Google Scholar from inception to 19 November 2020 for RCTs evaluating perioperative iron administration in adult patients undergoing cardiac surgery. The RCTs were assessed using a risk of bias assessment and the quality of evidence was assessed using the grading of recommendations, assessments, development, and evaluations.

RESULTS

We reviewed 1,767 citations, and five studies (n = 554) met the inclusion criteria. The use of iron showed no statistical difference in incidence of transfusion (risk ratio, 0.86; 95% confidence interval, 0.65 to 1.13). Trial sequential analysis suggested an optimal information size of 1,132 participants, which the accrued information size did not reach.

CONCLUSION

The current literature does not support or refute the routine use of iron therapy in cardiac surgery patients.

TRIAL REGISTRATION

PROSPERO (CRD42020161927); registered 19 December 2019.

The relationship between diabetes and surgical site infection following coronary artery bypass graft surgery in current-era models of care

BACKGROUND

Although diabetes is a recognized risk factor for postoperative infections, the seminal Portland Diabetic Project studies in cardiac surgery demonstrated intravenous insulin infusions following open-cardiac surgery achieved near normal glycaemia and decreased deep sternal wound infection to similar rates to those without diabetes.

AIM

We sought to examine a contemporary cohort of patients undergoing coronary artery bypass graft surgery (CABGS) to evaluate the relationship between diabetes, hyperglycaemia and risk of surgical site infection (SSI) in current-era models of care.

METHODS

Consecutive patients who underwent CABGS between 2016 and 2018 were identified through a state-wide data repository for healthcare-associated infections. Clinical characteristics and records of postoperative SSIs were obtained from individual chart review. Type 2 diabetes (T2D), perioperative glycaemia and other clinical characteristics were analysed in relation to the development of SSI.

FINDINGS

Of the 953 patients evaluated, 11% developed SSIs a median eight days post CABGS, with few cases of deep SSIs (<1%). T2D was evident in 41% and more prevalent in those who developed SSIs (51%). On multivariate analysis T2D was not significantly associated with development of SSI (odds ratio (OR) 1.35; P=0.174) but body mass index (BMI) remained a significant risk factor (OR 1.07, P<0.001). In patients with T2D, perioperative glycaemia was not significantly associated with SSI.

CONCLUSION

In a specialist cardiac surgery centre using perioperative intravenous insulin infusions and antibiotic prophylaxis, deep SSIs were uncommon; however, approximately one in 10 patients developed superficial SSIs. T2D was not independently associated with SSI yet BMI was independently associated with SSI post CABGS.

Iron supplementation for patients undergoing cardiac surgery: a protocol for a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Iron administration has been evaluated in several randomized controlled trials for the potential of increasing baseline hemoglobin values and decreasing the incidence of red blood cell transfusion during cardiac surgery. We describe the protocol for a study aiming to evaluate the efficacy and safety of perioperative iron administration in patients undergoing cardiac surgery.

METHODS

We will search MEDLINE, Embase, the Cochrane Central Register of Controlled Trials and the Web of Science, from inception to Nov. 19, 2020, for randomized controlled trials in any language evaluating the perioperative administration of iron in adult patients undergoing cardiac surgery; we will also include the first 50 results from Google Scholar. The primary outcome will be the incidence of red blood cell transfusion from the study intervention time until 8 weeks postoperatively. The secondary outcomes will be the number of red blood cell units transfused; change in ferritin level, reticulocyte count and hemoglobin concentration after iron administration; and adverse events. We will assess the risk of bias with the Cochrane Collaboration Risk of Bias Tool, and will analyze the primary and secondary outcomes using a random-effects model.

INTERPRETATION

This study will summarize the current evidence about perioperative iron administration in patients undergoing cardiac surgery, help determine whether this intervention should be included in enhanced-recovery protocols, and shape future research if needed. The final manuscript will be submitted to a peer-reviewed journal.

TRIAL REGISTRATION

PROSPERO no. CRD42020161927.

Predictors and Outcomes of Coronary Artery Bypass Grafting: A Systematic and Untargeted Analysis of More Than 120,000 Individuals and 1,300 Disease Traits

OBJECTIVE

To perform an untargeted data-driven analysis on the correlates and outcomes of coronary artery bypass grafting (CABG).

DESIGN

FinnGen cohort study.

SETTING

The authors collected information on up to 1,327 disease traits before and after CABG from nationwide healthcare registers.

PARTICIPANTS

A mixed population and patient sample of 127,911 individuals including 3,784 CABG patients.

INTERVENTIONS

The authors assessed the association between (1) traits and incident CABG and (2) CABG and incident traits using multivariate-adjusted Cox models.

MAIN RESULTS

Patients who underwent CABG and were in the fourth quartile of a risk score based on the top predictors of mortality had 12.2-fold increased risk of dying (95% confidence interval [CI], 10.3-14.5) compared with those in the first quartile. Cardiovascular disease (CVD) and CVD risk factors were most strongly associated with incident CABG. However, CABG was associated with death due to cardiac causes (hazard ratio [HR], 3.7; 95% CI, 3.5-4.0) or other causes (HR, 2.5; 95% CI, 2.4-2.7). CABG also was related to increased risk of several non-CVD traits, including anemia (HR, 3.4; 95% CI, 2.8-4.1), gastrointestinal disorders (HR, 2.2; 95% CI, 1.8-2.6), acute renal failure (HR, 4.2; 95% CI, 3.5-5.1), septicemia (HR, 3.6; 95% CI, 3.1-4.1), lung cancer (HR, 2.3; 95% CI, 1.9-2.8), Alzheimer's disease (HR, 2.5; 95% CI, 2.2-2.7), and chronic obstuctive pulmonary disease (HR, 2.5; 95% CI, 2.2-2.9).

CONCLUSIONS

Known CVD risk factors associate most strongly with incident CABG. However, CABG is associated with increased risk of several, somewhat unexpected, non-CVD traits. More detailed study of these links is warranted to establish potential causality and pathogenesis.

Does the anthropometric profile influence infection morbidity after coronary artery bypass grafting?

BACKGROUND

Infection after cardiovascular surgery is multifactorial. We sought to determine whether the anthropometric profile influences the occurrence of infection after isolated coronary artery bypass grafting (CABG).

METHODS

Between January 2011 and June 2016, 1777 consecutive adult patients were submitted to isolated coronary artery bypass grafting. Mean age was 61.7 ± 9.8 years and 1193 (67.1%) were males. Patients were divided into four groups according to the body mass index (BMI) classification: underweight (BMI < 18.5 kg/m² ; N = 17, 0.9%), normal range (BMI: 18.5-24.99 kg/m² ; N = 522, 29.4%), overweight (BMI: 25-29.99 kg/m² ; N = 796, 44.8%), and obese (BMI > 30 kg/m² ; N = 430, 24.2%). In-hospital outcomes were compared and independent predictors of infection were obtained through multiple Poisson regression with a robust variation.

RESULTS

Independent predictors of any infection morbidity were female sex (relative ratio [RR], 1.47; p = .002), age > 60 years (RR, 1.85; p < .0001), cardiopulmonary bypass > 120 min (RR, 1.89; p = .0007), preoperative myocardial infarction < 30 days (RR, 1.37; p = .01), diabetes mellitus (RR, 1.59; p = .0003), ejection fraction < 48% (RR, 2.12; p < .0001), and blood transfusion (RR, 1.55; p = .0008). Among other variables, obesity, as well as diabetes mellitus, were independent predictors of superficial and deep sternal wound infection.

CONCLUSIONS

Other factors rather than the anthropometric profile are more important in determining the occurrence of any infection after CABG. However, surgical site infection has occurred more frequently in obese patients. Appropriate patient selection, control of modifiable factors, and application of surgical bundles would minimize this important complication.

Surgical Site Infections in Cardiac Surgery

Surgical site infection (SSI) can be a significant complication of cardiac surgery, delaying recovery and acting as a barrier to enhanced recovery after cardiac surgery. Several risk factors predisposing patients to SSI including smoking, excessive alcohol intake, hyperglycemia, hypoalbuminemia, hypo- or hyperthermia, and Staphylococcus aureus colonization are discussed. Various measures can be taken to abolish these factors and minimize the risk of SSI. Glycemic control should be optimized preoperatively, and hyperglycemia should be avoided perioperatively with the use of intravenous insulin infusions. All patients should receive topical intranasal Staphylococcus aureus decolonization and intravenous cephalosporin if not penicillin allergic.

Sternal-Wound Infections following Coronary Artery Bypass Graft: Could Implementing Value-Based Purchasing be Beneficial?

BACKGROUND/OBJECTIVES

Sternal-wound infections (SWIs) are rare but consequential healthcare-healthcare-associated infections following coronary artery bypass graft surgery (CABG). The impact of SWIs associated on the cost of health care provision is unknown. The aim of this study was to quantify the burden of CABG-related SWIs across countries with mature health care systems and estimate value-based purchasing (VBP) levels based on the local burden.

METHODS

A structured literature review identified relevant data for 14 countries (the Netherlands, France, Germany, Austria, the United Kingdom, Canada, Italy, Japan, Spain, the United States, Brazil, Israel, Taiwan, and Thailand). Data, including SWI rates, CABG volume, and length of stay, were used to populate a previously published Markov model that simulates the patient's CABG-care pathway and estimates the economic (US$) and care burden of SWIs for each country. Based on this burden, scenarios for VBP were explored for each country. A feasible cost of intervention per patient for an intervention providing a 20% reduction in the SWI rate was calculated.

RESULTS

The SWI burden varied considerably between settings, with SWIs occurring in 2.8% (the United Kingdom) to 10.4% (the Netherlands) of CABG procedures, while the costs per SWI varied between US$8172 (Brazil) to US$54 180 (Japan). Additional length of stay after SWI was the largest cost driver. The overall highest annual burden was identified in the United States (US$336 million) at a mean cost of US$36 769 per SWI. Given the SWI burden, the median cost of intervention per patient that a hospital could afford ranged from US$20 (US$13 to US$42) in France to US$111 (US$65 to US$183) in Japan.

CONCLUSIONS

SWIs represent a large burden with a median cost of US$13 995 per case and US$900 per CABG procedure. By tackling SWIs, there is potential to simultaneously reduce the burden on health care systems and improve outcomes for patients. Mutually beneficial VBP agreements might be one method to promote uptake of novel methods of SWI prevention.

An Extended Duration of the Pre-Operative Hospitalization is Associated with an Increased Risk of Healthcare-Associated Infections after Cardiac Surgery

Nosocomial infections are a common complication in clinical practice with major impact on surgical success and patient outcome. The probability of nosocomial infections is rapidly increasing during hospitalization. Therefore, we investigated the impact of a prolonged pre-operative hospital stay on the development of post-operative infection. Within this prospective observational study, 200 patients scheduled for elective cardiac surgery were enrolled. Patients were followed during hospital admission and screened for the development of nosocomial infection. Logistic regression analysis was used to assess the impact of a prolonged pre-operative hospital stay on the development of infection. A total of 195 patients were suitable for the final analysis. We found a strong and direct association of the duration of pre-operative hospital stay and the number of patients developing infection (+23.5%; p = 0.006). Additionally, the length of patients’ pre-operative hospital stay was independently associated with the development of post-operative nosocomial infection, with an adjusted OR per day of 1.38 (95%CI: 1.02–1.86; p = 0.036). A prolonged pre-operative hospital stay was significantly associated with the development of nosocomial infection after cardiac surgery. Those findings need to be considered in future clinical patient management in order to prevent unnecessary antibiotic use and potential harm to patients.

The Effectiveness of Sterile Wound Drapes in the Prevention of Surgical Site Infection in Thoracic Surgery

Background

The rate of surgical site infections (SSIs) has decreased in parallel to advances in sterilization techniques. Such infections increase morbidity and hospitalization costs. The use of iodine-impregnated sterile wound drapes (SWDs) is recommended to prevent or reduce the incidence of these infections. However, there is a paucity of data regarding their use in thoracic surgical procedures. The aim of the present study was to evaluate the effectiveness of sterile wound drapes in the prevention of these infections and the effects on hospitalization costs.

Methods

Perioperative iodine-impregnated SWDs have been used since January 2015 in the Thoracic Surgery Clinic of our hospital. A retrospective evaluation was made of patients who underwent anatomic pulmonary resection via thoracotomy with SWD in the period January 2015–2017, compared with a control group who underwent the same surgery without SWD in the 2-year period before January 2015. Factors that may have increased the risk of surgical site infection were documented and the occurrence of SSI was recorded from postoperative follow-up data. The cost analysis was performed as an important criterion to investigate the benefits of SWD.

Results

Evaluation was made of 654 patients in the study group (n:380) using SWD, the operation time was significantly longer, and perioperative blood transfusion was significantly higher, whereas treatment costs (p=0.0001) and wound culture positivity (p=0.004) were significantly lower and less surgical wound debridement was performed (p=0.002).

Conclusion

The findings suggest that the use of sterile wound draping in thoracic surgery procedures reduces surgical site infections and hospitalization costs.

Randomized Trial of Endoscopic or Open Vein-Graft Harvesting for Coronary-Artery Bypass

BACKGROUND

The saphenous-vein graft is the most common conduit for coronary-artery bypass grafting (CABG). The influence of the vein-graft harvesting technique on long-term clinical outcomes has not been well characterized.

METHODS

We randomly assigned patients undergoing CABG at 16 Veterans Affairs cardiac surgery centers to either open or endoscopic vein-graft harvesting. The primary outcome was a composite of major adverse cardiac events, including death from any cause, nonfatal myocardial infarction, and repeat revascularization. Leg-wound complications were also evaluated.

RESULTS

A total of 1150 patients underwent randomization. Over a median follow-up of 2.78 years, the primary outcome occurred in 89 patients (15.5%) in the open-harvest group and 80 patients (13.9%) in the endoscopic-harvest group (hazard ratio, 1.12; 95% confidence interval [CI], 0.83 to 1.51; P=0.47). A total of 46 patients (8.0%) in the open-harvest group and 37 patients (6.4%) in the endoscopic-harvest group died (hazard ratio, 1.25; 95% CI, 0.81 to 1.92); myocardial infarctions occurred in 34 patients (5.9%) in the open-harvest group and 27 patients (4.7%) in the endoscopic-harvest group (hazard ratio, 1.27; 95% CI, 0.77 to 2.11), and revascularization occurred in 35 patients (6.1%) in the open-harvest group and 31 patients (5.4%) in the endoscopic-harvest group (hazard ratio, 1.14; 95% CI, 0.70 to 1.85). Leg-wound infections occurred in 18 patients (3.1%) in the open-harvest group and in 8 patients (1.4%) in the endoscopic-harvest group (relative risk, 2.26; 95% CI, 0.99 to 5.15).

CONCLUSIONS

Among patients undergoing CABG, we did not find a significant difference between open vein-graft harvesting and endoscopic vein-graft harvesting in the risk of major adverse cardiac events. (Funded by the Cooperative Studies Program, Office of Research and Development, Department of Veterans Affairs; REGROUP ClinicalTrials.gov number, NCT01850082 .).