Preoperative Glycosylated Hemoglobin: A Risk Factor for Patients Undergoing Coronary Artery Bypass

The Creation of Data-Driven Preoperative Hemoglobin A1c and Same-Day Glucose Strata to Stratify Complication Risk Following Total Hip Arthroplasty

BACKGROUND

This study identifies data-driven strata for preoperative Hemoglobin A1c (HbA1c) and same-day glucose levels that maximize differences in the likelihood of complications following total hip arthroplasty (THA).

METHODS

Patients who underwent THA from 2013 to 2022 were identified using a national database. In total, 18,728 patients were identified with a mean age of 67 years (range, 18 to 80). Stratum specific likelihood ratio (SSLR) analysis determined separate strata for HbA1c and same-day glucose levels that minimized the likelihood of 90-day complications following THA. Each stratum was propensity-score matched based on age, sex, hypertension, heart failure, chronic obstructive pulmonary disease, and obesity to the lowest respective stratum. The risk ratio (RR) with respect to the lowest matched stratum was observed.

RESULTS

Our SSLR analysis identified 3 data-driven HbA1c strata (4.5 to 5.9, 6.0 to 6.9, and 7.0+) and two same-day glucose strata (60 to 189 and 190+) that predicted 90-day major complications. For HbA1c, when compared to the lowest strata (4.5 to 5.9), the risk of 90-day major complications sequentially increased as the HbA1c strata increased: 6.0 to 6.9 (RR: 1.21; P = .041), 7+ (RR: 1.82; P < .001). For same-day glucose, when compared to the matched lowest strata (60 to 189), the risk of 90-day major complications was higher for the 190+ strata (RR: 1.5; P < .001).

CONCLUSIONS

Our results support the use of multiple HbA1c strata that can be incorporated into preoperative risk-stratification models. Additionally, we identified a single cut-off level of 190 as a maximum target blood glucose level perioperatively.

Enhanced recovery after cardiac surgery: A literature review

Enhanced recovery after cardiac surgery (ERACS) represents a constellation of evidence-based peri-operative methods aimed to reduce the physiological and psychological stress patients experience after cardiac surgery, with the primary objective of providing an expedited recovery to pre-operative functional status. The method involves pre-operative, intra-operative, and post-operative interventions as well as direct patient engagement to be successful. Numerous publications in regard to the benefits of enhanced recovery have been presented, including decreased post-operative complications, shortened length of stay, decreased overall healthcare costs, and higher patient satisfaction. Implementing an ERACS program undeniably requires a culture change, a methodical shift in the approach of these patients that ultimately allows the team to achieve the aforementioned goals; therefore, team-building, planning, and anticipation of obstacles should be expected.

Preoperative Glycosylated Haemoglobin Screening to Identify Older Adult Patients with Undiagnosed Diabetes Mellitus-A Retrospective Cohort Study

More than 25% of older adults in Europe have diabetes mellitus. It is estimated that 45% of patients with diabetes are currently undiagnosed, which is a known risk factor for perioperative morbidity. We investigated whether routine HbA1c screening in older adult patients undergoing surgery would identify patients with undiagnosed diabetes. We included patients aged ≥65 years without a diagnosis of diabetes who visited the preoperative assessment clinic at the Amsterdam University Medical Center and underwent HbA1c screening within three months before surgery. Patients undergoing cardiac surgery were excluded. We assessed the prevalence of undiagnosed diabetes (defined as HbA1c ≥ 48 mmol·mol-1) and prediabetes (HbA1c 39-47 mmol·mol-1). Using a multivariate regression model, we analysed the ability of HbA1c to predict days alive and at home within 30 days after surgery. From January to December 2019, we screened 2015 patients ≥65 years at our clinic. Of these, 697 patients without a diagnosis of diabetes underwent HbA1c screening. The prevalence of undiagnosed diabetes and prediabetes was 3.7% (95%CI 2.5-5.4%) and 42.9% (95%CI 39.2-46.7%), respectively. Preoperative HbA1c was not associated with days alive and at home within 30 days after surgery. In conclusion, we identified a small number of patients with undiagnosed diabetes and a high prevalence of prediabetes based on preoperative HbA1c screening in a cohort of older adults undergoing non-cardiac surgery. The relevance of prediabetes in the perioperative setting is unclear. Screening for HbA1c in older adult patients undergoing non-cardiac surgery does not appear to help predict postoperative outcome.

Association between HbA1c and deep sternal wound infection after coronary artery bypass: a systematic review and meta-analysis

BACKGROUND

Deep sternal wound infection (DSWI) constitutes a serious complication after coronary artery bypass grafting (CABG) surgery. The aim of this study is to evaluate the dose-response relationship between glycated hemoglobin (HbA1c) level and the risk of DSWI after CABG.

METHODS

PubMed, Scopus, and Cochrane Library databases were searched to identify potentially relevant articles. According to rigorous inclusion and exclusion criteria, fourteen studies including 15,570 patients were enrolled in our meta-analysis. Odds ratio (OR) with 95% confidence intervals (CIs) was used as the summary statistic. The robust-error meta-regression model was used to synthesize the dose-response relationship.

RESULTS

Our meta-analysis shows that among patients undergoing CABG, preoperative elevated HbA1c was associated with the risk of developing DSWI (OR = 2.67, 95% CI 2.00-3.58) but with low prognostic accuracy (diagnostic OR = 2.70, 95% CI 1.96-3.73; area under the curve = 0.66, 95% CI 0.62-0.70) for predicting postoperative DSWI. Subgroup analyses showed the relationship became nonsignificant in patients without diabetes and studies adopting lower HbA1c thresholds. Dose-response analysis showed a significant nonlinear (p = 0.03) relationship between HbA1c and DSWI, with a significantly increased risk of DSWI when HbA1c was > 5.7%.

CONCLUSIONS

An elevated HbA1c level of > 5.7% was related to a higher risk of developing DSWI after CABG, and the risk increased as the HbA1c level grew. The association between HbA1c and DSWI was nonsignificant among nondiabetic patients while significant among diabetic patients.

Lack of Association of A1C With Postoperative Complications in Children With Type 1 or Type 2 Diabetes

Not meeting recommended A1C targets may be associated with postoperative complications in adults, but there are no studies reporting on the relationship between preoperative A1C and postoperative complications in children with type 1 or type 2 diabetes. The objective of this study was to determine whether elevated A1C levels were associated with an increased incidence of postoperative complications in children with diabetes presenting for elective noncardiac surgery or diagnostic procedures. It found no such association, suggesting no need to delay elective surgery in children with diabetes until A1C is optimized.

[Enhanced recovery after surgery (ERAS®) in cardiac anesthesia]

Enhanced Recovery After Cardiac Surgery (ERACS) is a multidisciplinary and multiprofessional treatment approach in cardiac surgery. Recently, a transfer and adaptation of enhanced recovery after surgery (ERAS) protocols from other disciplines, such as colorectal surgery, to cardiac surgery has been performed in different settings. First, prehabilitation programs have been established and investigated to improve patients' physical, psychological and nutritional status including treatment of preoperative anemia. Second, intraoperative therapeutic steps are described, such as infection reduction bundles, rigid sternal closure and guidance of perioperative anesthesia. For this, the use of short-acting agents, goal-directed fluid management and multimodal anesthesia are among the important measures. Third, early recovery and restoration of patient autonomy are achieved with early extubation and mobilization, efficient postoperative analgesia and diagnosis and treatment of delirium.The introduction of an ERACS protocol is a team effort requiring a protocol adapted to the institutional conditions and a willingness to perform a shift of culture in perioperative care. So far, the successful establishment of ERACS protocols in minimally invasive cardiac surgery has been reported and encourages the development of protocols of specific patient groups, such as pediatric cardiac surgery or left ventricular assist device implantation.

Enhanced recovery after surgery multimodality pain regimen performs similar to PRN narcotics on outcomes and pain control after cardiac surgery: A quality improvement project

BACKGROUND

While enhanced recovery after surgery (ERAS) pathways have been successfully applied for cardiac surgery, there has been limited research directly comparing ERAS protocols to ad hoc narcotic use after surgery. We hypothesized that a standardized ERAS protocol would provide similar pain management and psychoemotional outcomes while decreasing the use of opioids in the hospital and after discharge.

METHODS

As part of a 7-month quality improvement project, cardiac surgery patients on a fast-tracked to extubate pathway were assigned pro re nata (PRN) narcotic pain management for 3 months (n = 49). After a 1-month ERAS protocol optimization period, a separate group of patients were given the ERAS protocol (n = 34). Clinical outcomes were gathered, and participants completed a quality of recovery survey that allowed for the assessment of pain and symptom control at four-time points after surgery.

RESULTS

Among 83 participants, 66% were male and the mean age was 53 years. There were no differences in patient characteristics between PRN and ERAS groups (all p > .244). There were no differences between ERAS and PRN groups for surgery characteristics (all p > .060), inpatient outcomes (all p > .658), or after-discharge outcomes (all p > .397). Furthermore, across all time-point comparisons, there were no supported differences in patient-reported outcome and pain control between the ERAS and PRN narcotic groups (all p > .075).

CONCLUSIONS

An ERAS protocol demonstrated similar patient outcomes and pain control to traditional opioid use for postoperative cardiac surgery patients. Further research is recommended to further confirm the results of this study.

Hemoglobin A1c and preoperative glycemia as a decision tool to help minimise sternal wound complications: a retrospective study in OPCAB patients

Background

Poor glycemic control has been associated with an increased risk of wound complications after various types of operations. However, it remains unclear how hemoglobin A1c (HbA1c) and preoperative glycemia can be used in clinical decision-making to prevent sternal wound complications (SWC) following off-pump coronary artery bypass grafting (OPCAB).

Methods

We conducted a retrospective study of 1774 consecutive patients who underwent OPCAB surgery between January 2010 and November 2016. A new four-grade classification for SWC was used. The associations of HbA1c and preoperative glycemia with incidence and grade of SWC were analysed using logistic regression analysis and proportional odds models, respectively.

Results

During a median follow-up of 326 days (interquartile range (IQR) 21–1261 days), SWC occurred in 133/1316 (10%) of non-diabetes and 82/458 (18%) of diabetes patients (p < 0.001). Higher HbA1c was significantly associated with a higher incidence of SWC (odds ratio, OR 1.24 per 1% increase, 95% confidence interval, CI 1.04;1.48, p = 0.016) as well as a higher grade of SWC (OR 1.25, 95% CI 1.06;1.48, p = 0.010). There was no association between glycemia and incidence (p = 0.539) nor grade (p = 0.607) of SWC. Significant modifiers of these effects were found: HbA1c was associated with SWC in diabetes patients younger than 70 years (OR 1.41, 95% CI 1.17;1.71, p < 0.001), whereas it was not in those older than 70 years. Glycemia was associated with SWC in patients who underwent non-urgent surgery (OR 2.48, 95% CI 1.26;4.88, p = 0.009), in diabetes patients who received skeletonised grafts (OR 4.83, 95% CI 1.28;18.17, p = 0.020), and in diabetes patients with a BMI < 30 (OR 2.19, 95% CI 1.01;4.76, p = 0.047), whereas it was not in the counterparts of these groups.

Conclusions

Under certain conditions, HbA1c and glycemia are associated SWC following OPCAB. These findings are helpful in planning the procedure with minimal risk of SWC.

Impact of preoperative glycometabolic status on outcomes in cardiac surgery: Systematic review and meta-analysis

BACKGROUND

Historically, impaired glucose metabolism has been associated with early and late complicated clinical outcomes after cardiac surgery; however, such a condition is not specific to subjects with diabetes mellitus and involves a larger patient population.

METHODS

Databases were screened (January 2000 to December 2020) to identify eligible articles; studies that evaluated the association between preoperative metabolic status, as assessed by glycosylated hemoglobin levels and clinical outcomes, were considered. The studies were stratified in thresholds by baseline glycosylated hemoglobin level (lower vs higher).

RESULTS

Thirty studies, involving 34,650 patients, were included in the review. In a meta-analysis stratified by glycosylated hemoglobin levels, early mortality was numerically reduced in each threshold comparison and yielded the highest reductions when less than 5.5% versus greater than 5.5% glycosylated hemoglobin levels were compared (risk ratio, 0.39; 95% confidence interval, 0.18-0.84; P = .02). Comparing higher glycosylated hemoglobin threshold values yielded comparable results. Late mortality was reduced with lower levels of glycosylated hemoglobin. Low preoperative glycosylated hemoglobin was associated with the lowest risk of sternal wound infections (risk ratio, 0.50; 95% confidence interval, 0.32-0.80; P = .003 and risk ratio, 0.53; 95% confidence interval, 0.39-0.70; P < .0001) for comparisons of less than 7.5% versus greater than 7.5% and less than 7.0% versus greater than 7.0% glycosylated hemoglobin thresholds, respectively. Additionally, levels of glycosylated hemoglobin lower than 7% were associated with reduced hospital stay, lower risk of stroke/transient ischemic attack (risk ratio 0.53; 95% confidence interval, 0.39-0.70; P < .0001), and acute kidney injury (risk ratio, 0.65; 95% confidence interval, 0.54-0.79; P < .0001).

CONCLUSIONS

Lower levels of glycosylated hemoglobin in patients undergoing cardiac surgery are associated with a lower risk of early and late mortality, as well as in the incidence of postoperative acute kidney injury, neurologic complications, and wound infection, compared with higher levels.

Diabetes management during cardiac surgery in the UK: A survey

AIM

To determine current practice regarding the diabetes management of people undergoing cardiac surgery in the UK.

METHODS

We conducted an online survey of UK cardiothoracic surgeons. All cardiothoracic surgeons listed in the Society of Cardiothoracic Surgery membership directory were invited to participate. The survey, compiled using SurveyMonkey software, comprised 15 closed and open-ended questions about the management of people with diabetes pre- and peri-operatively.

RESULTS

Sixty-two cardiothoracic surgeons from all 33 UK cardiac centres completed the survey. Of these, 44% responded that they routinely measure HbA_1c preoperatively for all patients, 19% had an HbA_1c threshold above which they would not operate and 21% currently undertake a point-of-care HbA_1c measurement during the cardiothoracic outpatient visit. A total of 74% of respondents reported that it was 'easy' or 'very easy' to obtain a diabetes team review; diabetes nurse specialists were the members of the diabetes team working most closely with cardiac surgeons. Up to a third of the surgeons did not provide physical activity recommendations prior to admission and over 80% did not have a different preoperative or surgical diabetes protocol. Inconsistency in the responses within centres suggests that differences in practice may depend on individual surgeons rather than local policy.

CONCLUSIONS

The study demonstrates there is only limited peri-operative management of diabetes in people undergoing cardiac surgery in the UK. There is an opportunity for greater involvement of the diabetes specialist team both before and during admission for surgery to improve outcomes. (Trial registration: ISRCTN10170306).

Guidelines for enhanced recovery after cardiac surgery. Consensus document of Spanish Societies of Anesthesia (SEDAR), Cardiovascular Surgery (SECCE) and Perfusionists (AEP)

The ERAS guidelines are intended to identify, disseminate and promote the implementation of the best, scientific evidence-based actions to decrease variability in clinical practice. The implementation of these practices in the global clinical process will promote better outcomes and the shortening of hospital and critical care unit stays, thereby resulting in a reduction in costs and in greater efficiency. After completing a systematic review at each of the points of the perioperative process in cardiac surgery, recommendations have been developed based on the best scientific evidence currently available with the consensus of the scientific societies involved.

Obesity and Preoperative Anaemia as Independent Risk Factors for Sternal Wound Infection After Coronary Artery Bypass Graft Surgery with Pedicled (Non-Skeletonized) Internal Mammary Arteries: The Role of Thoracic Wall Ischemia?

Purpose

Obesity remains statistically associated with coronary artery disease, for which coronary artery bypass graft surgery (CABG) remains the standard of care. However, obesity is also associated with sternal wound infection (SWI) which is a severe complication of CABG despite advances in surgery and in infection prevention and control. Strategies to reduce the incidence of SWI are still being investigated, and we therefore conducted a retrospective study to revisit factors other than obesity associated with SWI after CABG.

Patients and Methods

Data were extracted from the medical records of 182 patients who underwent elective on-pump CABG using one or both pedicled internal mammary artery grafts in Reims University Hospital between May 2015 and May 2016. All preoperative or perioperative variables with a p value<0.10 in univariate analysis were entered into a stepwise logistic regression model.

Results

Among the 182 patients (145 male (79.6%), median age 68.0 [45.0-87.0] years), 138 (75.8%) underwent CABG using bilateral internal mammary artery grafts. Median BMI was 27.7 [18.7-50.5] kg/m², and there were 51 (28.0%) and 79 (43.4%) patients with obesity and overweight, respectively. Twenty-three out of the 182 patients (12.6%) developed SWI. In-hospital mortality was not statistically different between patients with and without SWI but the median length of stay was (6.0 [2.0-38.0] versus 5.0[3.0-21.0] days in the intensive care unit, p=0.03, and 26.0 [9.0-134.0] versus 9.0 [7.0-51.0] days in hospital, p<0.0001). Obesity and preoperative anaemia were independently associated with SWI, as was the number of red blood cell (RBC) units transfused (OR 14.61 [2.64-80.75], OR 4.64 [1.61-13.34] and OR 1.27 [1.02-1.58], respectively).

Conclusion

The independent association of SWI with the number of RBC units transfused and the existence of preoperative anaemia and obesity suggests a mechanism of thoracic wall ischemia in SWI after CABG, thus leaving insufficient perfusion of the thoracic wall in patients with obesity. Medical strategies are warranted to try to prevent this costly complication.

Long-term preoperative glycemic control restored the perioperative neutrophilic phagocytosis activity in diabetic mice

BACKGROUND

The risk of surgical site infection has been reported to be higher in patients with poorly controlled diabetes. Since chronic hyperglycemia impairs neutrophil functions, preoperative glycemic control may restore neutrophil function. However, long-term insulin therapy may lead to a delay in surgery, which may be a problem, especially in cancer surgery. It is therefore unfortunate that there have been few studies in which the optimal duration of perioperative glycemic control for diabetes with chronic hyperglycemia was investigated. Therefore, we investigated the effects of preoperative long-term insulin therapy and short-term insulin therapy on perioperative neutrophil functions in diabetic mice with chronic hyperglycemia.

METHODS

Five-week-old male C57BL/6 J mice were divided into four groups (No insulin (Diabetes Mellitus: DM), Short-term insulin (DM), Long-term insulin (DM), and Non-diabetic groups). Diabetes was established by administrating repeated low-dose streptozotocin. The Short-term insulin (DM) group received insulin therapy for 6 h before the operation and the Long-term insulin (DM) group received insulin therapy for 5 days before the operation. The No insulin (DM) group and the Non-diabetic group did not receive insulin therapy. At 14 weeks of age, abdominal surgery with intestinal manipulation was performed in all four groups. We carried out a phagocytosis assay with fluorescent microspheres and a reactive oxygen species (ROS) production assay with DCFH-DA (2',7'-dichlorodihydrofluorescein diacetate) before and 24 h after the operation using FACSVerse™ with BD FACSuite™ software.

RESULTS

Blood glucose was lowered by insulin therapy in the Short-term insulin (DM) and Long-term insulin (DM) groups before the operation. Neutrophilic phagocytosis activities before and after the operation were significantly restored in the Long-term insulin (DM) group compared with those in the No insulin (DM) group (before: p = 0.0008, after: p = 0.0005). However, they were not significantly restored in the Short-term insulin (DM) group. Neutrophilic ROS production activities before and after the operation were not restored in either the Short-term insulin (DM) group or Long-term insulin (DM) group.

CONCLUSIONS

Preoperative and postoperative phagocytosis activities are restored by insulin therapy for 5 days before the operation but not by insulin therapy for 6 h before the operation.

Effects of antidiabetic medications on cardiovascular outcomes

OBJECTIVES

Hyperglycemia is associated with an increased risk of adverse cardiovascular outcomes, such as heart failure, coronary heart disease, stroke, and in-hospital mortality. For those receiving cardiac surgery, up to half develop hyperglycemia while 30% have a diagnosis of diabetes, which is defined by chronic hyperglycemia. Due to a prothrombic state and endovascular damage, patients with diabetes have a twofold increased risk of cardiovascular events.

METHODS

Electronic literature search was done to identify articles that have discussed antidiabetic medications and how it is impacting the glycemia status as well as cardiovascular outcomes. No limits were placed on timing of the publication or type of the article. Key words and MeSH terms were used to conduct the search and the results are summarized in a narrative manner within each relevant section.

RESULTS

Antidiabetic medications play a key role in lowering blood glucose levels to reduce adverse cardiovascular outcomes. However, it is a challenge to assess their cardiovascular safety due to confounding factors, such as age, obesity, smoking, hyperlipidemia, and high blood pressure. Further research in this field is required to understand this correlation closely.

CONCLUSION

Optimizing blood glucose level during the perioperative period with correct medication and dose have a significant role in reducing morbidities. Measures should be taken to provide a safe blood glucose level for optimum outcomes.

Do preoperative glycosylated hemoglobin (HbA1C) and random blood glucose levels predict wound healing complications following exodontia in type 2 diabetes mellitus patients?-a prospective observational study

BACKGROUND

Many dental surgeons consider a type 2 diabetic patient to be at higher risk for wound healing complications following exodontia. Random blood glucose (RBG) and glycosylated hemoglobin (HbA1C) values help the surgeon determine the glycemic control and assess if the patient can undergo the surgical procedure.

OBJECTIVES

The purpose of this study was to analyze if preoperative HbA1C and RBG testing could predict the risk of wound healing and infectious complications in type 2 DM patients undergoing exodontia in an office setting.

METHODS

This prospective observational study included 133 type 2 diabetic patients and age- and gender-matched non-diabetic patients undergoing exodontia. Preoperative HbA1C values and random blood glucose levels were obtained for patients in both groups. Wound healing and infectious complications and additional interventions performed were recorded.

RESULTS

Duration of diabetes ranged from 1 to 25 years. 80.5% of diabetics were treated with oral hypoglycemics. A vast majority of patients in both groups underwent extraction of only a single tooth. There was no significant difference in non-infectious complications between the two groups. The absolute risk of infectious complications in diabetics was 10.5% compared to a 6.8% risk among the control group. Age, RBG values, HbA1C, duration of DM, and number and nature of exodontia performed did not show any statistical significance.

CONCLUSION

This study observed a slight, but not statistically significant increase in the risk of infectious complications in type 2 DM patients undergoing exodontia. Surgical site infections were amenable to surgical drainage with or without oral antibiotics on an outpatient basis with favorable healing outcomes.

CLINICAL RELEVANCE

The RBG and HbA1C values were not significantly associated with risk of infectious complications. Resorting to prophylactic antibiotics and warning about possible adverse healing for routine exodontia in type 2 DM patients is unnecessary.

Effects of Preoperative HbA1c Levels on the Postoperative Outcomes of Coronary Artery Disease Surgical Treatment in Patients with Diabetes Mellitus and Nondiabetic Patients: A Systematic Review and Meta-Analysis

AIMS

To investigate the effect of preoperative HbA1c levels on the postoperative outcomes of coronary artery disease surgery in diabetic and nondiabetic patients.

METHODS AND RESULTS

The MEDLINE (via PubMed), Cochrane Library, Web of Science, Embase, Wanfang Data, China National Knowledge Infrastructure (CNKI), and Chinese Biology Medicine (CBM) databases were used to search the effects of different preoperative HbA1c levels on the postoperative outcomes of coronary artery disease surgical treatment in diabetic and nondiabetic patients from inception to December 2018. Two review authors worked in an independent and duplicate manner to select eligible studies, extract data, and assess the risk of bias of the included studies. We used a meta-analysis to synthesize data and analyze subgroups, sensitivity, and publication bias as well as the GRADE methodology if appropriate. The literature search retrieved 886 records initially, and 23 cohort studies were included in the meta-analysis. In this meta-analysis, we found that there was a reduced incidence of surgical site infections (OR = 2.94, 95% CI 2.18-3.98), renal failure events (OR = 1.63, 95% CI 1.13-2.33), and myocardial infarction events (OR = 1.69, 95% CI 1.16-2.47), as well as a shortened hospital stay (MD = 1.08, 95% CI 0.46-1.71), in diabetic patients after coronary artery disease surgical treatment with lower preoperative HbA1c levels. For nondiabetic patients, a higher preoperative HbA1c level resulted in an increase in the incidence of mortality (OR = 2.23, 95% CI 1.01-4.90) and renal failure (OR = 2.33, 95% CI 1.32-4.12). No significant difference was found between higher and lower preoperative HbA1c levels in the incidence of mortality (OR = 1.06, 95% CI 0.88-1.26), stroke (OR = 1.49, 95% CI 0.94-2.37), or atrial fibrillation (OR = 0.94, 95% CI 0.67-1.33); the length of ICU stay (MD = 0.20, 95% CI -0.14-0.55); or sepsis incidence (OR = 2.49, 95% CI 0.99-6.25) for diabetic patients or for myocardial infarction events (OR = 1.32, 95% CI 0.27-6.31) or atrial fibrillation events (OR = 0.99, 95% CI 0.74-1.33) for nondiabetic patients. The certainty of evidence was judged to be moderate or low.

CONCLUSION

This meta-analysis showed that higher preoperative HbA1c levels may potentially increase the risk of surgical site infections, renal failure, and myocardial infarction and reduce the length of hospital stay in diabetic subjects after coronary artery disease surgical treatment and increase the risk of mortality and renal failure in nondiabetic patients. However, there was great inconsistency in defining higher preoperative HbA1c levels in the studies included; we still need high-quality RCTs with a sufficiently large sample size to further investigate this issue in the future. This trial is registered with CRD42019121531.

Association of elevated pre-operative HbA1c and post-operative complications in patients undergoing gynaecological oncology surgery

HbA1c testing provides average blood glucose control, an elevated result may be associated with adverse post-operative outcomes. Our objective was to evaluate the association between elevated pre-operative HbA1c and post-operative complications in patients undergoing major gynaecological oncology surgery. HbA1c was measured pre-operatively in 364 patients. We identified 65 (16%) patients at risk of developing diabetes with borderline HbA1c measurements.Patients with borderline HbA1c (42-47 mmol/mol) had almost double the incidence of infections compared to patients with normal HbA1c (15.8% vs. 6.5%, p=.038). There were significantly less infections between patients with a normal HbA1c (<42 mmol/mol) and those with an HbA1c of over 42 mmol/mol (6.5% vs. 22.8%, p<.05). There was an association between elevated HbA1c and infective complications especially in patients with a borderline HbA1c. It is suggested that knowing HbA1c status, intervention can be made to prevent post-operative infective complications and improve outcomes.Impact statementWhat is already known on this subject? Obesity is a common risk factor for gynaecological cancer and elevated HbA1c. Chronically elevated HbA1c may lower immunity. An association has been shown previously between elevated HbA1c and post-operative complications.What the results of this study add? This study examined infective complications in patients undergoing gynaecological surgery; showing that patients with a borderline HbA1c (42-47 mmol/mol), especially those with a diagnosis of diabetes to be most at risk. This suggests that pre-operative HbA1c should be used routinely to guide care rather than diabetic status alone to prevent post-operative infections.What the implications are of these findings for clinical practice and/or further research? More research needs to be carried out to find the optimal pre-operative HbA1c targets to reduce post-operative infection rates. Work needs to be done in conjunction with general practitioners to help patients to reduce their HbA1c prior to treatment.

The association of preoperative haemoglobin A1c with 30-day postoperative surgical site infection following non-cardiac surgery

Diabetes has been shown to be associated with postoperative infections; however, the association of haemoglobin A1c (HbA1c) with postoperative surgical site infections (SSI) is unclear. All HbA1c data from patients receiving general, vascular, or orthopaedic surgeries between 1 January 2014 and 1 December 2016 were identified from hospital records. The primary outcome was 30-day SSI. Multivariable logistic regression was performed to determine if HbA1c was associated with infection. The cohorts assessed were: (1) HbA1c < 6.5% (reference group); (2) greater than or equal to 6.5% and less than 8.0%; (3) greater than or equal to 8.0% and less than 10.0%; and (4) greater than or equal to 10.0%. There were 3064 patients included in the final analysis. The overall rate of 30-day SSI was 2.42%. After adjusting for confounders, when compared to the reference group, HbA1c ≥ 8.0% and less than 10.0% (OR 2.4, 95% CI 1.2-4.7, p = 0.015) and HbA1c ≥ 10.0% (OR 3.0, 95% CI 1.2-7.3, p = 0.016) had increased odds ratio for 30-day SSI. A HbA1c of 8.0% or higher significantly increased the odds ratio of developing postoperative SSI (p < 0.05). This may aid in the development of guidelines for optimising diabetic patients.

Increased Glucose Variability Is Associated With Major Adverse Events After Coronary Artery Bypass

BACKGROUND

Elevated preoperative hemoglobin A_1c (HbA_1c) is a predictor of poor outcomes after coronary artery bypass grafting (CABG), but the role of postoperative glucose variability (GV) is unknown. We hypothesized that short-term postoperative GV is associated with major adverse events (MAEs) after isolated CABG.

METHODS

This retrospective study evaluated 2215 patients who underwent isolated CABG from January 2012 to March 2018 at 2 medical centers. Postoperative GV in the first 12 hours and 24 hours was measured by the SD, coefficient of variation, and mean amplitude of glycemic excursions. The primary outcome (MAEs) was the composite of postoperative cardiac arrest, pneumonia, renal failure, stroke, sepsis, reoperation, and 30-day mortality. Multivariate logistic regression assessed the independent association of GV with MAE.

RESULTS

A total of 2215 patients met the study criteria, and an MAE developed in 260 patients (11.7%). High 12-hour and 24-hour postoperative GV were associated with elevated HbA_1c, insulin-dependent diabetes, renal failure, and nonelective operation. Multivariate logistic regression analysis showed MAEs were associated with increased mean postoperative glucose in the first 12 hours (odds ratio [OR], 1.013; 95% confidence interval [CI], 1.008-1.018; P < .001), the first 24 hours (OR, 1.017; 95% CI, 1.010-1.024; P < .001), and 24-hour postoperative GV (OR, 1.22; 95% CI, 1.09-1.37; P < .001). MAEs were not associated with preoperative HbA_1c or 12-hour postoperative GV.

CONCLUSIONS

Increased 24-hour but not 12-hour postoperative GV after CABG is a predictor of poor outcomes. Preoperative HbA_1c is not associated with MAEs after adjusting for postoperative mean glucose and GV.

Diabetes, dysglycemia, and vascular surgery

BACKGROUND

Abnormalities in glucose metabolism are common in patients with arterial disease. Chronic hyperglycemia and insulin resistance contribute to the complexity of vascular disorders. They also overlap with the effects of perioperative hyperglycemia on adverse perioperative outcomes. We provide an overview of the pathophysiologic consequences of dysglycemia and the evidence behind glycemic control in patients undergoing vascular surgery.

METHODS

We searched the literature for major studies evaluating the pathophysiology of hyperglycemia in microvascular and macrovascular beds, randomized trials in perioperative populations, and meta-analyses. The literature was summarized to guide therapy in the population of vascular patients and for the perioperative period.

RESULTS

National standards for glycemic control after vascular interventions were not identified. Mounting evidence exists for the long-term consequences of poor glycemic control on the progression of vascular disease. Similarly, there is a large body of evidence supporting tight control of hyperglycemia after general and cardiac surgery during the critical perioperative period. The absolute glucose target remains controversial. Randomized controlled studies are lacking in vascular surgery patients, but the current evidence can be extrapolated to guide management after vascular interventions. Glycated hemoglobin is a biomarker for increased mortality and vascular morbidity after vascular surgery.

CONCLUSIONS

Hyperglycemia contributes to poor outcome in the vascular patient. Further vascular focused studies are required to determine the proper perioperative serum glucose target and the long-term glycated hemoglobin range.

Effect of glycemic control on mortality and infections in patients undergoing coronary artery bypass grafting: a Genesee County experience

Background: We report post-coronary artery bypass outcomes and factors affecting the outcomes from the Genesee County, MI, where the population is distinctly characterized by a higher prevalence of renal failure (RF), diabetes, obesity and smoking than the national average. Methods: We performed a retrospective cohort study on 1133 patients undergoing isolated CABG at our hospital from June 2012 to July 2017. Primary outcome was the association between preoperative hemoglobin A1c (HbA1c) and all-cause postoperative mortality after CABG, secondary outcomes included the association between HbA1c and a composite of postoperative infections including sternal-wound infections, leg harvest-site infections, pneumonia or sepsis. Logistic Regression analyses were also performed. Results: There was no difference in the mortality rate (OR 1.0, 95% CI 0.4-2.3) and composite of all infections (OR 1.0, 95% CI 0.7-1.6) between the controlled (HbA1c ≤7%) and uncontrolled (HbA1c >7%) groups. However, RF (OR 5.9, 95% CI 1.5-22.9), smoking (OR 3.7, 95% CI 1.3-11.2) and ejection fraction <35% (OR 3.4, 95% CI 1.4-8.3) were independently associated with increased mortality after CABG. Additionally, low EF (OR 2.4, 95% CI 1.4-4.1) and smoking (OR 2.3, 95% CI 1.2-4.1) were associated with an increased rate of composite of all infections after CABG. Conclusion: Although not different in controlled and uncontrolled diabetic groups, mortality, in our population was associated with comorbidities like RF, smoking and congestive heart failure that are highly prevalent, emphasizing the need for interventions at primary care level to improve the postoperative outcomes after CABG.

Diabetes and elevated preoperative HbA1c level as risk factors for postoperative delirium after cardiac surgery: an observational cohort study

INTRODUCTION

Postoperative delirium (POD) is a common complication of cardiac surgery associated with increased mortality, morbidity, and long-term cognitive dysfunction. Diabetic patients, especially those with poor diabetes control and long-standing hyperglycemia, may be at risk of developing delirium. The aim of this study was to analyze whether the occurrence of POD in cardiac surgery is associated with diabetes or elevated preoperative glycated hemoglobin (HbA1c) level.

MATERIALS AND METHODS

We performed a cohort analysis of prospectively collected data from a register of cardiac surgery department of a university hospital. Delirium assessment was performed twice a day during the first 5 days after the operation based on Diagnostic Statistical Manual of Mental Disorders, fifth edition criteria.

RESULTS

We analyzed a cohort of 3,178 consecutive patients, out of which 1,010 (31.8%) were diabetic and 502 (15.8%) were diagnosed with POD. Patients with delirium were more often diabetic (42.03% vs 29.86%, P<0.001) and on oral diabetic medications (34.66% vs 24.07%, P<0.001), no difference was found in patients with insulin treatment. Preoperative HbA1c was elevated above normal (≥6%) in more delirious than nondelirious patients (44.54% vs 33.04%, P<0.001), but significance was reached only in nondiabetic patients (20.44% vs 14.86%, P=0.018). In univariate analysis, the diagnosis of diabetes was associated with an increased risk of developing POD (OR: 1.703, 95% CI: 1.401-2.071, P<0.001), but only for patients on oral diabetic medications (OR: 1.617, 95% CI: 1.319-1.983, P<0.001) and an association was noted between HbA1c and POD (OR: 1.269, 95% CI: 1.161-1.387, P<0.001). Multivariate analysis controlled for diabetes showed that POD was associated with age, heart failure, preoperative creatinine, extracardiac arteriopathy, and preoperative HbA1c level.

CONCLUSION

More diabetic patients develop POD after cardiac surgery than nondiabetic patients. Elevated preoperative HbA1c level is a risk factor for postcardiac surgery delirium regardless of the diagnosis of diabetes.

The role of newly diagnosed diabetes mellitus for poor in-hospital prognosis of coronary artery bypass grafting

Background: The management of coronary artery disease in patients with type 2 diabetes (T2DM) who need myocardial revascularization is a great challenge. Aims: To study the role of newly diagnosed T2DM in the development of in-hospital adverse outcomes after coronary artery surgery (CABG). Methods: 708 consecutive patients underwent CABG were included. All patients without history of T2DM and with border fasting hyperglycemia underwent an oral glucose tolerance test. Results: The screening allowed to diagnose T2DM in 8.9% and prediabetes in 10.4% of the study population. The the number of patients with T2DM increased from 15.2% to 24.1%, and with prediabetes from 3.0% to 13.4%. The total number of patients with carbohydrate metabolism disorders increased from 18.2% to 37.5%. The trend towards higher rate of in-hospital complications after CABG was defined among patients with newly diagnosed and previously diagnosed T2DM. The regression analysis demonstrated the presence of the relationships between the previously diagnosed T2DM and the total number of significant complications (odds ratio (OR) 1.350, 95% confidence interval (CI): 1.0571.723, p=0.020) and prolonged in-hospital stay (OR 1.609, 95%CI 1.2022.155, p=0.001). The significance of these relationships increased with the addition of newly diagnosed T2DM to the regression model (for in-hospital complications: OR 1.731, 95% CI 1.1312.626, p=0.012; for prolonged in-hospital stay: OR 2.229, 95%CI 1.4123.519, p0.001). Moreover, additional associations between T2DM and the risk of developing multiple organ dysfunction (OR 2.911, 95% CI 1.0727.901, p=0.039), urgent lower extremity surgery (OR 1.638, 95%CI 1.00915.213, p=0.020) and the need for extracorporeal correction of hemostasis (OR 3.472, 95%CI 1.04211.556, p=0.044) have been defined. Importantly, the presence of these associations would not have been identified without including newly diagnosed DM in the regression model. Conclusion: The newly diagnosed T2DM affects the prognosis of CABG as well as the previously diagnosed T2DM. The obtained results suggest the importance of active preoperative T2DM screening.

Intensity of Glycemic Control Affects Long-Term Survival After Coronary Artery Bypass Graft Surgery

BACKGROUND

A patient's hemoglobin (Hb) A_1c level, regardless of diabetic status, is a measure of glycemic control. Studies have found it is an independent predictor of short-term death in patients undergoing coronary artery bypass grafting (CABG). In this study, we used preoperative HbA_1c to assess whether levels are associated with short-term and long-term survival after CABG.

METHODS

From a regional registry of consecutive cases, we identified 6,415 patients undergoing on-pump isolated CABG from 2008 to 2015 with documented preoperative HbA_1c level. We defined four HbA_1c groups: less than 5.7% (n = 1,713), 5.7% to 6.4% (n = 2,505), 6.5% to 8.0% (n = 1,377), and more than 8% (n = 820). Relationship to in-hospital outcomes and long-term survival was assessed. Outcome rates and hazard ratios were adjusted for patient and disease risk factors using multivariable logistic regression and Cox models.

RESULTS

The study included 3,740 patients (58%) not diagnosed as having diabetes and 2,674 with diabetes. Prediabetes (HbA_1c 5.7% to 6.4%) was documented in 52% (n = 1,933) of nondiabetic patients. Higher HbA_1c values were associated with younger age, female sex, greater body mass index, more comorbid diseases, lower ejection fraction, more 3-vessel coronary disease, and recent myocardial infarction (p < 0.05 trend for all). After adjustment for patient risk, greater HbA_1c values were not associated with higher rates of in-hospital death or morbidity. Long-term survival was significantly worse as HbA_1c increased. Risk of death increased by 13% for every unit increase in HbA_1c (adjusted hazard ratio, 1.13; 95% confidence interval, 1.07 to 1.19; p < 0.001).

CONCLUSIONS

Preadmission glycemic control, as assessed by HbA_1c, is predictive of long-term survival, with higher levels associated with poorer prognosis. Whether this risk can be modified by better glycemic control postoperatively remains to be determined.