The Association Between Preoperative Hemoglobin A1C and Postoperative Glycemic Variability on 30-Day Major Adverse Outcomes Following Isolated Cardiac Valvular Surgery

Postoperative Insulin Dose for Cardiac Artery Bypass Graft and Other Cardiac Surgeries in Patients with Type 2 Diabetes: A Retrospective Study

Purpose

Recommendations on perioperative glycemic control in cardiac surgery are based on coronary artery bypass graft surgery (CABG), though coronary artery disease and valvular disease are pathologically distinct. We aimed to compare the postoperative insulin requirement between CABG and other cardiac surgeries in type 2 diabetic patients and identify predictive factors for the maximum postoperative insulin dose.

Patients and Methods

We retrospectively included 60 Japanese patients with diabetes/glucose intolerance (HbA1c > 37 mmol/mol [5.6%]) who were hospitalized for cardiovascular surgery between April 2017 and March 2019. We categorized the subjects into the CABG and non-CABG groups, and performed subgroup analysis on patients who received postoperative insulin therapy.

Results

The CABG group required a significantly higher insulin dose on postoperative days 2, 5, 6, and 7, and a significantly higher maximum postoperative insulin dose (24.6 U vs 9.7 U, P < 0.001) than the non-CABG group. Multivariate linear regression analyses showed that the independent determinants of the maximum postoperative insulin dose were HbA1c and duration of diabetes in the non-CABG group, and HbA1c in the CABG group.

Conclusion

CABG had a higher postoperative insulin requirement than other cardiovascular surgeries; early aggressive insulin therapy is indicated, especially for patients with higher HbA1c levels/longer duration of diabetes.

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.

Acute Glycemic Variability and Early Outcomes After Cardiac Surgery: A Meta-Analysis

The influence of acute glycemic variability (GV) on early outcomes of patients after cardiac surgery remains not fully determined. We performed a systematic review and meta-analysis to evaluate the association between acute GV and in-hospital outcomes of patients after cardiac surgery. Relevant observational studies were obtained by search of electronic databases including Medline, Embase, Cochrane Library, and Web of Science. A randomized-effects model was selected to pool the data by incorporating the influence of potential heterogeneity. Nine cohort studies involving 16 411 patients after cardiac surgery were included in this meta-analysis. Pooled results showed that a high acute GV was associated with an increased risk of major adverse events (MAE) during hospitalization for patients after cardiac surgery [odds ratio [OR]: 1.29, 95% CI: 1.15 to 1.45, p<0.001, I22=38%]. Sensitivity analysis limited to studies of on-pump surgery and GV evaluated by coefficient of variation of blood glucose showed similar results. Subgroup analysis suggested that a high acute GV was related to an increased incidence of MAE in patients after coronary artery bypass graft, but not for those after isolated valvular surgery (p=0.04), and the association was weakened after adjustment of glycosylated hemoglobin (p=0.01). Moreover, a high acute GV was also related to an increased risk of in-hospital mortality (OR: 1.55, 95% CI: 1.15 to 2.09, p=0.004; I22=0%). A high acute GV may be associated with poor in-hospital outcomes in patients after cardiac surgery.

Intensified glycemic control by HbA1c for patients with coronary heart disease and Type 2 diabetes: a review of findings and conclusions

The occurrence and development of coronary heart disease (CHD) are closely linked to fluctuations in blood glucose levels. While the efficacy of intensified treatment guided by HbA1c levels remains uncertain for individuals with diabetes and CHD, this review summarizes the findings and conclusions regarding HbA1c in the context of CHD. Our review showed a curvilinear correlation between regulated level of HbA1c and therapeutic effectiveness of intensified glycemic control among patients with type 2 diabetes and coronary heart disease. It is necessary to optimize the dynamic monitoring indicators of HbA1c, combine genetic profiles, haptoglobin phenotypes for example and select more suitable hypoglycemic drugs to establish more appropriate glucose-controlling guideline for patients with CHD at different stage of diabetes.

A nomogram for accurately predicting the surgical site infection following transforaminal lumbar interbody fusion in type 2 diabetes patients, based on glycemic variability

Surgical site infection (SSI) is a common and serious complication of transforaminal lumbar interbody fusion (TLIF), and the occurrence of SSI usually leads to prolonged hospitalisation, increased medical costs, poor prognosis, and even death. The objectives of this study were to compare the incidence of SSI in patients with type 2 diabetes, investigate the correlation between perioperative glycemic variability and postoperative SSI, and develop a nomogram model to predict the risk of SSI. This study retrospectively analysed 339 patients with type 2 diabetes who underwent TLIF in the spinal surgery department of the Affiliated Zhongda Hospital of Southeast University from January 2018 to September 2021. The medical records of all patients were collected, and postoperative infection cases were determined according to the diagnostic criteria of surgical site infection. The risk factors for postoperative SSI were analysed by univariate and multivariate logistic regression. And Nomogram prediction model was established and validated. The nomogram incorporated seven independent predictors. Preoperative FPG-CV was the most important independent risk predictor of SSI, followed by preoperative MFBG, duration of drain placement, postoperative FPG-CV, preoperative blood glucose control scheme, duration of diabetes >5 years, and the number of fused vertebrae ≥2. The nomogram showed good diagnostic accuracy for the SS of both the training cohort and the validation cohort (AUC = 0.915 and AUC = 0.890). The calibration curves for the two cohorts both showed optimal agreement between nomogram prediction and actual observation. In conclusion, preoperative and postoperative glycemic variability is closely related to the occurrence of SSI. We developed and validated a nomogram to accurately predict the risk of SSI after TLIF surgery. It's helpful for spinal surgeons to formulate reasonable treatment plans and prevention strategies for type 2 diabetes patients.

[Position statement: surgery and diabetes mellitus (Update 2023)]

This position statement reflects the perspective of the Austrian Diabetes Association concerning the perioperative management of people with diabetes mellitus based on the available scientific evidence. The paper covers necessary preoperative examinations from an internal/diabetological point of view as well as the perioperative metabolic control by means of oral antihyperglycemic and/or insulin therapy.

Preoperative hemoglobin A1c and perioperative blood glucose in patients with diabetes mellitus undergoing spinal cord stimulation surgery: A literature review of surgical site infection risk

AIMS

The aim of our study was to review the surgical literature regarding the relationship between hemoglobin A1c (HbA1c), diagnosis of diabetes mellitus (DM), and risk of postoperative surgical site infection (SSI).

METHODS

A librarian-assisted literature search was performed with two goals: (1) identify surgical publications related to SSI and HbA1c values, and (2) identify publications reporting infection risk with DM in spinal cord stimulation (SCS), intrathecal drug delivery systems (IDDS), and cardiovascular implantable electronic device (CIED) implantation surgeries. Published guidelines on perioperative management of DM are reviewed.

RESULTS

We identified 30 studies reporting SSI and HbA1c values. The literature review indicated that for many surgical procedures, elevated HbA1c is not correlated to rate of SSI. We identified 16 studies reporting infection rates within DM cohorts following SCS, IDDS, and CIED implantation surgeries. The data reviewed did not indicate DM as an independent risk factor for SSI.

CONCLUSION

Preoperative HbA1c levels in patients with a history of DM is not a singularly sufficient tool to estimate risk of perioperative infection in SCS implantation surgery. Published guidelines on perioperative management of DM do not suggest a specific HbA1c above which surgery should be delayed; intentional perioperative glycemic control is recommended.

Glycated haemoglobin and the risk of postoperative complications in people without diabetes: a prospective population-based study in UK Biobank

The aim of our study was to clarify the association between glycated haemoglobin (HbA1c ) and postoperative outcomes in people without an existing diagnosis of diabetes. Half a million adults were recruited into the UK Biobank prospective cohort study between March 2006 and October 2010. We divided participants into three groups: no diagnosis of diabetes and HbA1c  < 42 mmol.mol-1 ; no diagnosis of diabetes and elevated HbA1c (≥ 42 mmol.mol-1 with no upper limit); and prevalent diabetes (regardless of HbA1c concentration) at recruitment. We followed up participants by linkage with routinely collected hospital data to determine any surgical procedures undertaken after recruitment and the associated postoperative outcomes. Our main outcome measure was a composite primary outcome of 30-day major postoperative complications and 90-day all-cause mortality. We used logistic regression to estimate the odds of the primary outcome by group. We limited analyses to those who underwent surgery within one year of recruitment (n = 26,653). In a combined effects logistic regression model, participants not known to have diabetes with HbA1c  ≥ 42 mmol.mol-1 had increased odds of the primary outcome (OR [95% CI] 1.43 [1.02-2.02]; p = 0.04), when compared with those without diabetes and HbA1c  < 42 mmol.mol-1 . This effect was attenuated and no longer statistically significant in a direct effects model with adjustment for hyperglycaemia-related comorbidity (OR [95% CI] 1.37 [0.97-1.93]; p = 0.07). Elevated pre-operative HbA1c in people without diabetes may be associated with an increased risk of complications, but the association is likely confounded by end-organ comorbidity. In contrast to previous evidence, our findings suggest that to prevent adverse postoperative outcomes, optimisation of pre-existing morbidity should take precedence over reducing HbA1c in people without diabetes.

Is Delaying Urogynecologic Surgery for Patients With Elevated Hemoglobin A1C High-Value Care?

OBJECTIVE

Poor glycemic control is a risk factor for surgical complications. We evaluated the cost-effectiveness of immediate versus delayed pelvic reconstructive surgery for women with hemoglobin A1C (HbA1c) greater than 8%.

METHODS

We designed a decision tree model from a health care sector perspective to compare costs and effectiveness (quality-adjusted life-years [QALYs]) of 3 strategies: patients with HbA1c greater than 8% can undergo (1) immediate surgery, (2) delay surgery 6 months, or (3) delay surgery until HbA1c is less than 8%. Groups 2 and 3 undergo treatments to improve glycemic control. Our primary outcome was the incremental cost-effectiveness ratio. Time horizon was 1 year.

RESULTS

In the base case, immediate surgery compared with delaying surgery until HbA1c <8% had higher costs ($13,775 vs $6,622) and health utilities (0.78 vs 0.76). Immediate surgery was not cost effective (incremental cost-effectiveness ratio, $347,132/QALY). Delaying surgery for 6 months (group 2) was dominated (higher cost and lower effectiveness). For patients with either severe prolapse resulting in QALY less than 0.71 (base case 0.75), QALY after surgery greater than 0.84 (base case, 0.80), or the probability of complications with elevated HbA1c less than 17% (base case, 27%), immediate surgery became cost effective. Monte Carlo simulations showed that delaying surgery until HbA1c is less than 8% had a 58% chance of being the preferred strategy at a willingness-to-pay of $150,000/QALY.

CONCLUSIONS

For patients with HbA1c greater than 8%, delaying surgery until improved glycemic control is generally cost-effective. Surgery should not be delayed for a prespecified period. Immediate surgery can be cost-effective for patients with severe prolapse or if complication rates decrease to 60% of currently reported rates.

Intraoperative Glycemic Variability and Mean Glucose are Predictors for Postoperative Delirium After Cardiac Surgery: A Retrospective Cohort Study

Purpose

Postoperative delirium (POD) is a common but serious complication after cardiac surgery and is associated with various short- and long-term outcomes. In this study, we investigated the effects of intraoperative glycemic variability (GV) and other glycemic variables on POD after cardiac surgery.

Patients and Methods

A retrospective single-center cohort analysis was conducted using data from electronic medical record from 2018 to 2020. A total of 705 patients undergoing coronary artery bypass graft surgery and/or valve surgery, and/or aortic replacement surgery were included in the analysis. Intraoperative GV was assessed with a coefficient of variation (CV), which was defined as the standard deviation of five intraoperative blood glucose measurements divided by the mean. POD assessment was performed three times a day in the ICU and twice a day in the ward until discharge by trained medical staff. POD was diagnosed if any of the Confusion Assessment Method for the Intensive Care Unit was positive in the ICU, and the Confusion Assessment Method was positive in the ward. Multivariable logistic regression was used to identify associations between intraoperative GV and POD.

Results

POD occurred in 306 (43.4%) patients. When intraoperative glycemic CV was compared as a continuous variable, the delirium group had higher intraoperative glycemic CV than the non-delirium group (22.59 [17.09, 29.68] vs 18.19 [13.00, 23.35], p < 0.001), and when intraoperative glycemic CV was classified as quartiles, the incidence of POD increased as intraoperative glycemic CV quartiles increased (first quartile 29.89%; second quartile 36.67%; third quartile 44.63%; and fourth quartile 62.64%, p < 0.001). In the multivariable logistic regression model, patients in the third quartile of intraoperative glycemic CV were 1.833 times (OR 1.833, 95% CI: 1.132–2.967, p = 0.014), and patients in the fourth quartile of intraoperative glycemic CV were 3.645 times (OR 3.645, 95% CI: 2.235–5.944, p < 0.001) more likely to develop POD than those in the first quartile of intraoperative glycemic CV.

Conclusion

Intraoperative blood glucose fluctuation, manifested by intraoperative GV, is associated with POD after cardiac surgery. Patients with a higher intraoperative GV have an increased risk of POD.

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.

Increased glucose variability is associated with major adverse events in patients with infective endocarditis undergo surgical treatment

Background

This study aimed to investigate the prognostic value of glucose variability (GV) in predicting postoperative major adverse events (MAEs) in patients with infective endocarditis (IE) who underwent surgical treatment.

Methods

This retrospective observational study included a total of 381 consecutive patients who underwent surgical treatment in our institution from October 2007 to August 2019. The MAEs included all-cause death, stroke, myocardial infarction, acute heart failure, IE recurrence, acute renal failure and sepsis. Postoperative GV in the first 24 hours was measured by the mean 24-hour glucose, standard deviation, coefficient of variation (CV) and mean amplitude of glycemic excursions. Univariate and multivariate logistic regression analyses were performed to identify the independent association of GV with MAEs.

Results

Of the 381 patients, 79 (20.7%) developed MAEs. The 30-day mortality of the overall study cohort was 5.23%. The multivariate logistic regression analysis indicated that 24-hour GV, measured as the CV [odds ratio (OR) =1.49, 95% CI, 1.23–3.57, P=0.012], was significantly associated with MAEs in IE patients. For every 10% increase in 24‐hour CV, there was a 49% increase in the risk of MAEs. Furthermore, compared to patients in the low tertile of GV, patients in the top tertile of 24-hour GV had a higher 30-day mortality and an increased incidence of heart failure and hemodialysis as well as longer ventilation support.

Conclusions

The results of this retrospective investigation demonstrated that increased GV measured by CV is an independent predictor of postoperative MAEs in patients undergoing surgical treatment for IE.

Association of Preoperative Hemoglobin A1c with In-hospital Mortality Following Valvular Heart Surgery

Objective

To determine the association between the preoperative level of hemoglobin A1c (HbA1c) and in-hospital mortality in patients who underwent valvular heart surgery in our center in a retrospective cohort.

Methods

In this retrospective consecutive cohort study, patients with type 2 diabetes mellitus who were referred to our center for elective valvular surgery were enrolled and followed up. The endpoint of this study was in-hospital mortality. Based on the level of HbA1c, patients were dichotomized around a level of 7% into two groups: exposed patients with HbA1c ≥ 7% and unexposed patients with HbA1c < 7%. Then, the study variables were compared between the two groups.

Results

Two hundred twenty-four diabetic patients who were candidates for valvular surgery were enrolled; 106 patients (47.3%) had HbA1c < 7%, and 118 patients (52.6%) had HbA1c ≥ 7%. The duration of diabetes was higher in patients with HbA1c ≥ 7% (P=0.007). Thirteen (5.8%) patients died during hospital admission, of which nine patients were in the high HbA1c group. There was no significant difference between the groups regarding in-hospital mortality (P=0.899). Both the unadjusted and adjusted logistic regression models showed that HbA1c was not a predictor for in-hospital mortality (P=0.227 and P=0.388, respectively)

Conclusion

This study showed no association between preoperative HbA1c levels and in-hospital mortality in candidates for valvular heart surgery.

Comparison of Glycemic Variability Indices: Blood Glucose, Risk Index, and Coefficient of Variation in Predicting Adverse Outcomes for Patients Undergoing Cardiac Surgery

OBJECTIVES

Fluctuations in blood glucose (glycemic variability) increase the risk of adverse outcomes. No universally accepted tool for glycemic variability exists during the perioperative period. The authors compared 2 measures of glycemic variability-(1) coefficient of variation (CV) and (2) the Blood Glucose Risk Index (BGRI)-in predicting adverse outcomes after cardiac surgery.

DESIGN

Prospective, observational study.

SETTING

Single-center, teaching hospital.

PARTICIPANTS

A total of 1,963 adult patients undergoing cardiac surgery.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Postoperative blood glucose levels were measured hourly for the first 24 hours and averaged every 4 hours (4, 8, 12, 16, 20, and 24 hours). Glycemic variability was measured by CV and the BGRI. The primary outcome, major adverse events (MAEs), was a predefined composite of postoperative complications (death, reoperation, deep sternal infection, stroke, pneumonia, renal failure, tamponade, and myocardial infarction). Logistic regression models were constructed to evaluate the association. Predictive ability was measured using C-statistics. Major adverse events were seen in 170 (8.7%) patients. Only the fourth quartile of CV showed association (odds ratio [OR] 1.91; 95% confidence interval [CI] [1.19-3.14]; p = 0.01), whereas BGRI was related significantly to MAE (OR 1.20; 95% CI [1.10-1.32]; p < 0.0001). The predictive ability of CV and BGRI increased on adding the standard Society of Thoracic Surgeons (STS) risk index. The C-statistic for STS was 0.68, whereas STS + CV was 0.70 (p = 0.012) and STS + BGRI was 0.70 (p = 0.012).

CONCLUSION

Both CV and the BGRI had good predictive ability. The BGRI being a continuous variable could be a preferred measure of glycemic variability in predicting adverse outcomes (cutoff value 2.24) after cardiac surgery.

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 atrial fibrillation after coronary artery bypass

BACKGROUND

Elevated preoperative hemoglobin A1c (HbA1c) is a predictor of poor outcomes following coronary artery bypass grafting (CABG), but the role of increased postoperative glucose variability (GV) is unknown. We hypothesized that short-term postoperative GV is associated with an increased risk of postoperative atrial fibrillation following isolated CABG.

METHODS

Multicenter retrospective study of 2073 patients who underwent isolated CABG from January 2012 to March 2018. Postoperative GV in the first 24 hours was measured by standard deviation, coefficient of variation, and mean amplitude of glycemic excursions. Multivariate logistic regression assessed the independent association of GV with postoperative atrial fibrillation.

RESULTS

A total of 2073 patients met the study criteria, and 446 patients (21.5%) developed postoperative atrial fibrillation. Using multivariate logistic regression to adjust for covariates, postoperative atrial fibrillation was associated with increased 24-hour GV (odds ratio [OR] = 1.16, 95% confidence interval [CI], 1.05-1.27, P < 0.01) and increased 24-hour mean glucose (OR = 1.14, 95% CI, 1.08-1.21, P < 0.01). Thus, for every 10% increase in 24-hour GV or 10 mg/dL increase in mean glucose, there was a 16% or 14% increased risk of postoperative atrial fibrillation respectively.

CONCLUSIONS

Increased 24-hour GV and mean glucose are predictors of atrial fibrillation after CABG. Preoperative HbA1c is not a risk factor for postoperative atrial fibrillation after adjusting for postoperative mean glucose and GV. Further investigation is needed to determine the relationship between adherence to strict glucose control and adverse events following CABG.

Impact of post-procedural glycemic variability on cardiovascular morbidity and mortality after transcatheter aortic valve implantation: a post hoc cohort analysis

Background

Glycemic variability is associated with worse outcomes after cardiac surgery, but the prognosis value of early glycemic variability after transcatheter aortic valve implantation is not known. This study was therefore designed to analyze the prognosis significance of post-procedural glycemic variability within 30 days after transcatheter aortic valve implantation.

Methods

A post hoc analysis of patients from our center included in the FRANCE and FRANCE-2 registries was conducted. Post-procedural glycemic variability was assessed by calculating the mean daily δ blood glucose during the first 2 days after transcatheter aortic valve implantation. Major complications within 30 days were death, stroke, myocardial infarction, acute heart failure, and life-threatening cardiac arrhythmias.

Results

We analyzed 160 patients (age (median [interquartile] = 84 [80–88] years; diabetes mellitus (n) = 41 (26%) patients; logistic Euroscore = 20 [12–32]). The median value of mean daily δ blood glucose was 4.3 mmol l⁻¹. The rate of major complications within 30 days after procedure among patients with the lowest quartile of glycemic variability was 12%, increasing from 12 to 26%, and 39% in the second, third, and fourth quartiles, respectively. In multivariate analysis, glycemic variability was independently associated with an increased risk of major complications within 30 days after the procedure (odds ratio [95% CI] = 1.83 [1.19–2.83]; p = 0.006).

Conclusions

This study showed that post-procedural glycemic variability was associated with an increased risk of major complications within 30 days after transcatheter aortic valve implantation.

Trial registration Clinical trial registration number https://www.clinicaltrials.gov/; identifier: NCT02726958; date: April 4th, 2016

Glycaemic variability in diabetes: clinical and therapeutic implications

Glycaemic variability is an integral component of glucose homoeostasis. Although it has not yet been definitively confirmed as an independent risk factor for diabetes complications, glycaemic variability can represent the presence of excess glycaemic excursions and, consequently, the risk of hyperglycaemia or hypoglycaemia. Glycaemic variability is currently defined by a large and increasing number of metrics, representing either short-term (within-day and between-day variability) or long-term glycaemic variability, which is usually based on serial measurements of HbA_1c or other measures of glycaemia over a longer period of time. In this Review, we discuss recent evidence examining the association between glycaemic variability and diabetes-related complications, as well as non-pharmacological and pharmacological strategies currently available to address this challenging aspect of diabetes management.

Effects of Glucose Variability on Short-Term Outcomes in Non-Diabetic Patients After Coronary Artery Bypass Grafting: A Retrospective Observational Study

BACKGROUND

Postoperative hyperglycaemia has been shown to have adverse effects on patients after coronary artery bypass grafting surgery (CABG). However, whether glucose variability has an effect on patients' outcomes is still uncertain. The aim of this study is to explore the effects of glucose variability on short-term outcomes in non-diabetic patients undergoing coronary artery bypass grafting.

METHODS

This is a retrospective observational study utilising data collected after patients had left the hospital. This study was performed on 137 non-diabetic patients undergoing coronary artery bypass grafting from January 2011 to June 2013. Blood glucose at 72hours post operation was obtained and glucose variability was measured by mean postoperative blood glucose and mean of daily difference (MODD). Short-term outcomes included duration of intensive care unit (ICU) stay, mechanical ventilation time, length of hospital stay, and occurrence of arrhythmia. Patients with mean postoperative blood glucose ≥7.00mmol/L were defined as hyperglycaemic, and patients with MODD ≥1.40mmol/L were considered to be abnormal. Outcome variables were compared between patients in euglycaemic and hyperglycaemic groups, and between patients in normal and abnormal groups.

RESULTS

In our study, patients with hyperglycaemia spent more time staying in ICU (p<0.01), and patients with large glucose variability (abnormal MODD) had higher incidences of arrhythmia (23% vs 4.2%, p<0.05). Regression analysis showed that MODD can affect occurrence of arrhythmia (p=0.004) and that mean postoperative blood glucose levels can affect duration of ICU stay (p<0.001).

CONCLUSIONS

Patients' postoperative glucose variability after CABG is an important predictor of the negative outcomes regarding duration of ICU stay and occurrence of arrhythmia. Large glucose variability can have negative effects on short-term outcomes in patients.

Increased postoperative glucose variability is associated with adverse outcomes following orthopaedic surgery

Aims

The aim of this study was to examine the association between postoperative glycaemic variability and adverse outcomes following orthopaedic surgery.

Patients and Methods

This retrospective study analyzed data on 12 978 patients (1361 with two operations) who underwent orthopaedic surgery at a single institution between 2001 and 2017. Patients with a minimum of either two postoperative measurements of blood glucose levels per day, or more than three measurements overall, were included in the study. Glycaemic variability was assessed using a coefficient of variation (CV). The length of stay (LOS), in-hospital complications, and 90-day readmission and mortality rates were examined. Data were analyzed with linear and generalized linear mixed models for linear and binary outcomes, adjusting for various covariates.

Results

The cohort included 14 339 admissions, of which 3302 (23.0%) involved diabetic patients. Patients with CV values in the upper tertile were twice as likely to have an in-hospital complication compared with patients in the lowest tertile (19.4% versus 9.0%, p < 0.001), and almost five times more likely to die compared with those in the lowest tertile (2.8% versus 0.6%, p < 0.001). Results of the adjusted analyses indicated that the mean LOS was 1.28 days longer in the highest versus the lowest CV tertile (p < 0.001), and the odds of an in-hospital complication and 90-day mortality in the highest CV tertile were respectively 1.91 (p < 0.001) and 2.10 (p = 0.001) times larger than the odds of these events in the lowest CV tertile. These associations were significant even for non-diabetic patients. After adjusting for hypoglycaemia, the relationships remained significant, except that the CV tertile no longer predicted mortality in diabetics.

Conclusion

These results indicate that higher glycaemic variability is associated with longer LOS and in-hospital complications. Glycaemic variability also predicted death, although that primarily held for non-diabetic patients in the highest CV tertile following orthopaedic surgery. Prospective studies should examine whether ensuring low postoperative glycaemic variability may reduce complication rates and mortality. Cite this article: Bone Joint J 2018;100-B:1125–32.

Can Pre-Operative HbA1c Values in Coronary Surgery be a Predictor of Mortality?

Objective

One of the most frequently studied parameters in terms of outcome estimation in cardiac surgery is HbA1c. Several studies in literature suggest that high HbA1c value increases mortality and morbidity, but there is no relation between them. The primary aim of the present study is to investigate whether HbA1c value in diabetic patients undergoing coronary bypass graft surgery is an independent predictor for post-operative mortality and morbidity, and our secondary goal was to determine independent risk factors that cause mortality and morbidity in the same patient population.

Methods

380 diabetic patients diagnosed with diabetes who underwent coronary surgery with cardiopulmonary bypass in Mersin State hospital between July 2014 to December 2016 after the approval of the Mersin University Faculty of medicine ethics committee were included in this retrospective, observational, and cross-sectional study. Patient demographic and perioperative information were obtained from the electronic information operating system and from anesthesia-intensive care follow-up forms. The HbA1c threshold was accepted as 7%, which was reported to be more appropriate for evaluating high-risk groups.

Results

Three hundred and fifty-four patients with complete access to the data were included in the study. The mean age of the patients was 60.8±9.4 years. 37% of the patients (131 patients) were female. The number of patients with HbA1c≥7 was 194 (54,8%) in the entire patient population. In this study, high HbA1c (≥7) values in diabetic patients undergoing isolated coronary bypass graft surgery were not found to be independent predictors of post-operative mortality and morbidity. Mortality was seen in 28 patients (7.9%). Ejection fraction (EF) was found to be an independent predictor factor for pre-operative factors in logistic regression models constructed according to mortality predictors (OR:0.94; 95% CI: 0.90-0.99; p=0.016). Complications were seen in 50 patients (14.1%). In the models formed from the point of view of the complication predicators, only EF was found to be independent predictor (OR:0.95; 95% CI: 0.92-0.98; p=0.004). It was found that HbA1c was not predictive in all models for mortality and complication (p>0.05).

Conclusion

There are reports in the literature that mortality increases 4-fold when HbA1c value is higher than 8.6% in coronary surgery. However, there is a view that HbA1c alone cannot predict mortality in coronary surgery if diabetes associated factors are excluded. In this study, high HbA1c (≥7) values in diabetic patients undergoing isolated coronary bypass graft surgery were not found to be independent predictors of post-operative mortality and morbidity. Pre-operative low ejection fraction was found as an independent risk factor for post-operative mortality and morbidity in the general patient population.