Contemporary Outcomes of Coronary Artery Bypass Grafting Among Patients With Insulin-Treated and Non-Insulin-Treated Diabetes

Elevated glycosylated hemoglobin levels are associated with severe acute kidney injury following coronary artery bypass surgery

BACKGROUND

Diabetic patients are at increased risk of acute kidney injury (AKI) following surgery. The significance of uncontrolled diabetes on kidney function after coronary artery bypass grafting (CABG) remains controversial. Our aim was to study the association between pre-operative hemoglobin A1c (HbA1c) and severe cardiac surgery-associated AKI (CSA-AKI) following CABG.

METHODS

A single-center, retrospective cohort study including patients who underwent isolated CABG from 2010 to 2018 was performed. Patients were grouped into pre-operative HbA1c of <6.5 %, 6.5-8.5 %, and ≥8.5 %. Postoperative serum creatinine levels were queried for up to 30 days, and the 30-day risk of severe AKI was compared among groups. Multivariable logistic regression was used to study factors associated with severe CSA-AKI and the association of severe CSA-AKI with postoperative outcomes. Cox regression was used to study the association between severe CSA-AKI and all-cause mortality from the time of surgery to the last follow-up or death.

RESULTS

A total of 2424 patients met the inclusion criteria. Patients were primarily male (70.5 %), with a median age of 64 years (IQR 57-71). Median bypass and cross-clamp times were 95 (IQR 78-116) and 78 min (IQR 63-95). Severe CSA-AKI occurred within 30 days in 5.7 %, 6.7 %, and 9.1 % of patients with pre-op HbA1c of <6.5 %, 6.5-8.5 %, and ≥8.5 %, respectively. After adjusting for covariates, HbA1c >8.5 %, was independently associated with severe CSA-AKI 30 days after CABG (aOR 1.59, 95%CI 1.06-2.40). In addition, severe CSA-AKI was associated with increased 30- (aOR 15.83,95%CI 7.94-31.56) and 90- day mortality (aOR 9.54, 95%CI 5.46-16.67), prolonged length of stay (aOR 3.46,95%CI 2.41-4.96) and unplanned 30-day readmission (aOR 2.64, 95%CI 1.77-3.94). Lastly, severe CSA-AKI was associated with increased all-cause mortality (aHR 3.19, 95%CI 2.43-4.17).

CONCLUSION

Elevated preoperative HbA1c (≥8.5 %) was independently associated with an increased 30-day risk of severe CSA-AKI, which is a consistent predictor of adverse outcomes after CABG. Delaying surgery to achieve optimal glycemic control in an elective setting may be reasonable.

Risk factors associated with surgical site infections in patients undergoing cardiothoracic surgery: A systematic review and meta-analysis

Surgical site infections (SSIs) following cardiothoracic surgery can pose significant challenges to patient recovery and outcome. This systematic review and meta-analysis aim to identify and quantify the risk factors associated with SSIs in patients undergoing cardiothoracic surgery. A comprehensive literature search adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and based on the PICO paradigm was conducted across four databases: PubMed, Embase, Web of Science and the Cochrane Library, without any temporal restrictions. The meta-analysis incorporated studies detailing the risk factors for post-operative sternal infections, especially those reporting odds ratios (OR) or relative risks with 95% confidence intervals (CI). Quality assessment of the studies was done using the Newcastle-Ottawa Scale. Statistical analysis was executed using the chi-square tests for inter-study heterogeneity, with further analyses depending on I2 values. Sensitivity analyses were performed, and potential publication bias was also assessed. An initial dataset of 2442 articles was refined to 21 articles after thorough evaluations based on inclusion and exclusion criteria. Patients with diabetes mellitus have an OR of 1.80 (95% CI: 1.40-2.20) for the incidence of SSIs, while obese patients demonstrate an OR of 1.63 (95% CI: 1.40-1.87). Individuals who undergo intraoperative blood transfusion present an OR of 1.13 (95% CI: 1.07-1.18), and smokers manifest an OR of 1.32 (95% CI: 1.03-1.60). These findings unequivocally indicate a pronounced association between these factors and an elevated risk of SSIs post-operatively. This meta-analysis confirms that diabetes, obesity, intraoperative transfusion and smoking heighten the risk of SSIs post-cardiac surgery. Clinicians should be alert to these factors to optimise patient outcomes.

Surgical ablation for atrial fibrillation: impact of Diabetes Mellitus type 2

BACKGROUND

Diabetes mellitus (DM) type 2 is an independent risk factor for atrial fibrillation (AF). Surgical ablation or "maze procedure" is an option for patients with AF undergoing concomitant or isolated cardiac surgery. The aim of this study was to evaluate the impact of DM type 2 on early and long-term outcomes of patients following surgical AF ablation.

METHODS

We performed an observational cohort study in Israel's largest tertiary care center. All data of patients who underwent surgical AF ablation, between 2006 and 2021 were extracted from our departmental database. Patients were divided into Group I (non-diabetic patients) and Group II (DM type 2 patients). We compared the two groups with respect to freedom from recurrent atrial arrhythmia, and mortality rate.

RESULTS

The study population included 606 patients. Group I (non-DM patients), consisting of 484 patients, and Group II (DM type 2 patients), comprised 122 patients. Patients with DM were older, had more hypertension and incidence of cerebrovascular accident (CVA)/transient ischemic attack (TIA), higher EuroSCORE (p < .05 for all), and a longer bypass time-130 ± 40 vs. 122 ± 36 min (p = 0.028). The mean follow-up duration was 39.0 ± 22.7 months. Freedom from atrial fibrillation was similar between the non-DM and DM type 2 groups after a 1-year follow-up, 414 (88.2%) vs. 101 (87.1%) (p = 0.511), after a 3-year follow-up, 360 (86.3%) vs. 84 (79.9%) (p = 0.290) and after a 5-year follow-up, 226 (74.1%) vs. 55 (71.5%) (p = 0.622) respectively. Furthermore, 1- and 3-year mortality was similar between non-DM and DM type 2 groups, 2.5% vs. 4.9%, (p = 0.226) and 5.6% vs. 10.5% (p = 0.076) respectively. 5-year mortality was higher in Group II (DM type 2 patients) compared with Group I (non-DM patients), 11.1% vs. 23.4% (p = 0.009).

CONCLUSION

Surgical ablation had a high success rate, with freedom from recurrent atrial arrhythmia at 1- 3- and 5- years follow-up in both the DM type 2 and non-DM groups. Furthermore,1- and 3-year mortality after surgical ablation was also similar in both groups. However, 5-year mortality was higher in the DM type 2 group.

Multiple arterial versus single arterial grafting in patients with diabetes undergoing coronary artery bypass surgery

Background

Data on long-term outcomes in patients with diabetes receiving multiarterial grafting (MAG) versus single-artery grafting (SAG) are limited.

Objectives

The objective of this study is to compare long-term outcomes between MAG and SAG for coronary artery bypass graft (CABG) surgery in patients with diabetes.

Methods

Patients with diabetes who underwent isolated CABG surgeries between 2000 to 2016 were identified using the New Jersey mandatory state clinical registry linked with death records and hospital discharge data (last follow-up December 31, 2019). Patients who underwent CABG for single-vessel disease, with only venous conduits, patients with previous heart surgeries, or hemodynamically unstable were excluded. Patients undergoing MAG and SAG were matched by propensity score. Cox proportional hazard models were used to investigate long-term survival and competing risk analysis was used for secondary outcomes.

Results

Of 24,944 patients, 2955 underwent MAG, and 21,989 underwent SAG CABG. Patients receiving MAG were younger, predominantly men, with a lower prevalence of hypertension, peripheral vascular disease, congestive heart failure, chronic lung disease, and renal failure. MAG was associated with lower long-term mortality compared with SAG in 2882 propensity score-matched pairs (hazard ratio [HR], 0.75; 95% CI, 0.68-0.83); lower risks of repeat revascularization (subdistribution HR, 0.86; 95% CI, 0.76-0.97); and composite outcome defined as death from any cause, stroke, postoperative myocardial infarction, and/or repeat revascularization (HR, 0.76; 95% CI, 0.71-0.82). These results were confirmed in subgroup analyses of women, men, age <70 years, and age ≥70 years patients with diabetes. MAG was also associated with lower mortality compared with SAG in patients with diabetes taking insulin in the entire cohort (Video Abstract).

Conclusions

Patients with diabetes benefit from receiving MAG over SAG and demonstrated improved long-term survival, and lower hazards of secondary and composite outcomes. Coordinated efforts are needed to offer MAG to patients with diabetes.

Restrictive versus liberal transfusion in patients with diabetes undergoing cardiac surgery: An open-label, randomized, blinded outcome evaluation trial

AIM

To characterize the association between diabetes and transfusion and clinical outcomes in cardiac surgery, and to evaluate whether restrictive transfusion thresholds are harmful in these patients.

MATERIALS AND METHODS

The multinational, open-label, randomized controlled TRICS-III trial assessed a restrictive transfusion strategy (haemoglobin [Hb] transfusion threshold <75 g/L) compared with a liberal strategy (Hb <95 g/L for operating room or intensive care unit; or <85 g/L for ward) in patients undergoing cardiac surgery on cardiopulmonary bypass with a moderate-to-high risk of death (EuroSCORE ≥6). Diabetes status was collected preoperatively. The primary composite outcome was all-cause death, stroke, myocardial infarction, and new-onset renal failure requiring dialysis at 6 months. Secondary outcomes included components of the composite outcome at 6 months, and transfusion and clinical outcomes at 28 days.

RESULTS

Of the 5092 patients analysed, 1396 (27.4%) had diabetes (restrictive, n = 679; liberal, n = 717). Patients with diabetes had more cardiovascular disease than patients without diabetes. Neither the presence of diabetes (OR [95% CI] 1.10 [0.93-1.31]) nor the restrictive strategy increased the risk for the primary composite outcome (diabetes OR [95% CI] 1.04 [0.68-1.59] vs. no diabetes OR 1.02 [0.85-1.22]; P_interaction  = .92). In patients with versus without diabetes, a restrictive transfusion strategy was more effective at reducing red blood cell transfusion (diabetes OR [95% CI] 0.28 [0.21-0.36]; no diabetes OR [95% CI] 0.40 [0.35-0.47]; P_interaction  = .04).

CONCLUSIONS

The presence of diabetes did not modify the effect of a restrictive transfusion strategy on the primary composite outcome, but improved its efficacy on red cell transfusion. Restrictive transfusion triggers are safe and effective in patients with diabetes undergoing cardiac surgery.

Patient and hospital factors associated with 30-day readmissions after coronary artery bypass graft (CABG) surgery: a systematic review and meta-analysis

BACKGROUND

Readmission after coronary artery bypass graft (CABG) surgery is associated with adverse outcomes and significant healthcare costs, and 30-day readmission rate is considered as a key indicator of the quality of care. This study aims to: quantify rates of readmission within 30 days of CABG surgery; explore the causes of readmissions; and investigate how patient- and hospital-level factors influence readmission.

METHODS

We conducted systematic searches (until June 2020) of PubMed and Embase databases to retrieve observational studies that investigated readmission after CABG. Random effect meta-analysis was used to estimate rates and predictors of 30-day post-CABG readmission.

RESULTS

In total, 53 studies meeting inclusion criteria were identified, including 8,937,457 CABG patients. The pooled 30-day readmission rate was 12.9% (95% CI: 11.3-14.4%). The most frequently reported underlying causes of 30-day readmissions were infection and sepsis (range: 6.9-28.6%), cardiac arrythmia (4.5-26.7%), congestive heart failure (5.8-15.7%), respiratory complications (1-20%) and pleural effusion (0.4-22.5%). Individual factors including age (OR per 10-year increase 1.12 [95% CI: 1.04-1.20]), female sex (OR 1.29 [1.25-1.34]), non-White race (OR 1.15 [1.10-1.21]), not having private insurance (OR 1.39 [1.27-1.51]) and various comorbidities were strongly associated with 30-day readmission rates, whereas associations with hospital factors including hospital CABG volume, surgeon CABG volume, hospital size, hospital quality and teaching status were inconsistent.

CONCLUSIONS

Nearly 1 in 8 CABG patients are readmitted within 30 days and the majority of these are readmitted for noncardiac causes. Readmission rates are strongly influenced by patients' demographic and clinical characteristics, but not by broadly defined hospital characteristics.

Bilateral internal thoracic artery grafting in haemodialysis patients with diabetic nephropathy

OBJECTIVES

To compare postoperative outcomes in patients with diabetic nephropathy receiving haemodialysis and undergoing isolated coronary artery bypass grafting (CABG) using bilateral or single skeletonized internal thoracic artery (ITA).

METHODS

Among 1441 consecutive patients undergoing isolated CABG between 2002 and 2019 at our university hospital, we retrospectively analysed data for 107 patients with diabetic nephropathy receiving haemodialysis. After inverse probability of treatment weighting, we found no statistically significant differences regarding patients' preoperative characteristics.

RESULTS

All patients underwent myocardial revascularization using the off-pump technique. There was no statistical significance in postoperative deep sternal wound infection (P = 0.902) and 30-day mortality (P = 0.755). However, the bilateral ITA group had a lower rate of postoperative stroke versus the single group (0% vs 5.5%, respectively; P = 0.021). Follow-up was completed in 95.3% (102/107) of the patients, and the mean follow-up duration was 3.3 years. Thirty-eight deaths occurred in the bilateral ITA group and 18 in the single ITA group. There was no significant difference in all-cause death (P = 0.558) and cardiac death rates (P = 0.727). Multivariable Cox regression models showed that the independent predictors of all-cause death were age [hazard ratio (HR) 1.031; P = 0.010], previous percutaneous intervention (HR 1.757; P = 0.009) and gastroepiploic artery grafting (HR 0.582; P = 0.026).

CONCLUSIONS

Bilateral ITA grafting in patients with diabetic nephropathy receiving haemodialysis did not improve mid-term outcomes.

Short-term outcomes following coronary artery bypass graft surgery in insulin treated and non-insulin treated diabetes: A tertiary hospital experience in Australia

BACKGROUND AND AIMS

Outcomes after coronary artery bypass graft (CABG) surgery have improved due to advances in surgical technique and post-operative care. We aimed to describe contemporary clinical characteristics and short-term post-operative outcomes in diabetic patients undergoing CABG surgery.

METHODS

A retrospective analysis of patients who underwent CABG surgery over a 4.5-year period in a Western Australian tertiary hospital was performed in September 2019. The cohort was stratified according to pre-operative diabetes status.

RESULTS

A total of 1327 patients underwent CABG surgery, of which 572 (43.1%) had diabetes. Diabetic patients were more likely to be female (24.7% vs. 13.9%, p < 0.001) and have dyslipidaemia (83.0% vs. 68.1%, p < 0.001), hypertension (82.0% vs. 68.7%, p < 0.001), raised body mass index (29.8 ± 5.6 vs. 28.7 ± 5.1 kg/m², p < 0.001), prior myocardial infarction (62.8% vs. 54.8%, p = 0.004), prior stroke (8.6% vs. 5.0%, p = 0.010), congestive cardiac failure (20.2% vs. 15.1%, p = 0.014), reduced estimated glomerular filtration rate (86.7 ± 36.1 vs. 90.8 ± 32.1 ml/min/1.73 m², p = 0.036) and three-vessel coronary artery disease (74.8% vs. 67.3%, p = 0.003). Post-operative wound infections (3.1% vs. 1.5%, p = 0.022), new dialysis requirement (2.9% vs. 1.0%, p = 0.009) and 30-day hospital admission (13.1% vs. 8.5%, p = 0.007) was more likely in diabetic patients, but not myocardial infarction (3.0% vs. 2.0%, p = 0.247), stroke (1.4% vs. 0.8%, p = 0.286) or 30-day mortality (2.4% vs. 1.7%, p = 0.354). No significant differences were detected in short-term outcomes between patients with non-insulin (n = 398) versus insulin treated (n = 174) diabetes.

CONCLUSIONS

Diabetic patients continue to represent a higher-risk cohort, highlighting the need for further strategies to reduce short-term adverse outcomes following CABG surgery.

The Impact of Left Ventricular Assist Device Infections on Postcardiac Transplant Outcomes: A Systematic Review and Meta-Analysis

Left ventricular assist devices (LVADs) are associated with numerous short- and long-term complications, including infection. The impact LVAD infections have on clinical outcomes after transplantation is not well established. We sought to determine whether the presence of infection while on LVAD support negatively influences outcomes after cardiac transplantation. We searched electronic databases and bibliographies for full text studies that identified LVAD infections during support and also reported on posttransplant outcomes. A meta-analysis of posttransplant survival was conducted using a random effects model. Of 2,373 records, 13 bridge to transplant (BTT) cohort studies were selected (n = 6,631, 82% male, mean age 50.7 ± 2.7 years). A total of 6,067 records (91.5%) received transplant. There were 3,718 (56.1%) continuous-flow LVADs (CF-LVADs), 1,752 (26.4%) pulsatile LVADs, and 1,161 (17.5%) unknown type records. A total of 2,586 records (39.0%) developed LVAD infections. Patients with LVAD infections were younger (50.5 ± 1.5 vs. 51.3 ± 1.5, p = 0.02), had higher body mass indeices (BMIs) (28.4 ± 0.7 vs. 26.8 ± 0.4, p < 0.01), and longer LVAD support times (347.0 ± 157.6 days vs. 180.2 ± 106.0 days, p < 0.01). Meta-analysis demonstrated increased posttransplant mortality in those patients who had an LVAD infection (hazard ratio [HR] 1.30, 95% CI: 1.16-1.46, p < 0.001). Subgroup meta-analyses by continuous-flow and pulsatile device type demonstrated significant increased risk of death for both types of devices (HR 1.47, 95% CI: 1.22-1.76, p < 0.001 and 1.71, 95% CI: 1.19-2.45, p = 0.004, respectively). Patients who develop LVAD infections are younger, have higher BMIs and longer LVAD support times. Our data suggests that LVAD-related infections result in a 30% increase in postcardiac transplantation mortality. Strategies to prevent LVAD infections should be implemented to improve posttransplant outcomes in this high-risk population.

Type 2 diabetes mellitus increases the mortality risk after acute coronary syndrome treated with coronary artery bypass surgery

Background

Type 2 diabetes mellitus (DM) is a risk factor for cardiovascular diseases and is common among patients undergoing coronary artery bypass grafting (CABG) surgery. The main objective of our study was to investigate the impact of DM type 2, and its treatment subgroups, on short- and long-term mortality in patients with acute coronary syndrome (ACS) who undergo CABG.

Methods

The study included 1307 patients enrolled from the biennial Acute Coronary Syndrome Israeli Survey between 2000 and 2016, who were hospitalized for ACS and underwent CABG. Of them, 527 (40%) patients were with and 780 (60%) were without DM.

Results

Compared with the non-diabetic group, the diabetic group of patients comprised more women and had more comorbidities such as hypertension, dyslipidemia, renal impairment, peripheral vascular disease and prior ischemic heart disease. Overall 30-day mortality rate was similar between DM and non-DM patients (4.2% vs. 4%, p = 0.976). Ten-year mortality rate was higher in DM compared with non-diabetic patients (26.6% vs. 17.7%, log-rank p < 0.001), and higher in the subgroup of insulin-treated patients compared to non-insulin treated patients (31.5% vs. 25.6%, log-rank p = 0.019). Multivariable analysis showed that DM increased the mortality hazard by 1.61-fold, and insulin treatment among the diabetic patients increased the mortality hazard by 1.57-fold.

Conclusions

While type 2 DM did not influence the in-hospital mortality hazard, we showed that the presence of DM among patients with ACS referred to CABG, is a powerful risk factor for long-term mortality, especially when insulin was included in the diabetic treatment strategy.

Coronary artery bypass surgery in type 2 diabetic patients: predictors of mortality and morbidity

Background

Coronary artery bypass grafting has been widely admitted in the therapeutic arsenal of coronary artery disease in diabetics with low morbi-mortality. However, it requires special management which may be challenging in low-volume centers especially in African countries. We aimed to analyze the outcome of coronary artery bypass graft in our diabetic population and define predictors of adverse events.

Patients and methods

We retrospectively enrolled 529 consecutive diabetic patients (type 2) who underwent on-pump coronary artery bypass grafting at our institution between January 2000 and June 2018. The mean age was 61.1 ± 8.3 years with 4.04 as sex ratio (M/F) and 2.95 as mean EuroSCORE II. History of acute myocardial infarction, left main coronary artery stenosis, and three-vessel disease was present in respectively 58%, 26.1%, and 72.2% of patients. The average number of bypass was 2.4 ± 0.8. Duration of cardiopulmonary bypass and aortic cross-clamping were respectively 124.8 ± 43.5 and 79.7 ± 32.9 min.

Results

In-hospital mortality was 5.9% (n = 31) and the late mortality was 6.9% (n = 32). Duration of artificial ventilation, ICU stay, and postoperative stay were respectively 7 h, 44 h, and 13 days. Postoperative complications were myocardial infarction, superficial wound infection, mediastinitis, and low cardiac output syndrome in respectively 9.1%, 25.5%, 3.8%, and 12.7% of patients. Multivariable logistic regression analysis revealed that left ventricular ejection fraction < 40% (OR = 1.88; 95% CI 1.30–2.47; p = 0.03), poor perioperative glycemic control (OR = 1.53; 95% CI 1.12–2.38; p = 0.014), intra-aortic balloon pump insertion (OR = 2.29; 95% CI 1.47–3.10; p < 0.001), and postoperative cardiac complications (OR = 2.01; 95% CI 1.23–2.78; p < 0.001) were predictors of in-hospital mortality. Predictors of mediastinitis were obesity (OR = 5.86; 95% CI 1.43–23.95; p = 0.014), inotropic drugs use (OR = 8.14; 95% CI 1.57–42.34; p = 0.013), chest reopening for bleeding (OR = 4.01; 95% CI 0.62–25.85; p = 0.014), and blood transfusion (OR = 7.56; 95% CI 1.09–52.76; p = 0.041). Follow-up was 86.1% complete, with a mean follow-up of 63.5 ± 48.3 months (1–192 months), and cumulative survival at 5, 10, and 15 years was respectively 95.5 ± 1.1%, 86.3 ± 2.9%, and 76.9 ± 6.9%.

Conclusion

Even in low-volume centers in developing areas, coronary artery bypass surgery is an effective therapy for coronary artery disease in diabetic patients despite a relative high morbidity and mortality.

Effect of Diabetes Mellitus on Complication Rates of Coronary Artery Bypass Grafting

Previous studies have shown that diabetes mellitus (DM) is a risk factor for postoperative coronary artery bypass grafting (CABG) complications. More contemporary studies are needed to guide revascularization decisions in DM patients. We performed a single-center study of patients who underwent CABG. Patients with no DM were compared with patients with DM, subgrouped according to whether or not DM was treated with insulin before admission (Insulin and No Insulin Groups). Multivariable logistic regression was used to determine whether DM was a significant predictor of mortality, combined postoperative events, and specific postoperative complications after controlling for other predictive clinical variables. Of 11,590 consecutive patients who underwent CABG, 5,013 (43%) had DM and 6,577 (57%) had no DM. Of the patients with DM, 3,433 (68%) were not treated with insulin and 1,580 (32%) were treated with insulin before admission. Multivariable logistic regression analyses showed that DM was not significantly associated with in-hospital mortality or combined postoperative events after considering other clinical variables. The No Insulin Group was significantly associated with stroke, and the Insulin Group was significantly associated with surgical site infection and new renal failure. In conclusion, this study of consecutively treated CABG patients shows that DM is not a predictor of in-hospital mortality or combined in-hospital postoperative events after adjusting for other clinical factors. DM is a predictor of permanent stroke, surgical site infection, and new renal failure. These findings may help with case selection and management of DM patients undergoing CABG.

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.

Risk factors for readmission of inpatients with diabetes: A systematic review

AIM

We have limited understanding of which risk factors contribute to increased readmission rates amongst people discharged from hospital with diabetes. We aim to complete the first review of its kind, to identify, in a systematic way, known risk factors for hospital readmission amongst people with diabetes, in order to better understand this costly complication.

METHOD

The review was prospectively registered in the PROSPERO database. Risk factors were identified through systematic review of literature in PubMed, EMBASE & SCOPUS databases, performed independently by two authors prior to data extraction, with quality assessment and semi-quantitative synthesis according to PRISMA guidelines.

RESULTS

Eighty-three studies were selected for inclusion, predominantly from the United States, and utilising retrospective analysis of local or regional data sets. 76 distinct statistically significant risk factors were identified across 48 studies. The most commonly identified risk factors were; co-morbidity burden, age, race and insurance type. Few studies conducted power calculations; unstandardized effect sizes were calculated for the majority of statistically significant risk factors.

CONCLUSION

This review is important in assessing the current state of the literature and in supporting development of interventions to reduce readmission risk. Furthermore, it provides an important foundation for development of rigorous, pre-specified risk prediction models.

Impact of type 2 diabetes mellitus on short- and long-term mortality after coronary artery bypass surgery

Background

Type 2 diabetes mellitus (DM) is a frequent co-morbidity among patients undergoing coronary artery bypass grafting (CABG) surgery. The aim of this study was to evaluate the impact of DM on the early- and long-term outcomes of patients who underwent isolated CABG.

Methods

We performed an observational cohort study in a large tertiary medical center over a period of 11 years. All data from patients who had undergone isolated CABG surgery between 2004 and 2014 were obtained from our departmental database. The study population included 2766 patients who were divided into two groups: Group I (1553 non-diabetic patients), and Group II (1213 patients suffering from type 2 DM). Group II patients were then divided into two subgroups: subgroup IIA (981 patients treated with oral antihyperglycemic medications) and subgroup IIB (232 insulin-treated patients with or without additional oral antihyperglycemic drugs). In-hospital, 1-, 3-, 5- and 10-year mortality outcome variables were evaluated. Mean follow-up was 97 ± 41 months.

Results

In-hospital mortality was similar between Group I and Group II patients (1.87% vs. 2.31%, p = 0.422) and between the subgroups IIA and IIB (2.14% vs. 3.02%, p = 0.464). Long-term mortality (1, 3, 5 and 10 years) was higher in Group II (DM type 2) compared with Group I (non-diabetic patients) (5.3% vs. 3.6%, p = 0.038; 9.3% vs. 5.6%, p < 0.001; 15.3% vs. 9.3%, p < 0.001 and 47.3% vs. 29.6% p < 0.001). Kaplan–Meier analysis demonstrated that all-cause mortality was higher in Group II compared with Group I (p < 0.001) and in subgroup IIB compared with subgroup IIA (p = 0.001). Multivariable analysis showed that DM increased the mortality hazard by twofold, and among diabetic patients, insulin treatment increased the mortality hazard by twofold.

Conclusions

Diabetic and non-diabetic patients have similar in-hospital mortality rates. Survival rates of diabetic patients start to deteriorate 3 year after surgery. Type 2 DM is an independent predictor for long-term mortality after isolated CABG surgery. Mortality is even higher when the diabetes treatment strategy included insulin.

Electronic supplementary material

The online version of this article (10.1186/s12933-018-0796-7) contains supplementary material, which is available to authorized users.

Outcomes of Coronary Artery Bypass Graft Surgery Versus Percutaneous Coronary Intervention in Patients Aged 18-45 Years with Diabetes Mellitus

BACKGROUND

Debate on treatment for young patients with coronary artery disease still exists. This study aimed to investigate the intermediate- and long-term outcomes between coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) in patients aged 18-45 years with diabetes mellitus (DM).

METHODS

Between January 2006 and March 2016, a total of 2018 DM patients aged 18-45 years including 517 cases of CABG and 1501 cases of PCI were enrolled in the study. Using propensity score matching (PSM), 406 patients were matched from each group. The intermediate- and long-term data were collected. The primary end point of this study was long-term death. The secondary end points included long-term major adverse cardiovascular and cerebrovascular events (MACCEs), stroke, angina, myocardial infarction (MI), and repeat revascularization.

RESULTS

Before PSM, the in-hospital mortality was 1.2% in the CABG group and 0.1% in the PCI group, with statistically significant difference (P < 0.0001). The 10-year follow-up outcomes including long-term survival rate and freedom from MACCEs were better in the CABG group than those in the PCI group (97.3% vs. 94.5%, P = 0.0072; 93.2% vs. 86.3%, P < 0.0001), but CABG group was associated with lower freedom from stoke compared to PCI group (94.2% vs. 97.5%, P = 0.0059). After propensity score-matched analysis, these findings at 10-year follow-up were also confirmed. Freedom from MACCEs was higher in CABG group compared to PCI group, but no significant difference was observed (93.1% vs. 89.2%, P = 0.0720). The freedom from recurrent MI was significantly higher in CABG patients compared with PCI patients (95.6% vs. 92.5%, P = 0.0260). Furthermore, CABG was associated with a higher rate of long-term survival rate than PCI (97.5% vs. 94.6%, P = 0.0403). There was no significant difference in the freedom from stroke between CABG and PCI groups (95.3% vs. 97.3%, P = 0.9385). The hospital cost was greater for CABG (13,936 ± 4480 US dollars vs. 10,926 ± 7376 US dollars, P < 0.0001).

CONCLUSIONS

In DM patients aged 18-45 years, the cumulative survival rate, and freedom from MI and repeat revascularization for CABG were superior to those of PCI. However, a better trend to avoid stroke was observed with PCI.

Myocyte membrane and microdomain modifications in diabetes: determinants of ischemic tolerance and cardioprotection

Cardiovascular disease, predominantly ischemic heart disease (IHD), is the leading cause of death in diabetes mellitus (DM). In addition to eliciting cardiomyopathy, DM induces a ‘wicked triumvirate’: (i) increasing the risk and incidence of IHD and myocardial ischemia; (ii) decreasing myocardial tolerance to ischemia–reperfusion (I–R) injury; and (iii) inhibiting or eliminating responses to cardioprotective stimuli. Changes in ischemic tolerance and cardioprotective signaling may contribute to substantially higher mortality and morbidity following ischemic insult in DM patients. Among the diverse mechanisms implicated in diabetic impairment of ischemic tolerance and cardioprotection, changes in sarcolemmal makeup may play an overarching role and are considered in detail in the current review. Observations predominantly in animal models reveal DM-dependent changes in membrane lipid composition (cholesterol and triglyceride accumulation, fatty acid saturation vs. reduced desaturation, phospholipid remodeling) that contribute to modulation of caveolar domains, gap junctions and T-tubules. These modifications influence sarcolemmal biophysical properties, receptor and phospholipid signaling, ion channel and transporter functions, contributing to contractile and electrophysiological dysfunction, cardiomyopathy, ischemic intolerance and suppression of protective signaling. A better understanding of these sarcolemmal abnormalities in types I and II DM (T1DM, T2DM) can inform approaches to limiting cardiomyopathy, associated IHD and their consequences. Key knowledge gaps include details of sarcolemmal changes in models of T2DM, temporal patterns of lipid, microdomain and T-tubule changes during disease development, and the precise impacts of these diverse sarcolemmal modifications. Importantly, exercise, dietary, pharmacological and gene approaches have potential for improving sarcolemmal makeup, and thus myocyte function and stress-resistance in this ubiquitous metabolic disorder.

Impact of type 2 diabetes mellitus on the long-term mortality in patients who were treated by coronary artery bypass surgery: A systematic review and meta-analysis

BACKGROUND

Recent scientific reports have mainly focused on the comparison between coronary artery bypass surgery (CABG) and percutaneous coronary intervention. However, the impact of type 2 diabetes mellitus (T2DM) on mortality in patients who were treated by CABG was often ignored. Therefore, we aimed to compare the long-term mortality following CABG in patients with and without T2DM.

METHODS

Studies comparing the long-term adverse outcomes following CABG in patients with and without T2DM were searched from electronic databases. Total number of deaths (primary outcome) and events of myocardial infarction (MI), major adverse cerebrovascular and cardiovascular events (MACCEs), stroke, and repeated revascularization (secondary outcomes) were carefully extracted. An analysis was carried out whereby odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using the RevMan 5.3 software.

RESULTS

Eleven studies with a total number of 12,965 patients were included. Current results showed that mortality was significantly higher in patients with T2DM with OR: 1.54, 95% CI: 1.37 to 1.72, P < .00001; OR: 1.53, 95% CI: 1.36 to 1.72, P < .00001; and OR: 1.53, 95% CI: 1.26 to 1.87, P < .0001 at 1 to 15, 5 to 15, and 7 to 15 years, respectively. However, MI, repeated revascularization, MACCEs, and stroke were not significantly different with OR: 1.15, 95% CI: 0.81 to 1.64, P = .44; OR: 1.09, 95% CI: 0.88 to 1.36, P = .43; OR: 1.11, 95% CI: 0.83 to 1.48, P = .48; and OR: 1.69, 95% CI: 0.93 to 3.07, P = .08, respectively.

CONCLUSION

Following CABG, a significantly higher rate of mortality was continually observed in patients with T2DM compared to patients without T2DM showing that the former apparently has a high impact on the long-term mortality. However, even if T2DM is an independent risk factor for mortality, it should not be ignored that CABG remains the best revascularization strategy in these patients.

Comparing the Clinical Outcomes Between Insulin-treated and Non-insulin-treated Patients With Type 2 Diabetes Mellitus After Coronary Artery Bypass Surgery: A Systematic Review and Meta-analysis

Several studies have shown coronary artery bypass surgery (CABG) to be beneficial in patients with type 2 diabetes mellitus (T2DM) and multivessel coronary artery diseases. Patients with insulin-treated T2DM (ITDM) are usually patients with poor glycemic control and are expected to suffer more complications compared with patients with non-insulin-treated T2DM (NITDM). However, the adverse clinical outcomes in patients with ITDM and NITDM after CABG are still not very clear. Hence, to solve this issue, we aim to compare the short-and long-term adverse clinical outcomes in a larger number of patients with ITDM and NITDM after CABG, respectively.Randomized controlled trials and observational studies comparing the adverse clinical outcomes such as mortality, major adverse events (MAEs), stroke, myocardial infarction, and repeated revascularization in patients with ITDM and NITDM after CABG have been searched from Medline, EMBASE, Cochrane, and PubMed databases. A short-term follow-up (≤30 days) and a long-term follow-up (≥1 year) were considered. Odds ratio (OR) with 95% confidence interval (CI) was used to express the pooled effect on discontinuous variables and the pooled analyses were performed with RevMan 5.3.Eleven studies involving a total of 64,152 patients with T2DM (23,781 patients with ITDM and 40,371 patients with NITDM) have been included in this meta-analysis. During the short-term follow-up period, patients with ITDM had a significantly higher mortality (OR: 1.47; 95% CI: 1.33-1.61, P < 0.00001) and MAEs (OR: 1.66; 95% CI: 1.48-1.87, P < 0.00001). During the long-term follow-up period, patients with ITDM still had a significantly higher rate of mortality, MAEs, and stroke (OR: 1.23, 95% CI: 1.02-1.49, P = 0.03; OR: 1.50, 95% CI: 1.07-2.12, P = 0.02; OR: 1.39, 95% CI: 1.22-1.59, P < 0.00001, respectively) after CABG. However, our results showed similar repeated revascularization rate between the ITDM and NITDM groups after CABG (OR: 1.31, 95% CI: 0.81-2.12, P = 0.27).According to this study, patients with ITDM had a significantly higher rate of mortality and MAEs compared with patients with NITDM after CABG. Stroke was also significantly higher in patients with ITDM during a long-term follow-up period. However, since the result for the long-term mortality had a higher heterogeneity as compared with the other subgroups, and because a similar revascularization rate was observed between the ITDM and NITDM groups after CABG maybe because of a limited number of patients analyzed, further studies still need to be conducted to completely solve this issue.