On-Pump Versus Off-Pump Coronary Artery Bypass Grafting in Diabetic Patients: A Propensity Score Analysis

Off-pump Versus On-pump Coronary Artery Bypass Grafting in Diabetic patients: A Meta-analysis of Observational Studies with a Propensity-Score Analysis

PURPOSE

The debate between off-pump coronary artery bypass grafting (OPCAB) and on-pump coronary artery bypass grafting (ONCAB) in diabetic patients remains. This meta-analysis aimed to investigate outcomes after OPCAB versus ONCAB for patients with diabetes.

METHODS

Literature research was conducted up to December 2023 using Ovid Medline, EMBASE, and the Cochrane Library. Eligible studies were observational studies with a propensity-score analysis of OPCAB versus ONCAB. The primary outcomes were early mortality and mid-term survival. The secondary outcomes were cerebrovascular accidents, reoperation for bleeding, incomplete revascularization, myocardial infarction, low cardiac output, and renal replacement therapy.

RESULTS

Our research identified seven observational studies with a propensity-score analysis enrolling 13,085 patients. There was no significant difference between OPCAB and ONCAB for early mortality, mid-term survival, myocardial infarction, low cardiac output, and renal replacement therapy. OPCAB was associated with a lower risk of cerebrovascular accidents (OR 0.43; 95% CI, 0.24-0.76, P = 0.004) and reoperation for bleeding (OR 0.60; 95% CI, 0.41-0.88, P = 0.009). However, OPCAB was associated with a higher risk of incomplete revascularization (OR 2.07; 95% CI, 1.60-2.68, P < 0.00001).

CONCLUSION

Among patients with diabetes, no difference in early mortality and mid-term survival was observed. However, OPCAB was associated with a lower incidence of morbidity, including cerebrovascular accidents and reoperation for bleeding.

Clinical outcomes of off-pump coronary artery bypass graft in patients with diabetes and non-diabetics: A systematic review and meta-analysis

BACKGROUND AND AIM

Diabetes mellitus is a prevalent risk factor for developing coronary artery disease which worsens the clinical outcomes of patients undergoing coronary artery bypass grafting (CABG). This study aimed to determine the clinical outcomes of patients with diabetes and non-diabetic patients who underwent off-pump CABG surgery.

METHOD

Medline, Scopus, Proquest, Embase, Web of Science, and Google scholar were searched until September 10, 2021. The effect sizes including unstandardized mean difference and odds ratio with 95% confidence interval were calculated using "Metan" package. The Cochran's Q-test and I² statistic were used to assess heterogeneity, a random-effects model was applied to estimate the pooled effect sizes, and meta-regression was used to investigate the factors affecting heterogeneity between studies.

RESULTS

10 studies with 6200 sample sizes were included in the study. In groups with diabetes, Summary odds ratio (SOR) and 95% confidence interval of infection was 2.18 more than non-diabetic groups. Also, odds renal complication was 1.74 more than non-diabetic groups, and the odds cardiovascular complication in groups with diabetes was 1.30 more than non-diabetics. There were no differences in mortality, neurologic, respiratory and surgical complications between groups with diabetes and non-diabetics. Based on meta-regression results, age (Coefficient: 0.942; p = 0.009) had a significant direct relationship and sample size (Coefficient: 0.001; p = 0.009) had an indirect significant relationship with heterogeneity of neurologic outcomes. There was no significant publication bias in our results.

CONCLUSION

Our study revealed that off-pump CABG led to some significant outcomes in patients with diabetes compared to non-diabetics. Renal and infection complications were higher in patients with diabetes but no significant differences were seen in most of other postoperative outcomes between the two groups.

In-hospital mortality of patients with severe left ventricular dysfunction undergoing coronary artery bypass grafting in Iranian population

Background

Historically, coronary artery bypass grafting is associated with a higher mortality rate in patients with severe heart failure. This study aimed to assess the in-hospital mortality of CABG in patients with severe heart failure in Iranian patients and to identify factors associated with adverse outcomes.

Methods

This retrospective descriptive study enrolled patients with severe heart failure who underwent coronary artery bypass surgery from 2015 to 2020 in Madani Hospital, affiliated with Tabriz University of Medical Sciences.

Results

A total of 865 consecutive patients with a mean age of 60.65 ± 10.00 were enrolled in the study. Of all participants, 175 were female (20.4%), and 684 were male. The overall mortality rate was 9.5%. In the univariate analysis, predictors of ICU mortality were age, female sex, DM, and renal failure (P value < 0.05). None of the factors studied was an independent predictor of ICU mortality in the multivariate analysis.

Conclusion

This study established that although coronary artery bypass surgery is reported to have low mortality and postoperative morbidity in patients with severe heart failure, there are still centers that face higher mortality rates in these patients. Improving these patients' outcomes would be possible through identifying the associated risk factors and pre-and postoperative management.

The Effect of Acute Kidney Injury on TGF-β1 and Smad3 in Patients with Coronary Heart Disease after Off-Pump Coronary Artery Bypass Grafting

Background

Acute kidney injury (AKI) is one of the most common and serious complications for coronary disease (CAD) patients, suffering from coronary artery bypass surgery (CABG). AKI occurs in nearly 30% of cardiac surgery patients, including CABG patients, affecting renal function, prolonging hospitalization time, and increasing all-cause mortality. TGF-β1 and Smad3 are sensitive biomarkers in evaluating kidney function. Therefore, comparing the TGF-β1 and Smad3 levels between the AKI patients and non-AKI patients after CABG surgery might have an important significance for identifying the risk degree of AKI and applying effective preventive measures after CABG surgery.

Objective

This study aims at comparing the TGF-β1 and Smad3 levels between the AKI patients and non-AKI patients after CABG surgery to identify the risk degree of AKI and apply effective preventive measures after CABG surgery in clinics.

Materials and Methods

A total of 25 proper patients, diagnosed as coronary disease (CAD) and undergoing AKI after CABG, were selected as the AKI group. The 25 participants, who did not suffer from AKI after CABG, were recruited using the case-control matching method in SPSS 25.0 software as the non-AKI group. Also, corresponding surgical specimens (tissues) and samples of blood were collected from them. Histopathological analysis and immunofluorescent microscopy of lesion artery and kidney of patients, who have been treated with kidney transplants, were performed on surgical specimens to find the pathological and histological change difference between the two groups. RT-PCR and Western blot were conducted to quantify the levels of TGF-β1 and Smad3 expression in serum for the patients of AKI and non-AKI groups, respectively.

Results

Serious renal fibrosis was noted in patients of the AKI group. In addition, by H&E staining of the lesion artery, severe histopathological changes including smooth muscles proliferation with endothelial cell infiltration, focal degeneration and disruptions, and less collagen accumulation were found in the lesion artery of patients from the AKI group. Higher levels of TGF-β1 and Smad3 were observed in serum of patients of the AKI group.

Conclusion

: The increased levels of TGF-β1 and Smad3 in serum might be risk factors for triggering AKI for CAD patients undergoing CABG.

Risk Factors of On-Pump Conversion during Off-Pump Coronary Artery Bypass Graft

Background

Off-pump coronary artery bypass grafting (OPCABG) procedures can avoid the complications of an on-pump bypass. However, some cases unexpectedly require conversion to cardiopulmonary bypass during OPCABG. The risk factors associated with a sudden need for cardiopulmonary bypass were analyzed.

Methods

This retrospective study included 283 subjects scheduled for OPCABG from 2001 to 2010. These were divided into an OPCABG group and an on-pump conversion group. Preoperative, operative, and postoperative variables were compared between the 2 groups.

Results

Of the 283 patients scheduled for OPCABG, 47 (16%) were switched to on-pump coronary artery bypass grafting (CABG). The mortality of the both the OPCABG and on-pump conversion groups was not significantly different. The major risk factors for conversion to on-pump CABG were congestive heart failure (CHF) (odds ratio [OR], 3.5; p=0.029), ejection fraction (EF) <35% (OR, 4.4; p=0.012), and preoperative beta-blocker (BB) administration (OR, 0.3; p=0.007). The use of intraoperative (p=0.007) and postoperative (p=0.021) inotropics was significantly higher in the conversion group. The amount of postoperative drainage (p<0.001) and transfusion (p<0.001) also was significantly higher in the conversion group. There were no significant differences in stroke or cardiovascular complications between the groups over the course of short-term and long-term follow-up.

Conclusion

Patients who undergo OPCABG and have CHF or a lower EF (<35%) are more likely to undergo on-pump conversion, while preoperative BB administration could help prevent conversions from OPCABG to on-pump CABG.

Myocardial revascularization without extracorporeal circulation; Why hasn't it convinced yet?

Extracorporeal circulation has led to a great development in cardiovascular surgery during the last five decades. Its time-proven efficacy and safety have made on-pump coronary artery bypass grafting (CABG) the gold standard method of surgical revascularization. However, coronary revascularization on cardiopulmonary bypass and the accompanying aortic manipulation are related to plenty of deleterious complications. Therefore, off-pump CABG surgery was established to avoid complications. Nevertheless, despite the initial enthusiasm on this technique, only 20% of myocardial revascularization procedures worldwide are performed off-pump. Not only are off-pump cardiac procedures more technically difficult but also they do not provide better results in terms of graft patency, completeness of revascularization, repeat revascularization requirement, cost, and quality of life. Completeness of revascularization and anastomotic quality should not be compromised to avoid cardiopulmonary bypass.

Off-pump versus on-pump coronary artery bypass grafting in patients with diabetes: a meta-analysis

AIMS

The effects of off-pump CABG (OFF-CABG) versus on-pump CABG (ON-CABG) in diabetic patients remain controversial. The aim of our study was to compare mortality and postoperative morbidity between OFF-CABG and ON-CABG for diabetic patients.

METHODS

Electronic databases including PubMed, EMBASE and Cochrane Library for studies investigating clinical outcomes of OFF-CABG versus ON-CABG in diabetic patients were searched, collecting data from inception until June 2016. We pooled the odds ratios from individual studies and performed heterogeneity, quality assessment and publication bias analysis.

RESULTS

A total of 543,220 diabetic patients in 10 studies were included. The overall mortality (OR, 0.87; 95% CI, 0.58-1.31; p = 0.50) was comparable between the OFF-CABG and ON-CABG. OFF-CABG was associated with significantly fewer cerebrovascular accidents (OR, 0.45; 95% CI, 0.31-0.65; p < 0.0001), bleeding complications (OR, 0.59; 95% CI, 0.43-0.80; p < 0.001) and pulmonary complications. However, no differences in myocardial infarction (OR, 0.76; 95% CI, 0.52-1.12; p = 0.16), renal failure (OR, 0.74; 95% CI, 0.50-1.11; p = 0.14) and other postoperative morbidity outcomes were found.

CONCLUSIONS

OFF-CABG significantly reduces the incidence of postoperative cerebrovascular accidents and bleeding complications compared with ON-CABG in diabetic patients. No differences were found regarding mortality, myocardial infarction and renal failure between these two techniques. Our study suggests that OFF-CABG may be an optimal strategy for diabetic patients although adequately powered randomized trials are needed to further verify the finding.

Total arterial off-pump coronary artery bypass grafting was not associated with inferior outcomes for diabetic when compared with non-diabetic patients

OBJECTIVES

Diabetes mellitus is a strong risk factor that worsens the clinical outcome of patients undergoing coronary artery bypass grafting (CABG). With the development of the off-pump CABG technique, there is a current trend in revascularization strategies towards in situ all-arterial grafting. We were interested in whether total arterial off-pump CABG could improve the outcome for diabetic patients.

METHODS

From January 2002 to December 2013, a total of 1064 patients underwent off-pump CABG at our institution, with total arterial reconstruction carried out in 775 cases. Of the 775 patients, 436 had diabetes (DM) and 339 did not (nDM). After propensity score matching, 301 cases from each group were successfully matched.

RESULTS

All procedures were performed via the off-pump technique without conversion to on-pump. Four patients in the DM group and 1 in the nDM group died in hospital. Multivariate analysis revealed that chronic pulmonary disease [odds ratio (OR) 7.04, P = 0.036] and low (<40%) ejection fraction (OR 11.3, P = 0.009) are independent risk factors for hospital death, and advanced age for deep sternal infection (OR 1.07, P = 0.04). Follow-up was completed in 97.7% of the patients to a maximum of 11.9 years. The rate of 10-year freedom from all-cause mortality was 84.2% in the DM and 74.3% in the nDM group (P = 0.45). The corresponding rates for major adverse cardiac event were 93.3 and 86.9% (P = 0.09). Multivariate Cox regression analysis revealed chronic renal failure, older age, cerebrovascular accident, low ejection fraction and urgency as significant predictors of late death. Diabetes was not associated with any long- or short-term outcome.

CONCLUSIONS

Total arterial off-pump CABG using skeletonization technique can provide similar clinical outcome for diabetic patients in the long as well as in the short term as that for non-diabetic patients.

On-pump versus off-pump coronary artery bypass graft surgery among patients with type 2 diabetes in the Bypass Angioplasty Revascularization Investigation 2 Diabetes trial

OBJECTIVES

Conclusive evidence is lacking regarding the benefits and risks of performing off-pump versus on-pump coronary artery bypass graft (CABG) for patients with diabetes. This study aims to compare clinical outcomes after off-pump and on-pump procedures for patients with diabetes.

METHODS

The Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial enrolled patients with type 2 diabetes and documented coronary artery disease, 615 of whom underwent CABG during the trial. The procedural complications, 30-day outcomes, long-term clinical and functional outcomes were compared between the off-pump and on-pump groups overall and within a subset of patients matched on propensity score.

RESULTS

On-pump CABG was performed in 444 (72%) patients, and off-pump CABG in 171 (28%). The unadjusted 30-day rate of death/myocardial infarction (MI)/stroke was significantly higher after off-pump CABG (7.0 vs 2.9%, P = 0.02) despite fewer complications (10.3 vs 20.7%, P = 0.003). The long-term risk of death [adjusted hazard ratio (aHR): 1.41, P = 0.2197] and major cardiovascular events (death, MI or stroke) (aHR: 1.47, P = 0.1061) did not differ statistically between the off-pump and on-pump patients. Within the propensity-matched sample (153 pairs), patients who underwent off-pump CABG had a higher risk of the composite outcome of death, MI or stroke (aHR: 1.83, P = 0.046); the rates of procedural complications and death did not differ significantly, and there were no significant differences in the functional outcomes.

CONCLUSIONS

Patients with diabetes had greater risk of major cardiovascular events long-term after off-pump CABG than after on-pump CABG.

Long-term follow-up of off-pump and on-pump coronary artery bypass grafting

OBJECTIVE

Despite increasing recognition of the benefits of off-pump coronary artery bypass grafting (CABG), concerns persist regarding its impact on long-term mortality and freedom from reintervention. In this study, we assessed the impact of off-pump CABG on long-term outcomes.

METHODS

From January 2002 to December 2002, a total of 307 consecutive patients who underwent isolated multivessel off-pump CABG at our institution were compared with a control group of 397 patients who underwent multivessel on-pump CABG during the same period. Perioperative data were prospectively collected and compared. In addition, univariate and risk-adjusted comparisons between the two groups were performed at 10 years.

RESULTS

After adjusting for clinical covariates, off-pump CABG did not emerge as a significant independent predictor of long-term mortality [hazard ratio (HR), 0.91; 95% confidence interval (CI), 0.70-1.12], readmission to hospital for cardiac cause (HR, 0.96; 95% CI, 0.78-1.10), or the need for reintervention (HR, 0.93; 95% CI, 0.87-1.05).

CONCLUSIONS

At long-term follow-up, off-pump CABG remains a safe and effective myocardial revascularization strategy with no adverse impact on survival or freedom from reintervention.

Surgical revascularization techniques that minimize surgical risk and maximize late survival after coronary artery bypass grafting in patients with diabetes mellitus

OBJECTIVE

To identify surgical revascularization techniques that minimize surgical risk and maximize late survival in patients with diabetes undergoing coronary artery bypass grafting (CABG).

METHODS

From January 1972 to January 2011, 11,922 patients with diabetes underwent primary isolated CABG. The revascularization techniques investigated included bilateral internal thoracic artery (BITA) grafting (n=938; 7.9%) versus single ITA (SITA) grafting, off-pump (n=602; 5.0%) versus on-pump CABG, and incomplete (n=2109; 18%) versus complete revascularization. The median follow-up was 7.8 years and total follow-up, 104,516 patient-years. Multivariable analyses were performed to assess the effects of surgical techniques on hospital outcomes and long-term mortality.

RESULTS

After adjusting for patient characteristics, BITA versus SITA grafting was associated with a 21% lower late mortality (68% confidence limits, 16%-26%). However, BITA grafting was also associated with more deep sternal wound infections (DSWIs), but the considerable mortality from DSWI minimally affected overall survival because of its rare occurrence. The risk factors for DSWI were female sex (80% increased risk), higher body mass index (7% increased risk per kg/m2), medically treated diabetes (73% increased risk), previous myocardial infarction (58% increased risk), and peripheral arterial disease (73% increased risk). Off-pump and on-pump CABG had similar results. Complete versus incomplete revascularization had similar hospital outcomes; however, complete revascularization was associated with 10% lower late mortality (68% confidence limits, 7.0%-13%).

CONCLUSIONS

BITA grafting with complete revascularization maximizes long-term survival and is recommended for patients with diabetes undergoing CABG. BITA grafting should be used in all patients with diabetes whose risk of DSWI is low. It might be best avoided in obese diabetic women with diffuse atherosclerotic burden-those at greatest risk of developing these infections.

Coronary artery bypass grafting in patients with type 2 diabetes mellitus: a comparison between minimized and conventional extracorporeal circulation

Diabetes mellitus (DM) is an established independent risk factor for significant morbidity and mortality after coronary artery bypass grafting (CABG). The minimized extracorporeal circulation (MECC) allows a reduction of the negative effects associated with conventional extracorporeal circulation (CECC). In this study, the impact of the MECC on outcome of diabetic patients after CABG was assessed. Between January 2002 and December 2009, 1,184 patients with DM underwent elective isolated CABG using CECC (54.6%) or MECC (45.4%). All analysis was performed retrospectively. The extracorporeal circulation time was significantly reduced during MECC procedure. The postoperative increase of creatine kinase and lactate levels was significantly weaker in the MECC group (p < 0.001). Also, the transfusion requirements were significantly lower (p < 0.001). Furthermore, MECC patients had lower incidences of postoperative acute renal failure and sternal wound infections and shorter ICU and hospital lengths of stay (p < 0.05). Moreover, 30-day mortality was significantly reduced in the MECC group (p < 0.05). In conclusion, CABG surgery using MECC system is a safe alternative in patients with DM. A reduced postoperative mortality and lengths of stay, lower transfusion requirements, less renal and myocardial damage, and lower incidence of sternal wound infections encourage the usage of MECC system, especially in high-risk patients.

Desflurane-induced postconditioning of diabetic human right atrial myocardium in vitro

AIM

We tested the hypothesis that brief exposure to desflurane at the time of reoxygenation might be able to protect against hypoxia-reoxygenation injury in human myocardium from diabetic (insulin-dependent, ID; and non-insulin-dependent, NID) patients and non-diabetic (ND) subjects.

METHODS

The force of contraction (34 degrees C, stimulation frequency 1Hz) in the right atrial trabeculae was recorded during 30min of hypoxia followed by 60min of reoxygenation. Desflurane (at 3, 6 and 9%) was administered during the first 5min of reoxygenation. The force of contraction at the end of the 60-min reoxygenation period (FoC(60)) was compared in the study groups (means+/-SD).

RESULTS

In the ND group, desflurane at 3, 6 and 9% (FoC(60): respectively 78+/-10%, 84+/-4% and 85+/-12% of baseline) enhanced the recovery of FoC(60) compared with the ND-controls (53+/-7% of baseline; P<0.05). In the ID group, desflurane at 3% (61+/-4%) did not modify the recovery of FoC(60) compared with the ID-controls (54+/-6%), whereas desflurane at 6 and 9% (75+/-11% and 81+/-8%, respectively) enhanced the recovery of FoC(60)vs the controls (P<0.05). In the NID group, desflurane at 3% (57+/-5%) also failed to modify the recovery of FoC(60) compared with the NID-controls (52+/-10%), while desflurane at 6 and 9% (80+/-10% and 79+/-7%, respectively) enhanced the recovery of FoC(60)vs the controls (P<0.05).

CONCLUSION

Desflurane in vitro was able to postcondition diabetic (both ID and NID) human myocardium at 6 and 9%, but not at 3%.

Racial Disparity Persists After On-Pump and Off-Pump Coronary Artery Bypass Grafting

Background— Race has been shown to be an independent risk factor for operative mortality after coronary artery bypass grafting (CABG). This study sought to determine the extent to which race is a risk factor for adverse events, long-term mortality, and whether off-pump surgery (OPCAB) modifies that risk.

Methods and Results— The Society of Thoracic Surgeons Adult Cardiac Database at Emory Healthcare affiliated hospitals was queried for all primary isolated CABG records from 1997 to 2007. A propensity score was formulated to balance the patient groups with respect to treatment assignment (OPCAB or CABG on cardiopulmonary bypass). Multivariable logistic regression was used to assess the impact of black race and OPCAB on in-hospital outcomes (death, stroke, myocardial infarction, and their composite, major adverse cardiac events). Cox proportional hazards regression model and Kaplan–Meier curves determined whether black race affected long-term all-cause mortality. Interaction terms were constructed to test whether OPCAB surgery influences surgical results differently in black patients than in white patients. There were 12 874 consecutive CABG patients, including 2033 (15.8%) blacks and 10 841 (84.2%) whites. Survival at 3, 5, and 10 years for blacks (87.5%, 81.4%, 63.8%) was significantly lower than for whites (90.7%, 85.2%, 67.1%, P <0.001). Blacks (adjusted odds ratio, 0.77; 95% CI, 0.44 to 1.36) and whites (adjusted odds ratio, 0.72; 95% CI, 0.53 to 0.99) who had OPCAB had lower risk-adjusted odds of major adverse cardiac events than their racial counterparts who had CABG on cardiopulmonary bypass.

Conclusions— Short- and long-term outcomes are significantly worse in black than in white patients undergoing primary isolated CABG. OPCAB does not narrow the disparity in outcomes between blacks and whites.

Cardiopulmonary bypass increases postoperative glycemia and insulin consumption after coronary surgery

BACKGROUND

Perioperative hyperglycemia should be avoided in patients undergoing coronary surgery. The aim of our study was to find out what the influence of cardiopulmonary bypass is on postoperative glycemia and insulin consumption in patients with and without diabetes mellitus undergoing coronary artery surgery and whether a marked hyperglycemia in the early postoperative period is among the factors associated with early mortality and morbidity.

METHODS

We retrospectively reviewed all patients who underwent first-time coronary artery surgery in our institution during the 11-month period. Among 814 patients, 239 patients (29.4%) had diabetes and 575 patients (70.6%) were nondiabetic. Blood glucose levels were registered every 2 hours in all patients during the first 24 postoperative hours. Outcomes were difficult glycemic control (postoperative blood glucose levels >11.0 mmol/L despite aggressive insulin treatment), hospital mortality, and morbidity (defined as any postoperative complication such as stroke, renal failure, wound infection, perioperative myocardial infarction, ventilation > 24 hours, sepsis, and multiorgan failure).

RESULTS

Glycemic control was significantly worse in patients who underwent coronary artery bypass grafting, in comparison with off-pump coronary artery bypass grafting surgery, particularly in nondiabetic patients. Patients with difficult glycemic control had more serious postoperative complications resulting in higher mortality (2.5% versus 0.4%; p = 0.02). In the multivariate analysis, difficult glycemic control was significantly associated with a female sex (odds ratio [OR], 2.36), presence of diabetes (OR, 2.22), and the usage of cardiopulmonary bypass (OR, 1.81). Mortality was significantly associated with the left ventricular ejection fraction less than 0.35 (OR, 7.38), difficult glycemic control (OR, 7.06), and previous stroke (OR, 5.66). Difficult glycemic control was also significantly associated with postoperative morbidity (OR, 1.87).

CONCLUSIONS

Cardiopulmonary bypass increases postoperative glycemia and insulin consumption in both diabetic and nondiabetic patients. The use of cardiopulmonary bypass during coronary artery surgery in diabetic women is associated with a more difficult glycemic control in the early postoperative period. Difficult glycemic control is significantly associated with early mortality and morbidity in patients undergoing coronary artery surgery.

Influence of diabetes mellitus on long-term survival in systematic off-pump coronary artery bypass surgery

BACKGROUND

Diabetic patients generally present a more diffuse and calcified coronary artery disease than nondiabetic patients that can affect long-term outcome especially if an off-pump coronary artery bybass graft (OPCABG) technique is used. The aim of this study was to compare long-term results of OPCABG surgery for diabetic and nondiabetic patients.

METHODS

This is a retrospective analysis of prospectively gathered data over a 10-year period of 1,000 consecutive and systematic OPCABG patients operated on between September 1996 and April 2004. Average follow-up period was 66 +/- 28 months and was 97% complete. Overall survival as well as occurrence of major adverse cardiac events in diabetic and nondiabetic patients were specifically studied.

RESULTS

In all, 278 diabetic patients and 722 nondiabetic patients were treated. There was no difference in 30-day mortality between the two groups (p = 0.70). Diabetic patients had more postoperative acute renal insufficiency (p = 0.01) and infections (sepsis; p = 0.002), and deep sternal infections (p = 0.04) Ten-year survival (p = 0.006) and survival free of major adverse cardiac events (p = 0.02) was decreased in the diabetic group. Age (hazard ratio [HR] = 1.06), peripheral vascular disease (HR = 1.72), carotid disease (HR = 1.53), congestive heart failure (HR = 1.51), incomplete revascularization (HR = 2.37), chronic renal insufficiency (HR = 1.93), left ventricular ejection fraction (HR = 0.13), and a lesser use of multiple internal thoracic artery grafts (HR = 0.67), but not diabetes mellitus (p = 0.13) were significant determinants of long-term mortality. Similarly, peripheral vascular disease (HR = 1.92), chronic renal insufficiency (HR = 2.36), emergent operation (HR = 1.71), chronic obstructive pulmonary disease (HR = 1.76), previous percutaneous coronary intervention (HR = 1.66), left ventricular ejection fraction (HR = 0.26), ischemic mitral regurgitation (HR = 1.83), and a lesser use of multiple internal thoracic artery grafts (HR = 0.72) were determinants of decreased survival free of major adverse cardiac events but not diabetes (p = 0.2). Breaking down the major adverse cardiac events, diabetes was found an independent predictive factor of recurrent myocardial infarction (HR = 1.85) and a borderline cause of readmission for congestive heart failure (p = 0.06). Need for new revascularization was comparable for both population (p = 0.37).

CONCLUSIONS

In our series of OPCABG surgery patients, diabetic patients had a comparative operative mortality and perioperative myocardial infarction rate as nondiabetic patients. However, they had an increased prevalence of postoperative acute renal insufficiency and infections. They also had a worse outcome than nondiabetic patients, but that was mainly due to a higher prevalence of preoperative comorbidities and a lesser use of multiple internal thoracic artery grafts. However, diabetes itself was a potential risk factor for long-term occurrence of myocardial infarction and congestive heart failure.

Diabetes mellitus does not affect jugular bulb oxygen saturation in patients undergoing off-pump coronary artery bypass graft surgery

BACKGROUND

Diabetes mellitus (DM) is associated with the impairment of cerebral oxygenation during cardiac surgery. The aim of the present study was to investigate the effects of DM on cerebral oxygenation assessed by jugular bulb oxygen saturation (SjvO2) in patients undergoing off-pump coronary artery bypass graft surgery (OPCAB) in a prospective controlled trial.

METHODS AND RESULTS

Twenty-three diabetic patients with glycosylated hemoglobin above 7.0% (DM group) and 23 non-diabetic patients (control group) undergoing OPCAB with no-touch aortic technique were included. A fiberoptic oximetry catheter was inserted into the jugular bulb. The lowest SjvO2 and the number of patients with cerebral desaturation, defined as SjvO2 less than 50% over 5 min, were recorded during coronary grafting. Three neurocognitive tests were done before surgery and at postoperative day 2 and 7. There were no differences in SjvO2 between the groups. Furthermore, the number of patients with cerebral desaturation and all neurocognitive test scores were similar between the 2 groups. None of the patients developed neurocognitive dysfunction.

CONCLUSIONS

Cerebral oxygenation in diabetic patients was similar to that of non-diabetic patients and well maintained above the critical level without resulting in clinically significant postoperative neurocognitive dysfunction during OPCAB with no-touch aortic technique.

Coronary artery bypass surgery and acute kidney injury--impact of the off-pump technique

BACKGROUND

Acute kidney injury (AKI) is a serious and frequent complication after coronary artery bypass grafting (CABG). Cardiopulmonary bypass (CPB) was identified as a major AKI risk factor after CABG. Our aim was to assess the impact of the off-pump coronary artery bypass (OPCAB) compared to the on-pump coronary artery bypass (ONCAB) technique on the rate and severity of AKI, while taking other risk factors for AKI into account.

METHODS

An observational study of 201 consecutive adult patients was conducted; 100 were operated by the OPCAB and 101 by the ONCAB technique. All patients in each group were operated by a single, experienced surgeon. Fifteen pre-, intra- and postoperative variables that were repeatedly identified in previous studies as independent AKI risk factors were included in this analysis. AKI was defined as an increase of serum creatinine >/=50% or >/=0.3 mg/dL within 48 h and AKI severity was classified, according to current AKIN definitions.

RESULTS

Significantly fewer OPCAB patients developed AKI compared to ONCAB (14.0 versus 27.7%; P = 0.03). OPCAB was associated with milder stages of AKI, whereas ONCAB patients had more severe AKI. Congestive heart failure and chronic kidney disease were independent risk factors for AKI. The OPCAB technique for CABG was identified as the only independent factor associated with lower incidence of AKI.

CONCLUSIONS

Using current AKI definitions and classifications, the OPCAB technique for CABG, which avoids CPB; was associated with a significantly lower rate and less severe AKI compared to ONCAB. The OPCAB technique was identified as the only modifiable and potentially protective factor against postoperative AKI.

Current Status of Off-Pump Coronary Artery Bypass Surgery

The expanding indications for angioplasty coupled with the successful short and mid-term results of randomized controlled trials of drug-eluting stents have already had an unquestionable impact on the practice of coronary revascularization operations. However, coronary artery bypass grafting remains a major mode of therapy for coronary artery disease. It is likely that surgery will continue to be preferred for more complex subsets and that surgeons will have to continue to maintain good results in patients with more complex problems. Concerns regarding morbidity associated with conventional surgical myocardial revascularization on cardiopulmonary bypass have led to a resurgence of interest in off-pump bypass surgery during the last decade, with the expectation that it would be safer if cardiopulmonary bypass could be avoided. This review summarizes the impact of off-pump bypass surgery in reducing the morbidity and mortality associated with conventional coronary artery bypass on cardiopulmonary bypass by evaluating the current best-available evidence from randomized controlled trials and meta-analyses comparing off-pump surgery with conventional bypass grafting.

Off-pump CABG in diabetic patients: does insulin dependency matter?

BACKGROUND

We aimed to analyze influence of insulin dependency on short-term outcomes after OPCAB in patients with diabetes.

METHODS

Retrospective cohort study was planned based on chart review. Study population consisted of 148 diabetic cases (63 insulin-dependent diabetics in group I and 85 non-insulin-dependent diabetics in group II). Patients' preoperative data and risk factors for adverse outcomes are analysed. The primary endpoint was all causes of mortality during the in-hospital course. Preestablished secondary endpoints included all major postoperative complications, including non-fatal acute myocardial infarction, non-fatal stroke, sepsis, shock, mediastinitis, respiratory insufficiency, and renal insufficiency, and minor postoperative complications, including mechanical ventilation for more than 24 hours, inotropic support, reoperation for bleeding, and necessity of blood transfusion. Additional analysis was performed on the duration of stay in the intensive care unit and overall hospital stay.

RESULTS

Group I patients were significantly more likely to have hypertension (87.3% versus 82.5%, p=0.023), they also had a trend toward higher prevalence of hypercholesterolemia (71.4% versus 68.6%, p=0.092) and body mass index (28.1+/-4.2 versus 26.9+/-3.7, p=0.085). Angiographic characteristics and number of distal anastomosis were similar in the two groups. There was no significant difference in mortality during the in-hospital course as the primary endpoint. However, analysis in secondary endpoints revealed that group I patients were significantly more likely to have stroke (3.1% versus 2.3%, p=0.027), sternal wound infection (4.7% versus 3.4%, p=0.036) and atrial arrhythmia (28.3% versus 20.9%, p=0.021). Moreover, group I patients were significantly more likely to stay longer than 2 days in ICU (14.2% versus 11.6%, p=0.038). Higher prevalence of renal dysfunction was also observed in group I patients (7.9% versus 6.9%, p=0.069).

CONCLUSION

Similar to insulin dependent diabetes who had on-pump CABG, insulin dependent diabetes develop higher rate of major postoperative complications and stay longer in ICU after off-pump CABG.

Off-pump coronary artery bypass graft surgery is standard of care: where do you stand?

The cardiopulmonary bypass (CPB) has allowed the establishment of coronary artery bypass graft surgery (CABG) to be a safe and effective treatment for patients with ischemic heart disease. However, the concern that CPB may be responsible for CABG-related morbidity has been raised, and it has been suggested that CABG itself would be safer without CPB. The development of commercially available cardiac stabilization devices resulted in several large, nonrandomized retrospective case series. The studies demonstrated that CABG can be performed safely without CPB (off-pump surgery), and suggested that there are benefits compared with conventional CABG. However, the randomized controlled studies published to date have been, as a whole, unable to conclusively demonstrate advantages of off-pump CABG. The results of these randomized studies are likely responsible for the failure of off-pump CABG to become established as the standard of care.

Living with off-pump coronary artery surgery: evolution, development, and clinical potential for coronary heart disease patients

The enormous progress in interventional cardiology during the last 10 years has resulted in a major change in the spectrum of patients referred for coronary bypass surgery. These patients are older and sicker and frequently have had previous percutaneous coronary interventions. Consequently, cardiac surgery is responding by adding new surgical techniques: off-pump open-chest coronary bypass surgery (OPCAB), minithoracotomy bypass surgery, videothoracoscopic (robotic) procedures, etc. Several registries published to date have proved OPCAB to be safe and clinically effective. Randomized studies and meta-analysis research in this field provide scientific support and suggest that myocardial, renal, and neurological functions, amongst others, are better preserved by OPCAB than by classic techniques that use a cardiopulmonary bypass pump (CPB). Moreover, avoidance of CPB yields significantly reduced oxidative stress and systemic inflammatory response. This results in higher safety for ischemic heart disease patients undergoing revascularization, thus offsetting the propensity to lower costs. The present review examines the physiological advantages and clinical outcomes of this simple mode of myocardial revascularisation and evaluates the wider implications arising from its evolution.

Effect of risk-adjusted diabetes on mortality and morbidity after coronary artery bypass surgery

BACKGROUND

Diabetes is commonly regarded as a risk factor for mortality and morbidity after coronary artery bypass surgery.

METHODS

Between April 1997 and December 2002, 6,033 consecutive patients underwent isolated coronary artery bypass surgery. Eight hundred and fourteen (13.5%) patients had diabetes (530 oral-dependent, 284 insulin-dependent). Patients with diet-controlled diabetes were classified as nondiabetics. Deaths occurring over time were described using Kaplan-Meier techniques. To control for differences in patient characteristics, we constructed a propensity score (for diabetes) and this was included along with the comparison variable in multivariate logistic regression and Cox proportional hazards analyses.

RESULTS

In-hospital mortality was significantly higher for diabetic patients in the univariate analyses; however, this association disappeared after adjusting for the propensity score. Further analyses found that insulin-dependent diabetes was associated with an increased incidence of acute renal failure (adjusted odds ratio 4.15; p = 0.002), deep sternal wound infection (adjusted odds ratio 2.96; p = 0.039), and prolonged postoperative stay (adjusted odds ratio 1.60; p = 0.017). Oral-controlled diabetes was not associated with any of these outcomes. Four hundred and ninety-eight (8.3%) deaths occurred during the study follow-up. After adjusting for patient characteristics, the adjusted hazard ratio of midterm mortality for diabetes was 1.35; p = 0.013.

CONCLUSIONS

Insulin-dependent diabetes has a significant impact on in-hospital morbidity. Although diabetic patients are not at increased risk of in-hospital mortality, longevity is significantly decreased during a five-year follow-up period.

[Should we avoid cardiopulmonary bypass with diabetic patients?]

In the peri-operative and post-operative course of coronary bypass operations, the diabetic patient is susceptible to complications that cause morbidity and mortality. Morbidity might best be conceptualized as the cumulative effect of the diabetic patient chronically at risk and a variety of surgically related insults, including surgical stress, anaesthesia, hypo- and hypertension, anaemia, dysrhythmias, de- or hyperhydration and cardiopulmonary bypass (CPB) that exceed the compensatory capacities of the patient. Because all these factors for adverse outcome coexist, it becomes difficult to determine which ones are most important. However, it is reasonable that, in the presence of generalized atherosclerosis affecting the aorta ascendens, carotids and the cerebral arteries, the interaction of CPB-associated embolization, hypoperfusion and inflammation may cause neurologic morbidity. Many physiologic alterations (such as non-pulsatile perfusion and hemodilution) occur during CPB and may worsen renal dysfunction in patients with diabetic nephropathy. Pulmonary dysfunctions, associated with diabetic microangiopathy, could be unmasked by atelectasis, capillary leak and other pathophysiological conditions developing after the use of extracorporeal circulation. Actually, there is evidence that with the avoidance of CBP and the use of adequate OPCAB (Off Pump Coronary Artery Bypass) techniques, by experienced teams, the incidences of neurological, renal and pulmonary complications decrease, in high-risk patients, e. g. diabetics, as well as in unselected cohorts. Because it is not possible to identify confidently those patients who are at risk for CPB-associated complications, we use a strategy where all CABG (Coronary Artery Bypass Grafting) are performed in OPCAB technique. The total OPCAB approach will in addition ascertain the development of organizational OPCAB routines and expertise. The process of re-engineering the unit towards total OPCAB needs systematic training and re-training of cardiac surgeons by surgeons, experienced in both, OPCAB surgery and knowledge transfer, according to the principles of continuing medical education (CME). Thus, the chances of the OPCAB technique improving the outcome of diabetic patients can be fully realized.

How to revascularize patients with diabetes mellitus: bypass or stents and drugs?

The diabetic patient is at high risk for coronary artery disease. Incidence as well as severity of the disease is highly increased in comparison to non-diabetic patients. The revascularization of the diabetic patient is a great challenge, since the longterm results are disappointing when compared to non-diabetic patients. The success of coronary artery bypass grafting is limited by increased perioperative mortality and a faster occlusion of especially venous bypass grafts. In percutaneous interventions the excessive high restenosis rates worsen longterm results. Several clinical trials investigated the outcome of the two revascularization strategies and could demonstrate at least a tendency towards better results when the operative approach was chosen. Particularly, the BARI trial showed reduced mortality for surgery when compared to percutaneous coronary interventions. However, in this trial, in 87% of patients undergoing bypass surgery all stenoses were successfully treated, whereas in patients undergoing percutaneous coronary intervention only 76% of all stenoses were primarily successfully treated. In addition, no stents were used in this trial.Furthermore, the enrollment of the previous trials dates one decade ago. These trials do therefore not necessarily represent the current standard therapy, especially for percutaneous coronary interventions. The restenosis rate could be decreased in recent years by means of drug-eluting stents and an aggressive antiplatelet therapy from more than 50% to less than 10% leading to considerably improved long-term results. Therefore, percutaneous coronary interventions have developed to be a reasonable alternative to bypass surgery. Different clinical trials are currently underway (BARI 2D, CarDIA, FREEDOM) comparing the outcome of the two approaches.

Off-pump coronary artery bypass graft surgery: where should we stand?

Coronary artery bypass grafting (CABG) performed with cardiopulmonary bypass has become a well-established treatment modality for patients with coronary artery disease. However, there is increasing evidence that cardiopulmonary bypass may be responsible for some of the morbidity associated with CABG surgery. Thus, it has been proposed that CABG surgery would be safer if cardiopulmonary bypass could be avoided. The development of cardiac stabilization devices has allowed for the creation of safe and reproducible coronary anastomoses on the beating heart. Several large, non-randomized, retrospective case series have demonstrated that CABG surgery can be performed safely without cardiopulmonary bypass (off-pump) and have in fact suggested benefits when compared with conventional CABG. However, the randomized controlled studies published to date have, as a whole, been unable to conclusively demonstrate the advantages of off-pump surgery. Taken together, the evidence to date suggests that a large-scale, prospective, randomized trial may be required to resolve the dilemma.

Does Diabetes Affect the Postoperative Outcomes After Total Arterial Off-Pump Coronary Bypass Surgery in Multivessel Disease?

BACKGROUND

Previous studies have reported conflicting results regarding the adverse effects of diabetes on surgical outcomes after coronary artery bypass grafting (CABG). We reviewed our experience to determine the impact of diabetes on early and midterm surgical outcomes of patients with multivessel disease who underwent total arterial revascularization with avoidance of cardiopulmonary bypass.

METHODS

Between January 1998 and December 2003, 517 patients with multivessel disease underwent total arterial off-pump CABG; 214 were diabetic (DM group) and 303 were nondiabetic (NDM group). The DM group was sicker than the NDM group (more left ventricular dysfunction, postinfarction angina, previous myocardial infarction, and chronic renal failure). Mean follow-up period was 34 +/- 17 months. The multivariate risk factors for operative mortality, one-year angiographic patency, and midterm survival were analyzed.

RESULTS

Mean numbers of distal anastomoses were not different between the two groups (DM, 3.1 +/- 0.9; NDM, 3.0 +/- 0.8). Operative mortality was 1.4% (DM, 1.4% vs NDM, 1.3%; p = not significant [ns]). No differences were found in the incidences of postoperative morbidities, including mediastinitis and superficial wound problems, between the two groups. In immediate postoperative angiography, the patency rates were 99.2% in the DM and 98.9% in the NDM group (p = ns). One-year patency rates in angiography were also similar between the two groups (DM, 96.0%; NDM, 95.4%; p = ns). Multivariate analysis indicated that diabetes was not an independent risk factor of steno-occlusion at one-year follow-up angiography. Five-year cumulative survival was 87.7 +/- 4.1% in the DM, and 94.2 +/- 1.4% in NDM (p = ns) group. Five-year freedom from cardiac death was 99.0 +/- 0.7% in the DM, and 97.4 +/- 1.0% in the NDM (p = ns) group. Old age (age > 75 years) and chronic renal failure were independent risk factors for lower midterm survival. Our study failed to demonstrate that diabetes was an independent risk factor for lower midterm survival.

CONCLUSIONS

Diabetes mellitus did not affect the early postoperative and midterm results, including one-year graft patency, in patients with multivessel disease undergoing total arterial and off-pump CABG.