Myocardial injury in coronary artery bypass grafting: On-pump versus off-pump comparison by measuring high-sensitivity C-reactive protein, cardiac troponin I, heart-type fatty acid–binding protein, creatine kinase-MB, and myoglobin release

Machine learning in the prediction of cardiac surgery associated acute kidney injury with early postoperative biomarkers

Purpose

To establish novel prediction models for predicting acute kidney injury (AKI) after cardiac surgery based on early postoperative biomarkers.

Patients and methods

This study enrolled patients who underwent cardiac surgery in a Chinese tertiary cardiac center and consisted of a discovery cohort (n = 452, from November 2018 to June 2019) and a validation cohort (n = 326, from December 2019 to May 2020). 43 biomarkers were screened using the least absolute shrinkage and selection operator and logistic regression to construct a nomogram model. Three tree-based machine learning models were also established: eXtreme Gradient Boosting (XGBoost), random forest (RF) and deep forest (DF). Model performance was accessed using area under the receiver operating characteristic curve (AUC). AKI was defined according to the Kidney Disease Improving Global Outcomes criteria.

Results

Five biomarkers were identified as independent predictors of AKI and were included in the nomogram: soluble ST2 (sST2), N terminal pro-brain natriuretic peptide (NT-proBNP), heart-type fatty acid binding protein (H-FABP), lactic dehydrogenase (LDH), and uric acid (UA). In the validation cohort, the nomogram achieved good discrimination, with AUC of 0.834. The machine learning models also exhibited adequate discrimination, with AUC of 0.856, 0.850, and 0.836 for DF, RF, and XGBoost, respectively. Both nomogram and machine learning models had well calibrated. The AUC of sST2, NT-proBNP, H-FABP, LDH, and UA to discriminate AKI were 0.670, 0.713, 0.725, 0.704, and 0.749, respectively. In addition, all of these biomarkers were significantly correlated with AKI after adjusting clinical confounders (odds ratio and 95% confidence interval of the third vs. the first tertile: sST2, 3.55 [2.34-5.49], NT-proBNP, 5.50 [3.54-8.71], H-FABP, 6.64 [4.11-11.06], LDH, 7.47 [4.54-12.64], and UA, 8.93 [5.46-15.06]).

Conclusion

Our study provides a series of novel predictive models and five biomarkers for enhancing the risk stratification of AKI after cardiac surgery.

Graft preservation confers myocardial protection during coronary artery bypass grafting

Background

During on-pump coronary artery bypass grafting (ONCAB), graft flushing for distal anastomoses testing also perfuses the downstream myocardium. This single-center retrospective study evaluated the impact of specific preservation solutions on myocardial protection during ONCAB.

Materials and methods

Between July 2019 and March 2020 either DuraGraft (DG) or 0.9% Saline/Biseko (SB) was applied to 272 ONCAB. Overall, 166 patients were propensity-matched into two groups. Cardiac enzymes [high-sensitive Troponin I (hs-TnI) and creatine kinase (CK)] were evaluated 7 days post-surgery.

Results

Post-surgery, hs-TnI values were significantly lower from 3 to 6 h (h) up to 4 days in the DG group: 3–6 h: 4,034 ng/L [IQR 1,853–8,654] vs. 5,532 ng/L [IQR 3,633—8,862], p = 0.05; 12–24 h: 2,420 ng/L [IQR 1,408–5,782] vs. 4,166 [IQR 2,052–8,624], p < 0.01; 2 days: 1,095 ng/L [IQR 479–2,311] vs. 1,564 ng/L [IQR 659–5,057], p = 0.02 and at 4 days: 488 ng/L [IQR 232–1,061] vs. 745 ng/L [IQR 319–1,820], p = 0.03. The maximum value: 4,151 ng/L [IQR 2,056–8,621] vs. 6,349 ng/L [IQR 4,061–12,664], p < 0.01 and the median area under the curve (AUC): 6,146 ng/L/24 h [IQR 3,121–13,248] vs. 10,735 ng/L/24 h [IQR 4,859–21,484], p = 0.02 were lower in the DG group. CK values were not significantly different between groups: maximum value 690 [IQR 417–947] vs. 631 [464–979], p = 0.61 and AUC 1,986 [1,226–2,899] vs. 2,081 [1,311–3,063], p = 0.37.

Conclusion

Repeated graft flushing with DG resulted in lower Troponin values post-surgery suggesting enhanced myocardial protection compared to SB. Additional studies are warranted to further assess the myocardial protection properties of DG.

Neutrophil-Lymphocyte Ratio in Congenital Heart Surgery: What Is Known and What Is New?

Operative mortality after repair of congenital heart disease has improved dramatically over the past few decades. Nevertheless, there is always room for the additional mitigation of complications and mortality. Being able to anticipate adverse outcomes is clearly important, especially when using low-cost and easily accessible resources. The neutrophil-lymphocyte ratio (NLR) is defined as the ratio of the absolute neutrophil to lymphocyte count, which can be easily measured using a regular white blood cell count. Recently, preoperative NLR has been shown to be a predictor of outcomes in patients undergoing congenital heart surgery. Although it presented promising results, there are still many gaps to be filled like the normal value for children, the ideal cutoff value to predict adverse outcomes, the wide variation and its correlation with other biomarkers, and if it is a modifiable risk factor. The aim of this review is to understand the prognostic value of preoperative NLR as a biomarker predictor of outcomes in patients undergoing congenital heart surgery based on previous clinical studies and to propose future directions in order to solve the above-mentioned questions.

On-pump beating heart versus off-pump myocardial revascularization-a propensity-matched comparison

Objective

On-pump beating heart (OP-BH) coronary artery bypass grafting (CABG) is often undertaken as an alternative between off-pump coronary artery bypass (OPCAB) and conventional on-pump coronary artery bypass grafting (On-pump CABG), especially in India. However, outcome data following OP-BH surgery is sparse. The aim of this study was to compare the outcomes of OP-BH CABG with OPCAB.

Methods

From our institutional database, all patients undergoing OP-BH CABG (n = 531) were identified. A propensity-matched cohort undergoing OPCAB (n = 531) was identified from the database. Nearest neighbor matching technique was used and the groups were matched for variables including age, gender, body mass index, EuroSCORE, history of recent myocardial infarction or unstable angina, hypertension, peripheral vascular disease, chronic obstructive airway disease, diabetes, pre-op renal impairment, pre-op neurological events, and left ventricular function.

Results

The propensity-matched groups were well matched in terms of baseline characteristics. The mean EuroSCORE was 3.17 and 3.20 in the OP-BH and the OPCAB groups. The unadjusted 30-day mortality in the propensity-matched OPCAB group was 2.07% (11/531) while mortality in the on-pump beating heart group was significantly higher at 6.9% (37/531). Multivariate analysis showed that OP-BH CABG was an independent risk factor for 30-day mortality as well as major adverse post-operative outcomes including renal, neurological, and respiratory outcomes and post-operative atrial fibrillation.

Conclusions

OP-BH CABG is associated with worse clinical outcomes compared to patients undergoing OPCAB.

Evaluation of Left Ventricular Myocardial Work Performance in Patients Undergoing On-Pump and Off-Pump Coronary Artery Bypass Surgery

Purpose: Benefits of off-pump coronary bypass (OPCAB) over on-pump (ONCAB) remain controversial. We aimed to evaluate the early impacts of OPCAB vs ONCAB for varying left ventricular (LV) function baselines by applying the non-invasive myocardial work (MW) analysis, which enables further insights in cardiac mechanics, contractility, and efficacy.

Methods: We retrospectively analyzed 98 patients (55 ONCAB vs 43 OPCAB). Transthoracic echocardiography (TTE) and concurrent arterial blood pressure measurements taken at rest, prior to, and early after surgery were performed. Global myocardial work index (GMWI), global constructive work (GCW), and global work efficiency (GWE), inter alia, were quantified.

Results: Preoperatively, OPCAB patients had significantly lower values than ONCAB patients in terms of GMWI (1404.33 ± 585.41 mmHg% vs 1619.07 ± 535.42 mmHg%, p = 0.039), GWE (90% (60%, 96%) vs 93% (74%, 98%), p = 0.028). After surgery, GMWI was reduced in both groups. However, a more significant GMWI impairment occurred early after ONCAB than after OPCAB (−343.14 ± 35.20 mmHg%, p <0.001 vs −224.04 ± 120.91 mmHg%, p = 0.042).

Conclusion: Despite lower preoperative LV function in OPCAB patients, GMWIs after OPCAB were superior to ONCAB, indicating better preservation of systolic LV function early after OPCAB by means of contractility compared to ONCAB. Further studies should investigate the long-term course of MW response and their clinical impact.

A "crush" course on rhabdomyolysis: risk stratification and clinical management update for the perioperative clinician

Rhabdomyolysis, the release of myoglobin and other cellular breakdown products from necrotic muscle tissue, is seen in patients with crush injuries, drug overdose, malignant hyperthermia, muscular dystrophy, and with increasing frequency in obese patients undergoing routine procedures. For the perioperative clinician, managing the resultant shock, hyperkalemia, acidosis, and myoglobinuric acute kidney injury can present a significant challenge. Prompt recognition, hydration, and correction of metabolic disturbances may reduce or eliminate the need for long-term renal replacement therapy. This article reviews the pathophysiology and discusses key issues in the perioperative diagnosis, risk stratification, and management of rhabdomyolysis.

Ten-year outcomes after off-pump versus on-pump coronary artery bypass grafting: Insights from the Arterial Revascularization Trial

OBJECTIVE

We performed a post hoc analysis of the Arterial Revascularization Trial to compare 10-year outcomes after off-pump versus on-pump surgery.

METHODS

Among 3102 patients enrolled, 1252 (40% of total) and 1699 patients received off-pump and on-pump surgery (151 patients were excluded because of other reasons); 2792 patients (95%) completed 10-year follow-up. Propensity matching and mixed-effect Cox model were used to compare long-term outcomes. Interaction term analysis was used to determine whether bilateral internal thoracic artery grafting was a significant effect modifier.

RESULTS

One thousand seventy-eight matched pairs were selected for comparison. A total of 27 patients (2.5%) in the off-pump group required conversion to on-pump surgery. The off-pump and on-pump groups received a similar number of grafts (3.2 ± 0.89 vs 3.1 ± 0.8; P = .88). At 10 years, when compared with on-pump, there was no significant difference in death (adjusted hazard ratio for off-pump, 1.1; 95% confidence interval, 0.84-1.4; P = .54) or the composite of death, myocardial infarction, stroke, and repeat revascularization (adjusted hazard ratio, 0.92; 95% confidence interval, 0.72-1.2; P = .47). However, off-pump surgery performed by low volume off-pump surgeons was associated with a significantly lower number of grafts, increased conversion rates, and increased cardiovascular death (hazard ratio, 2.39; 95% confidence interval, 1.28-4.47; P = .006) when compared with on-pump surgery performed by on-pump-only surgeons.

CONCLUSIONS

The findings showed that in the Arterial Revascularization Trial, off-pump and on-pump techniques achieved comparable long-term outcomes. However, when off-pump surgery was performed by low-volume surgeons, it was associated with a lower number of grafts, increased conversion, and a higher risk of cardiovascular death.

The Effect of High-Dose Vitamin C on Biochemical Markers of Myocardial Injury in Coronary Artery Bypass Surgery

OBJECTIVE

To evaluate the effect of high-dose vitamin C on cardiac reperfusion injury and plasma levels of creatine kinase-muscle/brain (CK-MB), troponin I, and lactate dehydrogenase (LDH) in patients undergoing coronary artery bypass grafting (CABG).

METHODS

This is a double-blind randomized clinical trial study. Fifty patients (50-80 years old) who had CABG surgery were selected. The intervention group received 5 g of intravenous vitamin C before anesthesia induction and 5 g of vitamin C in cardioplegic solution. The control group received the same amount of placebo (normal saline). Arterial blood samples were taken to determine the serum levels of CK-MB, troponin I, and LDH enzymes. Left ventricular ejection fraction was measured and hemodynamic parameters were recorded at intervals.

RESULTS

High doses of vitamin C in the treatment group led to improvement of ventricular function (ejection fraction [EF]) and low Intensive Care Unit (ICU) stay. The cardiac enzymes level in the vitamin C group was lower than in the control group. These changes were not significant between the groups in different time intervals (anesthesia induction, end of bypass, 6 h after surgery, and 24 h after surgery) for CK-MB, LDH, and troponin I. Hemodynamic parameters, hematocrit, potassium, urinary output, blood transfusion, arrhythmia, and inotropic support showed no significant difference between the groups.

CONCLUSION

Vitamin C has significantly improved the patients' ventricular function (EF) 72 h after surgery and reduced the length of ICU stay. No significant changes in cardiac biomarkers, including CK-MB, troponin I, and LDH, were seen over time in each group.

IRCT CODE

IRCT2016053019470N33.

Loop isolation-based uploading preconditioning to protect heart from damage: a proof-of-concept study

BACKGROUND

Little is known on the role of indirect clamp releasing in coronary artery bypass grafting (CABG). Loop isolation-based uploading preconditioning (LiuPhD) was modified to protect the heart from damage and the question of whether this can attenuate reperfusion injury after global myocardial ischemia was examined.

METHODS

A post-hoc comparative analysis was conducted of a prospective single-arm trial on the use of the LiuPhD strategy for 60 multivessel-disease patients undergoing isolated first-time elective on-pump CABG versus 1:1 propensity score-matched patients from the historical database of the same center.

RESULTS

A total of 120 matched patients had a median age of 62.0 (interquartile range [IQR] 55.8-69.0) years, 27 (22.5%) women, 35 (29.2%) with left main disease, and median follow-up of 18.5 (10.9-35.4) months. The LiuPhD group had shorter post-bypass times than conventional controls (10 [6-13] vs 14 [10-19] mins; p = 0.003). The LiuPhD group had similar needs in terms of composite cardiac-specific interventions (38/60 vs 44/60; p = 0.29). At follow-up of safety, the risk for composite major adverse cardiac and cerebrovascular events was similar between groups (event-free survival: 82.3% vs 73.8%; hazard ratio 1.00 [0.39, 2.54], p log-rank test = 0.99).

CONCLUSION

The LiuPhD strategy is associated with short post-bypass times, comparable risk of myocardial injury, and similar safety compared with conventional direct clamp releasing.

Off-Pump Versus On-Pump Bypass Surgery for Left Main Coronary Artery Disease

BACKGROUND

Concerns remain for a greater risk of incomplete revascularization and reduced survival with off-pump coronary artery bypass grafting (CABG) surgery compared with on-pump surgery particularly in patients with left main disease and extensive underlying myocardial ischemia.

OBJECTIVES

This study sought to compare outcomes following off-pump versus on-pump surgery for left main disease by performing a post hoc analysis from the multicenter, randomized EXCEL (Evaluation of XIENCE versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization) trial.

METHODS

The EXCEL trial was designed to compare percutaneous coronary intervention with everolimus-eluting stents versus CABG in patients with left main disease. CABG was performed with or without cardiopulmonary bypass (on-pump vs. off-pump surgery) according to the discretion of the operator. The 3-year outcomes in the off-pump and on-pump groups were compared using inverse probability of treatment weighting (IPTW) for treatment effect estimation.

RESULTS

Among 923 CABG patients, 652 and 271 patients underwent on-pump and off-pump surgery, respectively. Despite a similar extent of disease, off-pump surgery was associated with a lower rate of revascularization of the left circumflex coronary artery (84.1% vs. 90.0%; p = 0.01) and right coronary artery (31.1% vs. 40.6%; p = 0.007). After IPTW adjustment for baseline differences, off-pump surgery was associated with a significantly increased risk of 3-year all-cause death (8.8% vs. 4.5%; hazard ratio: 1.94; 95% confidence interval: 1.10 to 3.41; p = 0.02) and a nonsignificant difference in the risk for the composite endpoint of death, myocardial infarction, or stroke (11.8% vs. 9.2%; hazard ratio: 1.28; 95% confidence interval: 0.82 to 2.00; p = 0.28).

CONCLUSIONS

Among patients with left main disease treated with CABG in the EXCEL trial, off-pump surgery was associated with a lower rate of revascularization of the coronary arteries supplying the inferolateral wall and an increased risk of 3-year all-cause death compared with on-pump surgery.

High-sensitivity cardiac troponin release after conventional and minimally invasive cardiac surgery

After cardiac surgery, a certain degree of myocardial injury is common. The arbitrarily proposed biomarker cut-off point in the Third Universal Definition for diagnosing coronary artery bypass grafting (CABG)–related perioperative myocardial infarction (PMI) is controversial and unvalidated for non-CABG surgery. Minimally invasive cardiac surgery is often thought to be associated with less myocardial damage compared to conventional surgical approaches. We conducted a real-life prospective study with serial sampling of high-sensitivity cardiac troponin T (hs-cTnT) in patients undergoing conventional and minimally invasive cardiac surgery. Four different types of cardiac surgery were performed in 400 patients (February 2014–January 2015): CABG, aortic valve replacement, minimally invasive mitral/tricuspid valve surgery through the HeartPort (HP) technique and combined CABG/valve surgery. Each group was further subdivided for comparison between the different surgical techniques. Blood samples were collected consecutively at intensive care unit (ICU) admission and 3, 6, 9, 12, 18, 24 and 48 h thereafter. The hs-cTnT values by peak timepoint differed significantly depending on the surgical approach. The overall peak timepoint for hs-cTnT occurred 6 h after ICU admission. The combined surgery and multiple-valve HP groups had the highest values (medians of 1067.5 (744.9–1455) ng/L and 1166 (743.7–2470) ng/L, respectively). The peak hs-cTnT values for patients developing PMI showed high variability. Differentiation between cardiac surgery–related necrosis and PMI remains challenging. This study emphasizes the importance of a clinically reliable biomarker cut-off value in addition to electrocardiography and echocardiography to optimize PMI diagnosis.

Comparisons of heart-type fatty acid-binding protein (H-FABP) levels in off-pump versus on-pump coronary artery bypass grafting

Introduction

Heart-type fatty acid-binding protein (H-FABP) is a novel indicator of myocardial damage. The aim of the study was to compare the levels of H-FABP in off-pump and on-pump coronary artery bypass grafting (CABG).

Material and methods

Thirty non-randomised 30 patients who underwent CABG between January 2009 and January 2010 were enrolled in the study. Patients were divided into two equal size (n = 15) groups as group A (off-pump CABG group) and group B (on-pump CABG group). Three arterial blood samples were obtained for H-FABP after sternotomy (H-FABP 1), after the last distal anastomosis in group A and immediately after the cross clamp was removed from the aorta in group B (H-FABP 2) and 24 h after the operation (H-FABP 3). Renal and liver functions and circulating fatty acid binding protein (FABP) levels were also assessed in blood samples obtained 24 h before and 1 h after the operation.

Results

At all three assessment points patients in group B had significantly higher H-FABP values when compared with group A. Preoperative renal and liver functions were similar in both groups and they did not differ significantly in group A and group B when preoperative and postoperative values were compared. In both groups circulating FABP levels increased in the postoperative period, and the increase was more pronounced in the on-pump CABG group.

Conclusions

On-pump surgery resulted in higher levels of H-FABP as an ischaemic marker in patients receiving coronary artery bypass surgery.

Effects of Remote Ischemic Preconditioning in Patients Undergoing Off-Pump Coronary Artery Bypass Graft Surgery

Purpose

This study aimed to evaluate effects of remote ischemic preconditioning (RIPC) on myocardial injury in patients undergoing off-pump coronary artery bypass graft surgery (OPCABG).

Methods

Sixty-five patients scheduled for the OPCABG were randomly assigned to control (n = 32) or RIPC group (n = 33). All patients received general anesthesia. Before the surgical incision, RIPC was induced on an upper limb with repeated 5-min ischemia and 5-min reperfusion for four times. Blood samples were collected from right internal jugular vein. Plasma levels of IL-6, IL-8, IL-10, TNF-α, cTnT, HFABP, IMA, and MDA were detected at pre-operatively and 0, 6, 18, 24, 48, 72, and 120 h after the surgery. Left internal mammary artery (LIMA) and great saphenous vein (GSV) was cut into 2–3 mm for Western blot analysis of Hif-1α.

Results

In the present study, RIPC treatment significantly reduced plasma levels of cardiac troponin T (p < 0.05), heart-type fatty acid binding protein (p < 0.05), ischemia modified albumin (p < 0.05), malondialdehyde (p < 0.05), as well as plasma levels of pro-inflammatory cytokines including IL-6, IL-8, and TNF-α (P < 0.05, respectively). RIPC treatment significantly increased hypoxia-inducible factor-1α (p < 0.05) expression as well. Mechanical ventilation time for postoperative patients was shortened in RIPC group than those in control group (17.4 ± 3.8 h vs. 19.7 ± 2.9 h, respectively, p < 0.05).

Conclusion

RIPC by upper limb ischemia shortens mechanical ventilation time in patients undergoing OPCABG. RIPC treatment reduces postoperative myocardial enzyme expression and pro-inflammatory cytokine production. RIPC is a protective therapeutic approach in the coronary artery bypass graft surgery.

Urinary Titin Is Increased in Patients After Cardiac Surgery

Background: Few non-invasive biomarkers have been used to detect myocardial injury in patients with heart diseases. Recently, the N-terminal fragment (N-titin) of titin, a giant sarcomeric protein, which is involved in muscular passive tension and viscoelasticity, has been reported to detect muscle damage in patients with cardiomyopathy as well as in patients with skeletal muscle dystrophy and in healthy volunteers with endurance exercise. In the present study, we evaluated whether urinary N-titin is changed during a perioperative period and whether its increase reflects myocardial damage.

Materials and Methods: In 18 patients who underwent cardiac surgery, blood and urine samples were obtained before and after surgery. We measured the urinary levels of N-titin with a highly sensitive ELISA system.

Results: Urinary N-titin to creatinine (N-titin/Cr) was significantly increased in all patients postoperatively (43.3 ± 39.5 pmol/mg/dL on the day of operation) and remained significantly high for at least 4 days postoperatively. Urinary N-titin/Cr was positively correlated with serum cardiac troponin T (r = 0.36, p = 0.0006, n = 90) but not creatine kinase-MB (CK-MB). We also found that urinary N-titin/Cr in patients after a coronary artery bypass grafting operation was higher by day 2 postoperatively than in patients following open cardiac surgeries.

Conclusion: The cleaved N-titin was significantly increased in urine after cardiac surgery. Urinary N-titin may be useful for detecting the risk of latent postoperative cardiac damage.

Off-pump versus on-pump coronary artery bypass grafting-a surreal controversy?

As per the findings of the SYNTAX Trial, it has been established that coronary artery bypass grafting (CABG) affords the best long-term results in patients with multivessel disease. However, it is still a point of contention whether 'off-pump' CABG (OPCAB) (on cardiopulmonary bypass) is better. Many studies appear to establish the superiority of one or the other. But there is still no well-planned multi-centre randomised controlled trial looking into all aspects of the issue that can, once and for all, put the controversy to rest. But as long as one is able to give the patient a good result, does it really matter whether the procedure is done off or on pump? This article looks at the available evidence with regard to various parameters comparing OPCAB and conventional CABG in an attempt to answer the question, if at all, it is a question!

Use of cardiopulmonary pump support during coronary artery bypass grafting in the high-risk: a meta-analysis

BACKGROUND

Data from randomized trials evaluating the efficacy of on- versus off-pump coronary artery bypass grafting remain inconclusive, particularly in high-risk populations.

AIMS

The aim of this study is to compare the outcomes associated with on- versus off-pump coronary artery bypass grafting among high-risk patients.

METHODS

We performed a meta-analysis of randomized control trials comparing on- versus off-pump coronary artery bypass grafting, focusing on high-risk populations. Studies focusing on "high-risk" features: European System of Cardiac Operative Risk Evaluation (EuroSCORE) ≥ 5, age > 70 years, preexisting renal insufficiency, history of stroke(s), and the presence of left ventricular dysfunction were included. MEDLINE, Scopus, and Embase were searched for all publications between January 1, 2000 and August 1, 2016, using the following terms: on-pump, off-pump, coronary artery bypass, high-risk, left ventricular dysfunction, elderly, aged, and renal insufficiency. Endpoints included cardiovascular and all-cause mortality, non-fatal myocardial infarction, stroke, need for revascularization, renal failure, and length of hospital stay.

RESULTS

Nine studies incorporating 11,374 patients with a mean age of 70 years were selected. There was no statistical difference in cardiovascular mortality, all-cause mortality, non-fatal myocardial infarction, and renal failure between the two groups. There was a decrease in further revascularization at 1 year with on-pump (OR 0.67 (0.50-0.89)). However, there was an increase in length of hospital stay by 2.24 days (p = 0.03) among the on-pump group with no difference in stroke (OR 1.34 (1.00-1.80)).

CONCLUSIONS

On-pump is associated with a decreased risk of additional revascularization by 1 year. However, this appears to be a cost of longer hospitalization.

Cardioprotection of Electroacupuncture for Enhanced Recovery after Surgery on Patients Undergoing Heart Valve Replacement with Cardiopulmonary Bypass: A Randomized Control Clinical Trial

We attempted to investigate cardioprotection of electroacupuncture (EA) for enhanced recovery after surgery on patients undergoing heart valve replacement with cardiopulmonary bypass. Forty-four patients with acquired heart valve replacement were randomly allocated to the EA group or the control group. Patients in the EA group received EA stimulus at bilateral Neiguan (PC6), Ximen (PC4), Shenting (GV24), and Baihui (GV20) acupoints twenty minutes before anesthesia induction to the end of surgery. The primary end point was cardioprotection effect of electroacupuncture postoperatively and the secondary endpoints were quality of recovery and cognitive functioning postoperatively. The present study demonstrated that electroacupuncture reduced the occurrence of complications and played a role of cardioprotective effect on patients after heart valve replacement surgery with cardiopulmonary bypass, and it benefits patients more comfortable and contributes to recovery after surgery. This trial is registered with ChiCTR-IOC-16009123.

High-Sensitivity Troponin Release Profile After Cardiac Surgery

BACKGROUND

Postoperative serum troponin levels and perioperative myocardial infarction (MI) rates correlate with mortality and morbidity following cardiac surgery. The objective of this study was to document the release profile of high sensitivity troponin T (hsTnT) following different cardiac operations.

METHODS

Patients undergoing one of five different isolated cardiac surgical procedures (eligible preoperative hsTnT <29ng/L, serum creatinine < 0.2mmol/L) were recruited prospectively. Serum hsTnT was measured at 0, 4, 6, 8, 10, 12, 24 and 72hours after the first surgical insult to myocardium, together with daily electrocardiographs.

RESULTS

There were 10 patients in the on-pump coronary artery bypass group and 5 each in the remaining groups (off-pump coronary artery bypass, open aortic valve replacement, transcutaneous aortic valve implantation and mitral valve replacement). Five additional patients were excluded due to perioperative MI or renal failure. Median [range] of peak hsTnT was 241[99-566], 64[50-136], 353[307-902], 115[112-275], and 918[604-1166] ng/L, respectively. Operations with the lowest peak hsTnT values peaked earliest (four hours) while those with highest values peaked latest (eight hours).

CONCLUSION

After cardiac surgery, the hsTnT profile peaks four to eight hours after the initial surgical insult. The magnitude and timing of the peak correlates to the expected degree of surgically-induced myocardial injury.

RANK/RANKL Expression Is Induced by Cardiac Surgical Operation

Background: Cardiac surgery provokes a systemic inflammatory response in any patient. This complex body reaction involves also RANK/RANKL molecules which have been recently identified as principal regulators of bone metabolism. Aims: To follow the changes in the expression of RANK/RANKL molecules on innate immune cells of cardiac surgical patients. Patients and Methods: Twenty-six patients undergoing cardiac surgical were assigned to undergo coronary artery bypass grafting using either cardiopulmonary bypass (“on-pump”) or modified “miniinvasive on-pump”. The expression of RANK/RANKL was performed by flow cytometry. Results: Significantly increased expression of RANK on monocytes of “miniinvasive on-pump” patients was found at the 1st, the 3nd, and 7th postoperative days. The similar pattern was found also for monocyte RANKL expression. In addition, RANKL expression was significantly increased at the 3rd postoperative day in “on-pump” patient. No significant differences between “miniinvasive on-pump” and “on-pump” cardiac surgical patients were found. Conclusion: The expression of both RANK and RANKL molecules is significantly enhanced on monocytes of “miniinvasive on-pump” cardiac surgical patients.

The impact of off-pump surgery in end-organ function: practical end-points

Most surgeons perform coronary bypass surgery with the aid of cardiopulmonary bypass, which inflicts a massive systemic inflammatory response to the body leading to adverse clinical outcome. In an attempt to make CABG less invasive, interest have been diverted to the off pump technique.

The current review attempts to bring an insight onto the last ten years knowledge on the off-pump impact in end organ function, with an aim to draw some clear conclusions in order to allow practitioners to reflect on the subject.

Off-pump coronary artery bypass grafting improves short-term outcomes in high-risk patients compared with on-pump coronary artery bypass grafting: Meta-analysis

OBJECTIVES

To assess the benefits and risks of off-pump coronary artery bypass (OPCAB) versus coronary artery bypass grafting (CABG) through a meta-analysis of randomized controlled trials (RCTs), and to investigate the relationship between outcomes and patient risk profile.

METHODS

PubMed, Embase, the Cumulative Index of Nursing and Allied Health Literature, Scopus, Web of Science, Cochrane Library, and major conference proceedings databases were searched for RCTs comparing OPCAB and CABG and reporting short-term (≤ 30 days) outcomes. Endpoints assessed were all-cause mortality, myocardial infarction (MI), and cerebral stroke.

RESULTS

The meta-analysis included 100 studies, with a total of 19,192 subjects. There was no difference between the 2 techniques with respect to all-cause mortality and MI (odds ratio [OR], 0.88; 95% confidence interval [CI], 0.71-1.09; P = .25; I(2) = 0% and OR, 0.90; 95% CI, 0.77-1.05; P = .19; I(2) = 0%, respectively). OPCAB was associated with a significant 28% reduction in the odds of cerebral stroke (OR, 0.72; 95% CI, 0.56-0.92; P = .009; I(2) = 0%). A significant relationship between patient risk profile and benefits from OPCAB was found in terms of all-cause mortality (P < .01), MI (P < .01), and cerebral stroke (P < .01).

CONCLUSIONS

OPCAB is associated with a significant reduction in the odds of cerebral stroke compared with conventional CABG. In addition, benefits of OPCAB in terms of death, MI, and cerebral stroke are significantly related to patient risk profile, suggesting that OPCAB should be strongly considered in high-risk patients.

ISMICS Consensus Conference and Statements of Randomized Controlled Trials of Off-Pump versus Conventional Coronary Artery Bypass Surgery

Objective

At this consensus conference, we developed evidence-informed consensus statements and recommendations on the practice of off-pump coronary artery bypass graft (OPCAB) by systematically reviewing and performing meta-analysis of the randomized controlled trials (RCTs) comparing OPCAB and conventional coronary artery bypass (CCAB).

Methods

All RCTs of OPCAB versus CCAB through April 2013 were screened, and 102 relevant RCTs (19,101 patients) were included in a systematic review and meta-analysis (15 RCTs of 9551 high-risk patients; and 87 RCTs of 9550 low-risk patients) in accordance with the Cochrane Collaboration and PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) methodology. Consensus statements for the risks and benefits of OPCAB surgery in mortality, morbidity, and resource use were developed based on best available evidence.

Results

Compared to CCAB, it is reasonable to perform OPCAB to reduce risks of stroke [class IIa, level of evidence (LOE) A], renal dysfunction/failure (class IIa, LOE A), blood transfusion (class I, LOE A), respiratory failure (class I, LOE A), atrial fibrillation (class I, LOE A), wound infection (class I, LOE A), ventilation time, and ICU and hospital length of stay (class I, LOE A). However, OPCAB may be associated with a reduced number of grafts performed (class I, LOE A) and with diminished graft patency (class IIa, LOE A, with increased coronary reintervention at 1 year and beyond (class IIa, LOE A), as well as increased mortality at a median follow-up of 5 years (class IIb, LOE A).

Conclusions

OPCAB compared with CCAB may improve outcomes in the short-term (stroke, renal dysfunction, blood transfusion, respiratory failure, atrial fibrillation, wound infection, ventilation time, and length of stay). However, over the longer-term, OPCAB may be associated with reduced graft patency, and increased risk of cardiac re-intervention and death.

Perioperative heart-type fatty acid binding protein is associated with acute kidney injury after cardiac surgery

Acute Kidney Injury (AKI) is a common complication after cardiac surgery and is associated with worse outcomes. Since heart fatty acid binding protein (H-FABP) is a myocardial protein that detects cardiac injury, we sought to determine if plasma H-FABP was associated with AKI in the TRIBE-AKI cohort; a multi-center cohort of 1219 patients at high risk for AKI who underwent cardiac surgery. The primary outcomes of interest were any AKI (Acute Kidney Injury Network (AKIN) stage 1 or higher) and severe AKI (AKIN stage 2 or higher). The secondary outcome was long-term mortality after discharge. Patients who developed AKI had higher levels of H-FABP pre- and post-operatively than patients who did not have AKI. In analyses adjusted for known AKI risk factors, first post-operative log(H-FABP) was associated with severe AKI (adjusted OR 5.39 [95% CI, 2.87-10.11] per unit increase), while pre-operative log(H-FABP) was associated with any AKI (2.07 [1.48-2.89]) and mortality (1.67 [1.17-2.37]). These relationships persisted after adjustment for change in serum creatinine (for first postoperative log(H-FABP)) and biomarkers of cardiac and kidney injury, including brain natriuretic peptide, cardiac troponin-I, interleukin-18, liver fatty acid binding protein, kidney injury molecule-1, and neutrophil gelatinase associated lipocalin. Thus, peri-operative plasma H-FABP levels may be used for risk-stratification of AKI and mortality following cardiac surgery.

Early detection of asymptomatic bypass graft abnormalities using a cardiac troponin I ratio following coronary artery bypass surgery

BACKGROUND

We sought to identify the best cardiac Troponin I (cTnI) ratio to detect asymptomatic graft or anastomoses anomalies after myocardial revascularization.

METHODS

Patients with a rising cTnI profile, based on measurements at 6 and 12 hours (cTnI 12 hours : 6 hours ratio >1) after the last anastomosis in off-pump surgery or after cardiopulmonary bypass in on-pump surgery, underwent a coronary angiogram, despite an uncomplicated postoperative course and absence of electrocardiogram changes. The optimal threshold value for the ratio was determined using a receiving operator characteristic (ROC) curve.

RESULTS

From April 2005 to May 2011, among 1693 patients undergoing isolated coronary artery bypass graft (CABG), 29 (1.7%) had a cTnI ratio >1 and underwent postoperative angiography. Twenty abnormalities were observed in 16 patients (55%). In the anastomoses, there were four occlusions and four stenosis. In the grafts, there were 12 stenosis: two of the Y graft anastomosis, two dissections, five hematomas and three kinking. TIMI flow grade based on results of the Thrombolysis In Myocardial Infarction trial was 3 in six patients, 1 in five, and 0 in five. In the 16 patients with lesions, the cTnI ratio was 2.1 ± 1.4 versus 1.4 ± 0.3 in patients with no lesions (p = 0.09). A ratio of 1.3 (p = 0.003) was determined by ROC curve analysis as having the greatest discriminant capacity, with associated sensitivity of 87.5% and specificity of 62%.

CONCLUSION

A cTnI 12 hours : 6 hours ratio >1.3 may be indicative of these abnormalities. Early identification of these anomalies may avoid adverse outcomes.

TLR2 AND TLR4 EXPRESSION ON BLOOD MONOCYTES AND GRANULOCYTES OF CARDIAC SURGICAL PATIENTS IS NOT AFFECTED BY THE USE OF CARDIOPULMONARY BYPASS

Cardiac surgery is inseparably linked to the activation of innate immunity cells recognizing danger signals of both endogenous and exogenous origin via pattern recognition receptors such as TLR receptors. Therefore, we followed by flow cytometry TLR2 and TLR4 expression on blood monocytes and granulocytes of patients who underwent coronary artery bypass grafting using beating heart surgery (off-pump, n = 34), with use of standard cardiopulmonary bypass (CPB), (on-pump, n = 30), and miniinvasive CPB (mini on-pump, n = 25), respectively, before, during surgery, and up to 7th postoperative day. TLR2 and TLR4 expression both on monocytes and granulocytes was significantly diminished already at the end of CPB being highly significantly decreased at the end of surgery in all patients’ groups. TLR2 and TLR4 expression reached preoperative value at the 1st postoperative day being significantly higher at the 3rd postoperative day. Using intracellular staining we found the peak of TLR2 and TLR4 expression inside of monocytes and granulocytes at the first postoperative day in a subgroup of on-pump patients. In conclusion, TLR2 and TLR4 expression is significantly modulated in patients undergoing coronary artery bypass grafting as a part of adaptive homeostatic mechanisms induced by major surgery. The very surgical trauma is responsible for TLR2 and TLR4 modulation. Surprisingly, cardiopulmonary bypass itself was little contributing to the modulation of TLR2 and TLR4 expression.

[Evaluation of postoperative myocardial injury by heart-type fatty acid-binding protein in off-pump coronary artery bypass grafting surgery]

BACKGROUND AND GOAL OF STUDY

Postoperative myocardial infarction is a serious and frequent complication of cardiac surgery. Nonetheless, diagnosis in this context it is occasionally challenging. We sought to evaluate the kinetics and diagnostic accuracy of the new biomarker « heart-type fatty acid-binding protein » (h-FABP) in the early detection of myocardial injury in patients undergoing off-pump coronary artery bypass grafting, compared with classical biomarkers.

MATERIALS AND METHODS

A prospective study was conducted on 17 consecutive patients who underwent off-pump coronary artery bypass grafting during a 2 month period. Blood samples were drawn for measurement of myocardial ischemic injury biomarkers (h-FABP, troponin, creatine kinase [CK] and CK-MB), at baseline (T1), immediate post-coronary artery bypass grafting (T2), on ICU admission (T3), and after 4 (T4), 8 (T5), 24 (T6) and 48 h (T7). Perioperative ischemic complications, defined according to electrocardiographic, echocardiographic and hemodynamic criteria, were recorded.

RESULTS

Earlier biomarkers peak plasma values occurred at T4 with troponin (2.9 ± 5.2 ng/mL), and at T5 with h-FABP (37.9 ± 55.5 ng/mL). Maximum values of CK and CK-MB occurred later, both in T6 (741 ± 779 and 37 ± 51 U/L, respectively). The optimized cut-off obtained for h-FABP was 19 ng/mL, providing a sensitivity and specificity of 77 and 75%, respectively, for diagnosis of perioperative ischemic injury, with an area under the ROC curve for h-FABP of 0.83 (95% CI 0.6-1.0) vs. 0.63 (95% CI 0.33-0.83) for troponin. This cut-off value for h-FABP is reached on average at T2 (mean value of h-FABP at T2: 18.9 ± 21.5 ng/mL).

CONCLUSION

This is the first study evaluating the kinetics of h-FABP biomarker in perioperative off-pump coronary artery bypass grafting, and the cut-off value established could help to extend earlier detection of myocardial ischemia in this context.

Malignant ventricular arrhythmias after off-pump coronary artery bypass

BACKGROUND/PURPOSE

Sustained ventricular tachycardia and ventricular fibrillation (VT/VF) are rare complications after coronary surgery. Off-pump coronary artery bypass (OPCAB) was developed to decrease postoperative complications. No studies to date have specifically addressed VT/VF after OPCAB. We sought to assess the incidence, risk factors, and outcome of VT/VF after OPCAB.

METHODS

The study included a retrospective review of 1010 patients undergoing OPCAB between 2000 and 2012. Data were compared between the VT/VF patients and control patients who were the first cases of OPCAB in each month during the study period and did not have VT/VF.

RESULTS

Twenty-three patients (2.3%) developed VT/VF after OPCAB. The hospital mortality rate was 17.4%. In univariate analysis, the risk factors for VT/VF were old age, rapid heart rate, prolonged corrected QT interval, severe congestive heart failure, poor left ventricular ejection fraction, large left ventricular end-diastolic diameter, chronic kidney disease, preoperative dialysis, low blood hemoglobin level, preoperative intubation, recent myocardial infarction, high European System for Cardiac Operative Risk Evaluation, urgent/emergent operation, use of intra-aortic balloon pump, conversion to on-pump beating heart, postoperative dialysis, and no use of beta-blockers after operation. Multivariate analysis identified preoperative corrected QT interval > 426 milliseconds [odds ratio (OR) = 4.501; 95% confidence interval (CI) = 1.153-17.570] and estimated glomerular filtration rate < 30 mL/minute/1.73 m(2) (OR = 4.876; 95% CI = 1.112-21.374) as independent risk factors.

CONCLUSION

Postoperative VT/VF was rare after OPCAB but was associated with high mortality. Prolonged corrected QT interval and chronic kidney disease were independent risk factors. Recognition of these risk factors, proper prevention, and early intervention may improve survival.

Acute kidney injury associated with rhabdomyolysis after coronary artery bypass graft: a case report and review of the literatures

BACKGROUND

Post-operative rhabdomyolysis is a well-known complication, especially after bariatric and orthopaedic surgeries. There are few published reports of rhabdomyolysis following cardiac surgery. Acute kidney injury had been distinguished as a serious complication of cardiac surgery. We report a case of 55-years-old male patient who developed rhabdomyolysis precipitated acute kidney injury after coronary artery bypass graft.

CASE PRESENTATION

The patient underwent urgent coronary artery bypass graft surgery, with a long duration of surgery due to technical difficulty during grafting. He developed rhabdomyolysis induced acute kidney injury necessitating hemodialysis. The patient in turn developed heart failure, which along with acute kidney injury lead to prolonged ventilation. There was supervening sepsis with prolonged intensive care unity stay and eventually prolonged hospitalization. The peak creatine kinase level was 39,000 IU/mL and peak myoglobin was 40,000 ng/ml. Reviewing the patient, surgery was prolonged due to technical difficulties encountered during grafting, leading to rhabdomyolysis induced acute kidney injury. The pre-operative use of statins by the patient could also have contributed to the development of rhabdomyolysis. He developed post-operative right heart failure and sepsis. The patient's renal function gradually improved over 4 week's duration. Favorable outcome could be achieved but after prolonged course of renal replacement therapy in the form of hemodialysis.

CONCLUSION

Prolonged duration of surgery is a well-recognized risk factor in the development of rhabdomyolysis. Early recognition of rhabdomyolysis induced acute kidney injury is important in reducing the post-operative morbidity and mortality in patients. A protocol based approach could be applied for early recognition and management.

Prolonged sevoflurane administration in the off-pump coronary artery bypass graft surgery: beneficial effects

PURPOSE

The benefits of intraoperative administration of halogenated agents in patients undergoing cardiac surgery have been shown by numerous studies. The mechanisms of preconditioning and postconditioning appear to be the cause of these benefits. The possibility of maintaining the early postoperative sedation with halogenated agents, after its intraoperative administration, can increase their benefits.

PATIENTS AND METHODS

This is a prospective trial with 60 patients undergoing coronary artery bypass graft surgery divided into 3 groups according to the administration of hypnotic drugs in the intraoperative and postoperative periods (sevoflurane, sevoflurane: SS, sevoflurane-propofol: SP, propofol-propofol: PP). For the first 48 hours, hemodynamic parameters, the need for inotropic drugs, N-terminal pro-brain natriuretic peptide, and troponin I plasmatic concentrations were obtained.

RESULTS

There were significant differences between group SS and the other 2 groups in the levels of N-terminal pro-brain natriuretic peptide (SS [501±280 pg/mL] compared with SP [1270±498 pg/mL] and PP [1775±527 pg/mL] [P<.05]) and troponin I (SS [0.5±0.4 ng/mL] compared with SP [1.61±1.30 ng/mL] and PP [2.27±1.5 ng/mL] [P<.05]) and a lower number of inotropic drugs.

CONCLUSION

Sevoflurane administration in patients undergoing off-pump coronary artery bypass graft, in the operating room and the intensive care unit, decreases myocardial injury markers compared with patients who only received sevoflurane in the intraoperative period, but both were a better option to decrease levels of myocardial markers when compared with the propofol group.

On-pump versus off-pump coronary artery bypass surgery: what is the status after ROOBY, DOORS, CORONARY and GOPCABE?

Off-pump coronary artery bypass surgery has been purported to be safer than conventional coronary artery bypass surgery performed using cardiopulmonary bypass. This theory was supported by a number of early series, but failed to be confirmed by a number of small, randomized, controlled trials. Conversely, it has been suggested that revascularization after off-pump surgery is associated with fewer grafts and lower graft patency, potentially leading to a higher risk of cardiovascular morbidity and need for repeated coronary interventions. Since 2009, four major randomized controlled trials have been published, increasing the level of evidence significantly.

High peripheral levels of h-FABP are associated with poor prognosis in end-stage heart failure patients with mechanical circulatory support

Aim: To associate the time-course of h-FABP and N-terminal pro B-type natriuretic peptide (NT-proBNP)after left ventricular assist device (LVAD) implantation to outcome in end-stage heart failure patients. Materials & methods: Patients (n = 14, NYHA class III/IV; left ventricular ejection fraction <25% were enrolled; ten survived up to 1 month after LVAD (survivors) and four died of multiorgan failure within 2 weeks (nonsurvivors). Blood samples were obtained at admission; at 4, 24 and 72 h; and at 1 and 4 weeks after LVAD. Results: h-FABP significantly increases after surgery, decreasing since 72 h in all patients. At 72 h all survivor patients present h-FABP lower than the median value. N-terminal pro B-type natriuretic peptide is not associated with patient outcome at any time. Conclusion: High h-FABP levels, indicating the presence of more severe myocardial damage, are associated with a poor prognosis in patients with LVAD, suggesting that an early cardiac injury marker could improve the prediction of clinical outcome.

Effect of on-pump versus off-pump coronary bypass surgery on cardiac function assessed by intraoperative transesophageal echocardiography

PURPOSE

To compare cardiac function assessed by intraoperative transesophageal echocardiography in patients undergoing cardiac revascularization with or without cardiopulmonary bypass.

MATERIAL AND METHODS

Forty-one patients scheduled for elective, isolated cardiac revascularization (21 on-pump and 20 off-pump) were prospectively analyzed. Patients were matched for demographic (age and gender), anthropometric (BMI), clinical (co-morbidities, EuroScore) and laboratory variables (blood counts, renal function, left ventricular function). Transesophageal echocardiography was performed after induction of anesthesia, protamine sulfate administration, and chest closure. Left ventricular wall motion score index, end-diastolic area, fractional area change, right ventricular area change and end-diastolic area were assessed. Troponin I and C-reactive protein concentrations were measured.

RESULTS

Regarding echocardiographic parameters of left and right ventricular function no significant differences between on-pump and off-pump groups at any point-of-time measurements were found. Troponin I and C-reactive protein were higher in on-pump as compared to off-pump group (p=0.001 and p=0.002; p=0.003 and p=0.001, respectively).

CONCLUSIONS

In elective patients scheduled for cardiac revascularization there were no difference in cardiac performance assessed by intraoperative echocardiography regardless of surgical method used.

Preservation of myocardium during coronary artery bypass surgery

Myocardial protection aims to prevent reversible post-ischemic cardiac dysfunction (myocardial stunning) and irreversible myocardial cell death (myocardial infarction) that occur as a consequence of myocardial ischemia and/or ischemic-reperfusion injury. Although the mortality rate for isolated coronary artery bypass grafting has been markedly reduced during the past decade, myocardial death, as evidenced by elevation in creatine kinase-myocardial band and/or cardiac troponin, is common. This is ascribed to suboptimal myocardial protection during cardiopulmonary bypass or with off-pump technique, early graft failure, distal embolization, and regional or global myocardial ischemia during surgery. An unmet need in contemporary coronary bypass surgery is to find more effective cardioprotective strategies that have the potential for decreasing the morbidity and mortality associated with suboptimal cardioprotection. In the present review article on myocardial protection in contemporary coronary artery bypass surgery, we attempt to elucidate the clinical problems, summarize the outcomes of selected phase III trials, and introduce new perspectives.

Off-pump versus on-pump coronary artery bypass grafting for ischaemic heart disease

BACKGROUND

Coronary artery bypass grafting (CABG) is performed both without and with cardiopulmonary bypass, referred to as off-pump and on-pump CABG respectively. However, the preferable technique is unclear.

OBJECTIVES

To assess the benefits and harms of off-pump versus on-pump CABG in patients with ischaemic heart disease.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library (Issue 1, 2011), MEDLINE (OVID, 1950 to February 2011), EMBASE (OVID, 1980 to February 2011), Science Citation Index Expanded on ISI Web of Science (1970 to February 2011) and CINAHL (EBSCOhost, 1981 to February 2011) on 2 February 2011. No language restrictions were applied.

SELECTION CRITERIA

Randomised clinical trials of off-pump versus on-pump CABG irrespective of language, publication status and blinding were selected for inclusion.

DATA COLLECTION AND ANALYSIS

For statistical analysis of dichotomous data risk ratio (RR) and for continuous data mean difference (MD) with 95% confidence intervals (CI) were used. Trial sequential analysis (TSA) was used for analysis to assess the risk of random error due to sparse data and to multiple updating of accumulating data.

MAIN RESULTS

Eighty-six trials (10,716 participants) were included. Ten trials (4,950 participants) were considered to be low risk of bias. Pooled analysis of all trials showed that off-pump CABG increased all-cause mortality compared with on-pump CABG (189/5,180 (3.7%) versus 160/5144 (3.1%); RR 1.24, 95% CI 1.01 to 1.53; P =.04). In the trials at low risk of bias the effect was more pronounced (154/2,485 (6.2%) versus 113/2,465 (4.6%), RR 1.35,95% CI 1.07 to 1.70; P =.01). TSA showed that the risk of random error on the result was unlikely. Off-pump CABG resulted in fewer distal anastomoses (MD -0.28; 95% CI -0.40 to -0.16, P <.00001). No significant differences in myocardial infarction, stroke, renal insufficiency, or coronary re-intervention were observed. Off-pump CABG reduced post-operative atrial fibrillation compared with on-pump CABG, however, in trials at low risk of bias, the estimated effect was not significantly different.

AUTHORS' CONCLUSIONS

Our systematic review did not demonstrate any significant benefit of off-pump compared with on-pump CABG regarding mortality, stroke, or myocardial infarction. In contrast, we observed better long-term survival in the group of patients undergoing on-pump CABG with the use of cardiopulmonary bypass and cardioplegic arrest. Based on the current evidence, on-pump CABG should continue to be the standard surgical treatment. However, off-pump CABG may be acceptable when there are contraindications for cannulation of the aorta and cardiopulmonary bypass. Further randomised clinical trials should address the optimal treatment in such patients.

Effects of remote ischemic preconditioning with postconditioning in patients undergoing off-pump coronary artery bypass surgery--randomized controlled trial

BACKGROUND

Myocardial injury is associated with an adverse outcome after off-pump coronary artery bypass graft surgery (OPCAB). The authors conducted a randomized controlled trial to evaluate whether remote ischemic preconditioning (RIPC) with remote ischemic postconditioning (RIPostC) reduces myocardial injury in patients undergoing OPCAB.

METHODS AND RESULTS

Seventy patients scheduled for OPCAB were randomly assigned to an RIPC+RIPostC group (n=35) or a control group (n=35). In the RIPC+RIPostC group, 4 cycles of 5-min ischemia and 5-min reperfusion were done on a lower limb before anastomoses (RIPC) and after anastomoses (RIPostC). RIPC+RIPostC significantly reduced postoperative serum troponin I levels (P=0.001). The area under the curve for postoperative troponin I was 48.7% lower in the RIPC+RIPostC group (median [interquartile range], 21.3 h·ng⁻¹·ml⁻¹, 16.5-53.1 h·ng⁻¹·ml⁻¹ vs. 41.5 h·ng⁻¹·ml⁻¹, 24.6-90.2 h·ng⁻¹·ml⁻¹, P=0.020). There was no significant difference in creatinine levels and PaO₂/F(i)O₂ ratios between the 2 groups.

CONCLUSIONS

RIPC+RIPostC by lower limb ischemia decreased postoperative myocardial enzyme elevation by almost half postoperatively in patients undergoing OPCAB.

On-pump coronary surgery with and without cardioplegic arrest: comparison of inflammation, myocardial, cerebral and renal injury and early and late health outcome in a single-centre randomised controlled trial

OBJECTIVE

To assess the safety and efficacy of on-pump beating heart coronary surgery on organ function, and early and late health outcome as compared with conventional technique.

METHODS

A total of 81 patients were randomised to (1) coronary surgery with cardiopulmonary bypass (CPB) and cardioplegic arrest (CA) (on-pump with CA, n=41) or to (2) CPB without CA (on-pump without CA, n=40). Primary outcomes included serial measurement of interleukins (IL-6, IL-8 and IL-10) for inflammation, troponin I for myocardial injury, protein S100 for cerebral injury and creatinine clearance (CrCl) and urinary N-acetyl-β-d-glucosaminidase (NAG) for renal injury. In-hospital health outcome and 5-year event-free survival were secondary outcomes.

RESULTS

Baseline and intra-operative characteristics were similar between groups. A marked release of ILs was observed in both groups, but no significant differences between the groups were found (IL-6 +9%, 95% confidence interval (CI) -15% to +39%, p=0.49; IL-8 +4%, 95% CI -34% to +63%, p=0.86; IL-10 -0.1%, 95% CI -19% to +21%, p=0.93). Troponin I rose in both groups and was on average 34% higher in the on-pump without CA group but this did not reach statistical significance (95% CI -0.4% to +87%, p=0.08). S100 protein was higher in the on-pump without CA group at 12h (p=0.04) but did not differ at other times (p=0.16). The level of CrCl was higher 1h in the on-pump without CA group (+23%, 95% CI +1% to +50%, p=0.04), but not thereafter. NAG release was similar in both groups (+1% 95% CI -23% to +33%, p=0.91). Early and 5-year health outcomes were similar.

CONCLUSIONS

On-pump without CA coronary surgery does not provide any obvious advantage when compared with the conventional technique of on-pump with CA in elective patients. Both techniques provide a comparable degree of inflammatory activation, myocardial, cerebral and renal injury with similar 5-year event-free survival.

The effect of remote ischaemic preconditioning on myocardial injury in patients undergoing off-pump coronary artery bypass graft surgery

In several recent clinical trials on cardiac surgery patients, remote ischaemic preconditioning (RIPC) showed a powerful myocardial protective effect. However the effect of RIPC has not been studied in patients undergoing off-pump coronary artery bypass graft surgery. We evaluated whether RIPC could induce myocardial protection in off-pump coronary artery bypass graft surgery patients. Patients undergoing elective off-pump coronary artery bypass graft surgery were randomly allocated to the RIPC (n = 65) or control group (n = 65). After induction of anaesthesia, RIPC was induced by four cycles of five-minute ischaemia and reperfusion on the upper limb using a pneumatic cuff. Anaesthesia was maintained with sevoflurane, remifentanil and vecuronium. Myocardial injury was assessed by troponin I before surgery and 1, 6, 12, 24, 48 and 72 hours after surgery. There were no statistical differences in troponin I levels between RIPC and control groups (P = 0.172). Although RIPC reduced the total amount of troponin I (area under the curve of troponin increase) by 26%, it did not reach statistical significance (RIPC group 53.2 +/- 72.9 hours x ng/ml vs control group 67.4 +/- 97.7 hours x ng/ml, P = 0.281). In this study, RIPC by upper limb ischaemia reduced the postoperative myocardial enzyme elevation in off-pump coronary artery bypass graft surgery patients, but this did not reach statistical significance. Further study with a larger number of patients may be needed to fully evaluate the clinical effect of RIPC in off-pump coronary artery bypass graft surgery patients.

Extracorporeal membrane oxygenation induced cardiac dysfunction in newborn lambs

Extracorporeal membrane oxygenation (ECMO) is routinely used to support cardiopulmonary failure in infants and children. Suboptimal outcomes for primary cardiac support suggest a need for investigation of the impact of ECMO on the heart. Twenty-four newborn lambs received a brief period of ECMO support to investigate the hypothesis that ECMO produces cardiac dysfunction in newborn lamb. Dorset newborn lambs, 4-7 days of age, were exposed to ECMO for 5 min at a 100 ml/kg flow rate and quickly weaned off. Measurements included echocardiographic mean left ventricular (LV) velocity of circumferential fiber shortening corrected for heart rate (mVCFc), LV shortening fraction, and peak systolic wall stress plus hemodynamic measurement of LV maximum rate of pressure change with time (LV dp/dt max), maximum rate of pressure change divided by developed pressure (LV dp/dtP), right atrial pressure, pulmonary capillary wedge pressure, mean pulmonary artery pressure, LV peak and end-diastolic pressure, and aortic pressure. These measures were also obtained after an exposure to 5 min of ECMO and immediate disconnect for 5 min, followed by ECMO administration for 1 h again, followed by discontinuation of ECMO. LV mVCFc is decreased after exposure to 5 min of ECMO support despite a decrease in LV peak systolic wall stress that provides afterload reduction. LV mVCFc is inversely related to peak systolic wall stress at a significance level of p < 0.0001. The time period after initiation of ECMO is a significant factor in the model (p = 0.0097). Time [baseline] was different from the other time points with p = 0.0010. Average mVCFc at baseline is 1.27 ± 0.35 and decreases to 1.01 ± 0.42 after 5 min of ECMO that is then withdrawn. Peak systolic wall stress decreases from 36.0 ± 13.1 at baseline to 29.8 ± 12.1 after 5 min of ECMO. LV dp/dt max decreases from 1,769 ± 453 mmHg/s at baseline to 1,311 ± 513 mmHg/s after exposure to 5 min of ECMO (p = 0.0005). Baseline LV dp/dt max is different from each point after start of ECMO. Diastolic LVdp/dt min increased from -1,340 ± 477 mmHg/s to -908 ± 393 mmHg/s at 5 min. Echocardiographic mVCFc, when considered in isolation or as a function of LV peak systolic wall stress, shows diminished LV function after ECMO. Hemodynamic measurement of LV dp/dt max and LV dp/dt min confirms the observation. Separation of the humoral from mechanical effect of ECMO with the short exposure to the extracorporeal circuit shows that an immediate decrement of LV function occurs at initiation of ECMO, a finding that has not been stressed with previous studies of extracorporeal support. This implies a potentially outcome-limiting deleterious effect for the patient who requires ECMO support for the heart rather than the lungs. We should continue to strive to understand and ameliorate this deleterious effect of the extracorporeal circulation circuit.

Expression of CD200/CD200R regulatory molecules on granulocytes and monocytes is modulated by cardiac surgical operation

Aims: Cardiac surgical operation is inseparably linked to the induction of an inflammatory response. Both humoral and cellular regulatory mechanisms are operating to maintain body homeostasis. We followed the changes in the expression of CD200/CD200R regulatory molecules on monocytes and granulocyte of cardiac surgical patients operated on using either standard (OP) or modified “mini-invasive” cardiopulmonary bypass (MOP).

Methods: Expression of CD200/CD200R regulatory molecules was determined by flow cytometry.

Results: The expression of CD200R on granulocytes was increased after surgery in both groups of patients, but the increase was statistically significant only in OP patients (p<0.01). At this time point, there was a significant difference in CD200R expression on granulocytes when comparing OP to MOP patients, being higher in the former group (p<0.01). The expression of CD200R on monocytes was diminished after surgery and during an early postoperative period in both groups of patients. The expression of CD200 on monocytes was significantly diminished after surgery in both groups (p<0.01). Nonetheless, we observed an increase in CD200 expression in OP patients at the 3rd postoperative day. There was a statistically significantly increased CD200 expression on monocytes of OP patients (p<0.001) at the 3rd postoperative day when we compared OP and MOP groups. The expression of CD200 on granulocytes was significantly higher after surgery and at the 3rd postoperative day in OP when compared to MOP patients.

Conclusions: CD200R expression on granulocytes was significantly increased, while CD200 and CD200R expression on monocytes was decreased after cardiac surgery.