Undergoing Off-pump Coronary Artery Bypass Surgery Research Articles

Pecto-Intercostal Fascial Plane Block: Effect on the Postoperative Analgesia and Recovery After Off-PUMP Coronary Artery Bypass Surgery

Background: Anteromedial chest wall fascial plane blocks may serve as a valuable addition to postoperative multimodal pain management following median sternotomy for cardiothoracic surgeries. Objectives: This study aimed to evaluate the impact of implementing the pecto-intercostal fascial plane block (PIFB) in patients scheduled for off-pump coronary artery bypass (OPCAB) surgery. Methods: This randomized controlled study involved 40 adult patients aged 30 to 70 years undergoing OPCAB surgery. They were randomly assigned to two equal groups: Group PI received bilateral ultrasound (US)-guided PIFB with 20 mL of bupivacaine 0.25% with adrenaline 2.5 µg/mL, while group C (control group) received bilateral sham blocks with 20 mL of saline 0.9%. Pain scores in the postoperative period (primary outcome), perioperative analgesic consumption, time until extubation, and discharge from the intensive care unit (ICU) were assessed for both groups. Results: Postoperative pain scores, both at rest and during coughing, were significantly lower in group PI compared to group C. Group PI required significantly less fentanyl perioperatively and less tramadol for postoperative rescue compared to group C. The duration of postoperative ventilation and time to ICU discharge were significantly shorter in group PI than in group C. Conclusions: In patients undergoing OPCAB surgery, pre-incisional ultrasound-guided PIFB can be a beneficial and safe component of multimodal pain management. It provides improved postoperative pain control, reduces the need for perioperative opioids, and leads to faster extubation and ICU discharge.

Blood Products Utilization Status in Off-Pump Cardiac Surgery Patients.

Background: Transfusion support has an essential role in coronary artery bypass graft (CABG). The time-honored gold standard for CABG is the on-pump procedure (ONCAB); however, off-pump coronary artery bypass (OPCAB) is also a safe, cost-benefit procedure with fewer blood transfusion requirements. This study was performed to evaluate transfusion patterns in OPCAB due to the diversity of transfusion practices. Materials and Methods: This retrospective study was performed to determine the transfusion rate and triggers in OPCAB patients. Medical files of all patients undergoing OPCAB surgery at Sanandaj Tohid Hospital in 2014 were reviewed. Patients' demographics data, preoperative laboratory tests (PT, aPTT, Hb, Hct, Platelet count), underlying medical conditions, and their possible relation to further transfusions and the ward department in which the transfusion had taken place were extracted. SPSS 16 Chicago software, T-student Test, One Way Anova, and χ2 exam were applied for data analysis. P values ≤0.05was considered significant. Results: Among 91 elective OPCAB patients: 28(30.8%) women and 63(69.2%) men with mean age of 64.80±9.02 years, 63(69.23%) received a blood product. Mean utilization of PRBC, FFP, Platelet, and Cryoprecipitate were 2.17±2.044, 2.46±2.86, 2.86±3.80 and 0.40±2.10 units, respectively. ICU revealed the highest consumption rate for all products. Female sex (p<0.001), Hypertension (P=0.002), and low hemoglobin(P=0.004) were noted as predictive factors for transfusion. Conclusion: This study concluded that the transfusion rate in OPCAB is still very high in Iran (regarding a study in a countryside hospital) and that the highest utilization rate is seen in the ICU.

Association between intraoperative pulmonary artery pressure and cardiovascular complications after off-pump coronary artery bypass surgery: a single-center observational study

BackgroundThe impact of intraoperative pulmonary hemodynamics on prognosis after off-pump coronary artery bypass (OPCAB) surgery remains unknown. In this study, we examined the association between intraoperative vital signs and the development of major adverse cardiovascular events (MACE) during hospitalization or within 30 days postoperatively.MethodsThis retrospective study analyzed data from a university hospital. The study cohort comprised consecutive patients who underwent isolated OPCAB surgery between November 2013 and July 2021. We calculated the mean and coefficient of variation of vital signs obtained from the intra-arterial catheter, pulmonary artery catheter, and pulse oximeter. The optimal cut-off was defined as the receiver operating characteristic curve (ROC) with the largest Youden index (Youden index = sensitivity + specificity – 1). Multivariate logistic regression analysis ROC curves were used to adjust all baseline characteristics that yielded P values of < 0.05.ResultsIn total, 508 patients who underwent OPCAB surgery were analyzed. The mean patient age was 70.0 ± 9.7 years, and 399 (79%) were male. There were no patients with confirmed or suspected preoperative pulmonary hypertension. Postoperative MACE occurred in 32 patients (heart failure in 16, ischemic stroke in 16). The mean pulmonary artery pressure (PAP) was significantly higher in patients with than without MACE (19.3 ± 3.0 vs. 16.7 ± 3.4 mmHg, respectively; absolute difference, 2.6 mmHg; 95% confidence interval, 1.5 to 3.8). The area under the ROC curve of PAP for the prediction of MACE was 0.726 (95% confidence interval, 0.645 to 0.808). The optimal mean PAP cut-off was 18.8 mmHg, with a specificity of 75.8% and sensitivity of 62.5% for predicting MACE. After multivariate adjustments, high PAP remained an independent risk factor for MACE.ConclusionsOur findings provide the first evidence that intraoperative borderline pulmonary hypertension may affect the prognosis of patients undergoing OPCAB surgery. Future large-scale prospective studies are needed to verify the present findings.

Anesthesia management of patients undergoing off-pump coronary artery bypass grafting: A retrospective study of single center.

To summarize the current practice of anesthesia management for Chinese patients undergoing off-pump coronary artery bypass (OPCAB) surgery at a large-volume cardiovascular center. The clinical data of consecutive patients undergoing isolated, primary OPCAB surgery during the period from September 2019 to December 2019 were retrospectively analyzed. Patient characteristics, intraoperative data, and short-term outcomes were extracted from the Hospital Information System and the Anesthesia Information Management System. A total of 255 patients who underwent OPCAB surgery were enrolled in the current study. High-dose opioids and short-acting sedatives were the most commonly administrated anesthetics intraoperatively. Pulmonary arterial catheter insertion is frequently performed in patients with serious coronary heart disease. Goal-directed fluid therapy, a restricted transfusion strategy, and perioperative blood management were routinely used. Rational usages of inotropic and vasoactive agents facilitate hemodynamic stability during the coronary anastomosis procedure. Four patients underwent re-exploration for bleeding, but no death was observed. The study introduced the current practice of anesthesia management at the large-volume cardiovascular center, and the short-term outcomes indicated the efficacy and safety of the practice in OPCAB surgery.

Effect of preoperative ivabradine on hemodynamics during elective off-pump CABG.

Ivabradine is a specific heart rate (HR)-lowering agent which blocks the cardiac pacemaker If channels. It reduces the HR without causing a negative inotropic or lusitropic effect, thus preserving ventricular contractility. The authors hypothesized that its usefulness in lowering HR can be utilized in patients undergoing off-pump coronary artery bypass (OPCAB) surgery. To study the effects of preoperative ivabradine on hemodynamics (during surgery) in patients undergoing elective OPCAB surgery. Fifty patients, New York Heart Association (NYHA) class I and II, were randomized into group I (control, n = 25) and group II (ivabradine group, n = 25). In group I, patients received the usual anti-anginal medications in the preoperative period, as per the institutional protocol. In group II, patients received ivabradine 5 mg twice daily for 3 days before surgery, in addition to the usual anti-anginal medications. Anesthesia was induced with fentanyl, thiopentone sodium, and pancuronium bromide as a muscle relaxant and maintained with fentanyl, midazolam, pancuronium bromide, and isoflurane. The hemodynamic parameters [HR and mean arterial pressure (MAP)] and pulmonary artery (PA) catheter-derived data were recorded at the baseline (before induction), 3 min after the induction of anesthesia at 1 min and 3 min after intubation and at 5 min and 30 min after protamine administration. Intraoperatively, hemodynamic data (HR and MAP) were recorded every 10 min, except during distal anastomosis of the coronary arteries when it was recorded every 5 min. Post-operatively, at 24 hours, the levels of troponin T and brain natriuretic peptide (BNP) were measured. This trial's CTRI registration number is CTRI/005858. The HR in group II was lower when compared to group I (range 59.6-72.4 beats/min and 65.8-80.2 beats/min, respectively) throughout the study period. MAP was comparable [range (78.5-87.8 mm Hg) vs. (78.9-88.5 mm Hg) in group II vs. group I, respectively] throughout the study period. Intraoperatively, 5 patients received metoprolol in group I to control the HR, whereas none of the patients in group II required metoprolol. The incidence of preoperative bradycardia (HR <60 beats/min) was higher in group II (20%) vs. group I (8%). There was no difference in both the groups in terms of troponin T and BNP level after 24 hours, time to extubation, requirement of inotropes, incidence of arrhythmias, in-hospital morbidity, and 30-day mortality. Ivabradine can be safely used along with other anti-anginal agents during the preoperative period in patients undergoing OPCAB surgery. It helps to maintain a lower HR during surgery and reduces the need for beta-blockers in the intraoperative period, a desirable and beneficial effect in situations where the use of beta-blockers may be potentially harmful. Further studies are needed to evaluate the beneficial effects of perioperative Ivabradine in patients with moderate-to-severe left ventricular dysfunction.

Predictors of in-hospital mortality, 20-year survival and reflection on risk scoring in patients with impaired left ventricular function undergoing isolated coronary artery bypass grafting

Abstract Background Impaired left ventricular ejection fraction (LVEF) is a risk factor for mortality in patients undergoing coronary artery bypass grafting (CABG). Limited data is available on survival after 5 years and sensitivity of preoperative risk scoring systems in this high-risk population. Purpose To investigate in-hospital mortality, 20-year survival, predictors of early and late mortality and sensitivity of available risk-scoring systems in a large population with moderate to poor baseline LVEF and undergoing isolated CABG. Methods Patients presenting with moderate to poor LVEF and undergoing isolated CABG between 1996 and 2015 were selected for the purpose of this study. LVEF was defined moderate if between 30–39% and poor if &amp;lt;30%. Data collection was prospective and retrospectively analysed. Early and long-term mortality was derived from the NHS National Mortality Tracking system. Exclusion criteria included reoperations and combined procedures only. Patients undergoing urgent and emergency CABG procedures were included. Key outcome measures included 30-day health outcome, long-term survival, impact of incomplete revascularization (IC) and off-pump coronary artery bypass (OPCAB) surgery, independent predictors of poor in-hospital outcome and long-term mortality and reliability of Euroscore in predicting mortality in this high-risk population. Comparative analysis was conducted with Student t-test or Mann-whithney test fro numerical variable and Chi-Square for categorical variables. Survival were compared and reported using Log rank test and Kaplan Meier methods. A Cox Proportional Hazard model was developed to identify risk factors for long term mortality. Results 5016 patients with reduced LVEF were identifiedL1024 (20.4%) with poor and 3992 (79.6%) with moderate LVEF. After excluding reoperations and combined procedures, the final sample consisted of 3867 patients. Average age was68 years, 83% were male, 40% had NYHA IV; 12.5% of patients received IC and 44% underwent OPCAB surgery. 30-day mortality was 4.4%, stroke 1.4% and renal failure requiring dialysis of 2.9%. Survival at 1, 5, 10 and 20 years was 91.1%, 76.7%, 55.1% and 22.1% respectively (Figure). OPCAB surgery was not associated with long-term mortality. Independent predictors of late mortality as shown in Table. Additive Euroscore and Logistic Euroscore appeared to overestimate mortality in this patient population (AUC 0.78). Conclusions In patients with reduced LVEF the use of CABG is associated with low rates of in-hospital mortality, key post-operative complications and excellent long-term survival. Incomplete revascularization but not OPCAB surgery are surgical predictors of long-term mortality. Euroscore appears to overestimate the risk of mortality in this population. Funding Acknowledgement Type of funding sources: None. Cox Hazard Ratio Table

Effect of BMI on Postoperative Outcome, after Off-Pump CABG, A Prospective Observational Study

Background: Obesity and its complications are global health concerns with rising interests, and in Bangladesh, the scenario is not different. This study was designed to analyze the effect of BMI on postoperative outcomes in patients who underwent Off-Pump Coronary Artery Bypass (OPCAB)graft surgery. Methods: This prospective observational study was conducted from September 2017 to August 2018 in the department of cardiac surgery, NICVD &amp; 90 patients were divided into two groups. 43 patients in group A, with BMI ≥ 25 kg/m2 and 47 patients in group B, with BMI&lt;25 kg/m2. Results: In between groups, homogenous distribution was noted in terms of age and sex. Pre-operative risk factors, such as hypertension, dyslipidemia, and sternal wound infection, harvest site infection along with post-operative AF, were significantly higher in group A in comparison to group B. Conclusion: Obese patients undergoing OPCAB surgery should undergo maximum care. Meticulous tissue handling during OPCAB surgery in obese patients is needed to avoid or minimize sternal, and harvest site wound infection.

Do women benefit more than men from off-pump coronary artery bypass grafting?

ObjectivesOutcomes after coronary artery bypass grafting (CABG) are worse in women than in men. This study aims to investigate whether off-pump coronary artery bypass (OPCAB) surgery improves the outcomes in women by comparing different outcome measures in both genders.MethodsPatients who underwent isolated CABG, either on-pump (ONCAB) or OPCAB, between January 1998 and June 2017 were included. Primary endpoints were 30-day and 120-day mortality. Logistic regression models were constructed to evaluate the effect of the CABG technique on important outcomes such as mortality and the need for blood transfusion.ResultsThe data of 17,052 patients were analysed, 3,684 of whom were women (414 OPCAB) and 13,368 men (1,483 OPCAB). The mean number of grafts was lower in the OPCAB group of both genders (p < 0.001). Postoperatively, both men and women undergoing OPCAB surgery received fewer red blood cell transfusions (p < 0.001) and had higher postoperative haemoglobin levels (p < 0.001) than those undergoing ONCAB. Early mortality occurred less frequently after OPCAB surgery in both genders, although the difference was not significant. However, 120-day mortality was significantly lower after OPCAB surgery in women, even after correction for preoperative risk factors [odds ratio (OR) = 0.356, 95% confidence interval (CI) 0.144–0.882, p = 0.026]. The difference in 120-day mortality was not significant in men (OR = 0.787, 95% CI 0.498–1.246, p = 0.307).ConclusionsWomen undergoing CABG benefit more from OPCAB surgery than from ONCAB surgery in terms of 120-day mortality. This difference was not found in men in our patient population.

Conversion during off-pump coronary artery bypass graft surgery: A case-control study.

Objectives:Off pump coronary artery bypass (OPCAB) surgery is carried out as an alternative to conventional coronary artery bypass grafting using cardiopulmonary bypass (CPB). At times ‘conversion’ to CPB may be required to bail out a situation resulting from acute decompensation of the heart. It is reported that such conversion carries significant mortality risk. Since we conduct coronary revascularization by OPCAB technique as the preferred technique, we conducted this study with an aim to identify the markers of adverse outcome during conversion in Indian patients.Design:Case control retrospective study.Setting:Tertiary referral center.Participants:We conducted three thousand two hundred OPAB surgeries in the period between 2013 to16. Ninety patients (3.1%) required conversion to complete the revascularization (Con version group). Twice the number of patients who underwent OPCAB surgery without conver sion were chosen as controls (Control group).Intervention:OPCAB surgeryResults:Mortality in the conversion group was 5.56% in contrast to 0.06% in the controls (P = 0.01). The conversion group had higher left ventricular end diastolic pressure, incidence of endarterectomy, and intra-aortic balloon counter pulsation requirement. Female gender was also predictive of conversion. The total chest drain, duration of ventilation, ICU stay and hospital stay were also higher in the conversion group. Conversion was associated with 9.47 times the odds for mortality.Conclusion:Conversion during OPCAB is associated with significantly increased mortality. Female gender, increased left ventricular end diastolic pressure and preoperative requirement of Intra-aortic balloon are markers of increased risk of mortality when converted.

PREOPERATIVE STATINS REDUCE POSTOPERATIVE DELIRIUM FOLLOWING OFF PUMP CORONARY ARTERY BYPASS

The delirium is a common adverse event following cardiac surgery. Statins have an anti-inflammatory effect that can mitigate the postoperative neuro-inflammation. However, the role of statins in preventing postoperative delirium remains controversial. The aim of this study was the assess the impact of preoperative statin intake on postoperative delirium in patients undergoing off pump coronary artery bypass (OPCAB). From 1996 to 2007, 1400 patients underwent OPCAB surgery in our center. Patients were prospectively followed and data collected in a dedicated database. The mean age was 65 ± 1 years (21% female) and mean follow-up was 5.2 ± 0.1 years. Statins were taken by 615 (44%) patients preoperatively (the statin group). A propensity score was performed to match the statin group patients with the no-statin group (1:1) and resulted in 304 pairs. In the matched cohort, there was no difference in baseline characteristics between the two groups. The primary endpoint was the incidence of delirium. Secondary outcomes were the predictors of delirium and the impact of postoperative delirium on early and long-term mortality. Multivariable regressions were performed for the variables associated with postoperative delirium, early and late mortality in the unmatched cohort. Overall, the incidence of delirium was 12%. In the matched cohort, the postoperative delirium was significantly reduced in the statin group (10 vs 16%, p=0.03). In multivariable analysis, preoperative statin (OR: 0.62 [0.41-0.95], p=0.03), age (OR: 1.02 [1.00-1.04], p=0.05), ventilation time (OR:1.02 [1.01-1.03]) and postoperative transfusion (OR: 1.55 [1.00-2.42], p=0.05) were associated with postoperative delirium. The postoperative delirium was not associated with early and long-term mortality (p=0.47 and p=0.53). Preoperative statins reduce postoperative delirium following OPCAB surgery. In our study, postoperative delirium did not affect early and long-term mortality following OPCAB. Further randomized studies are needed to confirm these resutls.

Xenon as an Adjuvant to Propofol Anesthesia in Patients Undergoing Off-Pump Coronary Artery Bypass Graft Surgery: A Pragmatic Randomized Controlled Clinical Trial.

Xenon was shown to cause less hemodynamic instability and reduce vasopressor needs during off-pump coronary artery bypass (OPCAB) surgery when compared with conventionally used anesthetics. As xenon exerts its organ protective properties even in subanesthetic concentrations, we hypothesized that in patients undergoing OPCAB surgery, 30% xenon added to general anesthesia with propofol results in superior hemodynamic stability when compared to anesthesia with propofol alone. Fifty patients undergoing elective OPCAB surgery were randomized to receive general anesthesia with 30% xenon adjuvant to a target-controlled infusion of propofol or with propofol alone. The primary end point was the total intraoperative dose of norepinephrine required to maintain an intraoperative mean arterial pressure >70 mm Hg. Secondary outcomes included the perioperative cardiorespiratory profile and the incidence of adverse and serious adverse events. Adding xenon to propofol anesthesia resulted in a significant reduction of norepinephrine required to attain the predefined hemodynamic goals (cumulative intraoperative dose: median [interquartile range]: 370 [116-570] vs 840 [335-1710] µg, P = .001). In the xenon-propofol group, significantly less propofol was required to obtain a similar depth of anesthesia as judged by clinical signs and the bispectral index (propofol effect site concentration [mean ± SD]: 1.8 ± 0.5 vs 2.8 ± 0.3 mg, P≤ .0001). Moreover, the xenon-propofol group required significantly less norepinephrine during the first 24 hours on the intensive care unit (median [interquartile range]: 1.5 [0.1-7] vs 5 [2-8] mg, P = .048). Other outcomes and safety parameters were similar in both groups. Thirty percent xenon added to propofol anesthesia improves hemodynamic stability by decreasing norepinephrine requirements in patients undergoing OPCAB surgery.

Effect of preoperative statin therapy on early postoperative memory impairment after off-pump coronary artery bypass surgery.

Context:Frequent incidence of early postoperative memory impairment (POMI) after cardiac surgery remains a concern because of associated morbidity, impaired quality of life, and increased health care cost.Aim:To assess the effect of preoperative statin therapy on POMI in patients undergoing off-pump coronary artery bypass (OPCAB) surgery.Setting and Design:Prospective observational study in a tertiary level hospital. Methods:Sixty patients aged 45–65 years undergoing OPCAB surgery were allocated into two groups of 30 each. Group A patients were receiving statin and Group B patients were not receiving statins. All patients underwent memory function assessment preoperatively after admission to hospital and on the 6th postoperative day using postgraduate institute memory scale.Statistical Analysis:Appropriate tests were applied with SPSS 20 to compare both groups. The value P < 0.05 was considered statistically significant. Multiple regression analysis was performed with confounding factors to determine the effect on memory impairment.Results:Patients in Group A showed significant postoperative deterioration in 6 of the 10 functions and in Group B showed deterioration in 9 of 10 functions tested compared to preoperative scores. Intergroup comparison detected less POMI in Group A compared to Group B and was statistically significant in 8 memory functions. Multiple regression analysis detected statin as an independent factor in preventing memory impairment.Conclusions:Preoperative statin therapy attenuates the early POMI in patients undergoing OPCAB. Future long-term studies will define the efficacy of statin on POMI.

Off-pump coronary artery bypass surgery: Intra-aortic balloon pump aides multivessel revascularization in high-risk patients

Objective: Off-pump coronary artery bypass (OPCAB) has been demonstrated to be a safe technique with similar outcomes to on-pump coronary artery bypass (ONCAB) in low-risk patients, while its role and benefits in high-risk patients are the subject of ongoing clinical trials. This review compares our high-risk patients aided by intra-aortic balloon pump (IABP) with low-risk patients undergoing OPCAB to identify any differences in outcomes. Materials and Methods: One hundred and twenty-four patients who underwent OPCAB surgery between January 2004 and December 2013 were retrospectively reviewed. 61.3% were males, 57.3% were African Americans, mean age was 62.7 ± 13.3, and range was 30-90 years. Patients were divided into Group 1, 26 (21.0%) patients with IABP and Group 2, 98 (79.0%) patients without IABP. Group 1 patients had higher risk profile with mean ejection fraction (EF) 26.0 ± 10.8 and EF ≤20 present in 46.1% compared to 45.2 ± 11.9 and 5.1%, respectively, in Group 2 (P < 0.001). Results: 92.35% of Group 1 and 82.7% of Group 2 patients had multivessel disease with a mean number of bypass grafts 2.9 ± 0.97 versus 2.75 ± 0.8, respectively (P < 0.364). Left internal mammary artery (LIMA) to left anterior descending (LAD) was performed in all Group 1 and 97.9% of Group 2 patients, with saphenous vein graft (SVG) to the left circumflex and right coronary arteries in 73.1% versus 62.2% and 57.7% versus 52.0% of Groups 1 and 2, respectively. Complete revascularization occurred in 88.5% and 90.8% of Groups 1 and 2, respectively (P < 0.990). 4.0% were converted to ONCAB for either hemodynamic instability or intramyocardial coronary artery. Major morbidities were re-exploration for bleeding 3.8% versus 1.0%, stroke 3.8% versus 2.0%, acute kidney injury 11.5% versus 0%, and prolonged intubation 15.4% versus 2.0% in Groups 1 and 2, respectively. Euroscore II predicted (P) versus observed (O) mortality was 4.56% versus 4.03%, for Group 1, 7.82% versus 7.69% and Group 2, 3.64% versus 3.06%, and O/P ratios 0.88, 0.98 and 0.84 respectively. Two (2.0%) females in Group 2 with single LIMA to LAD underwent repeat revascularization with SVG to the LAD within 90 days. Conclusion: IABP helps stabilize hemodynamics during OPCAB in high-risk patients with moderate to severe left ventricular dysfunction. Mean number of bypass grafts and predicted versus observed mortality were similar between the low- and high-risk groups.

Protective effect of dexmedetomidine in coronary artery bypass grafting surgery

The aim of this study was to observe the impact of dexmedetomidine on postoperative myocardial injury in patients undergoing off-pump coronary artery bypass (OPCAB) grafting. One hundred and sixty-two patients who were undergoing OPCAB surgery were randomly divided into control and dexmedetomidine groups (groups C and Dex, respectively). Following the first vascular anastomosis grafting, the patients in group Dex received a continuous intravenous infusion of 0.2–0.5 μg/kg/h dexmedetomidine, until they were transferred to the Cardiac Surgery intensive care unit (ICU) for 12 h. Patients in group C received physiological saline intraoperatively and an intravenous infusion of 2–4 mg/kg/h isopropylphenol for postoperative sedation. Invasive arterial pressure and heart rate were continuously monitored for 5 min subsequent to entry into the operating theatre (T0), immediately following surgery (T1), 12 h post-surgery (T2), 24 h post-surgery(T3), 48 h post-surgery(T4) and 72 h post-surgery (T5). Blood samples were taken to determine the plasma levels of cardiac troponin I (cTnI) and creatine kinase-MB (CK-MB) at each time point. At 72 h post-surgery, a dynamic electrocardiogram was monitored. The blood pressure, heart rate, levels of cTnI, CK-MB, norepinephrine and cortisol, and postoperative arrhythmic events in the patients in group Dex all decreased compared with those in group C. The duration of mechanical ventilation and ICU residence time were also shorter than those in the control group (P<0.05). Dexmedetomidine reduced post-surgical myocardial injury in patients who had undergone OPCAB surgery.

Superior haemodynamic stability during off-pump coronary surgery with thoracic epidural anaesthesia: results from a prospective randomized controlled trial

Off-pump coronary artery bypass (OPCAB) surgery is a technically more demanding strategy of myocardial revascularization compared with the standard on-pump technique. Thoracic epidural anaesthesia, by reducing sympathetic stress, may ameliorate the haemodynamic changes occurring during OPCAB surgery. The aim of this randomized controlled trial was to evaluate the impact of thoracic epidural anaesthesia on intraoperative haemodynamics in patients undergoing OPCAB surgery. Two hundred and twenty-six patients were randomized to either general anaesthesia plus epidural (GAE) (n = 109) or general anaesthesia (GA) only (n = 117). Mean arterial blood pressure (MAP), heart rate (HR) and central venous pressure (CVP) were measured before sternotomy and subsequently after positioning the heart for each distal anastomosis. Both groups were well balanced with respect to baseline characteristics and received a standardized anaesthesia. The MAP decreased in both groups with no significant difference (mean difference (GAE minus GA) -1.11, 95% CI -3.06 to 0.84, P = 0.26). The HR increased in both groups after sternotomy but was significantly less in the GAE group (mean difference (GAE minus GA) -4.29, 95% CI -7.10 to -1.48, P = 0.003). The CVP also increased in both groups after sternotomy, but the difference between the groups varied over time (P = 0.05). A difference was observed at the third anastomosis when the heart was in position for the revascularization of the circumflex artery (mean difference (GAE minus GA) +2.09, 95% CI 0.21-3.96, P = 0.03), but not at other time points. The incidence of new arrhythmias was also significantly lower in the GAE compared with the GA group (OR = 0.41, 95% CI 0.22-0.78, P = 0.01). Thoracic epidural with general anaesthesia minimizes the intraoperative haemodynamic changes that occur during heart positioning and stabilization for distal coronary anastomosis in OPCAB surgery.

Avoidance of Aortic Side-Clamping for Proximal Bypass Anastomoses: Better Short-term Outcome?

The benefit of off-pump coronary artery bypass (OPCAB) surgery may be reduced by strokes caused by microemboli produced after aortic side-clamping for proximal bypass anastomoses. The Heartstring device allows constructing proximal bypass anastomoses without side-clamping of the aorta. This retrospective study describes 260 consecutive patients who underwent OPCAB surgery; 442 proximal anastomoses were performed with the Heartstring device in this series. Ten percent of the patients were randomly sampled before discharge to undergo a coronary angiogram for assessment of graft patency. Intraoperative Doppler measurements confirmed regular bypass function. Early mortality occurred in 4 patients (1.5%), and stroke occurred in 2 patients (0.8%). Device-related bleeding was negligible, and there were no cases of aortic dissection. Perioperative ischemia occurred in 8 patients (3.1%). Predischarge coronary angiography evaluations in 25 of the patients (of 260) showed that all 42 Heartstring-assisted anastomoses (of 442) were patent. Clampless performance of proximal bypass anastomoses combined with OPCAB is associated with a very low incidence of stroke complications. Short-term follow-up has shown excellent results regarding bypass patency and other adverse events. Prospective randomized trials are required to confirm the advantage of this technique.

Myocardial Protection with Isoflurane During Off-Pump Coronary Artery Bypass Grafting: A Randomized Trial

To analyze the hemodynamic effects and myocardial injury using troponin-T and creatine phosphokinase (CPK-MB) with isoflurane and compare it with a control group in patients undergoing off-pump coronary artery bypass (OPCAB) surgery. This prospective, randomized study was performed in patients scheduled for elective OPCAB surgery during February 2007 to February 2009. Tertiary care, university teaching hospital. Forty-five patients undergoing elective OPCAB surgery. Patients were randomly allotted to receive either isoflurane (inspired concentration between 1.0% and 2.5%) or propofol (1.5 to 3.5 mg/kg/h) during OPCAB surgery. The concentration of these agents was titrated such that the BIS value was maintained between 50 and 60. The hemodynamic data were measured and recorded after induction of anesthesia (baseline), during the distal anastomosis of each coronary artery, and 5 and 30 minutes after giving protamine. In addition, blood samples for troponin-T and CPK-MB were obtained after induction (baseline), after 6 hours and 24 hours postoperatively. The cardiac index was significantly higher in the isoflurane group at all stages, except during distal anastomosis of the diagonal branch of the left anterior descending artery (p < 0.05). There was a significant increase in troponin-T levels at 6 and 24 hours after surgery in the propofol group (from 0.037 ± 0.013 ng/mL to 0.098 ± 0.045 ng/mL and 0.081 ± 0.025 ng/mL, respectively, p < 0.05). Significant increases in the troponin-T levels were observed at 6 hours (from 0.033 ± 0.011 ng/mL to 0.052 ± 0.025 ng/mL, (p < 0.05) in the isoflurane group, and the levels in the propofol group were significantly higher than the isoflurane group at 6 and 24 hours after surgery (p < 0.05). The CPK-MB levels increased in both groups, but were not statistically different. Isoflurane provides protection against myocardial damage in a clinically used dosage as documented by lower levels of troponin-T in patients undergoing OPCAB surgery.

Comparison of Uncalibrated Arterial Pressure Waveform Analysis with Continuous Thermodilution Cardiac Output Measurements in Patients Undergoing Elective Off-Pump Coronary Artery Bypass Surgery

Monitoring of cardiac output is required during anesthesia for off-pump coronary artery bypass (OPCAB) surgery. Recently, FloTrac, a new device for arterial pressure waveform analysis for cardiac output (APCO) monitoring without external calibration, was developed. The authors have compared APCO with STAT-mode continuous cardiac output (SCCO) in patients undergoing OPCAB surgery. A clinical study. A university hospital (single institution). Thirty consecutive patients undergoing elective OPCAB surgery. Arterial pressure measurement with FloTrac, pulmonary arterial catheter insertion. APCO and SCCO measurements were recorded after pulmonary artery catheter insertion (T1), after sternotomy (T2), after heart positioning for left anterior descending artery anastomosis (T3, T4), after heart positioning for obtuse marginal artery anastomosis (T5, T6), after heart positioning for posterior descending artery anastomosis (T7, T8), and after sternal closure (T9). APCO and SCCO were compared using the Bland-Altman method and the percentage error by Critchley's criteria. SCCO and APCO ranged from 2.1 to 6.9 L/min and 1.2 to 7.4 L/min, respectively, and showed low correlation (r = 0.29). The overall bias by the Bland-Altman method between SCCO and APCO was -0.23 L/min, with a precision of -1.4 to 0.9 L/min, and the overall limits of agreement were -2.5 to 2.0 L/min. The overall mean CO was 4.0 ± 0.95 L/min. The overall percentage error between SCCO and APCO measurements was 57%. Uncalibrated APCO values do not agree with thermodilution SCCO and significantly overestimated the SCCO in patients undergoing OPCAB surgery. Further evaluation is required to verify the clinical acceptance of FloTrac APCO in OPCAB surgery.

A Randomized Clinical Trial Investigating the Relationship Between Aprotinin and Hypercoagulabilityin Off-Pump Coronary Surgery

Off-pump coronary artery bypass (OPCAB) surgery is associated with a hypercoagulable state in which the platelet thrombin receptor, protease-activated receptor-1 (PAR-1), helps propagate a thrombin burst within saphenous vein grafts. Aprotinin, used in cardiothoracic surgery mainly for its antifibrinolytic properties, also spares platelet PAR-1 activation due to thrombin. We hypothesized that this PAR-1 antagonistic property provides an antithrombotic benefit during OPCAB surgery. Patients were randomly assigned to receive saline (n = 38) or a modified full-dose regimen of aprotinin (n = 37) IV during OPCAB surgery. Blood sampled perioperatively from the coronary sinus, skin wounds, and systemic circulation was analyzed to test coagulation and platelet function. Major adverse cardiovascular events were monitored by obtaining troponin I at 24 h (myocardial infarction), predischarge computed tomography angiography (vein graft thrombosis), and by clinical examination for stroke. Coronary sinus blood obtained immediately after OPCAB surgery showed significantly less activation in the aprotinin group, as judged by reduced formation of platelet-leukocyte conjugates (P < 0.02) and platelet-derived microparticles (P < 0.05). The aprotinin group showed inhibition of platelet aggregation induced by thrombin (P = 0.007) but not adenosine diphosphate. Thrombin generation, defined by F1.2 levels, was significantly reduced by aprotinin in the coronary sinus but not in skin wound incisions. Major adverse cardiovascular events were significantly reduced in aprotinin-treated patients (5.4% vs 29.7%, P < 0.05). Aprotinin also demonstrated antifibrinolytic properties through diminished red blood cell transfusion (P < 0.04) and reduced blood loss postoperatively (603 +/- 330 vs 810 +/- 415 mL, P < 0.004). This study demonstrates that aprotinin protects patients undergoing OPCAB surgery from a hypercoagulable state by diminishing thrombin-induced platelet activation and thrombin generation within saphenous vein grafts, while maintaining systemic hemostatic and antifibrinolytic benefits. These results support further investigation of aprotinin and other PAR-1 antagonists in OPCAB surgery.

Weaning Mechanical Ventilation After Off-Pump Coronary Artery Bypass Graft Procedures Directed by Noninvasive Gas Measurements

Partial pressure of carbon dioxide and oxygen were transcutaneously measured in adults after off-pump coronary artery bypass (OPCAB) surgery. The clinical use of such measurements and interchangeability with arterial blood gas measurements for weaning patients from postoperative mechanical ventilation were assessed. This was a prospective observational study. Tertiary referral heart hospital. Postoperative OPCAB surgical patients. Transcutaneous oxygen and carbon dioxide measurements. In this prospective observational study, 32 consecutive adult patients in a tertiary care medical center underwent OPCAB surgery. Noninvasive measurement of respiratory gases was performed during the postoperative period and compared with arterial blood gases. The investigator was blinded to the reports of arterial blood gas studies and weaned patients using a "weaning protocol" based on transcutaneous gas measurement. The number of patients successfully weaned based on transcutaneous measurements and the number of times the weaning process was held up were noted. A total of 212 samples (pairs of arterial and transcutaneous values of oxygen and carbon dioxide) were obtained from 32 patients. Bland-Altman plots and mountain plots were used to analyze the interchangeability of the data. Twenty-five (79%) of the patients were weaned from the ventilator based on transcutaneous gas measurements alone. Transcutaneous carbon dioxide measurements were found to be interchangeable with arterial carbon dioxide during 96% of measurements, versus 79% for oxygen measurements. More than three fourths of the patients were weaned from mechanical ventilation and extubated based on transcutaneous gas values alone after OPCAB surgery. The noninvasive transcutaneous carbon dioxide measurement can be used as a surrogate for arterial carbon dioxide measurement to manage postoperative OPCAB patients.