Patients Undergoing Off-pump Coronary Artery Bypass Surgery Research Articles

Does Chronic Obstructive Pulmonary Disease Impact Outcome after Coronary Artery Bypass Grafting? A Population-Based Retrospective Study in Germany.

Background: The interaction between chronic obstructive pulmonary disease (COPD) and coronary artery bypass grafting (CABG) is discussed controversial. Methods: In this population-based retrospective analysis including non-emergency CABG in Germany between 2015 and 2021, the aim was to compare in-hospital mortality, hospital length of stay (HLOS), and perioperative ventilation time (VT) in patients affected by COPD and not affected by COPD. In addition, we compared outcomes after off-pump coronary artery bypass (OPCAB) and on-pump coronary artery bypass (ONCAB) surgery and outcomes after CABG with a minimally invasive technique with and without cardiopulmonary bypass (CPB) in COPD patients. Results: Of the 274,792 analyzed cases undergoing non-emergency CABG, 7.7% suffered from COPD. COPD patients showed a higher in-hospital mortality (6.0% vs. 4.2%; p < 0.001), a longer HLOS (13 days (10-19) vs. 12 days (9-16); p < 0.001), and a longer VT (33 h (11-124) vs. 28 h (9-94); p < 0.001). In subgroup analyses, COPD patients undergoing OPCAB surgery showed a lower in-hospital mortality (3.5% vs. 6.4%; p < 0.001), a shorter HLOS (12 days (9-16) vs. 13 days (10-19); p < 0.001) and a shorter VT (20 h (10-69) vs. 36 h (11-135); p < 0.001) compared to ONCAB surgery. Regression analyses confirmed that using cardiopulmonary bypass in COPD patients is associated with a higher risk of in-hospital mortality (OR, 1.86; 95% CI: 1.51-2.29, p < 0.001), a longer HLOS (1.44 days; 95% CI: 0.91-1.97, p < 0.001), and a longer VT (33.67 h; 95% CI: 18.67-48.66, p < 0.001). In further subgroup analyses, COPD patients undergoing CABG with a minimally invasive technique without CPB showed a lower in-hospital mortality (3.5% vs. 16.5%; p < 0.001) and a shorter VT (20 h (10-69) vs. 65 h (29-210); p < 0.001) compared to CABG with a minimally invasive technique and CPB. Regression analyses confirmed that using CPB in COPD patients undergoing CABG with a minimally invasive technique is associated with a higher risk of in-hospital mortality (OR, 4.80; 95% CI: 2.42-9.51, p < 0.001). Conclusions: COPD negatively impacts outcomes after non-emergency CABG. According to our results, OPCAB surgery and CABG with a minimally invasive technique without CPB seem to be beneficial for COPD patients. Further studies should be performed to confirm this.

The Effects of Pulmonary Artery Catheter on the Short-Term Outcomes of Patients Undergoing Off-Pump Coronary Artery Bypass Grafting: A Single-Center Retrospective Study.

Pulmonary artery catheters (PAC) are widely used in patients undergoing off-pump coronary artery bypass (OPCAB) grafting surgery. However, primary data suggested that the benefits of PAC in surgical settings were limited. Therefore, the present study sought to estimate the effects of PAC on the short-term outcomes of patients undergoing OPCAB surgery. The characteristics, intraoperative data, and postoperative outcomes of consecutive patients undergoing primary, isolated OPCAB surgery from November 2020 to December 2021 were retrospectively extracted. Patients were divided into two groups (PAC and no-PAC) based on PAC insertion status. Data were analyzed with a 1:1 nearest-neighbor propensity score matched-pair in PAC and no-PAC groups. Of the 1004 Chinese patients who underwent primary, isolated OPCAB surgery, 506 (50.39%) had PAC. Propensity score matching yielded 397 evenly balanced pairs. Compared with the no-PAC group (only implanted a central venous catheter), PAC utilization was not associated with improved in-hospital mortality in the entire or matched cohort. Still, the matched cohort showed that PAC utilization increased epinephrine usage and hospital costs. The current study demonstrated no apparent benefit or harm for PAC utilization in OPCAB surgical patients. In addition, PAC utilization was more expensive.

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.

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.

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.

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.

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.

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.

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.

Predictive Value of C-Reactive Protein for Major Postoperative Complications Following Off-Pump Coronary Artery Bypass Surgery Prospective and Observational Trial

To prospectively investigate the predictive value of the preoperative C-reactive protein (CRP) concentration for major postoperative complications following off-pump coronary artery bypass (OPCAB) surgery. From January 2007 to December 2007, 185 consecutive patients scheduled for elective OPCAB surgery were allocated to a low-CRP group (n=137, CRP <0.3 mg/dl) and a high-CRP group (n=48, CRP > or = 0.3 mg/dl). The incidence of major postoperative complications, defined as postoperative myocardial infarction, and 5 major morbidity endpoints including permanent stroke, renal dysfunction, any cardiac surgery reoperation, ventilation for more than 48 h, and deep sternal wound infection were assessed and compared. Multivariate logistic regression was used to determine the predictors of major postoperative complications. Patients in the high-CRP group had a significantly higher overall incidence of major postoperative complications, particularly renal dysfunction. In the multivariate logistic regression model, adjusting all the significant univariate predictors, baseline CRP >0.3 mg/dl and preoperative chronic renal failure (CRF) remained as significant independent predictors of major postoperative complications. Elevated preoperative CRP level and/or preoperative CRF indicate increased risk of developing major postoperative complications, particularly acute postoperative renal dysfunction in patients undergoing OPCAB surgery.

Off-pump coronary artery bypass surgery by left anterolateral thoracotomy versus median sternotomy: A matched comparison

Background. Off-pump coronary artery bypass (OPCAB) surgery is an established technique for the management of threevessel coronary artery disease. This study compared the clinical results of two different surgical approaches: median sternotomy and left anterolateral thoracotomy in patients undergoing OPCAB surgery. Methods. The study included two groups of 50 patients each with multivessel coronary artery disease matched for age, gender, extent of coronary disease, diabetes, hypertension and ejection fraction. Results. Preoperative characteristics were similar in the two groups. There were no deaths, or stroke. Patients undergoing median sternotomy received more grafts than those undergoing left anterolateral thoracotomy (3.30+/-0.8 vs 2.48+/-0.8 p<.001). The only difference in early hospital morbidity was the need for greater transfusion in the sternotomy than the thoracotomy group (p<.031). Hemoglobin levels (24 hours post-operatively) were also higher in the thoracotomy group (p<.001). Conclusion. The anterolateral thoracotomy is a safe surgical approach and a reliable alternative to median sternotomy in patients undergoing OPCAB surgery.

Comparison between Regional Cerebral Oxygen Saturation and Jugular Bulb Venous Oxygen Saturation in Patients Undergoing OPCAB Surgery

Background: Hypoperfusion during manipulation of the heart in off-pump coronary artery bypass (OPCAB) surgery may lead to postoperative neurological complications. Therefore, it will be necessary to monitor cerebral function during OPCAB surgery. In this study, we compared regional cerebral oxygenation (rSO2) by near-infrared spectroscopy (NIRS) with jugular bulb venous oxygen saturation (SjvO2) and assessed whether rSO2 measured by NIRS could be an alternative method of SjvO2 during OPCAB surgery. Methods: A total of 20 patients who underwent OPCAB surgery were studied. A fiberoptic catheter was placed in the right jugular bulb to measure SjvO2 while a cerebral oximeter based on NIRS, INVOS 5100B was used to monitor rSO2. Radial arterial and jugular bulb blood samples were drawn simultaneously from baseline every hour during operation. The values of rSO2 were compared with SjvO2 values. Results: For all data points (n = 78) for all patients combined, rSO2 values were significantly correlated with SjvO2 values (r = 0.513, P ＜ 0.0001). There were significant correlations between arterial carbon dioxide and values of SjvO2 (r = 0.393, P = 0.0002) and rSO2 (r = 0.432, P ＜ 0.0001). Conclusions: We concluded that NIRS correlates with SjvO2 in this patient population. These findings suggest that near-infrared spectroscopy may be useful in assessing cerebral oxygenation during OPCAB surgery. (Korean J Anesthesiol 2008; 54: 47～52)

Comparison of sevoflurane and isoflurane in OPCAB surgery

Maintenance of anaesthesia with volatile anaesthetic agents affects the perioperative course of patients undergoing off-pump coronary artery bypass (OPCAB) surgery. This facilitates adequate depth of anaesthesia, reduction in need of analgesic dosage, early extubation and transfer from Intensive Care Unit. We compared two volatile anaesthetic agents sevoflurane and isoflurane in terms of haemodynamic effects, amount of analgesic needed during surgery, quantity of agent needed for maintenance of anaesthesia and postoperative recovery in 40 patients undergoing OPCAB surgery. Anaesthesia was induced with fentanyl, midazolam and thiopentone, and vecuronium was used for muscle relaxation. An Octopus stabiliser was used and coronary anastomosis was performed using internal mammary artery and saphenous vein grafts. Routine monitoring was performed. The depth of anaesthesia was monitored using Bispectral index monitor. The inspired/expired concentration of anaesthetic agents to maintain the desired BIS and the amount of volatile anaesthetic agent needed was also noted. The amount of analgesic used intraoperatively was noted in both the groups. The 'time of awakening' defined as eye opening on verbal commands, and time of extubation were noted. There were no differences in haemodynamic parameters, depth of anaesthesia, and quantity of agent needed, but patients in isoflurane group required more intraoperative analgesics than sevoflurane group. Time of awakening (48+/-13 vs 114 +/- 21 mins; P < 0.001) and subsequent extubation (124 +/- 25 vs 177 +/- 36 mins, P<0.001) was earlier in sevoflurane group than isoflurane group. There was no evidence of perioperative myocardial infarction in both the groups. We conclude that sevoflurane and isoflurane can both be safely used in OPCAB surgery, but the awakening and extubation times are significantly less with sevoflurane.

Early outcomes of coronary artery bypass with and without cardiopulmonary bypass in octogenarians

Off-pump coronary artery bypass (OPCAB) surgery has been successfully used in diverse patient populations and has been postulated to be safer than conventional coronary artery bypass (CCAB) surgery in some high-risk patients, including the elderly. To compare the safety of OPCAB surgery versus CCAB surgery in the octogenarian population of two large southwestern Ontario cardiac surgical units. Two hundred thirty-six consecutive octogenarians underwent primary isolated coronary artery bypass surgery from November 2000 to March 2005. Patients undergoing OPCAB surgery tended to have higher Parsonnet scores, while patients undergoing CCAB surgery had a greater number of emergent operations. The Canadian Cardiovascular Network predicted that mortality risk was similar in both groups. In-hospital mortality was similar between groups, as was postoperative myocardial infarction and new onset of renal dysfunction. However, in the OPCAB group, there was a decreased incidence of postoperative neurological dysfunction (2.3% in the OPCAB group versus 10.5% in the CCAB group, P=0.01), in particular cerebrovascular accidents (1.5% in the OPCAB group versus 7.6% in the CCAB group, P=0.05), and a decreased incidence of prolonged intubation (5.3% in the OPCAB group versus 13.3% in the CCAB group, P=0.04). Multivariable analysis found that cardiopulmonary bypass had no significant impact on mortality or length of stay. In octogenarian patients, OPCAB surgery is as safe as CCAB surgery in terms of mortality and major morbidity. Furthermore, a significant reduction in neurological dysfunction and prolonged intubation was seen in the OPCAB group compared with the CCAB group.

Prognostic Role of New Biomarkers in Off-Pump Coronary Artery Bypass Surgery

The value of biomarkers of myocardial damage or inflammation in off-pump coronary artery bypass (OPCAB) surgery has not yet been established. In a prospective study of 51 consecutive patients scheduled for elective OPCAB surgery, preoperative levels of troponin T, C-reactive protein, interleukin-6 and tumor necrosis factor-alpha were determined. The primary endpoint was the combination of cardiac death or acute myocardial infarction (AMI) within 30 days. Seven patients (14%) presented with an adverse event: three cardiac deaths and six AMIs. Univariate analysis identified the following adverse event predictors: renal failure (50% vs 11%, P=.028), left ventricular ejection fraction 0.10 ng/dL (43% vs 9%, P=.016), and EuroSCORE rating (7.6 [2.5] VS. 5.2 [2.6], P=.031). A preoperative troponin-T level > 0.10 ng/dL (P=.03) was the only independent adverse event predictor. No significant differences were found with biomarkers of inflammation (P.05). The presence of a preoperative troponin-T level > 0.10 ng/dL is associated with a higher risk of cardiac death or AMI in patients undergoing OPCAB surgery.

Analysis of thoracic aortic blood flow during off-pump coronary artery bypass surgery.

The non-invasive monitoring of thoracic aortic blood flow (TABF) during off-pump coronary artery bypass (OPCAB) surgery is becoming more commonly used and proved to be invaluable in the early detection of haemodynamic compromise due to heart displacement. The aim of this study was to analyze the changes in the TABF during OPCAB using transoesophageal Doppler and compare them with the changes observed by other monitoring methods as cardiac output, invasive pulmonary and radial pressures and mixed venous oxygen saturation. The measurements obtained from classic haemodynamic monitoring methods including the radial artery line and the pulmonary artery catheter with continuous monitoring of the cardiac output and mixed venous blood oxygen saturation were compared to the measurements of TABF obtained from a transoesophageal Doppler probe in 15 consecutive patients who underwent OPCAB surgery. The TABF decreased significantly during the construction of coronary anastomoses from 3.42 +/- 0.94 l/min (baseline) to 2.2 +/- 0.8 l/min during the first coronary anastomosis and then to 2.14 +/- 1.12 l/min during the second coronary anastomosis (F=4.29, P=0.008). TABF returned to the baseline values (2.85 +/- 1.19 l/min) at chest closure. The cardiac output measurement showed no significant decrease compared to baseline. Low TABF occurred without significant changes in the measurements obtained from classic haemodynamic monitoring methods during OPCAB surgery. This finding could be of vital importance in helping improve the monitoring and consequently the management of patients undergoing OPCAB surgery.

Does Gender Influence Resource Utilization in Patients Undergoing Off-Pump Coronary Artery Bypass Surgery?

Objective: The purpose of the present study was to examine if gender influences duration of tracheal intubation, blood transfusion needs, intensive care unit length of stay (ICULOS), postoperative length of stay (PLOS), and total length of stay (LOS) in patients undergoing off-pump coronary artery bypass (OPCAB) surgery. Design: Retrospective study of consecutive patients undergoing OPCAB surgery. Setting: University teaching hospital. Tertiary care referral center for cardiac surgery. Participants: Three hundred seventy-two consecutive male and female patients undergoing OPCAB surgery. There were 110 women and 262 men. Interventions: None. Measurements and Main Results: Gender, duration of tracheal intubation, units of blood transfused, ICULOS, PLOS, and LOS were collected from the records of patients undergoing OPCAB surgery at the authors’ institution over a period of 16 months. There were a total of 372 patients: 110 women and 262 men. Median intubation time was 4.5 hours for women and 4.0 hours for men ( p = 0.749); 59.1% of women received red blood cells versus 31.3% of men ( p < 0.001). Median ICU LOS was 1 day for women and 1 day for men ( p = 0.597) Median PLOS was 4 days for women and 4 days for men. Median LOS was 8 days for women and 6 days for men ( p = 0.001). Conclusion: Female sex was a predictor of increased blood transfusion and longer PLOS and LOS in patients undergoing OPCAB surgery. The study implies that female sex does not predict increased duration of tracheal intubation and mechanical ventilation and ICULOS in this group of patients. Females undergoing OPCAB surgery require increased resource utilization as measured by increases in blood transfusion, PLOS, and LOS.