Optimal coronary artery bypass grafting strategy for acute coronary syndrome

Objective

Conventional coronary artery bypass grafting (CABG) using cardiopulmonary bypass and cardiac arrest is associated with higher mortality and morbidity rates in acute coronary syndrome (ACS) patients undergoing surgery. Although off-pump CABG (OPCAB) is beneficial for high-risk patients, its efficacy for ACS is unknown, with on-pump beating CABG an adjunctive method. We investigated the effects of OPCAB and on-pump beating CABG for ACS.

Methods

We evaluated 121 consecutive patients with ACS (91 males, 30 females; mean age 69.5 ± 10.3 years) who underwent CABG since 2000. Seventy-five had unstable angina (UA) and 46 acute myocardial infarction (AMI) [non-ST elevation (NSTEMI): 22, ST elevation (STEMI): 24]. We assessed CABG for acute coronary syndrome under our primary OPCAB strategy, and compared perioperative status between UA and AMI patients.

Results

(1) Sixty-five (87 %) with UA underwent OPCAB, 8 on-pump beating CABG, and 2 conventional CABG. Conversion from OPCAB was seen in 4 patients. In-hospital mortality was 1.3 %. (2) All UA patients who had intra-aortic balloon pumping (IABP) underwent OPCAB. No patients with preoperative IABP experienced conversion from OPCAB. (3) In AMI patients, hospital mortality was higher (8.9 %) and the ratios for OPCAB, on-pump beating CABG, and conventional CABG were 39, 57, and 4 %, respectively. Mortality was exclusively seen in patients with STEMI who underwent conventional CABG.

Conclusions

OPCAB might have beneficial effects for ACS patients with UA, while IABP was found essential for completing OPCAB. In AMI patients, on-pump beating CABG might be reasonable for avoiding conversion from OPCAB and ischemic perfusion injury.     

Mistaken grafting to diagonal branch in minimally invasive direct coronary artery bypass: a case required reoperation

The patient was a 75 year-old male who was admitted with recurrent chest pain during hemodialysis one year after PTCA to the right coronary artery and left circumflex branch (LCX). He had the history of cerebral infarction and chronic renal insufficiency. Coronary angiography showed severe stenosis from the left main trunk to left anterior descending artery (LAD) and restenosis at the PTCA site of LCX. The LCX lesion was dilated with PTCA. Minimally invasive coronary artery bypass (MIDCAB) with left internal thoracic artery (LITA) to LAD was carried out uneventfully. However, chest pain appeared on 1 POD. LITA angiography revealed that LITA was anastomosed to the diagonal branch that had occluded completely in the preoperative angiography. Off-pump CAB to LAD using inferior epigastric artery was carried out through median sternotmy on the same day. He recovered smoothly, and LITA angiography before discharge demonstrated that both grafts to LAD and diagonal branch are patent.     

On-pump versus off-pump coronary artery bypass: independent risk factors and off-pump graft patency.

OBJECTIVE: Current knowledge on off-pump coronary artery bypass (OPCAB) generally stems from single surgeons' experience or from series where OPCABs constituted a minor fraction of coronary operations. The present center decided to venture as far into OPCAB as possible during 1999. The present series thus represents the average surgeon's experience. METHODS: During 1999, 533 patients underwent coronary artery bypass grafting using cardiopulmonary bypass (CPB) in 368 and OPCAB in 165 including the circumflex artery (CX) area in 91. Coronary arteriography was performed before discharge in the first 103 OPCAB patients. RESULTS: The CPB and OPCAB groups differed as regards left ventricular ejection fraction (53+/-13 versus 57+/-11, P < 0.0001) and frequency of triple-vessel or left main stem disease (84 versus 32%, P < 0.0001) but were comparable as regards diabetes (12%), prior myocardial infarct (57%), unstable angina (21%), and previous heart surgery (3%). Using multivariate analyses, 30-day mortality (1.3%), P-creatine kinase myocardial band (CKMB) > 80 microg/l (11.1%), re-sternotomy for bleeding (4.5%) or dehiscense (1.7%), transitory cerebral ischemia and stroke (1.7%), supraventricular tachycardia (27.4%), and hospital stay (mean 8 days) were unrelated to off- versus on-pump surgery as well as to OPCAB in triple-vessel disease. CX branches < or = 1mm, > or = 5 distal anastomoses, prior heart surgery, right coronary artery (RCA) branches < or = 1.5mm, 8-21 days old myocardial infarct, female gender, and preoperative acute arrhythmia (among others) were identified as independent risk factors for mortality or increased CKMB in all 533 patients. The latter five risk factors were reproduced in the OPCAB group isolated. The patency in the 103 OPCABs was 95.3, 91.8, and 85.3% in the left anterior descending artery (LAD), CX, and RCA, respectively. Patency was inversely related to diameter of the grafted vessel in the LAD and CX areas, unlike the RCA area. CONCLUSIONS: The results after beating heart surgery were good also in patients with triple-vessel disease, but specific gains relative to on-pump surgery could not be shown. The independent risk factors in the OPCAB group may indicate relative contraindications for OPCAB grafting.     

Beating heart coronary artery bypass grafting for acute myocardial infarction

We consider that off-pump coronary artery bypass grafting (CABG) [OPCAB], which results in local myocardial ischemia, is more effective for patients with acute myocardial infarction (AMI) than conventional CABG under cardiac arrest with global myocardial ischemia. Twenty-one patients (15 males, 6 females) received OPCAB for AMI, among whom surgery was performed following percutaneous coronary intervention (PCI) failure in 4 and PCI was performed prior to OPCAB in 2, while PCI was not performed in the remaining 15. Preoperatively, 16 patients had intraaortic balloon pumping (IABP), and 4 had IABP and percutaneous cardiopulmonary support (PCPS). The mean interval from onset to surgery was 11.7 (range 3 to 40) hours. In 20 cases, a complete revascularization was performed. The mean number of bypasses was 2.3 and OPCAB was carried out in 14 patients. In 2 cases, OPCAB was converted to on-pump beating CABG for complete revascularization. Fourteen patients (67%), each maintained with preoperative left ventricular ejection fraction (EF), were discharged with an elective bypass. Four patients died after on-pump beating CABG, in whom EF was lower than 10%. In addition, 3 died of low cardiac output syndrome (LOS) under PCPS and 1 of ventricular fibrillation. Based on our results, we considered that complete revascularization using OPCAB was effective for cases of AMI with PCI difficulty. However, in shock cases requiring PCPS, cardiac function was not improved even after revascularization. Therefore, it is necessary to study new procedures for shock cases during the period from onset to surgery.     

Influence of preoperative factors on off-pump coronary aortic bypass grafting success

Heart displacement during off-pump CABG (OPCAB) might induce the hemodynamic instability. We attempted to show which preoperative factors would contribute to an increase in that incident during OPCAB. Between February 2000, and October 2000, 51 patients underwent CABG in Okamura Memorial Hospital. Of these patients, 42 patients (82.4%) underwent OPCAB and 9 patients (17.6%) were operated upon under cardiac arrest with cardiopulmonary bypass (NOPCAB). To expose target coronary arteries for OPCAB, 3 deep pericardial traction stitches were placed near the left lower pulmonary vein (LPV), the left of the inferior vena cava (IVC) and the mid portion between LPV and IVC. To further assist in providing good presentation, patients were placed in Trendelenburg position (30 degree head-down tilt) and the right decubitus (30 degree the right side-down tilt). There were no OPCAB patients to be converted to on-pump CABG during anastomosis. Mean number of grafts in OPCAB group was 2.5 +/- 0.1 per patient, while that in NOPCAB group was 3.4 +/- 0.2 (p < 0.01). The bypass patient rate were 97.1% (100/103) in OPCAB group and 100% (31/31) in NOPCAB group (p = NS). In both groups, bilateral internal thoracic arteries were actively used for reperfusion to the left coronary artery. In the preoperative catheterization findings, pulmonary capillary wedge pressure (PCW) and left ventricular end-diastolic pressure (LVEDP) were significantly higher in NOPCAB group than those in OPCAB group (PCW: 14.0 vs 7.9 mmHg, LVEDP: 14.0 vs 8.7 mmHg: p < 0.05), and there was a tendency of low preoperative ejection fraction (EF) and cardiac index (CI) in NOPCAB group compared with those in OPCAB group, although there were no differences in left ventricular end-diastolic and end-systolic volume index (LVEDVI and LVESVI) between both groups. These findings suggested that PCW and LVEDP within the normal limit could be credited for the success with OPCAB, while an increase of the left ventricular volume would not contribute to the actual success.     

Evaluation of preoperative intraaortic balloon pumping for high risk off-pump coronary artery bypass grafting

We evaluated the effect of preoperative intraaortic balloon pumping (IABP) support in high risk patients undergoing off-pump coronary artery bypass grafting (OPCAB). Between November 1999 and December 2010, 65 high-risk patients underwent OPCAB with the support of IABP inserted preoperatively. High risks were considered as (1) left main coronary artery stem stenosis > or = 75%, (2) unstable angina requiring intravenous nitrates and heparin, (3) preoperative left ventricular ejection fraction < or = 30%, (4) bilateral carotid artery stenosis > or = 75%. There were no hospital deaths or cerebrovascular complications. During operations, hemodynamics was stable with the support of low dose catecholamines, and no patient needed conversion to on-pump coronary artery bypass grafting. All patients were able to be weaned from IABP within 3 days (mean 5.7 hours) after the operation and were extubated within 4 days (mean 11.5 hours) after the operation. One patient had a peripheral embolism which might be related to insertion of IABP (1.5%). Preoperative IABP in high-risk patients undergoing OPCAB was considered to be useful and safe.     

Coronary artery bypass in patients 80 years and over: is off-pump the operation of choice?

BACKGROUND: Octogenarians are at increased risk for perioperative morbidity and mortality after coronary artery bypass. In this study we compared our experience with patients undergoing on-pump coronary artery bypass (CAB) and those undergoing off-pump coronary artery bypass (OPCAB) to assess outcomes. METHODS: We used hospital database analysis in patients 80 years and older who underwent nonemergent coronary artery bypass with (N = 169) and without (N = 60) cardiopulmonary bypass from January 1999 through June 2001. RESULTS: Both groups were at increased perioperative risk based on the Society of Thoracic Surgeons risk model (7.7% OPCAB vs 5.8% CAB, p = 0.03). There were no operative deaths in the OPCAB group but there were eight (4.7%) in the CAB group (p = NS). Perioperative stroke (0% OPCAB vs 7.1% CAB, p = 0.04), prolonged ventilation (1.7% OPCAB vs 11.8% CAB, p = 0.02), and transfusion rate (33% OPCAB vs 70.4% CAB, p < 0.001) were all lower in the OPCAB group. A shorter hospital stay (6.3 days OPCAB vs 11.5 days CAB, p < 0.001) resulted in lower hospital cost in the OPCAB group ($9,363 OPCAB vs $12,312 CAB, p < 0.001). CONCLUSIONS: In this study, off-pump coronary artery bypass grafting in elderly patients was associated with fewer complications, a shorter hospital stay, and lower hospital cost. Off-pump coronary artery bypass grafting may be the operation of choice for octogenarians requiring surgical myocardial revascularization.     

Changes in systolic and diastolic function during multivessel off-pump coronary bypass grafting.

OBJECTIVE: To measure the changes in systolic and diastolic left ventricular function that occur during off-pump coronary artery bypass grafting (OPCAB) as a consequence of positioning the heart and interrupting coronary flow. METHODS: 2-D Transoesophageal echocardiography was used to derive systolic wall motion indices and pulsed Doppler parameters of diastolic function including the E/A ratio, PVS/PVD ratio, and deceleration time. A continuous cardiac output thermodilution pulmonary artery catheter was used to provide hemodynamic measures of left ventricular function. Data was obtained prior to, during and following coronary grafting. RESULTS: Thirty-four consecutive anastomoses were evaluated, including eight circumflex (LCX), 17 left anterior descending artery (LAD) and nine right coronary artery (RCA) anastamoses. Significant changes in diastolic and systolic cardiac function were identified in those patients who underwent LCX grafting. Specifically during LCX grafting, both wall motion score index (2.4+/-1.4 vs 1.5+/-0.63 and 1.9+/-0.91) and the E/A ratio were significantly increased (3.5+/-1.4 vs 1.1+/-0.33 and 1.2+/-0.44) when compared to RCA and LAD grafting, respectively. The PVS/PVD ratio was significantly decreased during left circumflex grafting (0.7+/-0.45 vs 1.1+/-0.19 and 1.0+/-0.58) when compared to RCA and LAD grafting, respectively. All functional parameters returned to baseline by the end of surgery. CONCLUSIONS: Multivessel OPCAB can be achieved with mild impairment of left ventricular function that returns to baseline by the end of the procedure. Impairment of diastolic function is most marked during circumflex grafting as demonstrated by a restrictive filling pattern. Measures of diastolic function may be helpful in developing better strategies for exposure of the circumflex graft site.     

Comparison of off-pump and on-pump coronary artery bypass grafting in midterm results.

OBJECTIVE: Off-pump coronary artery bypass grafting (OPCAB) has become a procedure of choice for surgical treatment of coronary artery disease. Although early advantages of OPCAB were confirmed in comparison with conventional on-pump coronary artery bypass grafting (CABG), late cardiac complications are still controversial. We examined midterm results of OPCAB compared with standard CABG. METHODS: Between July 1997 and April 2002, 736 consecutive patients who underwent isolated CABG were retrospectively reviewed. The OPCAB group (Group I) comprised 357 patients (49%), and the on-pump CABG group (Group II) 379 patients (51%). Their preoperative, intraoperative, and follow-up data were analyzed. RESULTS: The mean number of distal anastomoses and the early graft patency were not greatly different between the two groups. The actuarial survival rate at 3 years was not significantly different between Group I (98.3%) and Group II (98.2%) (p = 0.71). The frequency of cardiac events was 4.2%/patient-year in Group I and 2.6%/patient-year in Group II (p = 0.12). The actuarial event free rates were not different between the two groups (p = 0.61). The cardiac event free rates at 3 years were significantly (p = 0.011) higher in patients with complete revascularization (96.7%) than without complete revascularization in Group I (69.2%) and in Group II (92.7% versus 85.9%, p = 0.026). CONCLUSIONS: Midterm clinical outcome in OPCAB is as good as conventional on-pump CABG. Incomplete revascularization caused cardiac events more frequently than complete revascularization both in OPCAB and on-pump CABG in the intermediate follow-up.     

Surgical treatment of coronary aneurysm after percutaneous coronary intervention

A 61-year-old man with acute myocardial infarction underwent percutaneous coronary intervention with stent for the left main coronary artery (LMT) and the left anterior descending artery (LAD). Three months later, we recognized the LMT aneurysm complicated with possible thrombus formation, which developed in size during 6 months. In addition, the LAD stent showed significant in-stent stenosis. For the purpose of supplying blood flow to the distal of LAD, and avoiding myocardial infarction due to distal thrombosis possibly originated from LMT aneurysm, we decided to perform surgical operation. On preoperative examination, this patient had an obstruction of the right internal carotid artery. Although the direct repair of LMT aneurysm requires conventional approach with cardiopulmonary bypass, we applied off-pump coronary artery bypass grafting( OPCAB) considering the risk of cerebrovascular event. Consequently, OPCAB was performed in usual fashion [right internal thoracic artery (RITA) -LAD, left internal thoracic artery-left circumflex artery (LITA-LCX)] followed by the ligation of the proximal of LAD and LCX without cardiopulmonary bypass. The patient had a good operative course.     

Single vessel revascularization with beating heart techniques -- minithoracotomy or sternotomy?

OBJECTIVE: The purpose of the study was to evaluate the best surgical approach in off-pump single vessel revascularization of the left anterior descending coronary artery (LAD). METHODS: In 256 patients a single left internal mammary artery (LIMA) to LAD bypass was performed with beating heart techniques through a left anterior minithoracotomy (minimally invasive direct coronary artery bypass (MIDCAB), n=129) or a full sternotomy (off-pump coronary artery bypass (OPCAB), n=127). RESULTS: In the OPCAB group, significantly more severe comorbidities (P=0.001) and redo-operations were noted (P<0.001). Conversion to sternotomy or CPB was necessary in five MIDCAB patients and one OPCAB patient. No cerebrovascular accident was seen in both groups. There was no hospital death in MIDCAB- and two deaths in OPCAB procedures (P=ns). There was a significant reduction in time of surgery (P=0.028) and coronary occlusion (P=0.009) in the OPCAB group. No differences in postoperative ventilation time, ICU stay and length of hospital stay were recorded between groups. Wound infections occurred in six MIDCAB patients (4.7%) and one OPCAB patient (0.8%). Early postoperative reoperation due to graft failure was necessary in three patients after MIDCAB and two patients after OPCAB (P=ns). Confirmed by angiography, the early graft patency rate was 96 and 98%, respectively (P=ns). CONCLUSIONS: Both beating heart techniques showed good results with low hospital mortality, low early complications and comparable angiographic results. Nevertheless, MIDCAB is a challenging technique as demonstrated by the longer times of surgery and coronary occlusion with a tendency towards a higher risk of conversion and wound infection. Thus, this technique should only be performed in selected patients with favourable coronary anatomy. Through a sternotomy approach, single vessel revascularization can be performed safely off-pump even in high-risk patients.     

Evaluation of serial haemodynamic changes during coronary artery anastomoses in patients undergoing off-pump coronary artery bypass graft surgery: initial experiences using two deep pericardial stay sutures and octopus tissue stabilizer

Objective: This study was designed to evaluate the serial haemodynamic changes during coronary artery anastomoses using two deep pericardial stay sutures and octopus tissue stabilizer in patients undergoing initial experiences of off-pump coronary artery bypass graft surgery (OPCAB) using continuous cardiac output and mixed venous oxygen saturation (SvO₂) monitoring. Methods: With IRB approval, thirty patients undergoing OPCAB were studied. Pulmonary artery catheter (PAC) for continuous cardiac output and SvO₂ monitoring was inserted before anaesthesia. Haemodynamic measurements were recorded after pericardiotomy for baseline value. During each coronary artery anastomosis, haemodynamic variables were measured at 1,3,5,10, and 15 min after the application of tissue stabilizer and after the removal. Vasopressors were used to maintain mean arterial pressure (MAP) higher than 60 mmHg. Results: MAP and heart rate (HR) were maintained without significant change during the anastomoses of all three arteries. Cardiac index (CI), and SvO₂ decreased significantly after stabilizer application in all three arteries. CI was below 2.5 l/min/m² and SvO₂ was under 70% during left circumflex artery (LCX) anastomosis. The decrease in CI and SvO₂ were significantly greater during LCX anastomosis. The increase in mean pulmonary artery pressure (MPAP) and pulmonary capillary wedge pressure (PCWP) was significant only in left anterior descending artery (LAD). Central venous pressure (CVP) increased significantly during the anastomosis of all three coronary arteries. The differences in MPAP, PCWP and CVP among the three coronary arteries were not statistically significant. The highest dose of vasoconstrictor was used during LCX anastomosis. Conclusions: When the coronary anastomoses were performed with two deep pericardial stay sutures and octopus tissue stabilizer on the beating heart, CI and SvO₂ decreased significantly during all coronary artery anastomoses immediately after the stabilizer application and the degree of reduction in CI and SvO₂ increased with time, though MAP was maintained constantly. CI and SvO₂ during LCX anastomosis were consistently below normal values. Therefore close monitoring and proper managements are needed during graft anastomoses.     

Comparison of off-pump and on-pump coronary artery bypass grafting in midterm results

Objective: Off-pump coronary artery bypass grafting (OPCAB) has become a procedure of choice for surgical treatment of coronary artery disease. Although early advantages of OPCAB were confirmed in comparison with conventional on-pump coronary artery bypass grafting (CABG), late cardiac complications are still controversial. We examined midterm results of OPCAB compared with standard CABG. Methods: Between July 1997 and April 2002, 736 consecutive patients who underwent isolated CABG were retrospectively reviewed. The OPCAB group (Group I) comprised 357 patients (49%), and the on-pump CABG group (Group II) 379 patients (51%). Their preoperative, intraoperative, and follow-up data were analyzed. Results: The mean number of distal anastomoses and the early graft patency were not greatly different between the two groups. The actuarial survival rate at 3 years was not significantly different between Group I (98.3%) and Group II (98.2%) (p=0.71). The frequency of cardiac events was 4.2%/patient-year in Group I and 2.6%/patient-year in Group II (p=0.12). The actuarial event free rates were not different between the two groups (p=0.61). The cardiac event free rates at 3 years were significantly (p=0.011) higher in patients with complete revascularization (96.7%) than without complete revascularization in Group I (69.2%) and in Group II (92.7% versus 85.9%, p=0.026). Conclusions: Midterm clinical outcome in OPCAB is as good as conventional on-pump CABG. Incomplete revascularization caused cardiac events more frequently than complete revascularization both in OPCAB and on-pump CABG in the intermediate follow-up.     

A case report of emergency off-pump CABG in an aged patient with ACS renewing ventricular fibrillation.

An emergency off-pump coronary artery bypass (OPCAB) was performed successfully in an aged patient with acute coronary syndrome (ACS). The patient, an 80-year-old woman residing in a nursing home, suddenly lost consciousness during lunch. The electrocardiogram (ECG) showed ventricular fibrillation (Vf) but defibrillation successfully recovered the sinus rhythm. The patient was brought to our hospital as an emergency. She underwent emergency cardiac catheterization. Coronary angiography demonstrated severe three vessel disease with left main coronary trunk (LMT) stenosis. Even during intra-aortic balloon pumping (IABP), the hemodynamic state was unstable, with repeated development of ventricular tachycardia and fibrillation. An emergency coronary artery bypass without a cardiopulmonary bypass was performed. Saving her life was of primary importance and revascularization of the left anterior descending artery (LAD) branch, was performed. Thanks to the advances made in various devices, safe and reliable anastomoses have become possible in OPCAB applied to ACS. OPCAB for ACS have become safe and reliable anastomoses following development of various devices. We think that OPCAB is an effective surgical technique for coronary revascularization for emergency or serious cases involving elderly patients.     

Myocardial revascularization without extracorporeal circulation

Contemporary treatment of coronary disease includes: drug treatment, percutaneous coronary angioplasty (PCI), with or without stent implantation and surgical myocardial revascularization. For more than 30 years, conventional coronary bypass (on-pump CABG), using cardiopulmonary bypass (CPB), represented the standard regarding myocardial revascularization, particularly in patients suffering from three vessel disease or left main coronary artery stenosis. Recent development of invasive cardiology and increased interest in coronary surgery on the beating heart (OPCAB), challenging traditional on-pump CABG procedure, as optimal strategy for the treatment of coronary artery disease. In order to improve clinical outcome, OPCAB seems to be a good choice in patients with co-morbidities critical for use of CPB. Results of OPCAB revascularization in general patient population are considerably different and require further evaluation. This review article shows the development of OPCAB and elaborates potential advantages and weaknesses of this method of revascularization, from both, theoretical and clinical point of view, compared to standard surgical myocardial revascularization.     

Effect of off-pump coronary artery bypass grafting on risk-adjusted and cumulative sum failure outcomes after coronary artery surgery

BACKGROUND AND AIM: We have shown that cumulative sum (CUSUM) failure analysis may be more sensitive than standard statistical methods in detecting a cluster of adverse patient outcomes after cardiac surgical procedures. We therefore applied CUSUM, as well as standard statistical techniques, to analyze a surgeon's experience with off-pump coronary artery bypass grafting (OPCAB) and on-pump procedures to determine whether the two techniques have similar or different outcomes. METHODS: In 320 patients undergoing nonemergent, first time coronary artery bypass grafting, preoperative patient characteristics, rates of mortality and major complications, and ICU and hospital lengths of stay were compared between the on-pump and OPCAB cohorts using Fisher's exact tests and Wilcoxon two sample tests. Predicted mortality and length of stay were determined using previously validated models of the Cardiac Care Network of Ontario. Observed versus expected ratios of both variables were calculated for the two types of procedures. Furthermore, CUSUM curves were constructed for the on-pump and OPCAB cohorts. A multivariable analysis of the predictors of hospital length of stay was also performed to determine whether the type of coronary artery bypass procedure had an independent impact on this variable. RESULTS: The predicted mortality risk and predicted hospital length of stay were almost identical in the 208 on-pump patients (2.2 +/- 3.9%; 8.2 +/- 2.5 days) and the 112 OPCAB patients (2.0 +/- 2.2%; 7.8 +/- 2.1 days). The incidence of hospital mortality and postoperative stroke were 2.9% and 2.4% in on-pump patients versus zero in OPCAB patients (p = 0.09 and 0.17, respectively). Mechanical ventilation for greater than 48 hours was significantly less common in OPCAB (1.8%) than in on-pump patients (7.7%, p = 0.04). The rate of 10 major complications was 14.9% in on-pump versus 8.0% in OPCAB patients (p = 0.08). OPCAB patients experienced a hospital length of stay that was a median of 1.0 day shorter than on-pump patients (p = 0.01). The observed versus expected ratio for length of stay was 0.78 in OPCAB patients versus 0.95 in on-pump patients. On CUSUM analysis, the failure curve in OPCAB patients was negative and was flatter than that of on-pump patients throughout the duration of the study. Furthermore, OPCAB was an independent predictor of a reduced hospital length of stay on multivariable analysis. CONCLUSIONS: OPCAB was associated with better outcomes than on-pump coronary artery bypass despite a similar predicted risk. This robust finding was documented on sensitive CUSUM analysis, using standard statistical techniques and on a multivariable analysis of the independent predictors of hospital length of stay.     

Resource utilization in on- and off-pump coronary artery surgery: factors influencing postoperative length of stay--an experience of 1,746 consecutive patients undergoing fast-track cardiac anesthesia

OBJECTIVE: The purpose of the present investigation was to examine factors influencing resource utilization in patients undergoing on-pump coronary artery bypass graft and off-pump coronary artery bypass (OPCAB) graft surgery at a major university hospital. The resources examined were time to extubation, packed red blood cell (PRBC) transfusion, intensive care length of stay (ICULOS), preoperative and postoperative length of stay (PLOS), and total length of stay (LOS). DESIGN: Observational study of consecutive patients undergoing on- and off-pump coronary artery bypass surgery. SETTING: Tertiary care cardiac referral center. PARTICIPANTS: One thousand seven hundred forty-six consecutive male and female patients undergoing primary coronary artery bypass graft (CABG) surgery over a period of 3 years (1999-2001). Eight hundred eighty-one patients underwent CABG with pump, and 865 patients underwent off-pump coronary artery bypass (OPCAB) surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The mean time to extubation after surgery was 7.4 hours for on-pump patients and 5.8 hours for the OPCAB group (p72 hours to postoperative tracheal extubation compared with 1.5% in the OPCAB group (p=0.041). Hospital mortality was 2.7% for the on-pump group and 1.0% for the OPCAB group (p=0.010). CONCLUSION: The authors found that patients undergoing on-pump CABG have significantly longer time to tracheal extubation, increased blood use, longer ICULOS, PLOS, and total LOS and higher in-hospital mortality, which would translate into significant differences in the expenses associated with these 2 surgical approaches to coronary surgery.     

Two cases of left main trunk lesion treated with coronary artery bypass grafting the proximal circumflex coronary artery (# 11)

Two cases are reported of coronary artery bypass graft (CABG) surgery to the proximal left circumflex artery (LCX) system and left anterior descending artery (LAD) system. Both patients suffered from unstable angina due to left main trunk (LMT) lesions and required semi-emergent coronary revascularization. In both cases, the obtuse marginal branch and postero-lateral branch were too small to be grafted, although there are the usual target branches in the LCX system. CABG to the proximal portion (# 11) of LCX in the atrioventricular groove using saphenous vein grafts was performed and good blood flow rates were seen intra-operatively. Both patients recovered uneventfully and had no recurrence of anginal attacks. Postoperative coronary angiography confirmed good graft patency and an adequate coronary blood supply. CABG to LCX (# 11) is feasible without special techniques or tools. This method seems to be useful in patients with LMT lesions or with proximal lesions of LCX in which the branches are too small to be grafted.     

Clinical outcomes of low-risk patients undergoing beating-heart surgery with or without pulmonary artery catheterization

OBJECTIVE: For patients who undergo off-pump coronary artery bypass (OPCAB) surgery, pulmonary artery catheterization (PAC) has been proposed as a useful intraoperative monitoring tool. This study was designed to determine if the choice of PAC versus central venous pressure monitoring (CVP) had any effect on outcome after OPCAB. This study compared these 2 methods of hemodynamic monitoring in low-risk patients undergoing beating-heart surgery via a median sternotomy and evaluated their effect on morbidity and in-hospital mortality. DESIGN: Retrospective database and medical record review. SETTING: Tertiary care teaching hospital. PARTICIPANTS: Low-risk patients who had coronary revascularization via a median sternotomy on the beating heart. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: A population of 2,414 low-risk patients who had beating-heart coronary revascularization between January 2000 and December 2003 was reviewed. Most patients (1,671 or 69.2%) received a PAC, whereas 743 (30.8%) had CVP monitoring. Risk-adjusted logistic regression analyses were performed to investigate the effect of each technique on clinical outcomes. The groups were comparable in both baseline characteristics and Parsonett's mortality risk (1.5 +/- 0.9, p = 0.58). Univariate analysis failed to show a difference in operative mortality (p = 0.76), on-pump conversion rate for completion of aortocoronary bypasses (p = 0.82), postoperative low cardiac output (p = 0.10), or prolonged inotropic agent use (p = 0.22). Similarly, in the multivariate analysis, both groups had a similar rate of conversion to an on-pump procedure for completion of coronary artery grafting (p = 0.91), intraoperative intra-aortic balloon pump use (p = 0.69), low cardiac output state (p = 0.16), or in-hospital mortality (p = 0.51). CONCLUSIONS: This single-institution, retrospective study suggests that in low-risk patients undergoing beating-heart surgery, CVP monitoring may be sufficient.     

Application of off-pump coronary artery bypass grafting for patients with acute coronary syndrome requiring emergency surgery.

Off-pump coronary artery bypass grafting (OPCAB) has become a more applicable procedure, even in patients with multi-vessel disease. However, the role of OPCAB for patients with acute coronary syndrome (ACS) requiring emergency revascularization has not been established yet. We reviewed our results of emergency coronary artery bypass grafting (CABG) for patients with ACS. Seventy-two patients with ACS who underwent emergency CABG were studied. Twenty-five underwent OPCAB and 47 on-pump CABG. OPCAB was mainly indicated for patients who were possibly at risk for cardiopulmonary bypass. When the coronary anatomy was suitable in younger or less risky patients, OPCAB was performed. Patients with multi-vessel disease or with a critical left main trunk lesion were not excluded from OPCAB. The mean number of grafted vessels was 2.6 per patient in the OPCAB group, and 3.8 per patient in the on-pump group (p<0.0001). However, none of the patients in either group required postoperative catheter intervention. Mean operative time was 195 minutes in the OPCAB group and 286 minutes in the on-pump group (p<0.0001). There were three postoperative deaths in the OPCAB group and four in the on-pump group. Multivariate logistic regression analysis revealed that preoperative cardiogenic shock was the only significant predictor for postoperative death (odds ratio, 7.33). The selection of the on-pump procedure or OPCAB did not correlate with operative death. Thus, we conclude that OPCAB can be performed safely and effectively in selected patients with ACS requiring emergency coronary revascularization.