Off-pump multivessel coronary artery surgery in high-risk patients

BACKGROUND: Coronary artery bypass surgery on cardiopulmonary bypass is associated with significant morbidity and mortality, which may be more marked in high-risk patients. We evaluated our results of off-pump coronary artery bypass (OPCAB) in high-risk patients with multivessel coronary artery disease and compared them with results in similar patients who underwent operation on cardiopulmonary bypass. METHODS: A total of 1,075 patients who underwent OPCAB between October 1996 and June 2001 and who had one or more of the following risk factors were included in the study: poor left ventricular function (EF < or = 30%), advanced age (> 70 years), left main stenosis, acute myocardial infarction, and redo coronary artery surgery. These patients were compared with 2,312 similar patients who underwent coronary artery bypass grafting on cardiopulmonary bypass during the same period. Preoperative risk factors, intraoperative variables, and postoperative results were analyzed and compared between two groups. RESULTS: The average number of grafts was 3.0 +/- 0.4 and 3.2 +/- 0.3 in the off-pump (OPCAB) and on-pump (CCAB) groups, respectively. Hospital mortality was 3.2% and 4.5% in OPCAB and CCAB groups respectively (p = 0.109). Perioperative myocardial infarction, requirement of inotropic agents, stroke, and renal dysfunction were comparable in two groups. Intubation time (19 +/- 5 vs 24 +/- 6 hours, p < 0.001), mean blood loss (362 +/- 53 vs 580 +/- 66 mL, p < 0.001), atrial fibrillation (14.3 vs 19.7%, p < 0.001), and prolonged ventilation (4.6 vs 7.6%, p = 0.002) were less in OPCAB group. Intensive care unit stay (20 +/- 8 hours) and hospital stay (6 +/- 3 days) were significantly less in the OPCAB group (p < 0.001). CONCLUSIONS: Off-pump coronary artery surgery can be safely performed in high-risk patients with multivessel coronary artery disease. Operative mortality is comparable to that associated with on-pump surgery, and avoidance of cardiopulmonary bypass is associated with reduced postoperative morbidity in these patients.     

Off-pump versus on-pump reoperative CABG via a left thoracotomy for circumflex coronary artery revascularization

OBJECTIVE: Reoperative CABG via a left thoracotomy (RCLT) has become a useful approach for revascularization of the circumflex coronary territory for patients who are at high risk for conventional approach. This study compares the results of RCLT using cardiopulmonary bypass (CPB) with those of a beating heart technique (OPCAB). METHODS: Thirty-two patients who underwent RCLT over the past 10 years were included. Fourteen patients undergoing on-pump RCLT (CPB) were compared to 18 patients undergoing off-pump RCLT (OPCAB). Baseline characteristics of the study groups were similar. Follow-up was 100% complete. A single graft was performed in all patients except one who had two grafts. RESULTS: There were no deaths or perioperative myocardial infarctions in either group. The incidence of atrial fibrillation (CPB: 29% vs. OPCAB: 11%) and the percentage of patients requiring ventilator support longer than 24 hours (21% vs. 6%) was not significantly different between the groups. However, allogeneic blood product utilization (0.9 +/- 1.2 vs. 0.3 +/- 0.7 units, p = 0.04), ICU stay (65 +/- 79 vs. 28 +/- 16 hours, p = 0.04) and total hospital length of stay (8 +/- 4 vs. 5 +/- 1 days, p = 0.001) were significantly lower in the OPCAB group. Average follow-up for the entire cohort was 33 +/- 9.8 months (range 2-102 months). Three-year survival was 74 +/- 9% with 9 deaths (28%) during the follow-up, but only 3 (9%) were cardiac related. Reinterventions were indicated in 6 patients (19%) (PTCA; 5, CABG: 1). Follow-up was longer for the CPB group (51 +/- 33 vs. 19.5 +/- 14 months, p = 0.001). Three-year survival (CPB 69 +/- 13%, OPCAB: 82 +/- 12%, p = 0.47) and reintervention rates (CPB: 3 [21%], OPCAB: 3 [17%], p = 0.33) were similar between the groups. CONCLUSIONS: RCLT is an effective and safe approach for circumflex artery revascularization with excellent short- and mid-term results using either technique. The OPCAB technique is associated with reduced blood product utilization and shorter ICU and hospital length of stay and, therefore, is more cost-effective.     

Benefits of off-pump bypass on neurologic and clinical morbidity: a prospective randomized trial

BACKGROUND: Neurologic and clinical morbidity after coronary artery bypass grafting (CABG) can be significant. By avoiding cardiopulmonary bypass, off-pump CABG (OPCAB) may reduce morbidity. METHODS: Sixty patients (30 CABG and 30 OPCAB) were prospectively randomized. Neurocognitive testing was performed before the operation and 2 weeks and 1 year after the operation. Neurologic testing to detect stroke and (99m)Tc-HMPAO whole-brain single photon emission computed tomography scanning to assess cerebral perfusion were performed before the operation and 3 days afterward. Bilateral middle cerebral artery transcranial Doppler scanning was performed intraoperatively to detect cerebral microemboli. All examiners were blinded to treatment group. Clinical morbidity and costs were compared. RESULTS: Coronary artery bypass grafting was associated with more cerebral microemboli (575 +/- 278.5 CABG versus 16.0 +/- 19.5 OPCAB (median +/- semiinterquartile range) and significantly reduced cerebral perfusion after the operation to the bilateral occipital, cerebellar, precunei, thalami, and left temporal lobes (p < or = 0.01). Cerebral perfusion with OPCAB was unchanged. Compared with base line, OPCAB patients performed better on the Rey Auditory Verbal Learning Test (total and recognition scores) at both 2 weeks and at 1 year (p < or = 0.05), whereas CABG performance was statistically unchanged for all cognitive measures. Patients who underwent CABG had more chest tube drainage (1389 +/- 1256 mL CABG versus 789 +/- 586 mL OPCAB, p = 0.02) and required more blood (3.9 +/- 5.8 U CABG versus 1.2 +/- 2.2 U OPCAB, p = 0.02), fresh frozen plasma (3.0 +/- 6.0 U CABG versus 0.5 +/- 2.2 U OPCAB, p = 0.03), and hours of postoperative use of dopamine (16.3 +/- 21.2 hours CABG versus 7.3 +/- 9.7 hours OPCAB, p = 0.04). These differences culminated in higher costs for CABG ($23,053 +/- $5,320 CABG versus $17,780 +/- $4,390 OPCAB, p < 0.0001). One stroke occurred with CABG, compared with none with OPCAB (p = NS). One OPCAB patient died because of a pulmonary embolus (p = NS). CONCLUSIONS: Compared with CABG, OPCAB may reduce neurologic and clinical morbidity as well as cost.     

Awake coronary artery bypass grafting: utopia or reality?

BACKGROUND: Off-pump coronary artery bypass grafting (OPCAB) was implemented to reduce trauma during surgical coronary revascularization. High thoracic epidural anesthesia further reduced intraoperative stress and postoperative pain. This technique also supports awake coronary artery bypass (ACAB), completely avoiding the drawbacks of mechanical ventilation and general anesthesia in high-risk patients. We compared our first results of the ACAB procedure with the conventional OPCAB operation. METHODS: Thirty-five patients underwent ACAB (group A) with left internal mammary artery to left anterior descending coronary artery grafting using a partial lower ministernotomy (n = 25) or double bypass grafting (n = 9) and even triple vessel coronary artery revascularization (n = 1) through complete median sternotomy. Thirty-four patients (group B), matched for age, sex, and comorbidity with group A, underwent either partial lower ministernotomy (n = 24) or OPCAB by complete sternotomy (n = 10). We recorded clinical outcomes and postoperative visual analog scale pain scores. RESULTS: In group A, 32 patients remained awake throughout the entire procedure. Three patients required secondary intubation because of incomplete analgesia (n = 1) or pneumothorax (n = 2). Patients in group A had a recovery room stay of 6.0 +/- 3.2 hours. In group B, mechanical ventilation was implemented for 4.8 +/- 3.1 hours and intensive care unit stay lasted 12 +/- 6.8 hours. Group A had no in-hospital deaths, compared with 1 death in the conventional OPCAB group. Each group had 1 patient with graft stenosis detected on the predischarge angiogram. Early postoperative pain was significantly less in group A than in group B (visual analog scale of 32 +/- 8 compared with 58 +/- 11, p < 0.0001). CONCLUSIONS: The present data demonstrate the feasibility and safety of surgical coronary revascularization without general anesthesia. Continuation of thoracic epidural analgesia provides better pain control and faster mobilization after such procedures. Surprisingly, the ACAB procedure was well accepted by the patients.     

Off-pump versus on-pump CABG in high-risk patients: short- and mid-term outcome

OBJECTIVE: During recent years Conventional Coronary Artery Bypass Grafting (cCABG) and Off-Pump Coronary Bypass (OPCAB) have been compared in several randomised and non-randomised studies. Focus has been on postoperative outcome with short-term follow-up in low-risk patients and therefore little is known of the effectiveness of OPCAB in high-risk patients. Furthermore, it is unknown if a potential beneficial short-term outcome is consistent over time. DESIGN: In 2001, 217 patients with a Euroscore > or =5 were included in an observational cohort study; 162 patients were operated by cCABG and 55 by OPCAB. Follow-up data were retrieved from the Danish national person registry. The study includes a mid-term follow-up, with a mean follow-up time of 3.97 years+/-0.32. RESULTS: No differences in mortality between OPCAB and cCABG were found. In-hospital mortality was 5.5% in the OPCAB group vs 5.6% in the cCABG group and mid-term mortality was 21.8% in the OPCAB group vs 24.7% in the cCABG group; p = 0.71. During the follow-up period 41.5% of patients with an EF < or =35% at the time of surgery and 43.3% of patients with a Euroscore >8 died. Seven percent in the cCABG group had a perioperative AMI vs none in the OPCAB group; p < 0.05. In 74.5% cCABG's allogenic transfusions of blood components was necessary vs only 55.6% OPCAB's (p < 0.05). No significant differences in CNS complications or atrial fibrillation could be demonstrated. CONCLUSION: A similar outcome between OPCAB in cCABG in high-risk patients with respect to mortality was found. OPCAB seems to have a beneficial effect on morbidity. A cautious approach to patients with a combined high Euroscore and low ejection fraction should be the strategy of choice.     

Usefulness of preoperative intraaortic balloon pump therapy during off-pump coronary artery bypass grafting in high-risk patients

BACKGROUND: In off-pump coronary artery bypass grafting (OPCABG) surgery, the most critical complication is hemodynamic deterioration, which can occur during displacement of the heart to expose the target vessels. Preoperative intraaortic balloon pump (IABP) therapy improves cardiac performance and facilitates access to the target coronary artery while maintaining hemodynamic stability, especially in high-risk patients. METHODS: One hundred thirty-three consecutive patients who underwent OPCABG through sternotomy between April 2000 and July 2003 were studied. We compared the clinical results of 32 patients who underwent preoperative IABP placement (group 1) with those of 101 patients who did not have IABP placement (group 2). Of the 32 patients satisfying the insertion criteria, 15 had critical left main artery disease, 20 had unstable angina, 5 had acute myocardial infarction, and 5 had left ventricular dysfunction. RESULTS: There were no significant differences in the average number of distal anastomoses performed between group 1 and group 2 (3.1 +/- 0.8 versus 3.3 +/- 0.9, p = not significant). The complete revascularization rate was 95% in both group. There was no conversion to on-pump surgery in either group. There was no operative death in group 1 and only 1 death in group 2. In group 1, the number of patients who required prolonged ventilatory support (longer than 48 hours) was higher (3 versus 1, p = 0.036), and there was a higher incidence of low cardiac output syndrome (1 versus 0, p = 0.074). There were no IABP-related complications in group 1. CONCLUSIONS: Preoperative IABP therapy for high-risk coronary patients is very effective in preventing hemodynamic instability and providing surgical results comparable with those in moderate- to lower-risk patients.     

Off-pump versus on-pump coronary bypass in high-risk subgroups

BACKGROUND: Cardiopulmonary bypass (CPB) has pathophysiologic sequelae that may be more severe in high-risk subsets. We wanted to determine whether off-pump coronary bypass (OPCAB) could optimize outcomes. METHODS: Our database of 242 OPCAB patients undergoing complete revascularization was compared to a base of 483 CABG patients undergoing CPB. Results were compared for the overall series and in the following high-risk subsets: 80 years of age or older, ventricular dysfunction (ejection fraction (EF) < or = 0.25), prior neurologic event or renal failure, chronic obstructive pulmonary disease (COPD), and reoperation. RESULTS: In the overall series, OPCAB significantly reduced the incidence of intraoperative transfusion requirements and showed a trend toward reduced morbidity in terms of postoperative neurologic and renal complications, prolonged ventilator requirement greater than 3 days, and bleeding requiring reexploration. Mortality was less in the OPCAB group (0.4% versus 2.7%, p = not significant). Similar results were achieved in the following high-risk subgroups (n = off-pump/on-pump): 80 years of age or older (n = 28/58), EF less than or equal to 25% (n = 13/26), preoperative neurologic event (n = 25/36), preoperative renal failure (n = 27/46), COPD (n = 33/43), and reoperation (n = 28/76). OPCAB decreased the incidence of prolonged ventilation in COPD patients (0/33 [0%] versus 4/43 [9.3%] p = not significant) and decreased the incidence of renal complications in the elderly (1/28 [3.6%] versus 9/58 [15.5%] p = not significant). Off-pump coronary bypass reduced but did not eliminate neurologic events in the elderly (2/28 [7.1%] versus 8/58 [13.8%] p = not significant). CONCLUSION: Off-pump coronary bypass significantly reduced the incidence of transfusion requirement compared to the CPB counterparts and had a consistent trend in reducing morbidity and mortality overall and in all high-risk subsets. Neurologic events are not eliminated in OPCAB.     

Elective intraaortic balloon counterpulsation in high-risk off-pump coronary artery bypass grafting

The beneficial effects of intraaortic balloon pump (IABP) in CABG with cardiopulmonary bypass (CPB) have been reported. However, the benefits of insertion of IABP electively in high-risk off-pump coronary artery bypass grafting (OPCAB) have not been established. Six hundred and twenty-five patients who underwent OPCAB form the study group. High-risk patients fulfilling two or more of the following: left main stem stenosis >70%, unstable angina, and poor left ventricular function, who had elective insertion of IABP preoperatively by the open technique (group I; n = 20) were compared with a similar high-risk group that did not (group II; n = 25). There were no significant differences in risk factors between the two groups (Euroscore 5.68). The mean number of grafts was similar. Postoperatively, there were no significant differences in the need for inotropes, duration of ventilation, arrhythmias, cerebrovascular, gastrointestinal, and infective complications (p = NS). There were no IABP-related complications. Acute renal failure requiring hemofiltration was higher in group II (n = 5; p < 0.05). Four patients (16%) in group II required postoperative IABP. Although intensive care stay was longer in group I (27.6 +/- 15.3 vs. 18.6 +/- 9.1 hours; p < 0.05), patients in group I were discharged earlier from hospital. There was no difference in mortality between the two groups (n = 1 in each group). In high-risk patients undergoing OPCAB, routine preoperative insertion of IABP electively reduces the incidence of acute renal failure. In addition it avoids the need for emergency insertion postoperatively and may result in earlier discharge.     

Morbidity outcome in patients with hypertrophic obstructive cardiomyopathy undergoing cardiac septal myectomy: early-extubation anesthesia versus high-dose opioid anesthesia technique

OBJECTIVE: Anesthetic management of patients with hypertrophic obstructive cardiomyopathy (HOCM) undergoing septal myectomy is challenging. The morbidity outcome of early-extubation anesthesia (EEA), or fast tracking, versus high-dose opioid (HDO) anesthesia was studied. DESIGN: Retrospective study. SETTING: University teaching hospital. PARTICIPANTS: One hundred seventy-five cardiac septal myectomy patients (EEA, n = 53; HDO, n = 122). INTERVENTIONS: EEA technique consisted of low-dose fentanyl, 10 to 15 microg/kg; propofol infusion; midazolam; and inhalation agent. HDO technique consisted of fentanyl, 50 to 100 microg/kg, and benzodiazepines, with or without an inhalation agent. Demographic data, preoperative symptoms, and data on anesthesia management and postoperative complications were recorded. MEASUREMENTS AND MAIN RESULTS: There were no differences between the groups (EEA v HDO, respectively) regarding age, sex, preoperative symptoms (dyspnea, 89% v 79%; palpitations, 28% v 26%; angina, 47% v 61%; syncope, 47% v 41%), redo surgery, or combined surgery. Mean +/- standard deviation time to tracheal extubation was 7.2 +/- 5.3 hours in EEA versus 19.4 +/- 10.5 hours in HDO patients (p < 0.0001). Intensive care unit (ICU) stay was significantly shorter in EEA versus HDO patients (2.2 v 3.0 days; p < 0.005), with the trend toward earlier hospital discharge (9.7 v 11.3 days; p = 0.09). There was a high requirement for temporary pacing in both groups immediately postoperatively (EEA, 60% v HDO, 48%; p > 0.08). Permanent pacemaker insertion postoperatively was required in 7 of 53 patients (13%) in the EEA group and 11 of 122 patients (9%) in the HDO group (p > 0.25). Atrial arrhythmias occurred postoperatively in 25% of EEA patients versus 34% of HDO patients (p > 0.08). CONCLUSION: EEA facilitates earlier tracheal extubation by 12 hours in patients with HOCM undergoing septal myectomy, significantly shortening ICU stay by 1 day without increasing perioperative cardiac morbidity or mortality.     

Surgical revascularization in patients with poor left ventricular function: on- or off-pump?

BACKGROUND: Patients with left ventricular dysfunction and low ejection fraction (EF) are at high-risk of complication and mortality after coronary artery bypass grafting (CABG). The potential success of off-pump CABG in this high-risk population has yet to be determined. The purpose of this study is to compare the outcome of off-pump coronary artery bypass (OPCAB) and conventional coronary artery bypass (CCAB) in patients with poor left ventricular function, all from a single institution. METHODS: Data on patient demographics, preoperative risk factors, operative and postoperative outcomes were collected retrospectively on all patients having undergone isolated CABG between January 1, 1998, and October 31, 2001. RESULTS: A total of 77 patients (31 OPCAB/46 CCAB) were identified as having an ejection fraction (EF) of < or = 0.35. Of these, 52 had EF < or = 0.30 (21 OPCAB/31 CCAB) and 31 patients had EF < or = 0.25 (10 OPCAB/21 CCAB). Operative mortality was 3.2% after the OPCAB procedure versus 10.9% for the CCAB (p = 0.39). Use of intraaortic balloon pump (6.5%) was rarely required. The OPCAB procedure resulted in significantly less requirement for blood transfusions (p < 0.05), fewer distal anastomoses per patient (p < 0.01), and a higher incidence of atrial fibrillation (p < 0.05) compared with CCAB. CONCLUSIONS: Patients with poor left ventricular function may undergo surgical revascularization using off-pump technique with relatively good results and low mortality levels. The lower number of grafts performed on the off-pump procedure did not seem to affect clinical outcomes.     

Does off-pump coronary artery bypass (OPCAB) surgery improve the outcome in high-risk patients?: a comparative study of 1398 high-risk patients.

OBJECTIVE: Although there has been some evidence supporting the theoretical and practical advantages of off-pump coronary artery bypass (OPCAB) over the conventional coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB), it has not yet been determined which group of patients would benefit most from it. It has been advocated recently that high-risk patients could benefit most from avoidance of CPB. The aim of this retrospective study is to assess the efficacy of the OPCAB technique in multi-vessel myocardial revascularization in a large series of high-risk patients. METHODS: The records of 1398 consecutive high-risk patients who underwent primary isolated CABG at Harefield Hospital between August 1996 and December 2001 were reviewed retrospectively. Patients were considered as high-risk and included in the study if they had a preoperative EuroSCORE of > or =5. Two hundred and eighty-six patients were operated on using the OPCAB technique while 1112 patients were operated on using the conventional CABG technique with CPB. The OPCAB patients were significantly older than the CPB patients (68.1+/-8.3 vs. 63.7+/-9.9 years, respectively, P<0.001). The OPCAB group included significantly more patients with poor left ventricular (LV) function (ejection fraction (EF) < or =30%) (P<0.001) and more patients with renal problems (P<0.001). RESULTS: There was no significant difference in the number of grafts between the groups. The CPB patients received 2.8+/-1.2 grafts per patient while OPCAB patients received 2.8+/-0.5 grafts per patient (P=1). Twenty-one (7.3%) OPCAB patients had one or more major complications, while 158 (14.2%) CPB patients (P=0.008) developed major complications. Thirty-eight (3.4%) CPB patients developed peri-operative myocardial infarction (MI) while only two (0.7%) OPCAB patients developed peri-operative MI (P=0.024). The intensive therapy unit (ITU) stay for OPCAB patients was 29.3+/-15.4 h while for CPB patients it was 63.6+/-167.1 h (P<0.001). There were ten (3.5%) deaths in the OPCAB patients compared to 78 (7%) deaths in the CPB patients (P=0.041) within 30 days postoperatively. CONCLUSIONS: This retrospective study shows that using the OPCAB technique for multi-vessel myocardial revascularization in high-risk patients significantly reduces the incidence of peri-operative MI and other major complications, ITU stay and mortality. Even though the OPCAB group included a significantly higher proportion of older patients with poor LV function (EF < or =30%) and renal problems, the beneficial effect of OPCAB was evident.     

The role of intraaortic balloon counterpulsation in patients undergoing cardiac operations.

Intraaortic balloon counterpulsation (IABC) was used to assist 60 patients undergoing cardiac operations for reasons of acute left ventricular failure (18 patients) or electively for indications in high-risk coronary and valvular heart disease (42 patients). Nine of 18 patients achieved hemodynamic stability when treated for acute perioperative or postoperative cardiogenic shock. Four of these died from problems unassociated with postoperative left ventricular failure and 5 were long-term survivors, indicating a potential salvage of 50%. In 42 high-risk patients, IABC was used electively to control preinfarction angina before operation (21 patients) and prophylactically to prevent postoperative low-output failure in another 21 patients with severe coronary and valvular heart disease. Thirty-nine, or 93%, of these patients survived. There were no deaths in the preinfarction angina group, 1 death in the group with coronary disease and ejection fractions less than 30%, and 2 deaths in those with valvular heart disease and congestive failure. Seven patients developed thrombotic or ischemic complications, but no permanent damage resulted. IABC is an important form of assistance for any patient with preoperative, intraoperative, or postoperative left ventricular failure and adds safety and hemodynamic stability for the high-risk patient with preinfarction angina or poor ventricular function.     

Total arterial off-pump versus on-pump coronary revascularization: comparison of early outcome

BACKGROUND AND AIM: To assess differences in the early outcome after complete arterial myocardial revascularization with (ONCAB) or without cardiopulmonary bypass (OPCAB). METHODS: Out of 870 consecutive CABG procedures 58 OPCAB and 91 ONCAB patients receiving exclusive arterial grafts were analyzed. OPCAB patients had more single-vessel (p < 0.0001), less triple-vessel (p < 0.0001) or left main disease (p = 0.0021), higher angina class (p = 0.003), unstable angina (p < 0.0001) or previous PTCAs (p < 0.0001). RESULTS: ONCAB was associated with longer operations (182.5 +/- 38 vs. 147 +/- 56 min; p = 0.0001) and more anastomoses/patient (3.2 +/- 1 vs. 2 +/- 0.9; p < 0.0001), but incomplete revascularization was similar in both groups (11% vs. 17%; p = ns). ITA use was identical, whereas single left internal thoracic artery (LITA) use (25.9% vs.1%; p < 0.0001) and LITA jump anastomoses (10.3% vs. 7.7%; p < 0.0001) were more frequent in OPCAB. Radial artery (RA) use (89% vs. 46.6%; p < 0.0001) and RA jump anastomoses (57.1% vs. 12.1%; p < 0.0001) were more frequent in ONCAB. Mortality, arrhythmias, cerebro-vascular accidents (CVA), and renal failure were similar, but ventilatory support shorter (8.8 +/- 11.8 vs. 15.6 +/- 9.4 h; p < 0.0001) and cardiac enzyme release smaller (p < 0.0001) after OPCAB with a trend toward less myocardial infarction (1.7% vs. 7.7%; p = 0.12) and low output (1.7% vs. 8.8%; p = 0.089), and more respiratory complications (10.3% vs. 2.2%; p = 0.056). CONCLUSIONS: Arterial OPCAB patients have less extensive CAD, but more severe symptoms. Early outcome is similar concerning mortality, arrhythmias, CVA, renal failure, or ICU and hospital stay, but with shorter ventilatory support and lower cardiac enzymes with a trend toward lower myocardial infarction and low output, but higher respiratory complication rates after OPCAB.     

Off-pump surgery decreases postoperative complications and resource utilization in the elderly.

BACKGROUND: Bypass surgery in the elderly (age >70 years) has increased mortality and morbidity, which may be a consequence of cardiopulmonary bypass. We compare the outcomes of a cohort of elderly off-pump coronary artery bypass (OPCAB) patients with elderly conventional coronary artery bypass grafting (CABG) patients. METHODS: Chart and provincial cardiac care registry data were reviewed for 30 consecutive elderly OPCAB patients (age 74.7 +/- 4.2 years) and 60 consecutive CABG patients (age 74.9 +/- 4.1 years, p = 0.82) with similar risk factor profiles: Parsonnet score 17.2 +/- 8.1 (OPCAB) versus 15.6 +/- 6.5 (CABG), p = 0.31; and Ontario provincial acuity index 4.5 +/- 1.9 (OPCAB) versus 4.3 +/- 2.0 (CABG), p = 0.65. RESULTS: Mean hospital stay was 6.3 +/- 1.8 days for OPCAB patients and 7.7 +/- 3.9 days for CABG patients (p < 0.05). Average intensive care unit stay was 24.0 +/- 10.9 h for OPCAB patients versus 36.6 +/- 33.5 h for CABG patients (p < 0.05). Atrial fibrillation occurred in 10.0% of OPCAB patients and 28.3% of CABG patients (p < 0.05). Low output syndrome was observed in 10% of OPCAB patients and 31.7% of CABG patients (p < 0.05). Cost was reduced by $1,082 (Canadian) per patient in the OPCAB group. Postoperative OPCAB graft analysis showed 100% patency. CONCLUSIONS: OPCAB is safe in the geriatric population and significantly reduces postoperative morbidity and cost.     

Intraaortic balloon pump therapy facilitates posterior vessel off-pump coronary artery bypass grafting in high-risk patients

Background. Displacement of the heart to expose posterior vessels during coronary artery bypass grafting (CABG) without cardiopulmonary bypass (off-pump CABG, or OPCAB) may impair cardiac function. We used the intraaortic balloon pump (IABP) preoperatively to reduce operative risk and to facilitate posterior vessel OPCAB in high-risk patients with left main coronary artery disease (> 75% stenosis), intractable resting angina, postinfarction angina, left ventricular dysfunction (ejection fraction < 35%), or unstable angina.

Methods. One hundred and forty-two consecutive patients who underwent multivessel OPCAB including posterior vessel revascularization were studied prospectively. The patients were divided into group I (n = 57), which received preoperative or intraoperative IABP, and group II (n = 85), which did not receive IABP. In group I, there were 34 patients with left main coronary artery disease, 24 patients with intractable resting angina, 8 patients with left ventricular dysfunction, 5 patients with postinfarction angina, and 40 patients with unstable angina. Seven patients received intraoperative IABP support owing to hemodynamic instability during OPCAB.

Results. There was no operative mortality in group I and 1 death in group II. The average number of distal anastomoses was not different between group I and group II (3.4 ± 0.9 versus 3.5 ± 0.9, p = not significant). There were no significant differences in the number of posterior vessel anastomoses per patient. There were no differences in ventilator support time, length of stay in the intensive care unit, hospital stay, and morbidity between the two groups. There was one IABP-related complication in group I.

Conclusions. IABP therapy facilitates posterior vessel OPCAB in high-risk patients, and surgical results are comparable with those in lower-risk patients.     

Low systemic vascular resistance state following off-pump coronary artery bypass grafting

OBJECTIVE: To determine the prevalence, hemodynamic characteristics, and risk factors for low systemic vascular resistance (SVR) state following after off-pump coronary artery bypass (OPCAB). PATIENTS AND METHODS: SVR data could be obtained for 116 OPCAB patients. Low SVR was defined as an indexed systemic vascular resistance (SVRi) of <1,800 dyne x s/cm(5) x m(2) at the end of operation. Hemodynamic data were recorded preoperatively, at the end of operation, just after entering ICU, and the following morning. RESULTS: Low SVR state was noted in 54 of 116 patients (53%). The SVRi values in low-SVR and non-low-SVR patients were 1,406+/-253 and 2,326+/-509 dyne x s/cm(5) x m(2) at the end of operation (p<0.0001). Increased CI level, decreased MAP level, but unchanged CVP level was observed postoperatively in the low-SVR patients. The increase in CI and decrease in MAP were maximal at the end of operation. Patients with low SVR were more likely to have a higher body mass index (24.5+/-3.6 vs. 22.9+/-2.9; p=0.013) and to be male (82% vs. 62%; p=0.036) than no-low-SVR patients. In low-SVR patients, fluid balance was more positive intraoperatively (3,537+/-1,411 vs. 3,068+/-1,597; p=0.09), but more negative at 6 hours postoperatively (-136+/-978 vs. 234+/-844; p=0.034) and 12 h postoperatively (-282+/-1,321 vs. 268+/-1,238; p=0.024). CONCLUSIONS: Low SVR state, a probable manifestation of systemic inflammatory response (SIRS), is common in patients who have undergone OPCAB. For these patients it is more reasonable to maintain MAP with vasopressors by restoring vascular tone, than by volume loading.     

Myocardial revascularization in patients with low ejection fraction < or =35%: effect of pump technique on early morbidity and mortality

BACKGROUND AND AIM: Left ventricular dysfunction is an important predictor of in-hospital mortality. Surgical risk among these patients remains high. The present study is conducted to evaluate the difference in early morbidity and mortality among patients with compromised left ventricular function (LVF) after myocardial revascularization using either off-pump or on-pump coronary artery bypass graft. METHODS: Between April 2000 and April 2004, 150 patients with ejection fraction (EF) < or =35% underwent isolated coronary artery bypass grafting. Eighty-four patients underwent conventional bypass (mean EF 30.1%+/- 4.2) and 66 patients had off-pump coronary artery bypass (mean EF 27.5%+/- 5.5). Different variables (preoperative, intraoperative, and postoperative) were evaluated and compared. Determination of operation risk was done using EuroSCORE. Patients who underwent OPCAB were more risky due to a high percentage of associated comorbidities, mean EuroSCORE was 12.96 +/- 13.21 in comparison to 8.47 +/- 10.22 in CCAB. RESULTS: The mean operative mortality was 8.7%. Patients who underwent OPCAB had a lower operative mortality than CCAB (6.1% vs. 10.7%) inspite of a higher preoperative predicted risk score. Completeness of revascularization was higher among the CCAB group (85.7% vs. 69.7%; p = 0.01). Subsequently, the mean number of grafts was significantly higher among this group (3.4+/-0.7 vs. 2.0 +/-0.9; p < 0.001). On the other hand, morbidity was significantly higher in CCAB (35.7% vs. 19.7%; p = 0.03). However, the incidence of both myocardial infarction and atrial fibrillation was more among OPCAB. CONCLUSIONS: Patients with left ventricular dysfunction are high-risk group. These patients can benefit from myocardial revascularization using either off-pump or conventional CABG, but both are associated with a higher mortality and morbidity than those with normal ventricle. The use of off-pump CABG resulted in better clinical outcome and mortality, but less number of grafts performed than those with conventional CABG especially in patients with lowest EF.     

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.     

体外循环和非体外循环冠状动脉旁路术围手术期心肌损伤程度的对比研究

目的　对比研究常规体外循环下冠状动脉旁路术 (CCABG)和非体外循环心脏跳动下冠状动脉旁路术 (OPCAB)围手术期心肌肌钙蛋白I(cTnI)动态变化规律 ,以明确心肌损伤的程度。方法　 5 9例不稳定心绞痛患者 ,射血分数 (EF) 0 35～ 0 5 6 ,其中 34例行OPCAB ,患者平均年龄 (5 9 1± 1 7)岁 ,平均搭桥数 1 0～ 5 0支 ,平均 (2 90± 0 8)支 ;2 5例行CCABG ,患者平均年龄 (5 6 5± 1 8)岁。搭桥数 2 0～ 5 0支 ,平均 (3 2± 0 7)支。分别在术前 ,术后第 8、2 4、48、72、96、12 0h时 ,采集患者静脉血标本 ,离心后取血浆测定cTnI值。cTnI的测定采用自动双抗体夹心酶联免疫荧光测定法 ,仪器检测灵敏度cTnI 0 35 μg/L。　 结果　术前 2组患者cTnI差异无显著性意义 (P >0 0 5 )。OPCAB手术组cTnI值在术后观察期内均低于CCABG组 ,差异有显著性意义 (t=1 9432 ,P =0 0 0 7)。全组患者无死亡 ,均痊愈出院。　结论　cTnI是诊断心肌损伤的良好指标。OPCAB手术心肌损伤程度显著低于CCABG手术。     

Surgical myocardial revascularization (CABG) in patients with pulmonary disease: beating heart versus cardiopulmonary bypass

BACKGROUND: Adverse effects on the respiratory system can be severe in many instances after coronarv artery bypass grafting (CABG) with cardiopulmonary bypass (CPBP). Recently, operative techniques without CPBP have gained widespread consent, thanks to the newly developed retractors that allow satisfactory immobilisation of the surgical field. METHODS: Thirty-seven patients operated upon in our Institution between April 1997 and April 1998 showed an obstructive and/or restrictive pulmonary disease. Twenty-one patients were operated on without CBPB (group A), while 16 patients were operated using CPBP (group B, control). The allocation in each group had been randomised. RESULTS: The length of the operation in group A was less than in group B (196+/-35 minutes vs 235+/-60 minutes), (p=0.014). A significant difference was found in postoperative bleeding: 562+/-381 ml vs 776+/-378 (p=0.046), in postoperative red cell count, hemoglobin level and Hct. Permanence on the ventilator was 19.1+/-13 hours in group B and 13.1+/-6.1 hours in group A (p=0.03). The length of stay in ICU was significantly different: 33.8+/-16.2 hours for group A vs 53.6+/-29.3 hours for group B (p=0.01). No respiratory failure occurred in group A; two patients experienced slow weaning from ventilation assistance and one died from that complication in group B. CONCLUSIONS: Myocardial revascularization without CPBP allows a better postoperative clinical course in patients with advanced pulmonary disease.