Economic outcome of off-pump coronary artery bypass surgery: a prospective randomized study

Off-Pump Coronary Artery Bypass Grafting Does Not Confer Superior Outcomes Among Frail Patients

Off-pump coronary revascularization (OPCAB) has been proposed to benefit patients who are at a greater surgical risk because it avoids the use of extracorporeal circulation. Although, historically, older patients were considered high-risk candidates, recent studies implicate frailty as a more comprehensive measure of perioperative fitness. Yet, the outcomes of OPCAB in frail patients have not been elucidated. Thus, using a national cohort of frail patients, we assessed the impact of OPCAB relative to on-pump coronary revascularization (ONCAB). Patients who underwent first-time elective coronary revascularization were tabulated from the 2010 to 2020 Nationwide Readmissions Database. Frailty was assessed using the previously-validated Johns Hopkins Adjusted Clinical Groups indicator. Multivariable models were used to consider the independent associations between OPCAB and the key outcomes. Of ∼26,529 frail patients, 6,322 (23.8%) underwent OPCAB. After risk adjustment and compared with ONCAB, OPCAB was linked with similar odds of in-hospital mortality but greater likelihood of postoperative cardiac arrest (adjusted odds ratio [AOR] 1.53, confidence interval [CI] 1.13 to 2.07) and myocardial infarction (AOR 1.44, CI 1.23 to 1.69). OPCAB was further associated with greater odds of postoperative infection (AOR 1.22, CI 1.02 to 1.47) but decreased need for blood transfusion (AOR 0.68, CI 0.60 to 0.77). In addition, OPCAB faced a +0.86-day increase in length of stay (CI 0.21 to 1.51) but similar costs (β $1,610, CI -$1,240 to 4,460) relative to ONCAB. Although OPCAB was associated with no difference in mortality compared with ONCAB, it was linked with greater likelihood of postoperative cardiac arrest and myocardial infarction. Our findings demonstrate that ONCAB remains associated with superior outcomes, even in the growing population of frail patients who underwent coronary revascularization.

Acute clinical and financial outcomes of on- versus off-pump coronary artery bypass grafting in octogenarians

BACKGROUND

Coronary artery bypass surgery in octogenarians is associated with increased postoperative morbidity. Off-pump coronary artery bypass surgery eliminates potential complications of cardiopulmonary bypass, but its use remains controversial. This study aimed to evaluate the clinical and financial impact of off-pump coronary artery bypass surgery compared to conventional coronary artery bypass surgery among this high-risk population.

METHODS

Patients ≥80 years undergoing first-time, isolated, elective coronary artery bypass surgery were identified using the 2010-2019 Nationwide Readmissions Database. Patients were grouped into off-pump or conventional coronary artery bypass surgery cohorts. Multivariable models were developed to assess the independent associations between off-pump coronary artery bypass surgery and key outcomes.

RESULTS

Of ∼56,158 patients, 13,940 (24.8%) underwent off-pump coronary artery bypass surgery. On average, the off-pump cohort was more likely to undergo single-vessel bypass (37.3 vs 19.7%, P < .001). After adjustment, undergoing off-pump coronary artery bypass surgery was associated with similar odds of in-hospital mortality (adjusted odds ratio 0.90, 95% confidence interval 0.73-1.12) relative to conventional bypass. Additionally, the off-pump and conventional coronary artery bypass surgery groups were comparable in odds of postoperative stroke (adjusted odds ratio 1.03, 95% confidence interval 0.78-1.35), cardiac arrest (adjusted odds ratio 0.99, 95% confidence interval 0.71-1.37), ventricular fibrillation (adjusted odds ratio 0.89, 95% confidence interval 0.60-1.31), tamponade (adjusted odds ratio 1.21, 95% confidence interval 0.74-1.97), and cardiogenic shock (adjusted odds ratio 0.94, 95% confidence interval 0.75-1.17). However, the off-pump coronary artery bypass surgery cohort was linked with an increased likelihood of ventricular tachycardia (adjusted odds ratio 1.23, 95% confidence interval 1.01-1.49) and myocardial infarction (adjusted odds ratio 1.34, 95% confidence interval 1.16-1.55). Furthermore, those undergoing off-pump coronary artery bypass surgery demonstrated reduced odds of non-home discharge (adjusted odds ratio 0.91, 95% confidence interval 0.83-0.99) and a decrement in hospitalization expenditures ($-1,290, 95% confidence interval -$2,370 to $200).

CONCLUSION

Off-pump coronary artery bypass surgery was linked with increased odds of ventricular tachycardia and myocardial infarction, but no difference in mortality. Our findings point to the safety of conventional coronary artery bypass surgery in octogenarians. Yet, future work is needed to consider long-term outcomes in this complex surgical cohort.

Successful introduction of off-pump coronary artery bypass grafting in southeastern Asian countries: A single Center's experience in Thailand

Background

Off-pump coronary artery bypass grafting has not been standardized in Southeastern Asian countries because it is technically demanding. However, this method could be suitable for economically disadvantaged institutions because it saves cost on the heart–lung machine. We summarized our results to assess the validity of our early introduction of this method.

Methods

We reviewed the data from 750 patients who underwent off-pump coronary artery bypass grafting at our institution. Before the introduction of off-pump coronary artery bypass grafting, experts from Japan were enlisted to teach our surgeons technicalities of the procedure. The primary outcome was in-hospital mortality, and secondary outcomes included any major adverse cardiac or cerebrovascular event.

Results

The in-hospital mortality rate was 1.5%. The rates of survival and freedom from major adverse cardiac or cerebrovascular event 3 years after the operation were 92.5% ± 1.8% and 90.7% ± 2.2%, respectively. In the multivariable analysis, the independent risk factors for major adverse cardiac or cerebrovascular event were chronic obstructive pulmonary disease (adjusted hazard ratio = 2.35, 95% confidence interval = 1.35–4.10, P = .003) and renal insufficiency (adjusted hazard ratio = 2.70, 95% confidence interval = 1.52–4.80, P = .001), whereas risk factors for in-hospital death were pump conversion (relative risk = 17.4, 95% confidence interval = 1.63–4.41, P < .001).

Conclusion

Successful introduction of off-pump coronary artery bypass grafting provided a favorable outcome almost equal to that in high-volume centers in developed countries.

Off-Pump Coronary Artery Bypass Grafting; is it Still Relevant?

Off-pump Coronary Artery Bypass Grafting (OPCAB) experienced a resurgence in the 1980s -2000s and developed steadily with improvement of the instrumentation and techniques. However questions about graft patency and long-term survival of OPCAB patients still exist. This review attempts to explore the current relevance of OPCAB.

Off-Pump versus Conventional Coronary Artery Bypass Grafting: A Meta-Analysis and Consensus Statement from the 2004 ISMICS Consensus Conference

Background

The purpose of this evidence-based consensus statement is to systematically review and meta-analyze the randomized and nonrandomized evidence comparing off-pump (OPCAB) to conventional coronary artery bypass (CCAB) surgery and to provide consensus on the role of OPCAB in low- and high-risk surgical patients.

Methods and Results

This consensus conference was conducted according to the American College of Cardiology (ACC)/American Heart Association (AHA) standards for development of clinical practice guidelines. The Steering Committee collated all published studies of OPCAB versus CCAB through May 2004 and developed six questions central to controversies surrounding OPCAB surgery in mortality, morbidity, and resource utilization. For mixed-risk patient populations, meta-analysis of 37 randomized clinical trials (3,369 patients, Level A) reported across a total of 53 papers, and two meta-analyses of nonrandomized trials (Level B) comparing OPCAB versus CCAB were identified. For high-risk patient populations, we performed a meta-analysis of 3 randomized and 42 nonrandomized trials (26,349 patients, Level B).

Conclusion

Meta-analysis of Level A and B evidence provided the basis for the following consensus statements in patients undergoing surgical myocardial revascularization: (1) OPCAB should be considered a safe alternative to CCAB with respect to risk of mortality [Class I, Level A]; (2) With appropriate use of modern stabilizers, heart positioning devices, and adequate surgeon experience, similar completeness of revascularization and graft patency can be achieved [Class IIa, Level A]; (3) OPCAB is recommended to reduce perioperative morbidity [Class I, Level A]; (4) OPCAB may be recommended to minimize midterm cognitive dysfunction [Class IIa, Level A]; (5) OPCAB should be considered as an equivalent alternative to CCAB in regard to quality of life [Class I, Level A]; (6) OPCAB is recommended to reduce the duration of ventilation, ICU and hospital stay, and resource utilization [Class I, Level A]; (7) OPCAB should be considered in high-risk patients to reduce perioperative mortality, morbidity, and resource utilization [Class IIa, Level B].

Costs, Clinical Outcomes, and Health-Related Quality of Life of Off-Pump vs. On-Pump Coronary Bypass Surgery

BACKGROUND

Off-pump coronary bypass surgery avoids the potential complications of cardiopulmonary bypass. However, its acceptance depends on medical and economic outcome. The aim of this prospective non-randomised study was to compare functional and economic outcome of off-pump and on-pump surgery at 1-year follow-up.

METHODS

102 patients (pts) treated with either off-pump (60pts) or on-pump surgery (42pts) were studied. Pts with left ventricular dysfunction, recent myocardial infarction (<1 month), renal impairment, valve surgery, previous stroke or coagulopathy were excluded. Variable and fixed costs were obtained for each treatment group during operative and postoperative care. In-hospital endpoints included all-cause mortality and complications (defined as excessive bleeding [>6 units blood transfusion], peri-operative myocardial infarction, atrial fibrillation, stroke, and infection). All cause mortality; cost-effectiveness and quality of life were assessed 1 year after surgery.

RESULTS

The in-hospital mortality was similar in the two treatment groups. Off-pump group had significantly fewer postoperative complication rate (off-pump 41% vs. on-pump 72%, p=0.001). The mean in-hospital cost was lower for off-pump surgery (off-pump 6.515+/-926 euro vs. on-pump 9.872+/-1.299 euro, p<0.0001) as well as the mean length of hospital stay (off-pump 4.93+/-0.93 days vs. on-pump 6.58+/-1.04 days, p<0.0001). At 1 year, all cause mortality, quality of life indices, return to work rate and treatment satisfaction was similar in both groups.

CONCLUSION

Off-pump myocardial revascularization maintains the advantages of conventional surgery in terms of survival and freedom from cardiac events while reducing the in-hospital cost.

Off Pump Coronary Artery Bypass Graft Surgery Versus Conventional Coronary Artery Bypass Graft Surgery: A Systematic Review of the Literature

The recent development of off-pump coronary artery bypass (OPCAB) graft surgical techniques has led to numerous observational and several randomized trials that have investigated outcomes compared with the current gold standard of conventional on-pump coronary bypass (CCAB) graft surgery. This systematic review assesses the current randomized trials that compare OPCAB and CCAB. Numerous end points were investigated, including mortality, stroke, myocardial infarction, atrial fibrillation, blood transfusions, wound infections, and renal failure. In addition to these important outcomes, resource utilization markers were also examined such as hospital length of stay, intensive care unit length of stay, and duration of intubation/ventilation. Finally, when level I evidence from randomized trials was unavailable, level II evidence was examined. This was done for subgroup analysis, where currently no randomized trials exist, looking at OPCAB in high-risk patients. Recommendations were made as to who should receive OPCAB and the potential benefits in this patient population.

Does Tranexamic Acid Reduce Blood Loss in Off-Pump Coronary Artery Bypass?

The hemostatic effect of tranexamic acid on the bleeding tendency and transfusion requirements in patients undergoing off-pump coronary artery bypass surgery was assessed in a prospective randomized double-blind study. Of 66 patients undergoing elective operations, 33 were given tranexamic acid (15 mg·kg−1 before infusion of heparin and 15 mg·kg−1 after protamine infusion), and the other 33 received only saline. Postoperative bleeding, transfusions, complications, hematological variables, and plasma D-dimer levels were recorded. Postoperative blood loss was significantly less in the tranexamic acid group compared to the control group (320 ± 38 vs 480 ± 75 mL). Patients in the tranexamic acid group received significantly less allogeneic blood products (0.46 vs 0.94 units per patient), and they had lower postoperative D-dimer levels. No postoperative thrombotic complications were observed in either group. Although off-pump coronary artery bypass surgery is associated with reduced frequency of hemorrhagic disorders, defective hemostasis still occurs, and tranexamic acid effectively reduces postoperative blood loss and the need for allogeneic blood products.

Isolated Human Pulmonary Artery Structure and Function Pre- and Post-Cardiopulmonary Bypass Surgery

BACKGROUND

Pulmonary dysfunction is a known complication after cardiac surgery using cardiopulmonary bypass, ranging from subclinical functional changes to prolonged postoperative ventilation, acute lung injury, and acute respiratory distress syndrome. Whether human pulmonary arterial function is compromised is unknown. The aim of the present study was to compare the structure and function of isolated and cannulated human pulmonary arteries obtained from lung biopsies after the chest was opened (pre-cardiopulmonary bypass) to those obtained at the end of cardiopulmonary bypass (post-cardiopulmonary bypass) from patients undergoing coronary artery bypass graft surgery.

METHODS AND RESULTS

Pre- and post-cardiopulmonary bypass lung biopsies were received from 12 patients undergoing elective surgery. Intralobular small arteries were dissected, cannulated, pressurized, and imaged using confocal microscopy. Functionally, the thromboxane mimetic U46619 produced concentration-dependent vasoconstriction in 100% and 75% of pre- and post-cardiopulmonary bypass arteries, respectively. The endothelium-dependent agonist bradykinin stimulated vasodilation in 45% and 33% of arteries pre- and post-cardiopulmonary bypass, respectively. Structurally, in most arteries smooth muscle cells aligned circumferentially; live cell viability revealed that although 100% of smooth muscle and 90% of endothelial cells from pre-cardiopulmonary bypass biopsies had intact membranes and were considered viable, only 60% and 58%, respectively, were viable from post-cardiopulmonary bypass biopsies.

CONCLUSIONS

We successfully investigated isolated pulmonary artery structure and function in fresh lung biopsies from patients undergoing heart surgery. Pulmonary artery contractile tone and endothelium-dependent dilation were significantly reduced in post-cardiopulmonary bypass biopsies. The decreased functional responses were associated with reduced cell viability.

CLINICAL TRIAL REGISTRATION

URL: http://www.isrctn.com/ISRCTN34428459. Unique identifier: ISRCTN 34428459.

Pulmonary Protection Strategies in Cardiac Surgery: Are We Making Any Progress?

Pulmonary dysfunction is a common complication of cardiac surgery. The mechanisms involved in the development of pulmonary dysfunction are multifactorial and can be related to the activation of inflammatory and oxidative stress pathways. Clinical manifestation varies from mild atelectasis to severe respiratory failure. Managing pulmonary dysfunction postcardiac surgery is a multistep process that starts before surgery and continues during both the operative and postoperative phases. Different pulmonary protection strategies have evolved over the years; however, the wide acceptance and clinical application of such techniques remain hindered by the poor level of evidence or the sample size of the studies. A better understanding of available modalities and/or combinations can result in the development of customised strategies for the different cohorts of patients with the potential to hence maximise patients and institutes benefits.

Predictors of prolonged mechanical ventilation after open heart surgery

Introduction: Due to the importance of prolonged mechanical ventilation (PMV) as a postoperative complication, predicting "high-risk" patients by identifying predisposing risk factors is of important issue. The present study was aimed to identify perioperative variables associated with PMV in patients undergoing open heart surgery.

Methods: A total of 743 consecutive patients, American Society of Anesthesiologists (ASA) physical status class III, who were scheduled to undergo open heart surgery using cardiopulmonary bypass were included in this observational study. Perioperative variables were compared between the patients with and without PMV, as defined by an extubation time of >48 h.

Results: PMV occurred in 45 (6.1%) patients. On univariate analysis, pre-operative variables; including gender, history of chronic obstructive pulmonary disease (COPD); chronic kidney disease and endocarditis, intra-operative variables; including type of surgery, operation time, pump time, transfusion in operating room and postoperative variables; including bleeding and inotrope-dependency were significantly different between patients with and without PMV (all P<0.001, except for COPD and transfusion in operating room; P=0.004 and P=0.017, respectively).

Conclusion: Our findings reinforce that risk stratification for predicting delayed extubation should be an important aspect of preoperative clinical evaluation in all anesthesiology settings.

Evolution of Off-Pump Coronary Artery Bypass Grafting over 15 Years: A Single-Institution Experience of 14,030 Cases

BACKGROUND

: Off-pump coronary artery bypass grafting for multivessel disease is an important alternative to conventional myocardial revascularization using cardiopulmonary bypass. The development of exposure and stabilization techniques has made this surgery simple, safe, and routine. Experience with the technique, its evolution, the learning curve, and the pitfalls is presented.

METHODS

: A retrospective analysis was made of 28,216 patients who underwent elective coronary artery bypass grafting over a 15-year period from January 1990 through December 2004. Isolated off-pump coronary artery bypass grafting was performed in 14,030 patients and on-pump coronary artery bypass grafting in 14,186 patients. The overall period was divided into 3 groups of 5 years each: group I (1990-1994), group II (1995-1999), and group III (2000-2004). Initially, off-pump coronary artery bypass grafting was performed selectively in high-risk patients (eg, atheromatous aorta, severe systemic impairment, chronic obstructive pulmonary disease, octogenarian). Recently (2000-2004), multivessel off-pump coronary artery bypass grafting has been performed electively in 96% to 98% of patients undergoing coronary artery bypass grafting. Patients' medical charts were reviewed for age, preoperative risk factors, operative findings, intraoperative conversion rate to cardiopulmonary bypass, postoperative complications, and length of hospital stay.

RESULTS

: In the years 1990-1994 (group I), mostly high-risk cases and cases with left anterior descending coronary artery lesions were included for off-pump coronary artery surgery. In the years 1995-1999 (group II), patients with double and triple vessel disease presenting for coronary artery bypass surgery were accepted for off-pump surgery irrespective of preoperative risk factors. However, in the years 2000-2004 (group III), off-pump coronary artery bypass surgery was the first choice of approach for any patient presenting for coronary artery bypass surgery. The mean number of grafts was lower in off-pump cases than in on-pump cases in group I (2.0 ± 0.4 vs. 3.2 ± 0.80) and group II (2.6 ± 0.6 vs. 3.3 ± 0.4), whereas the mean number of grafts was higher in off-pump cases than in on-pump cases in group III (3.5 ± 0.2 vs. 3.4 ± 0.8). In groups I and II, the conversion to cardiopulmonary bypass was 5.2% and 5.9%, respectively. The conversion to cardiopulmonary bypass decreased to 1.7% in group III, which was statistically significant. Perioperative myocardial infarction was 5.2% in group I, 1.7% in group II, and 1.5% in group III. The difference between groups II and III was not statistically significant. Hospital mortality was higher in group I (5.2%) than in group II (1.2%) or III (1.1%). The difference between groups II and III was not statistically significant. Length of intensive care unit stay was 36 ± 8 hours in group I, 28 ± 7 hours in group II, and 20 ± 8 hours in group III. These differences were statistically significant. Length of postoperative hospital stay was 8 ± 2 days in group I, 7 ± 2 days in group II, and 5 ± 2 days in group III These differences were statistically significant.

CONCLUSIONS

: As surgeons' experience matures, off-pump coronary artery bypass surgery permits total myocardial revascularization in virtually all patients with multivessel coronary artery disease. Despite a significant learning curve, evolution to routine off-pump coronary artery bypass with good patient outcomes can be achieved with careful patient selection during the "learning curve." The method is safe and reproducible, and patients benefit with shorter intensive care unit and hospital stays.

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

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

[Results of coronary artery bypass grafting with left ventricular dysfunction (comparison of off-pump versus on-pump)]

BACKGROUND

The aim of this study was to compare the results of myocardial revascularisation with or without cardiopulmonary bypass in patients with impaired left ventricular function.

PATIENTS AND METHODS

Five hundred and sixteen consecutive patients who underwent coronary artery bypass grafting from January 2000 through December 2007 were analyzed retrospectively. One hundred and eight cases had a left ventricular EF (ejection fraction) of 45% or less. Of these patients, 78 underwent conventional coronary artery bypass (CCABG) and 30 underwent off-pump procedure (OCABG). The CCABG group received 300IU/kg of heparin while the OCABG received 100IU/kg. The off-pump coronary surgery was carried out using a tissue stabilizer Octopus II. Different pre-, per- and postoperative variables were evaluated among both groups. Statistical analysis was performed by SPSS 11.5. The variables were compared between these two groups using univariate analysis (Chi(2) test, Fisher's test exact) for qualitative variable and (Student's t test, Mann-Whitney's test) for quantitative variable.

RESULTS

Patients profiles and risk factors were similar among both groups except for age (CCABG: 57.8±9.2 year vs OCABG: 52±9.9 year; P=0.004) and left ventricular EF (CCABG: 37.4±6.3% vs OCABG: 34±7.8%; P=0.02). The number of grafts performed per patient was significantly more among patients who underwent extracorporeal circulation (CCABG: 2.53±0.7 graft/patient vs OCABG: 1.77±0.8 graft/patient; P<0.0001). The hospital mortality was more among CCABG group 9% vs 3.3% in OCABG but the difference was not significant (P=0.3). However, the operative time and the operative room stay were long in CCABG (252±61min vs 175±38min; P<0.0001 - 389±70min vs 298±54min; P<0.0001). The ventilation time was also long in CCABG (32.3±67hour vs 10.4±5.9hour; P=0.15). There was more postoperative myocardial infarction in CCABG (P=0.008), but the EF increased and was better in CCABG.

CONCLUSION

Off-pump coronary artery bypass surgery provides satisfactory operative results for most patients with reduced left ventricular function. Prospective and randomly study will be necessary before concluding.

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

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Resource utilization in off-pump versus conventional coronary artery bypass grafting in a community hospital: a comparative analysis using propensity scoring

BACKGROUND

At a time when cost containment in health care is under increased scrutiny, coronary artery bypass grafting remains the most widely performed cardiac surgical procedure in the world. This study compares 30-day mortality, morbidity, and resource use for off-pump coronary artery bypass (OPCAB) versus conventional coronary artery bypass (CCAB) revascularization.

METHODS

From January 2000 through December 2008, 1003 patients underwent OPCAB grafting by a single surgeon (S.C.S.). Data were prospectively collected, entered into a Society of Thoracic Surgeons adult cardiac surgery database, and analyzed retrospectively. We used propensity-matching techniques to match this cohort to a group of 1003 patients who underwent CCAB.

RESULTS

The hospital mortality rate was lower for the OPCAB patients than for the CCAB patients: 2.0% (20/1003) versus 2.8% (28/1003). Predictors of hospital mortality for the entire cohort included age (P = .001), cardiogenic shock (P = .001), congestive heart failure (P = .019), history of myocardial infarction (P = .001), and reoperation (P = .007). The overall incidence of morbidity was lower for the OPCAB patients (reoperation for bleeding, P = .011; prolonged ventilation, P = .035; stroke, P = .045; cardiac arrest, P = .004). OPCAB patients experienced significantly reduced procedure times (P = .001), postoperative ventilation times (P = .035), post-operative lengths of stay (P = .035), and blood product use (intraoperative, P = .001; postoperative, P = .001).

CONCLUSION

These outcomes clearly demonstrate that OPCAB is a safe and effective procedure for myocardial revascularization. This retrospective, nonrandomized observational study has shown that the patients who underwent OPCAB had reduced morbidity and mortality, as well as decreased resource use, compared with those who underwent CCAB.

Five-year follow-up of a randomized comparison between off-pump and on-pump stable multivessel coronary artery bypass grafting. The MASS III Trial

BACKGROUND

Coronary artery bypass graft surgery with cardiopulmonary bypass is a safe, routine procedure. Nevertheless, significant morbidity remains, mostly because of the body's response to the nonphysiological nature of cardiopulmonary bypass. Few data are available on the effects of off-pump coronary artery bypass graft surgery (OPCAB) on cardiac events and long-term clinical outcomes.

METHODS AND RESULTS

In a single-center randomized trial, 308 patients undergoing coronary artery bypass graft surgery were randomly assigned: 155 to OPCAB and 153 to on-pump CAB (ONCAB). Primary composite end points were death, myocardial infarction, further revascularization (surgery or angioplasty), or stroke. After 5-year follow-up, the primary composite end point was not different between groups (hazard ratio 0.71, 95% CI 0.41 to 1.22; P=0.21). A statistical difference was found between OPCAB and ONCAB groups in the duration of surgery (240±65 versus 300±87.5 minutes; P<0.001), in the length of ICU stay (19.5±17.8 versus 43±17.0 hours; P<0.001), time to extubation (4.6±6.8 versus 9.3±5.7 hours; P<0.001), hospital stay (6±2 versus 9±2 days; P<0.001), higher incidence of atrial fibrillation (35 versus 4% of patients; P<0.001), and blood requirements (31 versus 61% of patients; P<0.001), respectively. The number of grafts per patient was higher in the ONCAB than the OPCAB group (2.97 versus 2.49 grafts/patient; P<0.001).

CONCLUSIONS

No difference was found between groups in the primary composite end point at 5-years follow-up. Although OPCAB surgery was related to a lower number of grafts and higher episodes of atrial fibrillation, it had no significant implications related to long-term outcomes. Clinical Trial Registration-URL: http://www.controlled-trials.com. Unique identifier: ISRCTN66068876.

Off-pump coronary artery bypass surgery and acute kidney injury: a meta-analysis of randomized controlled trials

BACKGROUND AND OBJECTIVES

Off-pump coronary artery bypass grafting (CABG) has been advocated to cause less inflammation, morbidity, and mortality than the more traditional on-pump technique. This meta-analysis compares these two surgical techniques with respect to causing acute kidney injury (AKI).

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This study searched for randomized controlled trials in MEDLINE and abstracts from the proceedings of scientific meetings through February 2010. Included were trials comparing off-pump to on-pump CABG that reported the incidence of AKI, as defined by a mixture of criteria including biochemical parameter/urine output/dialysis requirement. Mortality was evaluated among the studies that reported kidney-related outcomes. For primary and subgroup analyses, fixed-effect meta-analyses of odds ratios (OR) were performed.

RESULTS

In 22 identified trials (4819 patients), the weighted incidence of AKI in the on-pump CABG group was 4.0% (95% confidence interval [CI] 1.8%, 8.5%), dialysis requirement 2.4% (95% CI 1.6%, 3.7%), and mortality 2.6% (95% CI 1.6%, 4.0%). By meta-analysis, off-pump CABG was associated with a 40% lower odds of postoperative AKI (OR 0.60; 95% CI 0.43, 0.84; P = 0.003) and a nonsignificant 33% lower odds for dialysis requirement (OR 0.67; 95% CI 0.40, 1.12; P = 0.12). Within the selected trials, off-pump CABG was not associated with a significant decrease in mortality.

CONCLUSIONS

Off-pump CABG may be associated with a lower incidence of postoperative AKI but may not affect dialysis requirement, a serious complication of cardiac surgery. However, the different definitions of AKI used in individual trials and methodological concerns preclude definitive conclusions.

Clinical experience with the Ventrica distal anastomotic device in coronary surgery

The surgical treatment of coronary artery disease is based on bypassing demonstrated lesions with autogenous vascular grafts. The operations have traditionally been invasive, complicated procedures requiring skillful microvascular surgical technique, cardiopulmonary bypass, and temporary cardioplegia. Ventrica, Inc. has developed a coupling device based on magnetic attraction which simplifies the connection of the graft to the coronary artery. Perceived advantages are shortened operating time, the need for less operative exposure, ease of use, versatility, and reliability. Use of the device is easily learned. It is a gentle technique which may be abandoned at any point without grossly noticeable consequence; the vessel remains apparently undamaged and remains suitable for hand-sewn anastomosis. Patient recovery is swift and acceptance high. Immediate operative results, pre-discharge angiograms and 6 month follow up angiograms are all favorable. The device is applicable to multiple graft operations, to all autogenous graft conduits, to end or sequential anastomoses, and to potentially all coronary vessels.

Single transpulmonary thermodilution and continuous monitoring of central venous oxygen saturation during off-pump coronary surgery

BACKGROUND

Off-pump coronary artery bypass grafting (OPCAB) requires thorough monitoring of hemodynamics and oxygen transport. Our aim was to find out whether therapeutic guidance during and after OPCAB, using an algorithm based on advanced monitoring, influences perioperative hemodynamic and fluid management as well as the length of post-operative ICU and hospital stay.

METHODS

Patients were randomized into two groups of hemodynamic monitoring: the conventional monitoring (CM) group (n=20) and the advanced monitoring (AM) group (n=20). In the CM group, therapy was guided by central venous pressure, mean arterial pressure (MAP) and heart rate (HR), and in the AM group by the intrathoracic blood volume index, MAP, HR, central venous oxygen saturation (ScvO(2)) and cardiac index (CI). The measurements were performed before and during surgery, and at 2, 4 and 6 h post-operatively.

RESULTS

In the AM group, colloids and dobutamine were given more frequently and were accompanied by increments in ScvO(2), CI and oxygen delivery compared with baseline. The percentage of ephedrine administration was higher in the CM group. The algorithm guided by AM decreased time until achieving the status of 'fit for ICU discharge' and post-operative hospital stay by 15% and 25%, respectively.

CONCLUSIONS

A goal-directed algorithm based on advanced hemodynamic monitoring and continuous measurement of ScvO(2) facilitates early detection and correction of hemodynamic changes and influences the strategy for fluid therapy that can improve the course of post-operative period after coronary artery bypass grafting on the beating heart.

Effects of on- and off-pump coronary artery surgery on graft patency, survival, and health-related quality of life: long-term follow-up of 2 randomized controlled trials

OBJECTIVE

Off-pump coronary artery bypass grafting reduces postoperative morbidity and uses fewer resources than conventional surgical intervention with cardiopulmonary bypass. However, only 15% to 20% of coronary artery bypass grafting operations use off-pump coronary artery bypass. One reason for not using off-pump coronary artery bypass might be the surgeon's concern about the long-term patency of grafts performed with this technique. Therefore our objective was to compare long-term outcomes in patients randomized to off-pump coronary artery bypass or coronary artery bypass grafting with cardiopulmonary bypass.

METHODS

Participants in 2 randomized trials comparing off-pump coronary artery bypass and coronary artery bypass grafting with cardiopulmonary bypass were followed up for 6 to 8 years after surgical intervention to assess graft patency, major adverse cardiac-related events, and health-related quality of life. Patency was assessed by using multidetector computed tomographic coronary angiographic analysis with a 16-slice scanner. Two blinded observers classified proximal, body, and distal segments of each graft as occluded or not. Major adverse cardiac-related events and health-related quality of life were obtained from questionnaires given to participants and family practitioners.

RESULTS

Patency was studied in 199 and health-related quality of life was studied in 299 of 349 survivors. There was no evidence of attrition bias. The likelihood of graft occlusion was no different between off-pump coronary artery bypass (10.6%) and coronary artery bypass grafting with cardiopulmonary bypass (11.0%) groups (odds ratio, 1.00; 95% confidence interval, 0.55-1.81; P > .99). Graft occlusion was more likely at the distal than the proximal anastomosis (odds ratio, 1.11; 95% confidence interval, 1.02-1.20). There were also no differences between the off-pump coronary artery bypass and coronary artery bypass grafting with cardiopulmonary bypass groups in the hazard of death (hazard ratio, 1.24; 95% confidence interval, 0.72-2.15) or major adverse cardiac-related events or death (hazard ratio, 0.84; 95% confidence interval, 0.58-1.24), or mean health-related quality of life across a range of domains and instruments.

CONCLUSIONS

Long-term health outcomes with off-pump coronary artery bypass are similar to those with coronary artery bypass grafting with cardiopulmonary bypass when both operations are performed by experienced surgeons.

Tranexamic acid reduces blood loss in off-pump coronary artery bypass surgery

OBJECTIVE

This study was designed to evaluate the hemostatic effect of tranexamic acid in off-pump coronary artery bypass surgery.

DESIGN

A prospective, randomized, double-blind, placebo-controlled study.

SETTING

The Department of Anesthesiology and Cardiac Surgery, Medical Sciences University.

PARTICIPANTS

One hundred eight patients undergoing off-pump coronary artery bypass surgery were enrolled into the study. Eight patients were withdrawn, and 100 patients were divided into 2 groups.

INTERVENTIONS

Fifty patients received tranexamic acid (bolus 1 g before skin incision and followed by maintenance dose of 400 mg/h during surgery), and 50 patients received saline.

MEASUREMENT AND MAIN RESULTS

Hematologic parameters, volume of blood loss, blood transfusion, and other clinical data were recorded throughout the perioperative period. Twenty-four-hour postoperative blood loss was significantly less in the tranexamic acid group compared with the control group (471 +/- 182 v 844 +/- 303). Patients in the tranexamic acid group received significantly less allogeneic blood (8 v 31 units).

CONCLUSION

Bleeding and hemorrhagic complications and the consequent need for allogeneic transfusion are still major problems after off-pump coronary artery bypass surgery. Tranexamic acid appears to be effective in reducing postoperative bleeding and the need for allogeneic blood products.

Economic evaluation of coronary artery bypass grafting surgery with and without cardiopulmonary bypass: cost-effectiveness and quality-adjusted life years in a randomized controlled trial

The objective of this study is to evaluate the costs and health benefits of coronary artery bypass grafting (CABG) surgery with and without cardiopulmonary bypass (CPB). Randomized controlled clinical trial is used as the design. The setting is in a single tertiary cardiothoracic center in Middlesex, UK. Participants were 168 patients (27 females) requiring primary isolated CABG surgery. Patients were randomized to have the procedure performed by a single surgeon either with CPB (n = 84) or by an off-pump coronary artery bypass (OPCAB) surgery (n = 84). Health-related quality of life was assessed at baseline, 6 weeks, and 6 months using the World Health Organization Quality-of-Life (WHOQOL-100) questionnaire. Mean total costs of patient management by either technique were calculated using different available key sources. A utility measure, derived from WHOQOL-100, was used to calculate quality-adjusted life year (QALY) gained in each group, on basis of which a cost-effectiveness analysis was performed. The mean total costs of an OPCAB patient was 5859 pounds , whereas for a CPB patient it was 7431 pounds with a mean difference of 1572 pounds (standard error [SE] 674 pounds ; P = 0.02). Three patients died in the CPB group and two in the OPCAB group during the 6-month follow-up period. Mean QALYs over 6 months was 0.379 in the OPCAB group and 0.362 in the CPB group, but the difference was not significant (mean difference 0.017; SE 0.016; P = 0.305). OPCAB surgery offered patients in this randomized trial similar health benefits to CPB over a 6-month period, but at a significantly less cost.

What do patients really want? Patients' preferences for treatment for angina

OBJECTIVE

To measure preferences for angina treatments among patients admitted from accident and emergency with acute coronary syndrome.

BACKGROUND

Evidence suggests variability in treatment allocations amongst certain socio-demographic groups (e.g. related to age and sex), although it is unclear whether this reflects patient choice, as research on patients' treatment preferences is sparse. Given current policy emphasis on 'patient choice', providers need to anticipate patients' preferences to plan appropriate and acceptable health services.

DESIGN

Self-administered questionnaire survey.

SETTING

In-patients in a UK hospital.

PARTICIPANTS

A convenience sample of 53 newly admitted patients with acute coronary syndrome. Exclusion criteria were: a previous cardiologist consultation (including previous revascularization); a clinical judgement of too ill to participate; post-admission death; non-cardiac reasons for chest pain.

MAIN OUTCOME MEASURES

Patients' preferences for coronary artery bypass graft (CABG); angioplasty; and two medication alternatives.

RESULTS

Angioplasty was the preferred treatment (for 80% of respondents), and CABG was second (most preferred by 19%, but second most preferred for 60%). The two least preferred (and least acceptable) treatments were medications. The majority of patients (83%) would 'choose treatment based on the extent of benefits' and 'accept any treatment, no matter how extreme, to return to health'. There were some differences in preference related to age (>70 years preferred medication to a greater degree than <70 years) and sex (males preferred CABG surgery more than females).

CONCLUSIONS

There was general preference for procedural interventions over medication, but most patients would accept any treatment, however extreme, to return to former health. There was some evidence of differences in preferences related to age and sex. Furthermore, most patients preferred to have some input into treatment choice (e.g. nearly half wanted to share decision responsibility with their doctor), with only 4% preferring to leave the decision entirely to their doctor. Given these findings, and past findings that suggest there may be variability in treatment allocation according to certain socio-demographic factors, this study suggests a need to develop and use preference measures, and makes a step towards this.

Clinical outcomes in randomized trials of off- vs. on-pump coronary artery bypass surgery: systematic review with meta-analyses and trial sequential analyses

AIMS

To assess the clinical outcomes of off- vs. on-pump coronary artery bypass surgery in randomized trials.

METHODS AND RESULTS

We searched electronic databases and bibliographies until June 2007. Trials were assessed for risk of bias. Outcome measures were all-cause mortality, myocardial infarction, stroke, atrial fibrillation, and renewed coronary revascularization at maximum follow-up. We applied trial sequential analysis to estimate the strength of evidence. We found 66 randomized trials. There was no statistically significant differences regarding mortality [relative risk (RR) 0.98; 95% confidence interval (CI) 0.66-1.44], myocardial infarction (RR 0.95; 95% CI 0.65-1.37), or renewed coronary revascularization (RR 1.34; 95% CI 0.83-2.18). We found a significant reduced risk of atrial fibrillation (RR 0.69; 95% CI 0.57-0.83) and stroke (RR 0.53; 95% CI 0.31-0.91) in off-pump patients. However, when continuity correction for zero-event trials was included, the reduction in stroke became insignificant (RR 0.62; 95% CI 0.32-1.19). Trial sequential analysis demonstrated overwhelming evidence supporting that off-pump bypass surgery reduces atrial fibrillation.

CONCLUSION

Off-pump surgery reduces the risks of postoperative atrial fibrillation compared with on-pump surgery. For death, myocardial infarction, stroke, and renewed coronary revascularization, the evidence is still weak and more low-bias risk trials are needed.

Off-pump coronary artery bypass grafting in left ventricular dysfunction

Between August 2004 and May 2006, 124 patients undergoing coronary artery bypass grafting with ejection fractions <or= 35% were randomly assigned to off-pump or conventional procedures. Preoperative characteristics were the same in both groups, except for age and degree of mitral regurgitation. Off-pump coronary artery grafting was carried out using a tissue stabilizer and a single-suture technique; conventional coronary bypass employed cardiopulmonary bypass, moderate hypothermia, and antegrade-retrograde cold blood cardioplegic arrest. There were significantly fewer vessels grafted (3.09 +/- 0.41) in the off-pump group than in those who had a conventional procedure (3.42 +/- 0.86). The rates of mortality, morbidity, balloon pump support, inotropic usage, gastrointestinal bleeding, renal dysfunction, reintubation, as well as intensive care and hospital stay, were significantly lower in the off-pump group. The incidence of perioperative myocardial infarction did not differ significantly between groups. The results of this study indicate that beating-heart coronary bypass is safe and effective in patients with left ventricular dysfunction.

Current Status of Off-Pump Coronary Artery Bypass Surgery

The expanding indications for angioplasty coupled with the successful short and mid-term results of randomized controlled trials of drug-eluting stents have already had an unquestionable impact on the practice of coronary revascularization operations. However, coronary artery bypass grafting remains a major mode of therapy for coronary artery disease. It is likely that surgery will continue to be preferred for more complex subsets and that surgeons will have to continue to maintain good results in patients with more complex problems. Concerns regarding morbidity associated with conventional surgical myocardial revascularization on cardiopulmonary bypass have led to a resurgence of interest in off-pump bypass surgery during the last decade, with the expectation that it would be safer if cardiopulmonary bypass could be avoided. This review summarizes the impact of off-pump bypass surgery in reducing the morbidity and mortality associated with conventional coronary artery bypass on cardiopulmonary bypass by evaluating the current best-available evidence from randomized controlled trials and meta-analyses comparing off-pump surgery with conventional bypass grafting.

Coagulation and fibrinolytic protein kinetics in cardiopulmonary bypass

The development of Cardiopulmonary Bypass (CPB) catopulted the field of cardiothoracic surgery into a new dimension--one that changed the lives of individuals with congenital and acquired heart disease worldwide. Despite its contributions, CPB has clear limitations and creates unique challenges for clinicians and patients alike, stemming from profound hemostatic pertubations and accompanying risk for bleeding and possibly thrombotic complications.

Cost comparison of four revascularisation procedures for the treatment of multivessel coronary artery disease

OBJECTIVE

An economic evaluation was performed, using modelling techniques, to compare 1-year total costs of four revascularisation procedures in patients with multivessel disease: on-pump coronary artery bypass grafting (CABG); off-pump CABG; percutaneous coronary intervention (PCI) with bare-metal stents (BMS); and PCI with drug-eluting stents (DES).

METHODS

Clinical data were derived from four randomised clinical trials comparing CABG versus PCI, as well as from literature reviews. Resource use and unit cost estimates were modelled to reflect current Canadian practice.

RESULTS

This study demonstrated that 1 year after the initial revascularisation, PCI with BMS is the least costly procedure, followed by off-pump CABG, PCI with DES and on-pump CABG. DES became the most costly procedure if 3.5 or more DES were used or if staged PCI was performed.

Cardiac rehabilitation outcomes no different after on-pump versus off-pump coronary artery bypass surgery

PURPOSE

Clinical evidence supports lower morbidity with off-pump coronary revascularization surgery as well as superior short- and mid-term outcomes, equivalent graft patency, and reduced cost. The purpose of this study was to compare cardiac rehabilitation (CR) outcomes between patients undergoing on-pump versus off-pump coronary artery bypass surgery.

METHODS

Data were retrospectively examined for patients who participated in CR between 1996 and 2004. Two hundred ninety-five patients who underwent bypass surgery and completed at least 80% of their 36 required sessions were divided into on-pump and off-pump groups. Pre- and post-CR measures included grip strength, flexibility, energy expended during class, quality of life, and self-efficacy.

RESULTS

Both groups were similar with respect to age, sex, ejection fraction, and mean number of grafts. There were no statistical differences between the on-pump and off-pump groups (P > .05) for weight, abdominal and hip circumferences, grip strength, flexibility, and total energy expenditure. In addition, there were no between-group differences regarding quality of life and self-efficacy. Grip strength, flexibility, and energy expenditure during class improved with CR regardless of the surgical procedure (P = .001). Quality of life (P = .001) and self-efficacy (P = .001) also improved.

CONCLUSIONS

The present data support the concept that although there are clinical advantages to off-pump surgery, there is no benefit over on-pump surgery regarding CR. Subsequently, patients undergoing off-pump surgery should be managed similarly as their on-pump counterparts.

Single transpulmonary thermodilution in off-pump coronary artery bypass grafting: haemodynamic changes and effects of different anaesthetic techniques

BACKGROUND

Off-pump coronary artery bypass grafting (OPCAB) can be associated with severe cardiovascular changes, thus requiring advanced haemodynamic monitoring. Our aim was to investigate the feasibility of transpulmonary single thermodilution (STD) combined with pulse-contour analysis, a newly introduced method for cardiovascular monitoring, for assessment of changes in haemodynamics during different anaesthetic techniques in OPCAB.

METHODS

Thirty-six patients scheduled for elective OPCAB were randomized to receive anaesthesia either with midazolam, propofol or isoflurane, in addition to fentanyl and pipecuronium. After catheterization of the femoral artery, haemodynamic parameters were assessed using STD and pulse-contour analysis. The measurements were performed after induction of anaesthesia, during surgery and at 2, 4 and 6 h post-operatively.

RESULTS

At the end of surgery, the global ejection fraction decreased by 29% and 19% in the midazolam and the propofol groups, respectively, (P < 0.05) but remained unchanged in the isoflurane group. Moreover, in the isoflurane group, the left ventricular contractility index was higher and the mean arterial pressure (MAP) and the systemic vascular resistance index (SVRI) decreased in comparison with pre-operative values. Post-operatively, the cardiac index (CI) and the cardiac function index (CFI) increased in all groups (P < 0.05). The peri-operative requirement for ephedrine and nitroglycerin increased in the propofol and the midazolam groups, respectively (P < 0.05).

CONCLUSION

During OPCAB, STD and pulse-contour analysis displayed changes in preload, myocardial function and afterload that gave valuable guidance for the conduct of anaesthesia, fluid management, and the administration of vasoactive agents. As assessed using STD, isoflurane within the present dose range appears to maintain myocardial performance and vascular tone better than midazolam or propofol.

Living with off-pump coronary artery surgery: evolution, development, and clinical potential for coronary heart disease patients

The enormous progress in interventional cardiology during the last 10 years has resulted in a major change in the spectrum of patients referred for coronary bypass surgery. These patients are older and sicker and frequently have had previous percutaneous coronary interventions. Consequently, cardiac surgery is responding by adding new surgical techniques: off-pump open-chest coronary bypass surgery (OPCAB), minithoracotomy bypass surgery, videothoracoscopic (robotic) procedures, etc. Several registries published to date have proved OPCAB to be safe and clinically effective. Randomized studies and meta-analysis research in this field provide scientific support and suggest that myocardial, renal, and neurological functions, amongst others, are better preserved by OPCAB than by classic techniques that use a cardiopulmonary bypass pump (CPB). Moreover, avoidance of CPB yields significantly reduced oxidative stress and systemic inflammatory response. This results in higher safety for ischemic heart disease patients undergoing revascularization, thus offsetting the propensity to lower costs. The present review examines the physiological advantages and clinical outcomes of this simple mode of myocardial revascularisation and evaluates the wider implications arising from its evolution.

Acquiring proficiency in off-pump surgery: traversing the learning curve, reproducibility, and quality control

As the risk profile of patients considered for surgical revascularization worsens, the cumulative benefit of off-pump coronary artery bypass (OPCAB) over conventional coronary artery bypass grafting, in terms of lower morbidity and reduced healthcare costs, may increase. There is still resistance to the introduction of OPCAB surgery however, its practice is variable and surgical residents are rarely trained in these techniques. This article considers how the learning curve in OPCAB may be negotiated and prospectively monitored to ensure quality control. The evidence suggests that situations in which suitable senior expertise exists, OPCAB surgery can be introduced into surgical practice and safely taught to trainees without detriment to patients. This is achieved by a progressive increase in the complexity of the case mix and careful early supervision. The introduction of OPCAB has coincided with the increasing use of control charts as quality control tools. Performance monitoring provides reassurance that patients are not being put at risk during the introduction of OPCAB; control chart methods can be used prospectively for real time performance monitoring by consultant surgeons and residents alike. These techniques may ultimately be used to determine proficiency and accreditation. Increasing use of parallel training techniques, the development of structured training programs that encompass OPCAB and other new technologies in cardiac surgery, coupled with objective performance monitoring are warranted to meet the needs of a changing patient population.

Off-Pump Surgery Is Associated With Reduced Occurrence of Stroke and Other Morbidity as Compared With Traditional Coronary Artery Bypass Grafting

Background and Purpose— There is growing enthusiasm for coronary artery bypass grafting (CABG) without cardiopulmonary bypass (CPB). Although deleterious effects of CPB are known, it remains to be proven that avoiding CPB will result in reduction in morbidity. We sought to determine whether off-pump surgery is associated with reduced occurrence of adverse outcomes as compared with CABG with CPB.

Methods— Studies were identified by searching the MEDLINE, EMBASE and the Cochrane Register 1980 to 2006 (February). We also searched the reference lists of randomized clinical trials (RCT) and reviews to look for additional studies. Study selection: RCTs comparing off-pump surgery to CABG with CPB. No restriction applied on the size of the trial or end point reports. Data extraction: 2 reviewers independently searched for studies, read abstracts and abstracted all data. Data synthesis: combined estimates were obtained using fixed or random effect meta-analyses. Relative risks and risk differences were calculated. Heterogeneity was assessed using χ 2 and I 2 values.

Results— There were 3996 patients enrolled in 41 RCTs (mean age 62, 22% female). No study reported information on race. Off-pump CABG was associated with a 50% reduction in the relative risk of stroke (95% CI, 7% to 73%), 30% reduction in atrial fibrillation (AF; 95% CI, 16% to 43%) and 48% reduction in wound infection (95% CI, 26% to 63%) with no heterogeneity among RCTs. This translated into avoidance of 10 strokes, 80 cases of AF and 40 infections per 1000 CABG. Fewer distal grafts were performed and there was evidence for >10 reinterventions per 1000 with off-pump CABG. Long-term follow-up is not yet reported in the trials.

Conclusions— Off-pump CABG is associated with reduced risk of stroke, AF and infections as compared with CABG with CPB. Evidence should be generalized taking into account RCT enrollment limitations, drawbacks related to training requirements, propensity to perform fewer grafts and likely reinterventions after off-pump surgery.

Off-pump coronary artery bypass grafting through sternotomy: for whom?

PURPOSE OF REVIEW

Off-pump coronary artery bypass grafting hopes to avoid morbidity associated with cardiopulmonary bypass, improving clinical outcomes. Yet its technical difficulty and unfamiliarity raise concern that adoption of off-pump coronary artery bypass might be associated with poorer outcomes. Both surgeon-specific and patient-related factors are believed to play roles in the success of off-pump coronary artery bypass. This review sought to elucidate these factors.

RECENT FINDINGS

Current prospective data suggest that both techniques have similar rates of mortality but off-pump coronary artery bypass does provide patients with a lower morbidity. Multiple prospective studies suggest a decrease in stroke rates for off-pump coronary artery bypass grafting. There is a consensus that certain patients will have better outcomes if done off-pump. Surgeon experience with the procedure does impact patient outcome.

SUMMARY

Though every patient must be dealt with on an individual basis, it would appear that almost any patient is a candidate for off-pump coronary artery bypass and that, given time and an appropriate desire, most any surgeon can perform the procedure.

A cost comparison of off-pump CABG versus on-pump CABG at one-year: The Canadian off-pump CABG registry

BACKGROUND

Evidence suggests that off-pump coronary artery bypass graft surgery (CABG) is as safe and effective as on-pump CABG, and the cost of initial hospitalization for off-pump CABG is less expensive than on-pump CABG. However, it is uncertain whether the cost savings are sustained over a longer period of time.

OBJECTIVE

To assess in-hospital and one-year direct medical costs of off-pump CABG versus on-pump CABG in the context of the Canadian health care system.

METHODS AND RESULTS

From March 2001 to December 2002, 1657 consecutive patients enrolled in the Canadian Off-Pump CABG Registry were compared with 1693 consecutive on-pump patients from Hamilton Health Sciences CABG database. At one year, patients of both groups were followed by telephone interview. An economic analysis was conducted from the perspective of the Ontario Ministry of Health and Long-Term Care, and the data analysis was based on propensity score-matched registry patients (1233 pairs) to ensure the comparability of the two study groups. Clinical event and resource use information was collected from all patients. Unit costs from the Hamilton Health Sciences case-costing system were used to estimate hospital costs; all costs were reported in 2003 Canadian dollars. Sensitivity analyses were performed to account for uncertainties. The cost of initial hospitalization for off-pump CABG was significantly less than on-pump CABG (11,744 dollars versus 13,720 dollars, P < 0.001). Although follow-up costs were similar between the groups, the one-year total cost per patient for off-pump CABG remained significantly less than on-pump CABG (12,063 dollars versus 14,141 dollars, P < 0.001).

CONCLUSION

Off-pump CABG offers significant savings during initial hospitalization that are also sustained after one year.