Off-Pump Coronary Artery Bypass in Patients With Left Ventricular Dysfunction: A Meta-Analysis

Long-term results following off-pump coronary-artery bypass grafting in left ventricular dysfunction

Severe left ventricular (LV) dysfunction is an independent risk factor for early and long-term mortality after coronary-artery bypass grafting (CABG). Off-pump CABG (OPCAB) significantly reduces the early incidence of major complications in high-risk patients. Moreover, bilateral internal thoracic artery (BITA) grafting after CABG is associated with improved long-term outcomes. We aimed to evaluate the impact of multivessel OPCAB with BITA grafting for complete revascularization on postoperative and long-term outcomes in patients with low LV ejection fraction (EF). We included 121 patients with EF ≤ 30.0% who underwent isolated multivessel OPCAB (average LVEF, 24.8%) between April 2007 and December 2019. Sixty-six patients received BITA grafts, while 55 had single internal thoracic artery (SITA) grafts. We conducted multivariate analyses to examine the correlation between perioperative data and late mortality rate. The early mortality rate was 1.65%. After excluding in-hospital mortality cases, we performed long-term follow-up of 119 patients. Early postoperative echocardiography showed significant LVEF improvement in 89 (75.2%) patients. However, LVEF remained ≤ 30.0% in 30 (24.8%) patients. We recorded 15 and 30 cases of cardiac death and cardiac events, respectively, during the long-term follow-up period. Postoperative LVEF ≤ 30.0% (P < 0.01) and no use of BITA grafting (P = 0.03) were significant predictors of cardiac death and events; moreover, hemodialysis was a significant predictor of all-cause mortality rather than cardiac death. Multivessel OPCAB in patients with severe LV dysfunction was associated with acceptable in-hospital mortality and early postoperative improvement in LV function. Additionally, OPCAB with BITA grafting may provide long-term benefits with respect to cardiac death and events. However, the long-term benefits were significantly limited in patients without early postoperative improvement in LV function and patients with chronic hemodialysis.Clinical registration number: 5590 (14/5/2020 Tokyo Women's Medical University).

Effects of different surgical strategies and left ventricular remodelling on the outcomes of coronary artery bypass grafting in heart failure patients with reduced ejection fraction

Background

Ischaemic heart failure with reduced ejection fraction (HFrEF) caused by coronary artery disease accounts for the largest proportion of heart failure cases with the worst prognosis. Coronary artery bypass grafting (CABG) is the most effective treatment for ischaemic HFrEF. On-pump and off-pump are the two surgical methods used for CABG. Whether patients with HFrEF should undergo on- or off-pump CABG is controversial in coronary heart disease surgery. The left ventricular end-systolic volume index (LVSEVI) is the gold standard for evaluating the severity of left ventricular remodelling; however, its effect on the perioperative risk and long-term survival rate of patients with HFrEF undergoing CABG remains unclear.

Methods

This single centre prospective cohort analysis included 118 coronary heart disease patients with symptoms and signs of heart failure and a left ventricular ejection fraction (LVEF) of <40% who were enrolled consecutively from January 2019 to December 2023. Operative mortality, perioperative complications, and long-term survival were compared among patients treated with various LVESVIs and surgical methods. The primary outcomes were cardiac death, myocardial infarction, heart failure, stroke, and revascularization, (percutaneous coronary intervention or redo CABG) with a median follow-up of 38 ± 10 months.

Results

The 30-day postoperative mortality of 118 patients was 6.8%. Patients in the off-pump group had significantly higher perioperative mortality than those in the on-pump group (12.5% vs. 3.8%, p = 0.03). In the off-pump group, a higher proportion of patients required perioperative mechanical assistance, such as intra-aortic artery balloon pump (IABP) or extracorporeal membrane oxygenation (ECMO), compared to those in the on-pump group (IABP: 75% vs. 47.4%, p = 0.004; ECMO: 22.5% vs. 1.3%, p = 0.000). Patients in the off-pump group were more likely to have postoperative atrial fibrillation (AF) (35% vs. 14.1%, p = 0.01). In the on-pump group, the incidence of postoperative AF (25% vs. 6.5%, p = 0.02) and IABP use (62.5% vs. 36.9%, p = 0.03) were significantly higher in patients with more severe left ventricular remodelling than in those with less severe left ventricular remodelling. In the off-pump group, patients with more severe left ventricular remodelling had higher ECMO usage (38.9% vs. 9.1%, p = 0.04), incidence of postoperative AF (61.1% vs. 13.6%, p = 0.02), and perioperative mortality (22.2%). Major adverse cardiac event (MACE)-free survival rate was significantly higher in the on-pump group than in the off-pump group, and there was no significant difference in MACE free survival rates between the two groups of patients with different degrees of left ventricular remodelling.

Conclusion

On-pump bypass is a better surgical procedure for patients with ischaemic HFrEF, especially those with severe left ventricular remodelling. Left ventricular remodelling increases perioperative mortality but has no effect on long-term survival.

Off-pump minimally invasive coronary artery bypass grafting in patients with left ventricular dysfunction: the lampang experience

Introduction

The minimally invasive cardiac surgery off-pump coronary artery bypass (MICSOPCAB) is technically difficult; therefore, previous studies have indicated that MICSOPCAB should be contraindicated in patients with impaired left ventricular (LV) function. In this study, we investigated the feasibility of MICSOPCAB in patients with impaired LV function.

Methods

The 226 patients underwent MICSOPCAB between August 2017 and September 2022. Our study defined impaired LV function as ejection fraction (EF) in echocardiography 40% or less. The patients were divided into Low EF group (n = 39) and Normal EF group (n = 187).

Results

The Low EF group was in a more critical preoperative condition than Normal EF group (41.0% in the Low EF group vs. 14.4% in the Normal EF group; p < 0.001). For preoperative transthoracic echocardiography, LV end-diastolic diameter (5.5 ± 0.9 cm in the Low EF group vs. 5.0 ± 0.8 cm in the Normal EF group; p < 0.001) and LV end-systolic diameter (4.4 ± 1.0 cm in the Low EF group vs. 3.4 ± 1.0 cm in the Normal EF group; p < 0.001) were significantly larger in the Low EF group. No differences were found in the operative time (180 [160-240] min in the Low EF group vs. 205 [165-253] min in the Normal EF group; p = 0.231) and the median number of distal anastomoses (2 [1-2] in the Low EF group vs. 2 [1-3] in the Normal EF group; p = 0.073). Intensive care unit stay was longer in the Low EF group than in the Normal EF group (2 [1-2] in the Low EF group vs. 1 [1-2] in the Normal EF group; p = 0.010). Perioperative transfusion was more common in the Low EF group than in the Normal EF group (69.7% vs. 49.2%; p = 0.023). There were no differences in major complications, hospital stay, and 30-day mortality. The Kaplan-Meier curve showed no significant difference in postoperative major adverse cardiac or cerebrovascular events rates between the two groups (p = 0.185).

Conclusion

In this study, MICSOPCAB can be performed in patients with low EF having short- and mid-term outcomes similar to patients with normal EF. Therefore, low EF should not be contraindicated in MICSOPCAB.

Coronary artery bypass grafting in low ejection fraction: state of the art

PURPOSE OF REVIEW

As the number of patients with reduced ejection fraction secondary to ischemic cardiomyopathy (ICM) increases, coronary artery bypass grafting is being used with increasing frequency. In this review, we summarize the different operative considerations in this vulnerable patient population.

RECENT FINDINGS

Preoperative optimization with mechanical circulatory support devices, especially in the setting of hemodynamic instability, can reduce perioperative morbidity and mortality. The advantage of advanced techniques, such as off-pump CABG and multiple arterial grafting remains unclear. Concomitant procedures, such as ablation for atrial fibrillation remain important considerations that should be tailored to the individual patients risk profile.

SUMMARY

Despite improvements in perioperative care of patients undergoing CABG, patients with a reduced ejection fraction remain at elevated risk of major morbidity and mortality. Preoperative optimization and careful selection of intraoperative techniques can lead to improved outcomes.

Off-pump coronary artery bypass grafting is safe and effective in patients with severe left ventricular dysfunction

OBJECTIVES

Severe left ventricular dysfunction (LVD) is associated with increased risk following coronary artery bypass grafting (CABG). Due to a dearth of reports on the choice of CABG technique in patients with LVD, this study aims to compare the outcomes of off-pump CABG (OPCAB) and conventional CABG (ONCAB) in such patients.

METHODS

Retrospective single-centre propensity-matched analysis comparing early- and long-term outcomes of OPCAB and ONCAB in patients with severe LVD. Primary outcome was long-term all-cause mortality.

RESULTS

Between 2002 and 2014, a total of 1161 consecutive patients with severe LVD underwent isolated CABG [442 patients underwent OPCAB and 719 ONCAB (430 matched pairs)]. Incomplete revascularization was observed more frequently among OPCAB than ONCAB patients (35.3% vs 21.6%; P < 0.01). The overall 30-day mortality was 5% and was comparable between the matched groups [OR 0.64 (0.34-1.22); P = 0.18]. OPCAB patients had shorter median hospital stay (11 vs 12 days; P = 0.02) and lower packed red blood cell transfusion rates [2.7 (2.21-3.19) vs 4.4 (3.56-5.24); P < 0.01]. Estimated adjusted survival was 86.0% vs 85.8%, 69.1% vs 65.5% and 59.9% vs 49.1% at 1, 5 and 10 years for OPCAB and ONCAB patients, respectively (P = 0.99). Long-term risk of mortality was similar between groups [hazard ratio (HR) 0.94 (0.66-1.32); P = 0.7]. Incomplete revascularization was weakly associated with increased risk of long-term all-cause mortality [HR 1.33 (0.99-1.77); P = 0.05].

CONCLUSIONS

OPCAB is safe and effective in patients with severe LVD. Although incomplete revascularization is more commonly observed in patients undergoing OPCAB, it is not associated with increased late mortality.

Coronary artery bypass grafting under sole Impella 5.0 support for patients with severely depressed left ventricular function

Selection of the ideal surgical procedure for coronary revascularization in patients with severe cardiac dysfunction at times may represent a challenge. In recent years, with the advent of surgical large microaxial pumps, e.g., Impella 5.0 (Abiomed Inc., Boston, USA), specific support and effective unloading of the left ventricle has become available. In the interventional field, good results have been achieved with smaller microaxial pumps in the setting of so-called protected percutaneous coronary intervention. In this study, we would like to share our early experience with surgical coronary revascularization under the sole support of Impella 5.0, omitting the use of heart–lung machine in three cases of severe cardiac dysfunction due to complex ischemic heart disease. Effective circulatory support intraoperatively and postoperatively speaks in favor of this technique in selected patients.

Feasibility of off-pump coronary artery grafting for patients with impaired left ventricular ejection fraction: A retrospective cohort study from a single institutional database

OBJECTIVE

Despite substantial advances in surgical practice, the management of patients with impaired left ventricular ejection fraction (LVEF) remains challenging. Furthermore, evidence on the outcomes of off-pump coronary artery bypass (OPCAB) surgery in this population is inconsistent. We conducted the present study to compare the short- and long-term outcomes of OPCAB in patients with different ejection fractions.

METHODS

This retrospective cohort study used data from the Hua-Shan Cardiac Surgery and included consecutive patients aged ≥ 18 years who underwent OPCAB procedures during 2016-2019. The patients included in the study were followed up until death or the end of data collection. Patients with different ejection fractions were matched 1:2 using propensity score matching. Factors associated with short-term outcomes were determined using logistic regression, and Kaplan-Meier survival analyses for the differences in all-cause death were generated.

RESULTS

The two propensity score matched groups consisted of 40 left ventricular dysfunction (LVD) and 80 normal left ventricular function (NLVF) patients. No significant intergroup differences were observed in the postoperative outcomes for the occurrence of left heart failure (22.5% in LVD vs. 5.0% in NLVF, p = .009). Age (odds ratio = 1.11, 95% confidence interval = 1.04-1.18) but not the preoperative LVEF was shown to be a strong predictor of short-term events in logistic regression analyses. Kaplan-Meier curves displayed similar freedom from all-cause death (p = .119) or cardio-death (p = .092) between groups.

CONCLUSION

The immediate postoperative outcomes and long-term outcomes were similar between the groups, indicating that OPCAB is a safe and effective choice for patients with LVD.

Off-pump coronary artery bypass grafting for patients with severely reduced ventricular function-A justified strategy?

BACKGROUND AND AIM

Low ejection fraction (EF) has been identified as a main risk factor for perioperative complications and mortality after coronary artery bypass grafting (CABG). The purpose of this study was to compare the efficacy and early as well as midterm outcomes of off-pump CABG (OPCAB) and conventional CABG (ONCAB) surgery in patients with reduced EF.

METHODS

We performed a retrospective review of patient demographics, preoperative risk factors, operative and postoperative outcomes of patients with left ventricular EF (LV-EF) ≤35%, who underwent CABG at our institution between January 2015 and December 2017. Propensity score and multivariate logistic regression analysis were used to compare risk adjusted outcomes between groups.

RESULTS

Overall, 111 consecutive CABG-patients with LV-EF ≤ 35% underwent either ONCAB (46 patients, 41.4%) or OPCAB surgery (65 patients, 58.6%). There was no difference in early mortality (5% vs. 7.5%, p = .64) between groups. After propensity score matching, OPCAB-patients required significantly less re-sternotomies for bleeding (20% vs. 2.5%, p = .03) and consequently received significantly less blood transfusions (57.5% vs. 32.5%, p = .03). Fewer OPCAB-patients experienced low cardiac output syndrome (22.5% vs. 42.5%, p = .06) and suffered from postoperative delirium (22.5% vs. 42.5%, p = .06). There were no differences in completeness of revascularization between groups (median 1 (1.0-1.33; 1.0-1.33) OPCAB versus median 1 (1-1.33; 0.67-2) ONCAB, p = .95). Survival after 6 months, one year and three years was similar for ONCAB- and OPCAB-patients (ONCAB 92.3%, 89.4%, and 89.4% vs. OPCAB 89.8%, 85.7%, and 82.1%; p = .403). More ONCAB-patients needed a coronary re-intervention during follow-up (8.6% vs. 2.3%, p = .402).

CONCLUSION

OPCAB-surgery is a safe and effective option for patients with reduced EF. Furthermore, it does not come at the expense of less complete revascularization or increased coronary re-intervention during early follow-up.

Off-pump versus on-pump redo coronary artery bypass grafting: a systematic review and meta-analysis

Background:

Redo coronary artery bypass grafting (redo CABG) is associated with increased mortality and morbidity. The aim of this study was to systematically evaluate the evidence comparing the outcomes of off-pump with on-pump redo CABG.

Methods:

Studies were systematically searched and identified using PubMed, EMBASE, the Cochrane Library, and the International Clinical Trials Registry Platform (ICTRP) by two researchers independently. The primary outcome was 30-day mortality, and the secondary outcomes were in-hospital mortality, post-operative complications, completeness of revascularization, blood transfusion rate, duration of mechanical ventilation, intensive care unit and hospital stays.

Results:

The 21 studies including 4,889 patients were enrolled in our meta-analysis. Compared with on-pump, the off-pump technique was associated with significantly reduced 30-day mortality (odds ratio [OR] = 0.43, 95% confidence interval [CI] = 0.26-0.72, p = 0.001). Moreover, a notably decreased in-hospital mortality (OR = 0.55, 95% CI = 0.39-0.76, p = 0.0004) and incidence of post-operative new-onset atrial fibrillation, myocardial infarction, acute kidney injury, low cardiac output state, blood transfusion rate (OR = 0.46, 95% CI = 0.35-0.60, p < 0.00001; OR = 0.54, 95% CI = 0.38-0.78, p = 0.0007; OR = 0.51, 95% CI = 0.37-0.70, p < 0.0001; OR = 0.31, 95% CI = 0.20-0.47, p < 0.00001; OR = 0.29, 95% CI = 0.14-0.61, p = 0.001) and significantly shortened duration of mechanical ventilation, intensive care unit and hospital stays (mean difference [MD] = −8.21 h, 95% CI = −11.74 to −4.68, p < 0.00001; MD = −0.77 d, 95% CI = −0.81 to −0.73, p < 0.00001; MD = −2.24 d, 95% CI = −3.17 to −1.32, p < 0.00001) could be observed when comparing the outcomes of off-pump with on-pump redo CABG. There was nonsignificant difference between off-pump and on-pump redo CABG in completeness of revascularization.

Conclusion:

In patients undergoing redo CABG surgery, the off-pump technique was associated with decreased mortality, less post-operative complications when compared to on-pump.

Short-term outcomes of on- vs off-pump coronary artery bypass grafting in patients with left ventricular dysfunction: a systematic review and meta-analysis

Objectives

Does the manipulation of the off-pump CABG (OPCAB) in patient with depressed left ventricular function is better than on-pump CABG (ONCAB) approach in in-hospital mortality and morbidities? Here we undertook a meta-analysis of the best evidence available on the comparison of primary and second clinical outcomes of the off-pump and on-pump CABG.

Design

Systematic literature reviewer and meta-analysis.

Data sources

PubMed, EMBASE, Web of science and Cochrane Center Registry of Controlled Trials were searched the studies which comparing the use of the off-pump CABG(OPCAB) and on-pump CABG (ONCAB) for patients with LVD during January 1990.1 to January 2018.

Eligibility criteria

All observation studies and randomized controlled trials comparing on-pump and off-pump as main technique for multi-vessel coronary artery disease (defined as severe stenosis (>70%) in at least 2 major diseased coronary arteries) with left ventricular dysfunction(defined as ejection fraction (EF) 40% or less) were included.

Data extraction and synthesis

Authors will screen and select the studies extract the following data, first author, year of publication, trial characters, study design, inclusion and exclusion criteria, graft type, clinical outcome, assess the risk of bias and heterogeneity. Study-specific estimates will pool through the modification of the Newcastle-Ottawa scale for the quality of study and while leave-one-out analysis will be used to detect the impact of individual studies on the robustness of outcomes.

Results

Among the 987 screened articles, a total of 16 studies (32,354 patients) were included. A significant relationship between patient risk profile and benefits from OPCAB was found in terms of the 30-day mortality (odds ratio [OR], 0.84; 95% confidence interval [CI], 0.73–0.97; P = 0.02), stroke (OR, 0.69; 95% CI, 0.55–0.86; P = 0.00), myocardial infarction (MI) (OR, 0.71; 95% CI, 0.53–0.96; P = 0.02), renal failure (OR, 0.71; 95% CI, 0.55–0.93; P = 0.01), pulmonary complication (OR, 0.68; 95% CI, 0.52–0.90; P = 0.01), infection (OR, 0.67; 95% CI, 0.49–0.91; P = 0.00),postoperative transfusion (OR, 0.25; 95% CI, 0.08–0.84; P = 0.02) and reoperation for bleeding (OR, 0.56; 95% CI, 0.41–0.75; P = 0.00). There was no significant difference in atrial fibrillation (AF) (OR, 0.96;95%; CI, 0.78–1.41; P = 0.56) and neurological dysfunction (OR, 0.88; 95% CI, 0.49–1.57; P = 0.65).

Conclusions

Compared with the on-pump CABG with LVD, using the off-pump CABG is a better choice for patients with lower mortality, stroke, MI, RF, pulmonary complication, infection, postoperative transfusion and reoperation for bleeding. Further randomized studies are warranted to corroborate these observational data.

Revascularization in left ventricular dysfunction: an update

PURPOSE OF REVIEW

The purpose of this article is to provide an overview of revascularization in patients with coronary artery disease (CAD) and left ventricular dysfunction (LVD).

RECENT FINDINGS

Patients with significant CAD and LVD are a high-risk patient population. They make up a minority of the cases from the largest, prospective coronary revascularization trials. The Surgical Treatment for Ischemic Heart Failure (STICH) Trial and its substudies are the most important and well cited in this field. The 10-year data from STICH showed that surgical revascularization was associated with lower all-cause mortality compared with medical therapy. Several smaller studies have confirmed that surgical revascularization carries a significant risk of short-term mortality but overall improved long-term outcomes in patients with LVD. Data from multiple observational studies further confirm that coronary artery bypass graft (CABG) is superior to percutaneous coronary revascularization for long-term survival and freedom from repeat revascularization in patients with LVD. We suggest that patients with LVD undergoing CABG should be considered for multiarterial grafting and that some patients may benefit from an off-pump procedure.

SUMMARY

Surgical revascularization confers a long-term survival benefit in patients with significant CAD and LVD. Further studies will be needed to precisely determine the ideal candidate for surgical versus percutaneous revascularization.

Early and Mid-Term Outcomes of Patients Undergoing Coronary Artery Bypass Grafting in Ischemic Cardiomyopathy

Background Many observational studies and trials have shown that coronary artery bypass grafting improves the survival in patients with ischemic cardiomyopathy. However, these results are based on data generated from developed countries. Poor socioeconomic statuses, lack of uniformity in healthcare delivery, differences in risk profile, and affordability to access optimal health care are some factors that make the conclusions from these studies irrelevant to patients from India. Methods and Results One-hundred and sixty-two patients with severe left ventricular dysfunction (ejection fraction ≤35%) who underwent coronary artery bypass grafting from 2009 to 2017 were enrolled for this study. Mean age of the study population was 58.67±9.70 years. Operative mortality was 11.62%. Thirty day/in-house composite outcome of stroke and perioperative myocardial infarction were 5.8%. The percentage of survival for 1 year was 86.6%, and 5-year survival was 79.9%. Five-year event-free survival was 49.3%. The mean ejection fraction improved from 30.7±4.08% (range 18-35) to 39.9±8.3% (range 24-60). Lack of improvement of left ventricular function was a strong predictor of late mortality (hazard ratio, 21.41; CI 4.33-105.95). Even though there was a trend towards better early outcome in off-pump CABG , the 5-year survival rates were similar in off-pump and on-pump group (73.4% and 78.9%, respectively; P value 0.356). Conclusions We showed that coronary artery bypass grafting in ischemic cardiomyopathy was associated with high early composite outcomes. However, the 5-year survival rates were good. Lack of improvement of left ventricular function was a strong predictor of late mortality.

Early outcomes in patients undergoing off-pump coronary artery bypass grafting

Background

In spite of general decline worldwide, off-pump coronary artery bypass grafting (CABG) surgery is performed in more than 60% of patients undergoing CABG in India; mainly because of shorter operative time and reduced procedure cost. However, paucity of data exists in literature about early outcomes following off-pump CABG from India.

Methodology

We conducted a prospective observational study of 800 consecutive cases that underwent off-pump CABG (OPCAB) from August 2015 to October 2017. Primary end point of the study was the 30-day/in-hospital mortality from any cause.

Results

On multivariate analysis, emergency surgery (OR 9.72; CI 1.96-48.21, p value 0.005), severe left ventricular dysfunction (OR 2.28; CI 1.25-4.76, p value 0.026), postoperative atrial fibrillation (OR 9.95; CI 3.12-32.01, p value 0.05), and dialysis-dependent renal failure (OR 29.7, CI 10.02-87.99, p value 0.006) were the factors associated with mortality. The observed mortality was 1.6%, and the expected mortality by EuroSCORE II was 2.6%. The median EuroSCORE II of expired patients was 3.03 and of entire cohort was 1.54 (p value 0.001). Stroke rate was 0.9%. Deep sternal wound infection occurred in 0.9%, and 3.8% patients were readmitted to the hospital after discharge.

Conclusion

Early outcome of off-pump CABG was excellent in this study. Increased incidence of deep sternal wound infection remains a concern. Multicenter study with a larger sample size is required for a dependable evaluation of the efficacy of off-pump CABG in Indian population.

Myocardial revascularization without extracorporeal circulation; Why hasn't it convinced yet?

Extracorporeal circulation has led to a great development in cardiovascular surgery during the last five decades. Its time-proven efficacy and safety have made on-pump coronary artery bypass grafting (CABG) the gold standard method of surgical revascularization. However, coronary revascularization on cardiopulmonary bypass and the accompanying aortic manipulation are related to plenty of deleterious complications. Therefore, off-pump CABG surgery was established to avoid complications. Nevertheless, despite the initial enthusiasm on this technique, only 20% of myocardial revascularization procedures worldwide are performed off-pump. Not only are off-pump cardiac procedures more technically difficult but also they do not provide better results in terms of graft patency, completeness of revascularization, repeat revascularization requirement, cost, and quality of life. Completeness of revascularization and anastomotic quality should not be compromised to avoid cardiopulmonary bypass.

Minimally Circulatory-Assisted On-Pump Beating Coronary Artery Bypass Grafting for Patients With Complex Conditions for Off-Pump Surgery

Off-pump coronary artery bypass grafting (OPCAB) in patients with acute myocardial infarction (AMI) is difficult because of circulatory deterioration during displacement of the heart. At our institution, we performed minimally circulatory-assisted on-pump beating coronary artery bypass grafting (MICAB) in these patients. During MICAB, support flow was controlled at a minimal level to maintain a systemic blood pressure of approximately 100 mm Hg and a pulmonary arterial systolic pressure of <30 mm Hg, providing optimal pulsatile circulation for end-organ perfusion and prevention of heart congestion. From September 2006 to March 2012, MICAB was performed in 37 patients. Either emergent or urgent MICAB was performed in 27 patients following AMI because of hemodynamic instability during reconstruction. Elective MICAB was performed in the remaining 10 patients because of dilated left ventricle (LV) or small target coronary arteries. The details of bypass grafts, perioperative renal function, and early and mid-term morbidity and mortality were compared between the patients who received MICAB and the 37 consecutive patients who underwent OPCAB during the study period at our hospital. The assist flow indices (actual support flow/body surface area) during anastomosis to the left anterior descending artery, left circumflex artery, and right coronary artery were 0.95 ± 0.48 L/min/m² , 1.32 ± 0.53 L/min/m² , and 1.15 ± 0.47 L/min/m² , respectively, in the emergent and urgent patients following AMI, and 0.44 ± 0.39 L/min/m² , 1.25 ± 0.39 L/min/m² , and 1.14 ± 0.43 L/min/m² , respectively, in the elective patients with either dilated LVs or small target vessels. The lowest mixed venous oxygen saturation during pump support in the MICAB group was significantly higher than that in the OPCAB group (83.8 ± 10.8%, 71.6 ± 7.5%, P < 0.001). Comparing MICAB and OPCAB, the median number of distal bypass grafts for both groups was 4 (25th, 75th percentile: 3, 4) (P = 0.558); the complete revascularization rates were 94.6 and 97.3%, respectively (not significant [NS]); the acute patency rates were 98.9 and 99.2%, respectively (NS); and the 30-day mortality rates were 2.7 and 0%, respectively (NS). No instances of either cerebrovascular complications or newly occurring postoperative renal failure were noted in either group. There were no statistically significant differences between the groups with respect to early and mid-term results (freedom from all-cause death: 82.9 vs. 86.5%, respectively, and freedom from cardiac events at 3 years: 96.4 vs. 96.4%, respectively). MICAB is a safe alternative to OPCAB, particularly in patients with AMI and dilated LV. MICAB is associated with high rates of complete revascularization and acute graft patency, adequate preservation of end-organ function, and early and mid-term results comparable with those observed following OPCAB.

Off-pump coronary artery bypass: past, present and future of a controversial technology

PURPOSE OF REVIEW

This review will examine the current role of off-pump coronary artery bypass (OPCAB) surgery compared with on-pump coronary artery bypass (ONCAB) surgery for the revascularization of ischemic myocardium.

RECENT FINDINGS

Recent studies have confirmed earlier findings that OPCAB is associated with less grafts per patient and less complete revascularization, and increased incidence of recurrent angina and need for repeat revascularization procedures, and more frequent rehospitalization for cardiac-related issues. OPCAB does not prevent postoperative renal dysfunction and is associated with worse long-term outcomes. Hospital costs are not reduced and are increased in those OPCAB patients who require intraoperative conversion to ONCAB procedures; however, when multiple arterial grafts are used and a complete revascularization is performed, OPCAB outcomes are equivalent to those of ONCAB procedures.

SUMMARY

OPCAB should only be performed by surgeons experienced in this technique in patients in whom a complete revascularization can be achieved; preferably with multiple arterial grafts.

Preoperative intra-aortic balloon pump improves the clinical outcomes of off-pump coronary artery bypass grafting in left ventricular dysfunction patients

Severe left ventricular (LV) dysfunction patients undergoing off-pump coronary artery bypass grafting (OPCAB) are often associated with a higher mortality. The efficacy and safety of the preoperative prophylactic intra-aortic balloon pump (IABP) insertion is not well established. 416 consecutive patients with severe LV dysfunction (ejection fraction ≤35%) undergoing isolated OPCAB were enrolled in a retrospective observational study. 191 patients was enrolled in the IABP group; the remaining 225 patients was in control group. A total of 129 pairs of patients were propensity-score matched. No significant differences in demographic and preoperative risk factors were found between the two groups. The postoperative 30-day mortality occurred more frequently in the control group compared with the IABP group (8.5% vs. 1.6%, p = 0.02). There was a significant reduction of low cardiac output syndrome in the IABP group compared with the control group (14% vs. 6.2%, p = 0.04). Prolonged mechanical ventilation (≥48 h) occurred more frequently in the control group (34.9% vs. 20.9%, p = 0.02). IABP also decreased the postoperative length of stay. Preoperative IABP was associated with a lower 30-day mortality, suggesting that it is effective in patients with severe LV dysfunction undergoing OPCAB.

Developments in surgical revascularization to achieve improved morbidity and mortality

Coronary artery bypass graft surgery remains the main treatment modality for multivessel coronary artery disease and has consistently been demonstrated to have significantly lower rates of major adverse cardiac and cerebrovascular events in comparison to percutaneous coronary intervention. In this article we will explore the advances over time and the recent refinements in the techniques of surgical revascularization and how these contribute to the superior outcome profile associated with coronary artery bypass graft surgery. These include the current outcome status of coronary artery bypass grafting; the major landmark trials, registries and meta-analyses comparing coronary artery bypass grafting and percutaneous coronary intervention; the developments in coronary artery disease lesion classification; the techniques for the physiological assessment of coronary artery lesions; bypass grafting using arterial conduits; the role of off-pump coronary artery surgery; the outcomes of reoperative surgery; hybrid techniques for coronary revascularization; minimally invasive coronary artery surgery and finally robotic surgery.

A multidisciplinary approach to unplanned conversion from off-pump to on-pump beating heart coronary artery revascularization in patients with compromised left ventricular function

Aim. To comparably assess the perioperative risk factors that differentiate off-pump coronary artery bypass (OPCAB) grafting cases from those sustaining unplanned conversion to on-pump beating heart (ONCAB/BH) approach, in patients with left ventricular ejection fraction (LVEF) < 40%. Methods. Perioperative variables were retrospectively assessed in 216 patients with LVEF < 40%, who underwent myocardial revascularization with OPCAB (n = 171) or ONCAB/BH (n = 45) approach. The study endpoints were operative mortality (30-day) and morbidity assessed by length of intensive care unit stay (LOS-ICU), using 2 days as cut-off point. Results. Poor LVEF, increased EuroSCORE II, acute presentation, congestive heart failure, cerebrovascular disease, perioperative renal impairment, clinical status deterioration upon admission and during ICU stay, acute myocardial infarction, and low cardiac output syndrome supported by inotropes and/or balloon-pump counterpulsation were significantly related to ONCAB/BH group (P < 0.05). EuroSCORE II (P = 0.01) and LVEF (P = 0.03) were the most powerful discriminative predictors of intraoperative conversion to ONCAB/BH. Operative mortality was 2.9% in OPCAB and 6.6% in ONCAB/BH group (P = 0.224), while 23.4% participants in OPCAB and 42.2% in ONCAB/BH approach had a LOS-ICU > 2 days (P = 0.007). Conclusions. Patients with LVEF < 40% undergoing ONCAB/BH are subjected to more preoperative comorbidities and implicated ICU stay than their OPCAB counterparts, which influences adversely short-term morbidity, while operative mortality remains unaffected.

Is the evidence from first time off-pump coronary artery bypass graft surgery transferable to re-operative off-pump surgery?

On-pump coronary artery surgery remains the gold standard treatment for multi-vessel disease. The technique of off-pump surgery has evolved since its first use; however, currently less than 20% of all cases worldwide are performed this way. This poor uptake has been both the cause and the effect of widespread scepticism regarding the validity of the data on the technique, as well as criticism regarding the conversion-related adverse outcomes, graft patency and completeness of revascularisation. Consequently, there has been focus on patient selection from subgroups most likely to benefit from the technique. Re-operative patients, by virtue of their advanced age, complex co-morbidities and the technical challenges of re-operation, fall into this category. In this review, the authors will discuss the outcomes of off-pump surgery in comparison to on-pump, explore the potential beneficial effects of off-pump in re-operative surgery and formulate a decision-making strategy in patients undergoing reoperative coronary artery surgery.

On-pump versus off-pump coronary artery bypass graft surgery: what do the evidence show?

The main purpose of the off-pump coronary artery bypass surgery is to reduce morbidity and mortality due cardiopulmonary bypass. However, even though many studies have shown that off-pump coronary artery bypass is feasible and provides hospital morbidity and mortality similar to the on-pump coronary artery bypass graft surgery, probably better in some aspects, its long-term results have been questioned, since some trials have shown reduced survival with off-pump coronary artery bypass. It is likely that incomplete revascularization and/or poor graft patency with off-pump coronary artery bypass probably are responsible for such unfavorable outcome.

Off-pump coronary surgery: current justifications

Although the literature has failed to project an overall superiority of off-pump vs. on-pump surgery, nevertheless, small randomized control trials and large meta-analysis studies have concluded that the incidence of a stroke is less than 1 % when anaortic off-pump techniques are advocated in patients with diseased ascending aorta. Furthermore, off-pump techniques or their combination with hybrid procedures may lead to a reduction of adverse outcome in the aged high-risk population with concomitant poor left ventricular function and co-morbidities. However, despite this, controversy still exists among the cardiac surgery community in terms of the benefit of this technique and its safety; hence, off-pump is becoming out of fashion. In this review paper, by looking at a "marginal group of patients" (elderly, high risks, atherosclerotic aortas) we attempt to re-establish and justify this technique and re-invent its usage.

Off-pump versus on-pump revascularization in females: a meta-analysis of observational studies

BACKGROUND

Coronary revascularization in female patients presents several challenges, including smaller target vessels and smaller conduits. Furthermore, late presentation and more co-morbidities than males may increase complication rates. The aim of this study was to assess whether off-pump coronary artery bypass (OPCAB) improves outcomes when compared to on-pump coronary artery bypass (ONCAB) in the female population.

METHODS

A systematic literature review identified six observational studies, incorporating 23313 patients (n=9596 OPCAB, 13717 ONCAB). These were meta-analyzed using random effects modeling. Heterogeneity, subgroup analysis, quality scoring and publication bias were assessed. The primary endpoints were 30-day mortality and major cardiac, respiratory and renal complications. Secondary endpoints were the number of grafts per patient.

RESULTS

No statistically significant difference was observed in 30-day mortality between the OPCAB and ONCAB groups (4.8% vs. 0.7%; OR 0.96; 95% CI [0.41, 2.24], p=0.92). Significant inter-study heterogeneity was also present (I2=94%) and was not explained by study size or quality. Peri-operative myocardial infarction (OR 0.65; 95% CI [0.51, 0.84], p=0.0009) was significantly lower with OPCAB without significant heterogeneity; however, OPCAB did not significantly alter other morbidity outcomes. OPCAB was associated with a trend towards fewer grafts per patient than ONCAB.

CONCLUSIONS

OPCAB is a safe alternative to ONCAB in the surgical revascularisation of female patients and may reduce post-operative myocardial infarction (MI). However, this does not translate into a reduction in 30-day mortality and OPCAB does not significantly improve other cardiovascular, renal or neurological outcomes. Late outcome data remains lacking and a well-structured, randomized trial is required to answer vital questions regarding the effect of OPCAB on women in the long-term.

Off-pump surgery: is it beneficial in patients with left ventricular dysfunction?

On-pump coronary artery bypass surgery remains the gold standard for complex multivessel disease. Off-pump revascularization has matured as a technique over the last twenty years, but is used in less than 20% of cases worldwide. The poor uptake has been attributed to the significant learning curve in learning the procedure and conflicting evidence reports, together with concerns over mortality related conversion, graft patency and completeness of revascularization. Given these concerns, patient selection continues to be paramount and the subgroups that benefit most are hotly debated. Patients with left ventricular dysfunction constitute a high-risk subgroup which is enlarging in size. There is some evidence to suggest that avoidance of cardiopulmonary bypass in this group may lead to superior results in terms of early mortality, non-cardiac complications and organ dysfunction. Even with the theoretical risk of incomplete revascularization, the technique may be an attractive option in managing high-risk patients.

Long-term outcomes after off-pump coronary artery bypass grafting in left ventricular dysfunction

PURPOSE

We assessed the long-term clinical, angiographic, and echocardiographic outcomes of patients with left ventricular dysfunction (ejection fraction ≤40%) who underwent isolated off-pump coronary artery bypass grafting.

METHODS

One hundred sixty one patients were included. Mean age was 67.2 ± 11.4 years, and 20 patients (12.4%) were female. Eighty-eight patients (54.7%) were New York Heart Association functional class 3 or 4. Early postoperative and follow-up angiography and echocardiography findings were analyzed, and mid-term survival rates (mean follow-up 40.7 ± 25.6 months) were calculated.

RESULTS

Mean number of distal anastomoses was 4.4 ± 1.3. Bilateral internal thoracic artery grafts were used in 84.5% of patients. Operative mortality was 2.5%. Early patency rate of anastomoses was 98.3%. Early postoperative ejection fraction improved from 33.1 ± 5.6% preoperatively to 36.9 ± 9.5% (p <0.001). Seven-year survival rate was 73.9 ± 5.3%, and freedom from cardiac events rate was 68.5 ± 5.2%. One-year patency rate of anastomoses was 85.8%. Follow-up ejection fraction was 39.1 ± 10.7% (p <0.001).

CONCLUSIONS

Early and long-term outcomes of off-pump coronary artery bypass grafting in patients with left ventricular dysfunction were favorable, including early postoperative and follow-up patency rates of anastomoses and echocardiographic recovery of ejection fraction.

Does off-pump coronary revascularization reduce mortality in re-operative coronary artery surgery? A meta-analysis of observational studies

BACKGROUND

Re-operative coronary artery bypass grafting (CABG) is a challenging operation that is often performed in a high-risk patient group. Avoiding cardiopulmonary bypass (CPB) in these patients is hypothesised to be advantageous due to the reduced invasiveness and physiological stress of off-pump coronary artery bypass grafting (OPCAB). The aims of this study were to assess whether OPCAB may improve outcomes in patients undergoing re-operative CABG.

METHODS

Twelve studies, incorporating 3471 patients, were identified by systematic literature review. These were meta-analysed using random-effects modelling. Primary endpoints were 30-day and mid-term mortality. Secondary endpoints were completeness of revascularization, mean number of grafts per patient and the effect of intra-operative conversion on mortality.

RESULTS

A significantly lower rate of 30-day mortality was observed with OPCAB (OR 0.51, 95% CI [0.35, 0.74]), however, no difference was demonstrated in mid-term mortality. Significantly less complete revascularization and mean number of grafts per patient were observed in the OPCAB group. Meta-regression revealed no change in 30-day mortality when the effect of conversion from one technique to the other was assessed.

CONCLUSIONS

Off-pump techniques may reduce early mortality in selected patients undergoing re-operative CABG; however, this does not persist into mid-term follow-up. OPCAB may also lead to intra-operative conversion and, although this did not affect outcomes in this study, these results are constrained by the limited data available. Furthermore, OPCAB may increase target vessel revascularization and, consequently, incomplete revascularization which, whilst not reflected in the short-term outcomes, requires longer-term follow-up in order to be fully assessed.

Off-pump coronary artery bypass grafting--the current state

The optimal strategy for coronary revascularization remains controversial. Currently, most surgical revascularizations are performed with the use of cardiopulmonary bypass (ONCAB), yet over the past 20 years off-pump coronary artery bypass grafting (OPCAB) has been increasingly used because of the increased awareness of the deleterious effects of cardiopulmonary bypass (CPB) and aortic manipulation. Small, prospective, randomized controlled trials have lacked sufficient sample size to demonstrate differences in early and long-term outcomes. Larger observational studies that are better powered to statistically compare outcomes have shown more favorable in-hospital outcomes and equivalent long-term outcomes with OPCAB and ONCAB. The benefits of OPCAB techniques may be more apparent for patients at high risk for complications associated with CPB and aortic manipulation. Recent studies have demonstrated improved outcomes in higher-risk patients undergoing OPCAB, as well as improved neurological outcomes. The purpose of this review is to outline the recent literature comparing OPCAB with ONCAB, and to demonstrate efficacy of OPCAB as a useful technique for coronary revascularization.