Effects of on-pump and off-pump surgery in the Arterial Revascularization Trial

The Anaortic Technique with Bilateral Internal Thoracic Artery Grafting - Filling the Gap in Coronary Artery Bypass Surgery

Coronary artery bypass grafting (CABG) has consolidated its role as the most effective procedure for treating patients with advanced atherosclerotic coronary artery disease, reducing the long-term risk of myocardial infarction and death compared to other therapies and relieving angina. Despite the recognized benefits afforded by surgical myocardial revascularization, a subset of higher-risk patients bears a more elevated risk of perioperative stroke. Stroke remains the drawback of conventional CABG and has been strongly linked to aortic manipulation (cannulation, cross-clamping, and side-biting clamping for the performance of proximal aortic anastomoses) and the use of cardiopulmonary bypass. Adoption of off-pump CABG (OPCAB) is demonstrated to lower the risk of perioperative stroke, as well as reducing the risk of short-term mortality, renal failure, atrial fibrillation, bleeding, and length of intensive care unit stay. However, increased risk persists owing to the need for the tangential ascending aorta clamping to construct the proximal anastomosis. The concept of anaortic (aorta no-touch) OPCAB (anOPCAB) stems from eliminating ascending aorta manipulation, virtually abolishing the risk of embolism caused by aortic wall debris into the brain circulation. The adoption of anOPCAB has been shown to further decrease the risk of postoperative stroke, especially in higher-risk patients, entailing a step forward and a refinement of outcomes provided by the primeval OPCAB technique. Therefore, anOPCAB has been the recommended technique in patients with cerebrovascular disease and/or calcification or atheromatous plaque in the ascending aorta and should be preferred in patients with high-risk factors for neurological damage and stroke.

Repeat Coronary Artery Bypass Grafting: A Meta-Analysis of Off-Pump versus On-Pump Techniques in a Large Cohort of Patients

BACKGROUND

Redo coronary artery bypass grafting (CABG) can be performed with either the off-pump (OPCAB) or the on-pump (ONCAB) technique.

METHOD

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), this meta-analysis compared the safety and efficacy of OPCAB versus ONCAB redo CABG.

RESULTS

Twenty-three (23) eligible studies were included (OPCAB, n=2,085; ONCAB, n=3,245). Off-pump CABG significantly reduced the risk of perioperative death (defined as in-hospital or 30-day death rate), myocardial infarction, atrial fibrillation, and acute kidney injury. The two treatment approaches were comparable regarding 30-day stroke and late all-cause mortality.

CONCLUSIONS

Off-pump redo CABG resulted in lower perioperative death and periprocedural complication rates. No difference was observed in perioperative stroke rates and long-term survival between the two techniques.

Graft patency at 3 months after off- and on-pump coronary bypass surgery: a randomized trial

Purpose

Coronary artery bypass grafting (CABG) is performed either with the aid of cardiopulmonary bypass (on-pump) or without cardiopulmonary bypass (off-pump). There is a scarcity of angiographic data to support the non-inferiority of off-pump technique to on-pump technique. The objective of this study is to ascertain the non-inferiority of off-pump CABG when compared to on-pump CABG in terms of angiographically assessed graft patency at 3 months.

Methods

A total of 320 patients with multivessel coronary artery disease were enrolled in a multicenter prospective randomized trial either to on-pump CABG (n = 162) or off-pump CABG (n = 158) between March 2016 through March 2017. Graft patency was evaluated by using either multidetector computerized tomographic angiography or conventional coronary angiography at 3 months. The major adverse cardiac and cardiovascular events (MACCE) were also analyzed at 3 months.

Results

The median number of grafts per patient in off-pump was 3.00 (Q1:3.00 and Q3:4.00) vs on-pump 4.00 (Q1:3.00 to Q3:4.00), and the mean number of grafts per patient was lower in the off-pump CABG at 3.45 ± 0.75 vs 3.64 ± 0.70 in the on-pump CABG (p = 0.01). There was no significant difference in mortality at 3 months between the off-pump (0.63%) and on-pump groups (1.85%) with p value of 0.62. The cumulative combined MACCE showed significant difference between off-pump group (0.63%) and on-pump group (5.55%), p = 0.01. Follow-up angiograms were done in 239 (75%) patients with 120 off-pump and 119 in the on-pump group. The analysis was also done regarding graft patency in a graded manner—when analysis of A (excellent) grafts vs B (stenosed) grafts and O (occluded) grafts were made, there was no statistically significant difference in overall graft patency at 3 months between on-pump [376 /429 grafts (87.6%)] and off-pump [366 /420 grafts (87.1%)] groups (p = 0.82). The patency rates were similar among bypass conduits (left internal thoracic artery (ITA) in off-pump (91.4%) vs on-pump (92.9%) p = 0.66, right ITA in off-pump (82.1%) vs on-pump (81.8%) p = 0.97, radial artery in off-pump (84.4%) vs on-pump (82.6%) p = 0.81; saphenous vein in off-pump (85.8%) vs on-pump (86.3%), p = 0.86 and among 3 coronary territories.

Conclusions

Off-pump CABG is non-inferior to on-pump CABG in terms of overall graft patency at 3 months and was associated with a fewer combined cumulative MACCE compared to on-pump CABG.

Electronic supplementary material

The online version of this article (10.1007/s12055-019-00869-0) contains supplementary material, which is available to authorized users.

One-year outcomes of off- and on-pump coronary artery bypass grafting: PROMOTE patency trial

PURPOSE

Earlier we reported 3-month graft patency and clinical outcomes of prospective randomized comparison of off-pump and on-pump multivessel coronary artery bypass surgery to evaluate outcomes and graft patency (PROMOTE patency) trial. We now report major adverse cardiac and cerebrovascular events (MACCE) at 1 year of patients who underwent coronary artery bypass grafting (CABG) using either off-pump technique or on-pump technique.

METHODS

The PROMOTE patency trial is a two-arm, prospective, randomized, multicentre trial, and enrolled 320 patients with multivessel coronary artery disease from March 2016 through March 2017 at 6 centres and were randomly assigned to undergo either off-pump CABG (OPCAB) (n = 158 patients) or on-pump CABG (n = 162 patients). The outcomes at 1 year were assessed.

RESULTS

One mortality (0.64%) occurred in off-pump group (at 30 days) and 4 (2.48%) in on-pump group (1 at 30 days, 2 at 3 months, and 1 at 1 year) (p = 0.37). There was no difference between off-pump and on-pump groups in the outcomes of nonfatal myocardial infarction (1 in off-pump and 2 in on-pump group, p = 1.00) and cerebrovascular accident (none in off-pump and 2 in on-pump group, p = 0.49). Repeat revascularization was done in one patient in each group (p = 1.00).

CONCLUSION

There was no significant difference in the incidence of MACCE between off-pump and on-pump CABG group at 1 year.

Skeletonisation contributing to a reduction of sternal wound complications: a retrospective study in OPCAB patients

Background

Sternal wound complications (SWC) are a rare but potentially life-threatening complication after coronary artery bypass grafting (CABG) surgery. Especially the use of bilateral IMA (BIMA) grafts as opposed to single IMA (SIMA) grafts is associated with an increased risk of SWC. Skeletonised harvesting has been proposed to reduce this risk. The purpose of this study was to retrospectively investigate the effect of skeletonisation on SWC after off-pump coronary artery bypass grafting (OPCAB) in a centre with a high volume of off-pump procedures and high frequencies of BIMA.

Methods

From January 2010 to November 2016, 1900 consecutive patients underwent OPCAB surgery at the University Hospitals of Leuven. The first group (n = 1487) received non-skeletonised IMA grafts, whereas the second group (n = 413) received skeletonised grafts. Optimal wound management was pursued in all patients. A new four-grade classification for SWC was developed. Incidence and grade of SWC as well as overall survival were assessed.

Results

Analysis of diabetic patients showed a lower incidence of SWC in the skeletonised (12/141, 8.5%) compared to the non-skeletonised group (82/414, 19.8%) [odds ratio 0.46, 95% confidence interval (0.23;0.88), p = 0.019] as well as a lower grade [0.45 (0.24;0.871), p = 0.018]. There was no significant effect on overall survival [0.67 (0.19;2.32), p = 0.529]. Subanalysis of this population revealed that the observed effects were most prominent in patients receiving BIMA grafts, with 6/56 (10.7%) SWC in the skeletonised and 62/252 (24.6%) in the non-skeletonised group [0.37 (0.15;0.90), p = 0.028 for incidence], as well as a lower grade [0.36 (0.15;0.88), p = 0.025]. These advantages were not significant in diabetic patients receiving SIMA grafts nor in the full study population.

Conclusions

This study, using a more sensitive classification of SWC, shows in a large group of patients that, in combination with optimized wound management, the skeletonisation technique is associated with a clear reduction in the incidence and grade of SWC in diabetic patients receiving BIMA grafts. This encourages the extension of BIMA use in OPCAB to this risk population.

Electronic supplementary material

The online version of this article (10.1186/s13019-019-0985-9) contains supplementary material, which is available to authorized users.

Left lateral intercostal region versus subxiphoid position for pleural drain during elective coronary artery bypass graft surgery: randomized clinical trial

BACKGROUND

The pleural drain insertion site after coronary artery bypass graft (CABG) surgery may alter lung function, especially respiratory muscle strength. The main objective of this study was to compare the effectiveness and safety of use of the left lateral intercostal region versus the subxiphoid position for pleural drainage during elective CABG surgery using extracorporeal circulation (ECC).

DESIGN AND SETTING

Randomized trial conducted in a tertiary-level hospital in Porto Alegre, Brazil.

METHODS

48 patients were assigned to group 1 (pleural drain in the left lateral intercostal region) or group 2 (pleural drain in the subxiphoid position). Respiratory muscle strength was measured in terms of maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP), in cmH2O, by means of manovacuometry preoperatively, 24 and 72 hours after drain removal and before discharge from hospital. Painand dyspnea scales, presence of infections, pleural effusion and atelectasis, duration of drain use, drainage volumes and surgical reinterventions were also evaluated.

RESULTS

After adjustments, there were no significant differences between the groups at the end of the study (before discharge), in predicted percentages either for MIP (delta group 1: -17.21% versus delta group 2: -22.26%; P = 0.09) or for MEP (delta group 1: -9.38% versus delta group 2: -13.13%; P = 0.17). Therewere no differences between the groups in relation to other outcomes.

CONCLUSION

There was no difference in maximal respiratory pressures in relation to the pleural drain insertion site among patients who underwent CABG surgery using ECC.

TRIAL REGISTRATION

ReBEc V1111.1159.4447.

Off-pump Revascularization with Bilateral versus Single Mammary Arteries-A Propensity Score-Matched Analysis

BACKGROUND

Coronary artery bypass grafting is the first-line therapy for severe multivessel coronary artery disease. We aimed to investigate the clinical outcome in patients undergoing isolated off-pump surgery with the single or bilateral internal mammary artery (SIMA or BIMA) approach.

METHODS

We performed a propensity score-matched analysis in 1,852 consecutive patients, aged 50 to 70 years, who underwent myocardial revascularization at our institution between July 2009 and August 2016. Primary end point was the probability of survival.

RESULTS

Mean follow-up was 36.3 (range: 0.1-89.6) months. The probability of survival in the SIMA and BIMA groups was 98.6 and 99.0% at year 1, 92.0 and 92.5% at year 5, and 85.6 and 81.6% at year 7, respectively, with a hazard ratio (HR) of mortality for the BIMA group versus the SIMA group of 0.98 (95% confidence interval[CI]: 0.64-1.52; p = 0.94). There was evidence for interaction between diabetes and study group on mortality risk (HR = 2.59, 95% CI: 1.07-6.23; p = 0.034). Freedom from mediastinitis/wound infection was higher in the SIMA group than in the BIMA group (99.5 and 96.9%, respectively; HR of an event = 6.39, 95% CI: 2.88-14.18; p < 0.001). The corresponding values in the subgroups of diabetic patients were 98.6 and 90.9%, respectively (HR = 6.45, 95% CI: 2.24-18.58; p = 0.001). Mediastinitis/wound infection was associated with increased mortality risk (HR = 2.96, 95% CI: 1.29-6.78; p = 0.010).

CONCLUSION

Overall, our data indicate similar probability of survival up to a maximum follow-up of 7 years by off-pump surgery with the SIMA or BIMA approach. However, in diabetic patients, the clinical outcome indicates caution regarding the use of the BIMA approach.

Off-pump coronary artery bypass surgery with bilateral internal thoracic arteries: the Leipzig experience

Background

Contrasting results of recent randomized controlled trials (RCTs) comparing off-pump and on-pump coronary artery bypass graft (CABG) surgery, as well as the lack of evidence for any survival benefit of bilateral internal thoracic artery (ITA) grafting over single ITA use, has intensified the debate about the role of the off-pump technique and bilateral ITA use in CABG surgery. We therefore investigated our 15-year experience in off-pump CABG with bilateral ITA grafting and evaluated temporal trends in preoperative characteristics and postoperative outcomes.

Methods

Demographic, intra-operative, and outcome data of 1,199 consecutive patients undergoing off-pump CABG with bilateral ITA grafting was prospectively collected in a computerized database. Patients who underwent on-pump cardiac procedures and other extra-cardiac procedures were excluded from this study. Assessment of changes in perioperative characteristics and parameters with time was performed by dividing the whole cohort into three groups (2003-2007, 2008-2012, and 2013-2017) based on the year of surgery.

Results

The overall 30-day mortality was 0.6%, with no differences observed between the three time cohorts (0.6%, 0.7%, 0.5%; P=0.8). The perioperative stroke rate for whole cohort was 0.6% and demonstrated a significant reduction in the last two time cohorts (1%, 0.5%, 0.5%; P<0.0001). The overall incidence of deep sternal wound infections was 0.7%, but was marginally higher in the last time-cohort (0.6%, 0.5%, 0.9%; P=0.7). Overall survival for the entire cohort was 92.9%±1% and 78.9%±4% at 5 and 10 years follow-up, respectively. Older age at surgery and presence of peripheral vascular disease were the only predictors of late mortality.

Conclusions

Off-pump CABG with bilateral skeletonized ITAs is a safe operation and is associated with a low mortality and morbidity, which can be maintained in high volume center unit over a long period of time. The long-term survival of patients undergoing such an operation is excellent.

Hybrid Revascularization: A Review

Hybrid coronary revascularization (HCR) combines surgical bypass with percutaneous coronary intervention (PCI) performed either during the same procedure or in a staged approach within 60 days. Coronary artery bypass grafting using the left internal mammary artery (LIMA) has shown excellent long-term patency with improved patient survival. It remains the gold standard treatment for the majority of patients with multivessel coronary artery disease. However, saphenous vein grafts have poor long-term patency. Advances in stent technology have resulted in reduced rates of thrombosis and restenosis, making PCI a viable alternative to coronary surgery in selected patients. HCR is attractive as a less invasive method of coronary revascularization which preserves the benefits of the LIMA performed with less invasive surgical techniques with the efficacy of newer generation stents.

Randomized Trial of Bilateral versus Single Internal-Thoracic-Artery Grafts

BACKGROUND

The use of bilateral internal thoracic (mammary) arteries for coronary-artery bypass grafting (CABG) may improve long-term outcomes as compared with the use of a single internal-thoracic-artery plus vein grafts.

METHODS

We randomly assigned patients scheduled for CABG to undergo single or bilateral internal-thoracic-artery grafting in 28 cardiac surgical centers in seven countries. The primary outcome was death from any cause at 10 years. The composite of death from any cause, myocardial infarction, or stroke was a secondary outcome. Interim analyses were prespecified at 5 years of follow-up.

RESULTS

A total of 3102 patients were enrolled; 1554 were randomly assigned to undergo single internal-thoracic-artery grafting (the single-graft group) and 1548 to undergo bilateral internal-thoracic-artery grafting (the bilateral-graft group). At 5 years of follow-up, the rate of death was 8.7% in the bilateral-graft group and 8.4% in the single-graft group (hazard ratio, 1.04; 95% confidence interval [CI], 0.81 to 1.32; P=0.77), and the rate of the composite of death from any cause, myocardial infarction, or stroke was 12.2% and 12.7%, respectively (hazard ratio, 0.96; 95% CI, 0.79 to 1.17; P=0.69). The rate of sternal wound complication was 3.5% in the bilateral-graft group versus 1.9% in the single-graft group (P=0.005), and the rate of sternal reconstruction was 1.9% versus 0.6% (P=0.002).

CONCLUSIONS

Among patients undergoing CABG, there was no significant difference between those receiving single internal-thoracic-artery grafts and those receiving bilateral internal-thoracic-artery grafts with regard to mortality or the rates of cardiovascular events at 5 years of follow-up. There were more sternal wound complications with bilateral internal-thoracic-artery grafting than with single internal-thoracic-artery grafting. Ten-year follow-up is ongoing. (Funded by the British Heart Foundation and others; ART Current Controlled Trials number, ISRCTN46552265 .).

Current outcomes of off-pump versus on-pump coronary artery bypass grafting: evidence from randomized controlled trials

Coronary artery bypass grafting remains the standard treatment for patients with extensive coronary artery disease. Coronary surgery without use of cardiopulmonary bypass avoids the deleterious systemic inflammatory effects of the extracorporeal circuit. However there is an ongoing debate surrounding the clinical outcomes after on-pump versus off-pump coronary artery bypass (ONCAB versus OPCAB) surgery. The current review is based on evidence from randomized controlled trials (RCTs) and meta-analyses of randomized studies. It focuses on operative mortality, mid- and long-term survival, graft patency, completeness of revascularisation, neurologic and neurophysiologic outcomes, perioperative complications and outcomes in the high risk groups. Early and late survival rates for both OPCAB and ONCAB grafting are similar. Some studies suggest early poorer vein graft patency with off-pump when compared with on-pump, comparable midterm arterial conduit patency with no difference in long term venous and arterial graft patency. A recent, pooled analysis of randomised trials shows a reduction in stroke rates with use off-pump techniques. Furthermore, OPCAB grafting seems to reduce postoperative renal dysfunction, bleeding, transfusion requirement and respiratory complications while perioperative myocardial infarction rates are similar to ONCAB grafting. The high risk patient groups seem to benefit from off-pump coronary surgery.

On-Pump versus Off-Pump Complete Arterial Revascularization Using Bilateral Internal Mammary Arteries and the T-Graft Technique: Clinical and Angiographic Results for 3,445 Patients in 13 Years of Follow-Up

BACKGROUND

This is an investigation of complete arterial coronary artery bypass grafting (CACABG) using bilateral internal mammary arteries (IMA) and the T-graft technique either on- or off-pump as a routine approach to treat coronary artery disease.

METHODS

Between January 2000 and December 2012, 3,445 patients underwent on-pump (n = 2,216) or off-pump (n = 1,229) CACABG. A 30-day follow-up was performed prospectively, a long-term follow-up by a questionnaire, and coronary angiography in selected patients.

RESULTS

End points at 30 days were death, myocardial infarction, stroke, repeat revascularization, renal replacement, reoperation, sternal wound infection and atrial fibrillation. FitzGibbon A patency rates were 89.8 vs. 91.4% (p = 0.464) with consecutive percutaneous coronary intervention in the grafted area of 1.8 vs. 1.1% (p = 0.693) on- vs. off-pump, and no reoperation in the grafted area in both groups.

CONCLUSION

CACABG by use of skeletonized bilateral IMA with the T-graft technique performed either on- or off-pump is a safe and effective approach.