Association Between Coronary Artery Bypass Surgical Techniques and Postoperative Stroke

Comparative efficacy on outcomes of C-CABG, OPCAB, and ONBEAT in coronary heart disease: a systematic review and network meta-analysis of randomized controlled trials

IMPORTANCE

Coronary artery bypass grafting (CABG) remains the gold standard for the treatment of multivessel and left main coronary heart disease. However, the current evidence about the optimal surgical revascularization strategy is inconsistent and is not sufficient to allow for definite conclusions. Thus, this topic needs to be extensively discussed.

OBJECTIVE

The aim of this present study was to compare the clinical outcomes of off-pump CABG (OPCAB), conventional on-pump CABG (C-CABG), and on-pump beating heart (ONBEAT) CABG via an updated systematic review and network meta-analysis of randomized controlled trials.

DATA SOURCES

PubMed, Web of Science, and the Cochrane Central Registry were searched for relevant randomized controlled trials that were published in English before 1 December 2021.

STUDY SELECTION

Published trials that included patients who received OPCAB, C-CABG, and ONBEAT CABG were selected.

DATA EXTRACTION AND SYNTHESIS

Two authors independently screened the search results, assessed the full texts to identify eligible studies and the risk of bias of the included studies, and extracted data. All processes followed the Preferred Reporting Items for Systematic Review and Meta-analysis of Individual Participant Data.

MAIN OUTCOMES AND MEASURES

The primary outcome was postoperative mortality in patients who underwent C-CABG, OPCAB, or ONBEAT CABG. The secondary outcomes were postoperative myocardial infarction, stroke, and renal impairment in the three groups. The time point for analysis of outcomes was all time periods during the postoperative follow-up.

RESULTS

A total of 39 385 patients (83 496.2 person-years) in 65 studies who fulfilled the prespecified criteria were included. In the network meta-analysis, OPCAB was associated with an increase of 12% in the risk of all-cause mortality when compared with C-CABG [odds ratio (OR): 1.12; 95% CI: 1.04-1.21], a reduction of 49% in the risk of myocardial infarction when compared with ONBEAT (OR: 0.51; 95% CI: 0.26-0.99), a reduction of 16% in the risk of stroke when compared with C-CABG (OR: 0.84; 95% CI: 0.72-0.99) and a similar risk of renal impairment when compared with C-CABG and ONBEAT.

CONCLUSIONS AND RELEVANCE

OPCAB was associated with higher all-cause mortality but lower postoperative stroke compared with C-CABG. OPCAB was associated with a lower postoperative myocardial infarction than that of ONBEAT. Early mortality was comparable among OPCAB, ONBEAT, and C-CABG.

Off-pump vs. on-pump bypass surgery grafting in diabetic patients with three-vessel disease: a propensity score matching study

Background

Controversy exists regarding the advantages and risks of off-pump vs. on-pump coronary artery bypass grafting (CABG) for patients with diabetes. We therefore compare the early clinical outcomes of off-pump vs. on-pump procedures for diabetic patients with three-vessel disease.

Materials and methods

We conducted a retrospective analysis of clinical data obtained from 548 diabetic patients with three-vessel coronary artery disease who underwent isolated CABG between January 2016 and June 2020. To adjust the differences of baseline characteristics between the off-pump CABG (OPCAB) and on-pump CABG (ONCAB) groups, propensity score matching (PSM) was used. Following 1:1 matching, we selected 187 pairs of patients for further comparison of outcomes within the first 30 days after surgery.

Results

The preoperative characteristics of the patients between the two groups were clinically comparable after PSM. The OPCAB group exhibited a significantly higher incidence of incomplete revascularization (27.3% vs. 14.4%; P = 0.002) compared with the ONCAB group. No differences were seen in mortality within 30 days between the matched groups (1.1% vs. 3.7%; P = 0.174). Notably, the OPCAB group had a lower risk of respiratory failure or infection (2.1% vs. 7.0%; P = 0.025), less postoperative stroke (1.1% vs. 4.8%; P = 0.032), and reduced postoperative ventilator assistance time (35.8 ± 33.7 vs. 50.9 ± 64.8; P = 0.005).

Conclusion

OPCAB in diabetic patients with three-vessel disease is a safe procedure with reduced early stroke and respiratory complications and similar mortality rate, myocardial infarction, and renal failure requiring dialysis to conventional on-pump revascularization.

Off-pump or on-pump coronary artery bypass at 30 days: A propensity matched analysis

Introduction

This study was to determine whether coronary artery bypass grafting without cardiopulmonary bypass (off-pump CABG, OPCAB) could reduce early postoperative mortality and major complications compared with conventional coronary artery bypass grafting with cardiopulmonary bypass (on-pump CABG, ONCAB) by experienced surgeons.

Material and methods

From January 2016 to June 2020, isolated CABG was performed in 1200 patients (ONCAB 429, OPCAB 771) in Wuhan Union Hospital. The propensity score matching was used to adjust for differences in baseline characteristics between the ONCABG and OPCABG groups. After 1:1 matching, 404 pairs for each group were selected to compare outcomes within 30 days after surgery. All the operations were completed by experienced surgeons that had completed more than 500 on-pump and 200 off-pump CABG, respectively.

Results

After propensity matching, the two groups were comparable in terms of preoperative characteristics. The OPCAB group had less vein graft (2.5 ± 1.0 vs. 2.7 ± 0.9; P < 0.001) and a higher rate of incomplete revascularization (12.4 vs. 8.2%; P < 0.049) than the ONCAB group. There was no significant difference in early postoperative mortality between ONCAB and OPCAB groups (2.2 vs. 2.2%; P = 1.00). However, patients in the OPCAB group had a lower risk of postoperative stroke (1.5 vs. 4.7%; P = 0.008), new-onset renal insufficiency (8.9 vs. 18.8%; P < 0.001), respiratory failure (2.2 vs. 7.2%; P = 0.001), reoperation for bleeding (0.5 vs. 2.7%; P = 0.001), and required less ventilator assistance time (33.4 ± 37.9 h vs. 51.0 ± 66.1 h; P < 0.001) and intensive care unit (ICU) time (3.7 ± 2.7 days vs. 4.8 ± 4.3 days; P < 0.001).

Conclusions

In our study, patients undergoing OPCAB had fewer postoperative complications and a faster recovery. It is a feasible and safe surgical approach to achieve revascularization when performed by experienced surgeons.

Meta-Analysis of Bilateral Versus Single Internal Thoracic Artery Grafting in Patients ≥70 Years of Age

The optimal choice of graft material in patients ≥70 years of age undergoing coronary artery bypass grafting remains unknown. A systematic review of literature was conducted by searching PubMed, Embase, Web of Science, and Cochrane Library databases for original publications that compared bilateral internal thoracic artery (BITA) grafting with single internal thoracic artery grafting in patients ≥70 years of age. Data were extracted by 2 independent investigators and meta-analyzed with the use of random effects. A total of 10 studies, including 11,185 patients, met the inclusion criteria. No differences in early mortality and morbidity, with the exemption of sternal wound complications which were more frequently observed in the BITA group (odds ratio 1.72, 95% 1.00 to 2.96 confidence interval [CI], p = 0.05; propensity score-matched population odds ratio 1.58, 95% CI 1.09 to 2.29, p = 0.02), were observed. Overall survival was superior in the overall patient population (hazard ratio [HR] 0.76, 95% CI 0.66 to 0.86, p <0.001), after applying a blanking period of 3 months to the overall patient population (HR 0.77, 95% CI 0.64 to 0.92, p = 0.005) as well as in the matched population (HR 0.72, 95% CI 0.58 to 0.89, p = 0.002); in all cases, a benefit was readily seen within a few years after surgery. The difference in freedom from major adverse cardiac and cerebrovascular events failed to reach statistical significance (overall patient population HR 0.55, 95% CI 0.27 to 1.13, p = 0.10; matched population HR 0.52, 95% CI 0.23 to 1.16, p = 0.11). In conclusion, BITA grafting can be safely performed in patients ≥70 years of age as late clinical benefits are expected to manifest themselves readily within a few years after surgery.

Extensive corpus callosum ischemia after coronary artery bypass grafting on extracorporeal circulation

INTRODUCTION

Heart surgery can be associated with adverse ischemic brain events.

CASE REPORT

Here, we describe two patients who presented extensive infarction of the corpus callosum and of other brain watershed areas following coronary artery bypass grafting (CABG) on extracorporeal circulation (ECC).

DISCUSSION

Infarction of the corpus callosum is an extremely rare condition due to its abundant blood supply. Our findings are noteworthy since they diverge from classical brain watershed infarcts and from other cases of corpus callosum involvement. This suggests that in some cases, CABG surgery on ECC may be associated to a profound impairment of intracerebral circulation. However, it is also possible that the corpus callosum is particularly vulnerable to yet unknown metabolic modifications connected to ECC.

CONCLUSIONS

Further studies are needed in order to investigate the complex response of brain circulation and metabolism during heart surgery with ECC.

Percutaneous vs. surgical revascularization for patients with unprotected left main stenosis: a meta-analysis of 5-year follow-up randomized controlled trials

AIMS

A 5-year survival of patients with unprotected left main (ULM) stenosis according to the choice of revascularization (percutaneous vs. surgical) remains to be defined.

METHODS AND RESULTS

Randomized controlled trials (RCTs) comparing percutaneous coronary intervention (PCI) vs. coronary artery bypass graft (CABG) with a follow-up of at least 5 years were included. All-cause death was the primary endpoint. MACCE [a composite endpoint of all-cause mortality, myocardial infarction (MI), stroke, and repeat revascularization] along with its single components and cardiovascular (CV) death were the secondary ones. Analyses were stratified according to the use of first- vs. last-generation coronary stents. Subgroup comparisons were performed according to SYNTAX score (below or above 33) and to age (using cut-offs of each trial's subgroup analysis). Four RCTs with 4394 patients were identified: 2197 were treated with CABG, 657 with first generation, and 1540 with last-generation stents. At 5-year rates of all-cause death did not differ [odds ratio (OR) 0.93, 95% confidence interval (CI) 0.71-1.21], as those of CV death and stroke. Coronary artery bypass graft reduced rates of MACCE (OR 0.69, 95% CI 0.60-0.79), mainly driven by MI (OR 0.48, 95% CI 0.36-0.65) and revascularization (OR 0.53, 95% CI 0.45-0.64). Benefit of CABG for MACCE was consistent, although with different extent, across values of SYNTAX score (OR 0.76, 95% CI 0.59-0.97 for values < 32 and OR 0.63, 95% CI 0.47-0.84 for values ≥ 33) while was not evident for 'younger' patients (OR 0.83, 95% CI 0.65-1.07 vs. OR 0.65, 95% CI 0.51-0.84 for 'older' patients).

CONCLUSION

For patients with ULM disease followed-up for 5 years, no significant difference was observed in all-cause and cardiovascular death between PCI and CABG. Coronary artery bypass graft reduced risk of MI, revascularization, and MACCE especially in older patients and in those with complex coronary disease and a high SYNTAX score.

Surgical Risk Factors for Ischemic Stroke Following Coronary Artery Bypass Grafting. A Multi-Factor Multimodel Analysis

Background: Ischemic stroke after coronary artery bypass (CABG) has been often linked to aortic manipulation during surgery. Objectives: The objective of the study was to estimate the rate of postoperative ischemic stroke within 30 days from CABG by surgical risk factors alone or in combination. Methods: The multinomial propensity score for multiple treatments was used to create six models with a total of 16,255 consecutive patients undergoing isolated CABG. For each model, a different classification variable was used to stratify patients. Results: Balance achieved in all models was substantial, enabling unbiased estimation of the treatment estimand. Both off-pump techniques with (0.009; 95% CI 0.006-0.011) or without proximal anastomoses (0.005; 0.005-0.003), and surgery performed on the beating heart using cardiopulmonary bypass with (0.009; 0.006-0.011) or without proximal anastomoses (0.024; 0.021-0.029) showed a mean stroke estimate significantly lower than the other techniques. Off-pump surgery and on-pump surgery without an aortic cross-clamp yielded nearly equal incidences of stroke (0.012; 0.008-0.015 and 0.018; 0.012-0.023, respectively). Using an aortic cross-clamp significantly increased the stroke estimate (0.075; 0.061-0.088), whereas using a side-biting clamp did not (0.039; 0.033-0.044). The number of aortic touches (0.029; 0.026-0.031) and the number of proximal anastomoses (0.044; 0.035-0.047) did not significantly increase the incidence of stroke. Conclusions: Aortic cross-clamping was found to be the primary cause of post-CABG ischemic stroke. Instead, additional aortic manipulation from a side-biting clamp, on-pump surgery, multiple aortic touches, number of proximal anastomoses, and aortic cannulation were found not to increase the estimate of stroke significantly. Further research on this topic is warranted.

Simultaneous transaortic transcatheter aortic valve implantation and off-pump coronary artery bypass: An effective hybrid approach

INTRODUCTION

Transcatheter aortic valve implantation (TAVI) techniques are increasingly being adopted into clinical routine for various risk groups. Coronary artery disease (CAD) is seen in up to 75% of patients with severe aortic valve stenosis (AS) presenting with typical angina pectoris. Due to high mortality rates and procedural complications in these patients, a hybrid concept of simultaneous transaortic TAVI and off-pump coronary artery bypass (OPCAB) can be a feasible treatment option.

METHODS

Between April 2014 and July 2020, 10 consecutive high-risk patients underwent concomitant transaortic TAVI and OPCAB at our institution. All indications were discussed in Heart Team and decisions were made based on patients' comorbidities and complexity of CAD. The study endpoints were 30-day mortality, device success, and development of postoperative adverse events defined by the Valve Academic Research Consorium.

RESULTS

The mean age of the patients was 77.9 ± 7.1 years old. All patients presented with multiple comorbidities (mean logistic EuroSCORE 26.5 ± 12.3%, median EuroSCORE II 5.13% [interquartile range 4.2-9.5], mean STS-Score 6.04 ± 1.6%). Five patients (50%) presented with porcelain aorta. No conversion to conventional procedures was needed. 30-day mortality occurred in one patient (10%). Complete revascularization was achieved in seven (70%) of the patients. Device success rate was 100%. No paravalvular leakage was detected. No stroke, myocardial infarction or vascular complications were observed.

CONCLUSIONS

A hybrid approach combining transaortic TAVI and OPCAB might be a safe and feasible method of treatment in high-risk patients presenting with severe AS and CAD who are not eligible for conventional surgical or interventional solutions.

Use of native Y-saphenous vein graft in multi-vessel coronary bypass surgery

Objective. Demonstration of the advantages of using the natural Y shaped form of saphenous vein graft, which is the most preferred coronary bypass graft after internal thoracic artery (ITA). Methods. 32 patients with coronary artery disease who underwent coronary bypass grafting (CABG) with 3 or more distal anastomoses between January 2014 and January 2018 were included in the study. The natural Y saphenous vein grafts were used in these operations beside of LİMA-LAD anastomosis. Patients have been evaluated in terms of early and short-term survival, early cardiac events, the need for reoperation, and the need for percutaneous transluminal coronary angioplasty (PTCA). All patients were followed up directly by outpatient examination or telephone consultation. Results. New cardiac events, reoperation and death were not seen in the early postoperative period. Coronary angiography performed in 3 patients due to angina in the second and third years revealed that all anastomoses of y-saphenous grafts were open. No mortality was observed in the patients who were followed remotely. The duration of operation and the duration of cardiopulmonary bypass resulted in a reduction in the number of proximal anastomoses and the time by about 10 to 15 minutes. The incision in the saphenous leg was about 10 cm shorter for each anastomosis. Conclusion. The natural shaped Y saphenous vein can be used safely in multi vessel coronary artery disease (CAD) patients for reducing the surgical trauma.

On-pump beating-heart coronary artery bypass grafting in high-risk patients: A systematic review and meta-analysis

BACKGROUND

Operative technique for surgical myocardial revascularization in high-risk patients remains an argument of debate. On-pump coronary artery bypass graft (CABG) with cardioplegic arrest and off-pump CABG have intrinsic limitations. The hybrid approach of on-pump beating-heart CABG (OPBHC) has been proposed over the years with conflicting results. This systematic review and meta-analysis intends to summarize the contemporary literature.

METHODS

A literature search was conducted through major electronic databases. The systematic review provided a total of 279 articles, of those 17 studies were included in the present study.

RESULTS

Compared with on-pump CABG, OPBHC patients showed a preoperative higher risk profile but had reduced early mortality (risk ratio [RR], 0.59, 95% CI, 0.36-0.97) and reduced postoperative stroke (RR, 0.60, 95% CI, 0.39-0.91). Also, interesting trends towards reduced postoperative intra-aortic balloon pump use (RR, 0.56, 95% CI, 0.31-1.01) and myocardial infarction (RR, 0.48, 95% CI, 0.22-1.07) were observed. Baseline characteristics and postoperative complications were similar between OPBHC and off-pump CABG, but limited data are available. The risk of incomplete revascularization in OPBHC is lower than off-pump CABG (RR, 0.53, 95% CI, 0.33-0.87) but higher than conventional on-pump CABG (RR, 1.71, 95% CI, 1.23-2.39).

CONCLUSION

OPBHC is an effective technique to perform surgical revascularization in high-risk patients as preventing haemodynamic deterioration and guaranteeing adequate end-organ perfusion. OPBHC represents an alternative technique to on-pump and off-pump CABG, in those cases in which complications deriving from cardioplegic arrest or manipulation of the heart are more likely. For these reasons, OPBHC might be useful in patients with recent myocardial infarction or with left ventricular dysfunction.

Association Between Coronary Artery Bypass Surgical Techniques and Postoperative Stroke

Background The impact of the coronary artery bypass grafting (CABG) technique (on- versus off-pump, single versus multiple aortic clamping) on postoperative neurological outcome remains a matter of controversy. The aim of this study was to assess the association between the incidence of postoperative stroke and the degree of aortic manipulation in one of the largest contemporary CABG series. Methods and Results A retrospective, multicenter, international study was conducted in 25 388 patients undergoing isolated CABG procedures with on-pump CABG (ONCAB) or off-pump CABG (OPCAB) technique including single or multiple aortic clamping. Postoperative stroke was defined as a postoperative neurological deficit lasting more than 24 hours and associated with evidence of a brain lesion on computed tomography. The degree of aortic manipulation was assumed to be higher for on-pump versus off-pump surgery and for multiple versus single or no aortic clamping. Logistic regression and propensity matching were used. ONCAB procedures were performed in 17 231 cases and OPCAB in 8157. The incidence of postoperative stroke was significantly lower in the OPCAB group even after propensity matching (0.4% OPCAB versus 1.2% ONCAB, P=0.02). In the ONCAB group (but not in the OPCAB arm) the use of single aortic clamping was associated with significantly reduced postoperative stroke rate (odds ratio, 0.05; 95% CI, 0.008 to 0.07 [P<0.001]). Conclusions OPCAB and the use of single aortic clamping in the ONCAB arm were associated with a reduced incidence of postoperative stroke. Our data confirm a strong association between aortic manipulation and neurological outcome after CABG surgery.