Off-pump versus on-pump coronary artery bypass grafting in elderly patients at 30 days: a propensity score matching study

BACKGROUND

Elderly patients are at increased risk of perioperative morbidity and mortality after conventional on-pump coronary artery bypass grafting (ONCABG). This study was to determine whether such high-risk population would benefit from off-pump coronary artery bypass grafting (OPCABG).

METHODS

A retrospective analysis was performed on patients aged 65 years or older who underwent isolated coronary artery bypass grafting for the first time in Wuhan Union Hospital from January 2015 to January 2021. We used propensity score matching to adjust for differences in baseline characteristics between the ONCABG and OPCABG groups. Morbidity and mortality within 30 days after surgery were compared between the two groups. All operations were performed by experienced cardiac surgeons.

RESULTS

A total of 511 patients (ONCABG 202, OPCABG 309) were included. After 1:1 matching, the baseline characteristics of the two groups were comparable (ONCABG 173, OPCABG 173). The OPCABG group had higher rate of incomplete revascularization (13.9% vs. 6.9%; P = .035) than the ONCABG group. However, OPCABG reduced the risk of postoperative renal insufficiency (15.0% vs. 30.1%; P = .001) and reoperation for bleeding (0.0% vs. 3.5%; P = .030). There were no significant differences in early postoperative mortality, myocardial infarction, stroke, and other outcomes between the two groups.

CONCLUSIONS

OPCABG is an alternative revascularization method for elderly patients. It reduces the risk of early postoperative renal insufficiency and reoperation for bleeding.

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.

Preoperative Risk Prediction Score for and In-Hospital Clinical Outcomes of Reperfusion Ventricular Fibrillation After Release of Aortic Cross-Clamps: A Retrospective Study

Reperfusion ventricular fibrillation (VF) is a common arrhythmia after cardiac surgery. Predictors of reperfusion VF and its relationships with the adverse prognosis are still unclear. This study aimed to identify a risk score model to predict reperfusion VF and its effect on in-hospital outcomes. The authors enrolled 1,024 consecutive patients undergoing cardiac surgery, and a total of 823 patients were included in the study. A novel risk score model was developed following logistic regression analysis of the predictors of reperfusion VF. The receiver operating characteristic curve was used to validate this model, and the effect of VF on prognosis was later identified in multivariate or Kaplan-Meier analyses. Risk factors for reperfusion VF occurrence included weight >55 kg, preoperative left ventricular ejection fraction <50%, prior stroke, hypertension, aortic valve replacement, HTK solution, and the use of ≥3 grafts in coronary artery bypass grafting. A novel risk score model was developed using the abovementioned variables, and points were assigned to each risk factor according to its odds ratio. A high score (>6) predicted greater than 65% of patients with VF occurrence. Reperfusion VF increased the risk of in-hospital cardiovascular death (p = 0.03) and renal replacement therapy postoperatively (p = 0.022). More attention should be given to reperfusion VF due to an adverse postoperative prognosis, and the developed risk score model may predict this risk.

Comparative effects of on-pump versus off-pump coronary artery bypass grafting surgery on serum cytokine and chemokine levels

Coronary artery bypass grafting (CABG) surgery with two methods (on-pump or off-pump) can be used to rescue individuals with severe coronary artery disease (CAD). Each method might cause an inflammatory response, which can lead to some complications. The aim of this study was to compare the changes in serum concentrations of IFN-γ, tumor necrosis factor (TNF)-α, interleukin (IL)-1α, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, VEGF, MCP-1, and epidermal growth factor between the two CABG surgery methods. Forty-eight patients (22 = on-pump, 26 = off-pump) who underwent on-pump or off-pump CABG surgery were enrolled in this study. Serum cytokines levels were measured in two blood samples, the first sample was taken from each patient in the morning of the day of surgery after a 12-hr fasting and the second sample on the first postoperative day at 24-hr after surgery. In baseline, comparisons between the two groups of on-pump/off-pump surgery did not show any significant difference in demographic data, anthropometric parameters, lipid profile indices, and high-sensitivity C-reactive protein levels (p > .05). There was a significant difference between the serum levels of IL-4, IL-6, IL-10, vascular endothelial growth factor (VEGF), IFN-γ, and MCP-1 in patients with on-pump surgery and a significant increase in serum IL-6 (p < .001), IL8 (p < .05), VEGF (p < .001), and IFN-γ (p < .01) levels in patients with off-pump surgery in post-operation stage compared to pre-operation. Cardiopulmonary pump in patients under CABG surgery can activate systemic inflammation and the changes of serum cytokines levels in off-pump CABG were lower compared with on-pump CABG.

On-pump beating heart versus conventional on-pump coronary artery bypass grafting on clinical outcomes: a meta-analysis

Background

A hybrid surgery method, on-pump beating heart coronary artery bypass graft (ON-BH CABG), is supposed to be a promising technology for coronary artery revascularization. Here, we conducted a comprehensive meta-analysis of the data derived from published studies on ON-BH CABG and conventional on-pump coronary artery bypass graft (C-CABG) to compare their short-term and long-term clinical outcomes.

Methods

We searched major electronic databases and 24 studies incorporating 6,862 patients (1,847 ON-BH CABG and 5,015 C-CABG) were included eventually, and 9 studies of them were focusing on high-risk patients.

Results

Compared with ON-BH CABG, C-CABG was associated with a higher risk in early mortality [odds ratio (OR), 1.45; 95% confidence interval (CI), 1.09 to 1.93; P=0.01], myocardial infarction (MI) (OR, 2.60; 95% CI, 1.41 to 4.78; P<0.01), low output syndrome (LOS) (OR, 2.56; 95% CI, 1.55 to 4.23; P<0.01), renal failure (OR, 1.84; 95% CI, 1.38 to 2.44; P<0.01). In contrast, there was no significant difference in long-term survival [hazard ratio (HR), 1.08; 95% CI, 0.81 to 1.43; P=0.60]. In systematic analysis of the studies in high-risk patients, ON-BH CABG showed a lower risk in terms of early mortality, intra-aortic balloon pump (IABP) usage, renal failure, hemodialysis, MI and pulmonary complication. No significant difference was observed in the long-term survival between ON-BH CABG and C-CABG.

Conclusions

With experienced and adept surgical team and mature ON-BH technology, ON-BH CABG may reduce the risk of postoperative death and complications in some patients. It might be an attractive alternative for high-risk patient populations.

Beating-heart on-pump coronary artery bypass grafting vs. off-pump coronary artery bypass grafting: a systematic review and meta-analysis

Background

Beating-heart on-pump coronary artery bypass grafting (CABG), otherwise known as BH-ONCAB, can reduce myocardial injury by preserving native coronary blood flow while maintaining hemodynamic stability by the effective support of cardiopulmonary bypass (CPB). This study aimed to identify whether BH-ONCAB confers a survival, mortality, or morbidity benefit over off-pump CABG (OPCAB).

Methods

A systematic literature review identified 18 studies incorporating 5,615 patients (1,548 BH-ONCAB and 4,067 OPCAB cases) who satisfied the inclusion criteria. Outcome measures were meta-analyzed using random-effects modeling. Between-study heterogeneity was investigated through quality assessment and risk of bias analysis.

Results

The results demonstrated comparable early mortality and long-term survival between BH-ONCAB and OPCAB coronary revascularization with no significant statistical differences. The incidences of stroke, renal failure, blood loss, and arrhythmias were significantly higher in patients who underwent BH-ONCAB than patients who underwent OPCAB. However, BH-ONCAB conferred lower rates of incomplete revascularization and greater numbers of distal anastomoses.

Conclusions

BH-ONCAB is a safe and comparable alternative to OPCAB in terms of early mortality and late survival. BH-ONCAB may confer particular advantages in preventing incomplete revascularization and allowing more distal anastomoses compared to OPCAB. However, BH-ONCAB was associated with more postoperative complications due to the use of CPB. Future work should focus on larger matched studies and multicenter randomized controlled trials to optimize our surgical revascularization strategies.

Ten-year outcomes after off-pump versus on-pump coronary artery bypass grafting: Insights from the Arterial Revascularization Trial

OBJECTIVE

We performed a post hoc analysis of the Arterial Revascularization Trial to compare 10-year outcomes after off-pump versus on-pump surgery.

METHODS

Among 3102 patients enrolled, 1252 (40% of total) and 1699 patients received off-pump and on-pump surgery (151 patients were excluded because of other reasons); 2792 patients (95%) completed 10-year follow-up. Propensity matching and mixed-effect Cox model were used to compare long-term outcomes. Interaction term analysis was used to determine whether bilateral internal thoracic artery grafting was a significant effect modifier.

RESULTS

One thousand seventy-eight matched pairs were selected for comparison. A total of 27 patients (2.5%) in the off-pump group required conversion to on-pump surgery. The off-pump and on-pump groups received a similar number of grafts (3.2 ± 0.89 vs 3.1 ± 0.8; P = .88). At 10 years, when compared with on-pump, there was no significant difference in death (adjusted hazard ratio for off-pump, 1.1; 95% confidence interval, 0.84-1.4; P = .54) or the composite of death, myocardial infarction, stroke, and repeat revascularization (adjusted hazard ratio, 0.92; 95% confidence interval, 0.72-1.2; P = .47). However, off-pump surgery performed by low volume off-pump surgeons was associated with a significantly lower number of grafts, increased conversion rates, and increased cardiovascular death (hazard ratio, 2.39; 95% confidence interval, 1.28-4.47; P = .006) when compared with on-pump surgery performed by on-pump-only surgeons.

CONCLUSIONS

The findings showed that in the Arterial Revascularization Trial, off-pump and on-pump techniques achieved comparable long-term outcomes. However, when off-pump surgery was performed by low-volume surgeons, it was associated with a lower number of grafts, increased conversion, and a higher risk of cardiovascular death.

Which aortic clamp strategy is better to reduce postoperative stroke and death: Single center report and a meta-analysis

BACKGROUND

Stroke is severe complication of coronary artery bypass grafting (CABG) which may be associated with clamp strategy, there are 2 strategies to clamp aorta including single aortic clamp (SAC) and partial aortic clamp (PAC). It is controversial that which clamping strategy is better to reduce the postoperative stroke and death, so this study aims to investigate which is better for reducing postoperative stroke and death within 30 days.

METHODS

We collected 469 patients who had on-pump CABG in Fuwai Hospital during January 2014 to July 2015. The SAC group consisted of 265 patients while the PAC group included 204 patients. We compared the 2 group patient difference. At the same time, 12 studies were identified by systematic search. The odds ratio (OR) was used as effect index to compare SAC and PAC strategy by fix-effect modeling. We also tested heterogeneity and publication bias. The primary end point of study was occurrence of postoperative stroke within 30 days of operation, the second end point of study was the incidence of 30-day mortality.

RESULTS

The single center retrospective study showed that the patients in the SAC group were older than those in the PAC group (62.5 ± 8.1 vs 60.3 ± 8.0 years, P = .01). The proportions of peripheral vascular disease and hypertension of SAC were higher than PAC (71 (26.8%) versus 36 (17.6%), P = .02; 183 (69.1%) versus 115 (56.4%), P = .01, respectively). Besides, the number of vascular anastomosis was more in the SAC group (3.29 ± 0.74 versus 2.97 ± 0.974, P < .001). The linear-regression analysis suggested that the time of cardiopulmonary bypass of SAC was shorter than the PAC group (93.2 ± 22.4 vs.103.4 ± 26.8 minutes, P-regression < .001) and postoperative death within 30-days was similar (1 (0.4%) vs. 2 (1.0%), P-regression = .47). There was no stroke occurring in both the groups. And the meta-analysis suggested the postoperative stroke and death within 30-days were similar between SAC group and PAC group (OR: 0.78, 95% CI: 0.58-1.06; OR: 0.82, 95% CI: 0.61-1.10; respectively). Moreover, subgroup meta-analysis also had the same results.

CONCLUSION

There was no significant difference between SAC and PAC clamping strategy on postoperative stroke and death within 30-days; however, SAC can reduce the usage time of cardiopulmonary bypass.

Effect of different surgical type of coronary artery bypass grafting on kidney injury: A propensity score analysis

Acute kidney injury (AKI) after coronary artery bypass grafting (CABG) is associated with a less favorable outcome. Off-pump surgery results in lower kidney dysfunction than conventional on-pump arrest surgery. On-pump arrest surgery results in a lower revascularization rate compared with off-pump surgery. On-pump beating heart (OPBH) CABG combines the advantages of beating heart surgery and cardiopulmonary bypass. This study compared the renal outcomes of 3 cardiac surgical methods. From January 2010 to December 2012, 373 patients who underwent on-pump CABG were enrolled. Propensity analysis was performed to compare the postoperative outcomes of postoperative AKI, renal replacement therapy (RRT), intensive care unit (ICU) stay, mortality, and extubating time. In total, 98 patients received conventional on-pump surgery, 160 received OPBH surgery, and 115 received off-pump surgery. The Society of Thoracic Surgeons scores of these 3 groups were 6.1 ± 13.6, 7.4 ± 13.6, and 5.6 ± 10.9, respectively. Propensity analysis revealed lower AKI incidence in the off-pump group than in the on-pump surgery group. No substantial differences were observed in mortality, RRT, and the ICU stay between the off-pump and OPBH surgery groups. Among the 3 surgical methods, off-pump surgery results in lower AKI incidence. The short-term outcome, including kidney function, of OPBH surgery is similar to that of the off-pump group. Therefore, OPBH surgery is a considerable choice for patients with a high surgical risk.

Impact of cardiac surgery on the expression of CD40, CD80, CD86 and HLA-DR on B cells and monocytes

OBJECTIVE

We measured and compared changes in the percentage of cells expressing CD80, CD86, CD40, HLA-DR and the expression of these molecules on B cells and monocytes of patients who underwent either on-pump, mini on-pump or off-pump cardiac surgery.

METHODS

Blood samples from patients who underwent either on-pump, mini on-pump or off-pump cardiac surgery were collected before surgery, instantly after surgery and on the 1(st), 3(rd) and 7(th) days after surgery. Surface expression of CD80, CD86, CD40 and HLA-DR molecules was determined by flow cytometry.

RESULTS

Our results show that all three surgical techniques altered the expression of these molecules, as well as the percentage relative number of specific cell populations. We identified statistically significant differences when comparing different surgical techniques. On-pump surgery revealed a more pronounced impact on the phenotype of immune system cells than the other techniques. Therefore, it is likely that the function of immune cells is changed the most by on-pump surgery. We found a lower decrease in the number of CD80(+) monocytes and a lower drop in the CD40 expression on monocytes in off-pump patients in comparison with on-pump patients.

CONCLUSION

All the types of cardiac surgical techniques, off-pump, on-pump and modified mini-invasive on-pump, are associated with changes in CD80, CD86, CD40 and HLA-DR expression. We found several significant differences in the expression of the selected molecules when we compared all three groups of patients.

Comparison of off-pump and on-pump coronary endarterectomy for patients with diffusely diseased coronary arteries: early and midterm outcome

BACKGROUND

Coronary endarterectomy (CE) is an alternative for the diffusely diseased left anterior descending (LAD), but its mid and long term results are largely questionable. This study is to compare the early to mid-term results between off-pump and on-pump coronary endarterectomy with coronary artery bypass grafting.

METHODS

212 consecutive patients underwent CE and bypass grafting for diffusely diseased LAD. Ninety-two patients undergoing CE with off-pump (group off-pump) were compared with 120 patients undergoing CE with on-pump (group on-pump). The main preference for selection to an off-pump CE surgery were the preoperative high risk factors, especially previous cerebrovascular accident、chronic obstructive pulmonary disease (COPD)、calcified ascending aorta and right coronary artery (RCA) critical stenosis >90%.

RESULTS

There were three deaths in this group with total operative mortality of 1.4%. The perioperative mortality of group off-pump (1.1%) was similar with that of group on-pump (1.7%). The postoperative myocardial infarctions rate was 2.8%. There was no significant difference as for the morbidity between the group off-pump and group on-pump. Among survivors, the patency rate of the LIMA-LAD anastomosis was 89.4%. There was no difference as for the grafts patency rate between the two groups. Kaplan-Meier survival revealed no significant difference between the two groups. Kaplan-Meier freedom from cardiac events requiring hospital re-admission and angina recurrence were similar in both groups.

CONCLUSIONS

On-pump or off-pump CE is a good technique with the same early and mid-term outcomes. In the series of off-pump CE, we have shown that the effect of OPCABG with CE appears to be durable, and mid-term clinical outcomes are encouraging. Despite the higher risk profile, hospital mortality and major complications in our study are comparable to those for CCE.

Neurocognitive impairment after off-pump and on-pump coronary artery bypass graft surgery - an Iranian experience

BACKGROUND

Coronary artery bypass graft (CABG) surgery is one of the most commonly performed surgical procedures worldwide, and it may be accompanied by postoperative neurocognitive impairment. Although this complication has been attributed to the use of cardiopulmonary bypass, it is still a matter of debate whether the switch from on-pump to off-pump technique affects the cognitive function.

OBJECTIVE

The aim of this study was to compare the impact of the on-pump and off-pump techniques on neurocognitive impairment in low-risk CABG surgery groups.

METHODS

In a descriptive and analytic study, 201 CABG patients with left-ventricular ejection fraction >30%, and without cardiac arrhythmia were enrolled. Before the elective operation, all patients underwent neurological examination and neurocognitive test, Mini-Mental State Examination (MMSE). Two months following the operation, both on- and off-pump, the patients were re-examined by MMSE to detect any neurocognitive impairment.

RESULTS

Out of 154 patients included in the study, 95 (61.6%) and 59 (38.3%) patients were in off-pump and on-pump groups, respectively. Mean age of the patients was 57.17 ± 9.82 years. A 2-month postoperative neurocognitive impairment was detected among 17 patients of on-pump group (28.8%) and in 28 cases of off-pump group (29.4%) (P = 0.54). The mean postoperative MMSE scores were not comparable between groups (25.01 ± 4.49 in off-pump group versus 23.73 ± 4.88 in on-pump group, P = 0.09).

CONCLUSION

The present study revealed that in low-risk patients undergoing CABG surgery, either the techniques of on-pump or off-pump did not differ regarding the neurocognitive outcome 2 months after the procedure.

High-sensitivity C-reactive protein (hs-CRP) and tumor necrotizing factor-alpha (TNF-alpha) after on- and off- pump coronary artery bypass grafting

INTRODUCTION

Coronary artery bypass grafting (CABG) is one of the most frequently performed operations around the world. The aim of this study is to evaluate high-sensitivity C-reactive protein (hs-CRP) and tumor necrosis factor-alpha (TNF-alpha) differences between on-pump and off-pump coronary surgery.

METHODS

In this prospective study, 90 patients with coronary artery disease referred for CABG were enrolled from July 2006-November 2007. Levels of hs-CRP and TNF-alpha were measured by ELISA using commercial kits

RESULTS

hs-CRP levels significantly (p<0.001) increase after CABG. But no difference between off-pump and on-pump groups was noted for hs-CRP and TNF-alpha levels (p=0.4, p=0.8).

CONCLUSIONS

There was no difference in high-sensitivity C-reactive protein (hs-CRP) and TNF-alpha between on-pump and off-pump CABG surgery.

Platelet hyperreactivity in response to on- and off-pump coronary artery bypass grafting

Hypercoagulability has been reported after off-pump coronary artery bypass grafting (OPCAB) compared with patients undergoing standard coronary artery bypass grafting (CABG) with cardiopulmonary bypass. The aim of this study was to evaluate the changes in platelet reactivity in response to cardiac surgery, both OPCAB and CABG. Platelet reactivity was monitored pre- and postoperatively (days 1 and 4) in elective OPCAB (n = 29) and CABG (n = 24) patients using the maximal amplitude (MA) parameter obtained with thrombelastography. Platelet reactivity was also examined at 1 month in 30 of the 53 patients. Twenty-three percent of the patients (12/53) had a preoperative MA value above normal reference value (MA > 69 mm). By postoperative day 4, 88% of the patients presented with an MA > 69 mm, and significant increases in MA were shown in both groups (p < .0001). Of the 30 patients examined at 1 month after surgery, 75% of the patients with high preoperative MA (6/8) remained at this level. In contrast, only 4.5% of patients with normal preoperative MA (1/22) presented with high MA at day 30. MA has previously been shown to correlate with the incidence of thrombotic and ischemic complications and this study identified 23% of patients needing coronary bypass surgery to be at high risk for recurrent ischemic events at 1 month after surgery, based on the MA. These results suggest that a more aggressive antithrombotic treatment might be warranted for patients undergoing coronary artery bypass grafting, both OPCAB and CABG, presenting with a high MA pre- and postsurgery.