Mid-term outcomes of off-pump versus on-pump coronary artery bypass graft surgery; statistical challenges in comparison

Perioperative Red Blood Cell Transfusion and Long-Term Mortality in Coronary Artery Bypass Grafting: On-Pump and Off-Pump Analysis

Background/Objectives: The impact of different coronary artery bypass grafting (CABG) strategies, particularly on-pump versus off-pump techniques, on red blood cell (RBC) transfusions and their associated outcomes has not been fully investigated. This study aims to evaluate the association between RBC transfusion and survival in CABG patients, focusing on-pump strategy. Methods: Data from CABG patients were retrieved from the National Health Insurance Service database (2003 to 2019). Perioperative RBC transfusions were classified into three groups: no transfusion, RBC 1, and RBC ≥ 2 units. The primary endpoint was all-cause mortality rate. Subgroup analysis assessed the impact of RBC transfusion on mortality across the conventional on-pump (CCAB) and off-pump (OPCAB) groups. Results: Among the 6150 participants who underwent CABG, 2028 underwent CCAB and 4122 underwent OPCAB. The mean age was 66.2 ± 9.7 years, with a mean follow-up of 2.9 (2.53-3.35) years. Multivariable analysis showed a significant association between transfusion of ≥2 RBC units and increased mortality risk (HR 2.34 [1.65-3.32], p < 0.001). Subgroup analysis showed a similar trend in both CCAB and OPCAB groups (p for interaction = 0.2). Transfusion of ≥2 units significantly increased mortality in OPCAB (HR 2.28 [1.55-3.37], p < 0.001) but not in CCAB (HR 2.96 [0.97-9.06], p = 0.057). OPCAB and surgery at large volume center was associated with a reduced risk of RBC transfusion (p < 0.01). Conclusions: Increased RBC transfusion is associated with higher long-term mortality in patients undergoing CABG. Based on a large cohort predominantly consisting of OPCAB patients, OPCAB is associated with decreased RBC transfusion requirements.

Off-pump versus on-pump coronary artery bypass grafting in patients with chronic obstructive pulmonary disease: a systematic review and meta-analysis

INTRODUCTION

Off-pump coronary artery bypass graft surgery (OPCAB) has been suggested as superior to on-pump coronary artery bypass graft surgery (ONCAB) in certain high-risk subgroups, but its benefit in patients with chronic obstructive pulmonary disease (COPD) remains controversial. This meta-analysis aimed to evaluate OPCAB versus ONCAB outcomes in COPD patients.

METHODS

We followed PRISMA guidelines and searched PubMed, Embase, and the Cochrane Library in August 2024 for studies comparing OPCAB and ONCAB in COPD patients. Statistical analysis was conducted using Review Manager 5.4.1 and Rstudio with a fixed or random effects model.

RESULTS

Six studies with a total of 1,687 patients were included, of which 1,062 (62.95%) underwent OPCAB. The mean patient age was 63.6 years. OPCAB did not significantly affect all-cause mortality compared to ONCAB (OR 1.14; 95% CI 0.65-1.99). There were no significant differences in reintubation (OR 0.81; 95% CI 0.53-1.23), prolonged ventilation (OR 0.54; 95% CI 0.24-1.22), post-operative atrial fibrillation (OR 0.90; 95% CI 0.70-1.15), or ARDS (OR 0.43; 95% CI 0.14-1.33). However, ventilation time was significantly shorter in the OPCAB group (MD - 5.30 h; 95% CI - 7.22 to - 3.38).

CONCLUSION

OPCAB is associated with reduced ventilation time in COPD patients though it shows no significant difference in all-cause mortality or other post-operative complications compared to ONCAB.

Survival and Mid-Term Outcomes of On Pump vs. Off Pump Coronary Artery Bypass Grafting: A Propensity Score-Matched Analysis in A First Peruvian Registry

INTRODUCTION

The efficacy and outcomes of on-pump and off-pump coronary artery bypass grafting (CABG) remain uncertain, especially in Latin America. Our study aims to explore survival and shortand mid-term outcomes in the first reported Peruvian registry of patients treated with both techniques.

METHODS

This is an observational, analytical, and longitudinal study using a propensity score-matched (PSM) analysis in a single-center retrospective registry of 2280 patients during 2000-2019; 846 patients were analyzed after PSM (on-pump = 423 vs. off-pump = 423). Baseline variables, comorbidities, and major outcomes were studied in the short term (≤ 30 days) and in midterm (30 days-36 months) with major adverse cardiac and cerebrovascular events. The matched groups were compared by descriptive, multivariate, and Kaplan-Meier survival analyses.

RESULTS

Before PSM, previous myocardial infarction < 7 days (27.03%) and ejection fraction ≥ 50% (45.72%) were higher in off-pump CABG (P<0.05). After PSM, pre-surgery percutaneous coronary intervention (27.18% vs. 26.71%, P=0.049) and Society of Thoracic Surgeons risk score (1.98% vs. 1.90%, P=0.047) were higher in off-pump CABG. In the short term, there was higher mortality (2.12% vs. 0.47%, P=0.048), blood transfusion > 500 ml (57.91% vs. 7.56%, P=0.049), reintervention (7.32% vs. 2.12%, P=0.045), hospital stay (nine vs. four days, P=0.048), arrhythmia (9.92% vs. 4.96%, P=0.049), and renal failure (20.09% vs. 5.91%, P=0.009) in on-pump CABG. Long-term mortality (4.25% vs. 1.65%, P=0.044), myocardial infarction (17.02% vs. 7.32%, P=0.046), and repeat revascularization (17.49% vs. 8.26%, P=0.045) predominated in on-pump CABG. There was a higher 36-month adjusted survival for off-pump over on-pump CABG (97.88% vs. 93.63%, P=0.046).

CONCLUSION

This first reported Peruvian registry of patients treated with CABG has demonstrated that off-pump CABG is associated with lower shortand mid-term morbidity and mortality rates and better-adjusted survival rates compared to on-pump CABG; however, further multicenter studies in Latin America are needed to elucidate its benefits over classic on-pump CABG.

Prognostic factors of surgical management for heart failure patients with reduced left ventricular ejection fraction

Objectives

There are many available pharmaceutical and surgical management for Coronary artery disease (CAD) patients. However, coronary artery bypass grafting (CABG) is the preferred treatment modality for CAD patients with low ejection fraction (EF) in view of the more favorable outcomes. This study aimed to determine the associated factors of poor outcomes post-CABG for heart failure patients with reduced left ventricular ejection fraction who underwent on-pump and off-pump CABG.

Methods

A retrospective review of CAD patients who underwent isolated on-pump CABG (ONCAB) or off-pump CABG (OPCAB) in Beijing Anzhen Hospital Affiliated with Capital Medical University from January 2013 to March 2021. Only those with confirmed reduced left ventricular ejection fraction (LVEF) ≤40% on preoperative echocardiography were included. By analyzing the clinical and surgical data, postoperative mortality and morbidity, as well as major cardiovascular and cerebrovascular adverse events (MACCE) as endpoints, certain risk factors of the postoperative complications were identified.

Results

Out of the 500 patients, 64 developed MACCE, of which 14 (13.6%) occurred in the ONCAB group and 50 (14.0%) in the OPCAB group. Univariate COX regression analysis showed that age ≥65 years, history of diabetes, and preoperative renal insufficiency were independent risk factors for postoperative primary endpoint events in CAD patients with heart failure with reduced ejection fraction (HFrEF). Following the multivariate COX regression analysis, in addition to the above three risk factors, a history of previous percutaneous coronary angiography (PCI) intervention was also a risk factor for the occurrence of the primary endpoints post-CABG.

Conclusion

Based on the analysis, significant predictors of post-CABG MACCE in patients with HFrEF included being older than 65 years old, having diabetes, preoperative renal insufficiency, and having previous PCI.

The COVID-19 pandemic and temporal change in metabolic risk factors for cardiovascular disease: A natural experiment within the HELIUS study

The coronavirus disease 2019 (COVID-19) pandemic, including the restrictive measures taken to reduce the spread of the virus, negatively affected people's health behavior. We explored whether the pandemic also had an effect on metabolic risk factors for cardiovascular disease (CVD) in women and men. We conducted a natural experiment, using data from 6962 participants without CVD at baseline (2011-2015) of six ethnic groups of the HELIUS study in Amsterdam, the Netherlands. We studied whether participants whose follow-up measurements were taken within the 11 months before the pandemic (control group) differed from those whose measurements were taken taken within 6 months after the first lockdown (exposed group). Using sex-stratified linear regressions with inverse probability weighting, we compared changes in baseline- and follow-up data between the control and exposed group in six metabolic risk factors: systolic and diastolic blood pressure (SBP, DBP), total cholesterol (TC), fasting plasma glucose (FPG), hemoglobin A1c (HbA1c), and estimated glomerular filtration rate (eGFR). Next, we explored the mediating effect of changes in body-mass index (BMI), alcohol, smoking, depressive symptoms and negative life events at follow-up. We observed less favorable changes in SBP (+1.12mmHg for women, +1.38mmHg for men), DBP (+0.85mmHg, +0.80mmHg) and FPG (only in women, +0.12 mmol/L) over time in the exposed group relative to the control group. Conversely, changes in HbA1c (-0.65 mmol/mol, -0.84 mmol/mol) and eGFR (+1.06 mL/min, +1.04 mL/min) were more favorable in the exposed compared to the control group, respectively. Changes in SBP, DBP, and FPG were partially mediated by changes in behavioral factors, in particular BMI and alcohol consumption. Concluding, the COVID-19 pandemic, in particular behavioral changes associated with restrictive lockdown measures, may have negatively affected several CVD risk factors, in both women and men.

Intensive care unit length of stay and mortality comparison between on-pump and off-pump coronary artery bypass graft: a retrospective study

BACKGROUND

Recently, coronary artery bypass graft (CABG) techniques, both on-pump (ONCABG) and off-pump (OPCABG), were compared to seek the most effective approach to reduce the cost of prolonged intensive care unit length of stay (ICU LOS) and mortality. This study aims to compare ICU LOS and mortality in ONCABG and OPCABG.

RESULTS

Demographic data of 1569 patients show the variance of characteristics. The analysis shows significant and longer ICU LOS in OPCABG than ONCABG (2.151 ± 0.100 vs. 1.573 ± 0.246 days; p = 0.028). Similar results were demonstrated after adjustment of covariates effects (3.146 ± 0.281 vs. 2.548 ± 0.245 days; p = 0,022). Logistic regression shows no significant difference in mortality in OPCABG and ONCABG, both in the unadjusted (OR [CI 95%] 1.133 [0.485-2.800]; p = 0.733) and the adjusted models (OR [CI 95%] 1.133 [0.482-2.817]; p = 0,735).

CONCLUSION

ICU LOS was significantly longer in OPCABG patients than in ONCABG patients in the author's centre. There was no significant difference in mortality between the two groups. This finding highlights a discrepancy between recently published theories and the practices observed in the author's centre.

Comparison of in-hospital outcomes after coronary artery bypass graft surgery in elders and younger patients: a multicenter retrospective study

OBJECTIVES

We aimed to identify in-hospital outcomes in young (≤ 65 years) and old (> 65 years) patients after coronary artery bypass grafting (CABG) by analyzing the effect of age on adverse events after on-pump or off-pump CABG.

METHODS

Patients older than 65 years were defined as older patients and others were defined as younger patients. The qualitative data were compared by chi-square or Fisher's exact tests. The quantitative data were compared by the two-sample independent t-test or Mann-Whitney U test. Multifactor binary logistic regression was used to control for confounders and to investigate the effect of age on dichotomous outcome variables such as death.

RESULTS

In the on-pump CABG population, the postoperative in-hospital mortality, the incidence of postoperative symptomatic cerebral infarction (POSCI) and postoperative atrial fibrillation (POAF) was higher in older patients than in younger patients (P value < 0.05), and age > 65 years was associated with postoperative in-hospital mortality (OR = 2.370, P value = 0.031), POSCI (OR = 5.033, P value = 0.013), and POAF (OR = 1.499, P value < 0.001). In the off-pump CABG population, the incidence of POAF was higher in older patients than in younger patients (P value < 0.05), and age > 65 years was associated with POAF (OR = 1.392, P value = 0.011).

CONCLUSION

In-hospital outcomes after CABG are strongly influenced by age. In on-pump CABG, the risk of postoperative death, POSCI, and POAF was higher in older patients, and in off-pump CABG, the risk of POAF was higher in older patients.

Single-blind, randomized study comparing clinical equivalence of trulene and prolene polypropylene sutures in elective primary coronary artery bypass graft surgery

BACKGROUND

Coronary artery bypass graft surgery (CABG) is one of the principle therapies for coronary artery disease, as it improves survival rate and quality of life (QoL). Polypropylene suture is commonly used in vascular and cardiac surgeries for anastomosis due to its long-term tensile strength and minimal tissue trauma. This study compared the clinical equivalence of Trulene® (Healthium Medtech Limited) and Prolene® (Ethicon-Johnson & Johnson) polypropylene sutures regarding incidence of myocardial infarction, stroke, renal failure and cardiac death (MACCE) occurring up to 26 weeks' period post-CABG surgery.

METHODS

This multicenter, prospective, two-arm, parallel-group, randomized (1:1), single-blind study (n = 89) was conducted between August 2020 and September 2021. The primary endpoint, post-surgery cumulative incidence of MACCE was evaluated. In addition, anastomotic revision, surgical site infection (SSI), operative time, length of post-operative hospital stay, repeat revascularization, intraoperative suture handling characteristics, time taken to return to work and resume normal day to day activities, subject satisfaction score and QoL, and other adverse events were also recorded.

RESULTS

A total of 80 (89.89%) males and 9 (10.11%) females participated in the study. No incidence of MACCE was recorded in any of the study participants. Non-significant difference was observed in anastomotic revision, SSI, operative time, post-operative hospital stay, revascularization, return to work and normal day-to-day activities, subject satisfaction score and QoL, and intraoperative handling parameters (except ease of passage) between the treatment groups, Trulene® and Prolene®. Compared to screening visit, proportion of subjects with 'no problems' for each QoL dimension and the mean visual analogue scale increased with each subsequent follow-up visit.

CONCLUSION

Trulene® polypropylene suture is clinically equivalent to Prolene® polypropylene suture and is safe and effective for anastomosis construction in CABG surgery during a routine clinical procedure. Trial registration CTRI Registration No.: CTRI/2020/05/025157 (Registered on: 13/05/2020).

The Significance of Simple Inflammatory Markers in Off Pump Surgery-Review

The inflammatory background of coronary artery disease is gaining more attention in recent times. Off pump surgery is minimally invasive type of surgical revascularization with relatively low number of applications in cardiac surgery centers worldwide that allows for perioperative inflammatory reactions minimalization. The simple inflammatory markers (neutrophil to lymphocyte ratio (NLR), monocyte to lymphocyte ratio (MLR), platelets to lymphocyte ratio (PLR), systemic inflammatory index (SII), systemic inflammatory response index (SIRI), aggregate index of systemic inflammation (AISI)) possess a clinically significant impact on patients' prognosis and may help to improve patients' long-term results. The review presents the current knowledge regarding their utility in clinical practice. Assessment of inflammatory indices obtained from whole blood count analysis allows to indicate those patients who need scrupulous follow-up due to predicted worse long-term survival. Perioperative measurement and analysis of simple whole blood counts is inexpensive and easily available and may improve the results of surgical revascularization by better identification of patients at higher risk of worse outcomes.

BMI modifies HDL-C effects on coronary artery bypass grafting outcomes

BACKGROUND

Despite the recognized implications of high-density lipoprotein cholesterol (HDL-C) in cardiovascular diseases, the role of body mass index (BMI) in HDL-C association with cardiovascular outcomes remains unclear. This study investigated the possible modifying implications of BMI on the correlation between HDL-C and coronary artery bypass grafting (CABG) outcomes.

METHODS

The present cohort included isolated CABG patients (median follow-up: 76.58 [75.79-77.38] months). The participants were classified into three groups: 18.5 ≤ BMI < 25 (normal), 25 ≤ BMI < 30 (overweight), and 30 ≤ BMI < 35 (obese) kg/m². Cox proportional hazard models (CPHs) and restricted cubic splines (RCSs) were applied to evaluate the relationship between HDL-C and all-cause mortality as well as major adverse cardio-cerebrovascular events (MACCEs) in different BMI categories.

RESULTS

This study enrolled a total of 15,639 patients. Considering the final Cox analysis among the normal and overweight groups, HDL-C ≥ 60 was a significant protective factor compared to 40 < HDL-C < 60 for all-cause mortality (adjusted hazard ratio (aHR): 0.47, P: 0.027; and aHR: 0.64, P: 0.007, respectively). However, the protective effect of HDL-C ≥ 60 was no longer observed among patients with 30 ≤ BMI < 35 (aHR: 1.16, P = 0.668). RCS trend analyses recapitulated these findings; among 30 ≤ BMI < 35, no uniform inverse linear association was observed; after approximately HDL-C≈55, its increase was no longer associated with reduced mortality risk. RCS analyses on MACCE revealed a plateau effect followed by a modest rise in overweight and obese patients from HDL-C = 40 onward (nonlinear association).

CONCLUSIONS

Very high HDL-C (≥ 60 mg/dL) was not related to better outcomes among obese CABG patients. Furthermore, HDL-C was related to the post-CABG outcomes in a nonlinear manner, and the magnitude of its effects also differed across BMI subgroups.

Off-pump versus on-pump coronary artery bypass graft surgery outcomes in patients with severe left ventricle dysfunction: inverse probability weighted study

Objective

In this study we aimed to compare on-pump and off-pump coronary artery bypass grafting (CABG) outcomes in patients presented with low left ventricular ejection fraction (EF) as a high-risk group of patients.

Methods

In this registry-based study from 2014 and 2016, all patients with severe left ventricular dysfunction (EF less than 35%) were included and followed until 2020. The median follow-up period was 47.83 [38.41, 55.19] months. Off pump CABG (OPCABG) was compared with on-pump CABG (ONCABG) in terms of mid-term non-fatal cardiovascular events (CVEs) and all-cause mortality. Propensity score method (with inverse probability weighting technique) was used to compare these two groups.

Results

From 14,237 patients who underwent isolated CABG, 2055 patients with EF ≤ 35% were included; 1705 in ONCABG and 350 patients in OPCABG groups. Although OPCABG was associated with lower risk of 30-days mortality (Odds Ratio [OR]: 0.021; Confidence Interval [CI] 95% [0.01, 0.05], P < 0.001); there was no significant difference between OPCABG and ONCABG in term of mid-term mortality and non-fatal CVEs ((Hazard ratio [HR]: 0.822; 95%CI [0.605, 1.112], p = 0.208) and (HR: 1.246; 95%CI [0.805, 1.929], p = 0.324), respectively). Patients with more than three traditional coronary artery disease risk factors, had more favorable outcomes (in terms of mid-term mortality) if underwent OPCABG (HR: 0.420; 95%CI [0.178, 0.992], p = 0.048).

Conclusion

OPCABG was associated with lower risk of 30-days mortality; however, mid-term outcomes were comparable in both OPCABG and ONCABG techniques.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02895-0.