On-pump beating heart versus off-pump myocardial revascularization-a propensity-matched comparison

Pre-operative anaemia-does it influence post-operative outcomes after isolated coronary artery bypass grafting?

Introduction

Preoperative anaemia is prevalent in a number of patients undergoing coronary artery bypass grafting. Studies provide conflicting results due to several reasons including variation in the threshold of haematocrit used to define anaemia. We aimed to assess the independent effect of preoperative anaemia on outcomes in patients undergoing off pump coronary artery bypass grafting (OPCAB).

Methods

In this retrospective study, patients with a hemoglobin level less than 11g/dl (haematocrit <33%) were considered to have moderate-to-severe anaemia as per the recommendations of the World Health Organization. Association between haematocrit <33% and mortality as well as adverse post-operative outcomes was assessed. Multivariable logistic regression (MLR) was carried out to assess the independent effect of haematocrit<33% on 30-day mortality and other outcomes.

Results

The study included 4957 consecutive patients undergoing isolated OPCAB surgery between 2015 and 2020. Out of 4957, 635 (12.8%) had haematocrit <33% and 4322 (81.2%) had haematocrit ≥33%. Patients with haematocrit < 33% had a 30-day mortality of 13 (2%) compared to 38 (0.9%) in patients without anaemia and had a greater requirement for blood transfusion (p<0.0001). It was also associated with an increased incidence of renal failure (p<0.0001), tracheostomy (p=.0.012) and risk of re-intubation (p=0.006). On multiple linear regression (MLR), haematocrit < 33% was not an independent predictor of 30-day mortality odds ratio (OR) 1.47, 95% confidence interval (CI) 0.745-2.917; p=0.26. It was however an important independent risk factor for blood transfusion (OR 1.80, 95% CI 1.29-2.50, p<0.001) and renal failure (OR 3.06, 95% CI 1.338-7.012, p=0.008). The receiver operating characteristic (ROC)-area under the curve (AUC) was 0.63 suggesting moderate discriminatory value of haematocrit < 33% for 30-day mortality.

Conclusion

Haematocrit < 33% is an important risk factor for adverse outcomes following isolated, primary, elective OPCAB.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s12055-024-01746-1.

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.