10-Year Mortality of Off-Pump Versus On-Pump Coronary Artery Bypass Grafting: An Updated Systematic Review, Meta-Analysis, and Meta-Regression

The longstanding debate on off-pump coronary artery bypass grafting (OPCAB) versus on-pump coronary artery bypass grafting (ONCAB) has primarily focused on short-term and mid-term outcomes, with limited attention to long-term survival. This study aims to address this gap by providing an updated analysis of 10-year mortality rates after OPCAB versus ONCAB. We have conducted a systematic review and meta-analysis, incorporating 22 studies comprising 69,449 patients. The primary end point was all-cause mortality at 10 years. Meta-regression analysis explored sources of heterogeneity. The meta-analysis revealed no significant difference in long-term all-cause mortality between OPCAB and ONCAB (hazard ratio 1.000, 95% confidence interval 0.92 to 1.08, p = 0.95). Although substantial heterogeneity existed across studies, meta-regression identified older age as a significant factor favoring OPCAB. However, patient characteristics like gender, co-morbidities, and graft numbers did not significantly influence the choice of surgical technique. In conclusion, this study challenges historical concerns regarding OPCAB's quality of revascularization and long-term survival demonstrating comparable outcomes to ONCAB in well-selected patients when performed by experienced surgeons. The results emphasize the importance of surgeon proficiency and advocate for recognizing surgical revascularization as a subspecialty.

Cardiac surgery in the morbidly obese

BACKGROUND

Obesity rates globally continue to rise and in turn the body mass index (BMI) of patients undergoing cardiac surgery is set to mirror this. Patients who are Class III obese (BMI ≥ 40) pose significant challenges to the surgical teams responsible for their care and are also at high risk of complications from surgery and even death. To improve outcomes in this population, interventions carried out in the preoperative, operative, and postoperative periods have shown promise. Despite this, there are no defined best practice national guidelines for perioperative management of obese patients undergoing cardiac surgery.

AIM

This review is aimed at clinicians and researchers in the field of cardiac surgery and aims to form a basis for the future development of clinical guidelines for the management of obese cardiac surgery patients.

METHODS

The PubMed database was utilized to identify relevant literature and strategies employed at various stages of the surgical journey were analyzed.

CONCLUSIONS

Data presented identified the benefits of preoperative respiratory muscle training, off-pump coronary artery bypass grafting where possible, and early extubation. Further randomized controlled trials are required to identify optimal operative and perioperative management strategies before the introduction of such guidance into clinical practice.

Factors affecting mortality after coronary bypass surgery: a scoping review

OBJECTIVES

Previous research reports numerous factors of post-operative mortality in patients undergoing isolated coronary artery bypass graft surgery. However, this evidence has not been mapped to the conceptual framework of care improvement. Without such mapping, interventions designed to improve care quality remain unfounded.

METHODS

We identified reported factors of in-hospital mortality post isolated coronary artery bypass graft surgery in adults over the age of 19, published in English between January 1, 2000 and December 31, 2019, indexed in PubMed, CINAHL, and EMBASE. We grouped factors and their underlying mechanism for association with in-hospital mortality according to the augmented Donabedian framework for quality of care.

RESULTS

We selected 52 factors reported in 83 articles and mapped them by case-mix, structure, process, and intermediary outcomes. The most reported factors were related to case-mix (characteristics of patients, their disease, and their preoperative health status) (37 articles, 27 factors). Factors related to care processes (27 articles, 12 factors) and structures (11 articles, 6 factors) were reported less frequently; most proposed mechanisms for their mortality effects.

CONCLUSIONS

Few papers reported on factors of in-hospital mortality related to structures and processes of care, where intervention for care quality improvement is possible. Therefore, there is limited evidence to support quality improvement efforts that will reduce variation in mortality after coronary artery bypass graft surgery.

Adiposity in relation to readmission and all-cause mortality following coronary artery bypass grafting: A systematic review and meta-analysis

This study systemically reviewed evidence linking adiposity to readmission and all-cause mortality in post-coronary artery bypass grafting (CABG) patients. Keyword/reference search was performed in PubMed, Web of Science, CINAHL, and Cochrane Library for articles published before June, 2018. Eligibility criteria included study designs: experimental/observational studies; subjects: adult patients undergoing CABG; and outcomes: hospital/clinic readmissions, and short-term (≤30 days) and mid-to-long-term (>30 days) all-cause mortality. Seventy-two studies were identified. Meta-analysis showed that the odds of post-CABG readmission among patients with overweight was 30% lower than their normal-weight counterparts and the odds of mid-to-long-term post-CABG mortality among patients with overweight were 20% lower than their normal-weight counterparts. In contrast, no difference in post-CABG readmission rate was found between patients with obesity and their nonobese counterparts; no difference in short-term or in-hospital post-CABG mortality rate was found between patients with overweight or obesity and their normal-weight counterparts; and no difference in mid-to-long-term post-CABG mortality rate was found between patients with obesity and their normal-weight counterparts. In conclusion, patients with overweight but not obesity had a lower readmission and mid-to-long-term mortality rate following CABG relative to their normal-weight counterparts. Preoperative weight loss may not be advised to patients with overweight undergoing CABG.

Meta-Analysis Comparing ≥10-Year Mortality of Off-Pump Versus On-Pump Coronary Artery Bypass Grafting

Off-pump coronary artery bypass grafting (CABG) is suggested to be associated with an increase in long-term (≥5-year) all-cause mortality. To determine whether off-pump CABG is associated with an increase in very long-term (≥10-year) all-cause mortality, we performed a meta-analysis of propensity-score matched observational comparative studies of off-pump versus on-pump CABG. MEDLINE and EMBASE were searched through May 2017. A hazard ratio of follow-up (including early) all-cause mortality for off-pump versus on-pump CABG was extracted from each individual study. Study-specific estimates were combined using inverse variance-weighted averages of logarithmic hazard ratios in the random-effects model. Of 164 potentially relevant studies, our search identified 16 propensity-score matched observational comparative studies of off-pump versus on-pump CABG with ≥10-year follow-up enrolling a total of 82,316 patients. A pooled analysis of all the 16 studies demonstrated that off-pump CABG was significantly associated with an increase in all-cause mortality (hazard ratio 1.07, 95% confidence interval 1.03 to 1.12, p for effect = 0.0008; p for heterogeneity = 0.30, I² = 12%). In a sensitivity analysis, exclusion of any single hazard ratio from the analysis (leave-one-out meta-analysis) did not substantively alter the overall result. There was no evidence of a significant publication bias. In conclusion, off-pump CABG is associated with an increase in very long-term (≥10 years) all-cause mortality compared with on-pump CABG.

Obesity and coronary artery disease: evaluation and treatment

With the increasing prevalence of obesity, clinicians are now facing a growing population of patients with specific features of clinical presentation, diagnostic challenges, and interventional, medical, and surgical management. After briefly discussing the effect of obesity on atherosclerotic burden in this review, we will focus on strategies clinicians might use to ensure better outcomes when performing revascularization in obese and severely obese patients. These patients tend to present comorbidities at a younger age, and their anthropometric features might limit the use of traditional cardiovascular risk stratification approaches for ischemic disease. Alternative techniques have emerged, especially in nuclear medicine. Positron emission tomography-computed tomography might be the diagnostic imaging technique of choice. When revascularization is considered, features associated with obesity must be considered to guide therapeutic strategies. In percutaneous coronary intervention, a radial approach should be favoured, and adequate antiplatelet therapy with new and more potent agents should be initiated. Weight-based anticoagulation should be contemplated if needed, with the use of drug-eluting stents. An "off-pump" approach for coronary artery bypass grafting might be preferable to the use of cardiopulmonary bypass. For patients who undergo bilateral internal thoracic artery grafting, harvesting using skeletonization might prevent deep sternal wound infections. In contrast to percutaneous coronary intervention, lower surgical bleeding has been observed when lean body mass is used for perioperative heparin dose determination.