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Time for Judicious Application of Off-Pump CABG

Published:October 11, 2022DOI:https://doi.org/10.1053/j.jvca.2022.10.004
      CORONARY ARTERY disease (CAD) is a major cause of death worldwide, and it is estimated that it will cause more than 360,000 deaths annually in the Unites States.
      • Benjamin EJ
      • Blaha MJ
      • Chiuve SE
      • et al.
      Heart disease and stroke statistics-2017 update: A report from the American Heart Association.
      Surgical coronary artery bypass grafting (CABG) is the gold standard for revascularization of left main or three-vessel CAD.
      • Neumann FJ
      • Sousa-Uva M
      • Ahlsson A
      • et al.
      2018 ESC/EACTS guidelines on myocardial revascularization.
      However, even after 6 decades of its existence, whether the type of surgery should be off-pump (OPCAB) or conventional CABG with cardiopulmonary bypass remains unresolved. By circumventing the cardiopulmonary bypass, OPCAB is expected to improve long-term outcomes by decreasing the cerebrovascular complications, perioperative myocardial injury, and cardiac related mortality. Consequently, the early 2000s witnessed a dramatic increase in OPCABs.
      The initial trials comparing the 2 techniques were not conclusive and reported mixed results. The major concern about OPCAB is related to graft patency. A recent updated meta-analysis has concluded that graft patency is poorer with OPCAB.
      • Zhou Z
      • FU G
      • Feng K
      • et al.
      Randomized evidence on graft patency after off-pump versus on-pump coronary artery bypass grafting: an updated meta-analysis.
      Likewise, in a large-scale Korean patient cohort, it was shown that OPCAB is associated with higher long-term risk of mortality, myocardial infarction, and repeat revascularisation.
      • Park SJ
      • Jo AJ
      • Kim HJ
      • et al.
      Real-world outcomes of on-vs off-pump coronary bypass surgery: Result from Korean nationwide cohort.
      These results substantiated the earlier belief that primary perioperative benefits of OPCAB are outweighed by the risk of ineffective revascularization.
      • Shaefi S
      • Mittel A
      • Loberman D
      • Ramakrishna H.
      Off-pump versus on-pump coronary artery bypass grafting-A systematic review and analysis of clinical outcomes.
      Therefore, OPCAB has fallen out of favor, and, currently, in the United States and Europe, OPCAB is used only in about 20%-to-25% of patients.
      • Angelini GD.
      An old off-pump coronary artery bypass surgeon's reflections: A retrospective.
      It was even suggested that OPCAB should be considered a safe alternative in patients who lack significant circumflex-based CAD.
      • Shaefi S
      • Mittel A
      • Loberman D
      • Ramakrishna H.
      Off-pump versus on-pump coronary artery bypass grafting-A systematic review and analysis of clinical outcomes.
      Such patients are likely to have 1- or 2-vessel disease for which percutaneous coronary interventions are preferred. Does this mean that time has come to write an obituary for OPCAB? This is indeed a moot question that needs to be delved into further, as OPCAB can offer certain benefits (that the conventional CABG cannot) to a select group of high-risk elderly patients who are more likely to have comorbidities.
      A few meta-analyses in elderly patients have confirmed that OPCAB offers benefits or at least equivalent results (hospital mortality and survival at 6 months and 1 year) as compared with conventional CABG.
      • Diegeler A
      • Borgermann J
      • Kappert U
      • et al.
      Off-pump versus on-pump coronary artery bypass grafting in elderly patients.
      • Panesar SS
      • Athanasiou T
      • Nair S
      • et al.
      Early outcomes in the elderly: A meta-analysis of 4921 patients undergoing coronary artery bypass grafting-comparison between off-pump and on-pump techniques.
      Likewise, in a randomized controlled trial of patients with EuroSCORE >6, Lemma et al. showed that operative mortality, myocardial infarction, stroke, renal failure, reoperation from bleeding, and acute respiratory distress syndrome within 30 days postoperatively (composite end-point) were significantly lower in the OPCAB group.
      • Lemma MG
      • Coscioni E
      • Tritto FP
      • et al.
      On -pump versus off-pump coronary artery bypass surgery in high-risk patients: Operative results of a prospective randomized trial (on-off study).
      Another randomized controlled trial has revealed comparable early results,
      • Moller CH
      • Perko MJ
      • Lund JT
      • et al.
      No major differences in 30-day outcomes in high-risk patients randomized to off-pump versus on-pump coronary bypass surgery: The best bypass surgery trial.
      and observational studies have reported lower incidence of stroke with no difference in 1- and 5-year survival rates.
      • Marui A
      • Okabayashi H
      • Komiya T
      • et al.
      Benefits of off-pump coronary artery bypass grafting in high-risk patients.
      ,
      • Cavallaro P
      • Itagaki S
      • Seigerman M
      • et al.
      Operative mortality and stroke after on-pump vs off-pump surgery in high-risk patients: An analysis of 83914 coronary bypass operations.
      There is a body of evidence in the literature demonstrating beneficial results in dialysis-dependent chronic kidney disease patients. More recent literature has echoed similar results, and has concluded that the high-risk group of patients seem to benefit from OPCAB.
      • Guida GA
      • Chivasso P
      • Fudulu D
      • et al.
      Off-pump coronary artery bypass grafting in high-risk patients: A review.
      In redo surgeries, and in patients with poor left ventricular function, OPCAB offers early survival advantage and similar long-term mortality.
      • Zhang S
      • Huang S
      • Tiemuerniyazi X
      • et al.
      A meta-analysis of early, mid-term and long-term mortality of on-pump vs. off-pump in redo coronary artery bypass surgery.
      ,
      • Neumann A
      • Serna-Higuita L
      • Detzel H
      • et al.
      Off-pump coronary artery bypass grafting for patients with severely reduced ventricular function-a justified strategy?.
      These reassuring results indicate the role of OPCAB in a select high-risk elderly population.
      OPCAB is not an easy surgery, and it is acknowledged that it involves a great deal of surgical dexterity and skill.
      • Angelini GD.
      An old off-pump coronary artery bypass surgeon's reflections: A retrospective.
      In addition, adequate support from other team members, especially the anesthesiologists, is vital in defining the optimum results. The hemodynamic instability during the procedure can contribute toward compromising the quality of anastomosis, as well as decreased cerebral perfusion, which can influence the outcome. In other words, the benefits of OPCAB can only be seen if an expert team performs the surgery. In a propensity-matched study, it was shown that the long-term outcomes in higher-risk patients undergoing OPCAB (by experienced surgeons) was comparable to lower-risk patients undergoing conventional CABG.
      • Matkovic M
      • Tutus V
      • Bilbija I
      • et al.
      Long term outcomes of the off-pump and on-pump coronary artery bypass grafting in a high-volume center.
      A qualitative difference in outcome in high-volume versus lower-volume centers was indicated in the report by Park et al.
      • Park SJ
      • Jo AJ
      • Kim HJ
      • et al.
      Real-world outcomes of on-vs off-pump coronary bypass surgery: Result from Korean nationwide cohort.
      There is considerable enthusiasm among the Asian countries (Japan, India, and South Korea) to perform OPCAB, with 50%-to-75% of patients undergoing OPCAB. However, if the rates of OPCAB decline, the number of trained personnel available to perform this surgery also will decrease. This can be a limiting factor toward conducting future trials; but, more importantly, it also would reduce the number of expert teams available to perform this technically challenging surgery.
      In summary, discontinuation of OPCAB under the garb of poor long-term outcome appears inappropriate. Selection of deserving patients to undergo surgery by an expert team is the way forward. This would entail creation of specialized and supervised structured training programs in the right environment that would help to set up and strengthen the OPCAB programs at various centers. In addition, policies should be framed for prioritizing and allocation of patients to appropriate centers. Afterall, is it not our responsibility to ensure that the sick and elderly patients are not denied the benefits of this surgery?

      Declaration of Competing Interest

      D. K. T. is the Section Editor of the Journal of Cardiothoracic and Vascular Anesthesia. Other authors have no conflicts of interest to declare.

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