Using pump for bypass surgery - on-off-on again?

Abstract

Citation Shroyer AL, Grover FL, Hattler B, Collins JF, McDonald GO, Kozora E, Lucke JC, Baltz JH, Novitzky D for the Veterans Affairs Randomized On/Off Bypass (ROOBY) Study Group: On-pump versus off-pump coronary artery bypass surgery. N Engl J Med 2009, 361: 1827-37 Background Coronary-artery bypass grafting (CABG) has traditionally been performed with the use of cardiopulmonary bypass (on-pump CABG). CABG without cardiopulmonary bypass (off-pump CABG) might reduce the number of complications related to the heart-lung machine. Methods Objective: To compare off-pump to on-pump CABG in terms of short-and long-term composite of complications and death from any cause, as well as completeness and durability of the procedure/grafting, neuro psychological outcomes, and use of major resources. Design: Multi-center single-blind, randomized controlled trial. Setting: 18 Veterans Aff airs medical centers, 16 of which were teaching hospitals. Subjects: 2203 patients who were scheduled for urgent or elective CABG-only procedures. Intervention: Patients were randomized to either on-or off-pump CABG. They underwent neuropsychological testing at baseline and one year, as well as follow-up angiography. Outcomes: 1) Primary short-term end-point: composite of death or major complications (reoperation, new mechanical support, cardiac arrest, coma, stroke or renal failure requiring dialysis) at discharge or day 30. 2) Primary long-term composite end-point: death from any cause within 1 year, nonfatal myocardial infarction between 30 days and 1 year, or repeat revascularization between 30 days and 1 year. 3) Secondary outcomes: completeness of revascularization, graft patency at 1 year, scores on neuropsychological tests. Results There was no significant difference between off-pump and on-pump CABG in the rate of the 30-day composite outcome (7.0% and 5.6% respectively, P = 0.19). The rate of the 1-year composite outcome was higher for off pump than for on-pump CABG (9.9% vs 7.4%, P = 0.04). The proportion of patients with fewer grafts completed than originally planned was higher with off-pump CABG than with on-pump CABG (17.8% vs 11.1%, P < 0.001). Follow up angiograms in 1371 patients who underwent 4093 grafts revealed that the overall rate of graft patency was lower in the off-pump group than in the on-pump group (82.6% vs. 87.8%, P < 0.01). There were no treatment-based differences in neuropsychological outcomes or short-term use of major resources.. Conclusions At 1 year of follow-up, patients in the off-pump group had worse composite outcomes and poorer graft patency than did patients in the on-pump group. No significant differences between the techniques were found in the neuropsychological outcomes or use of major resources.