In the first study (ClinicalTrials.gov NCT00463294) the authors from the McMaster University in Hamilton, Canadaenrolled 4752 patients with coronary artery disease who were scheduled to undergo CABG and randomly assigned them to undergo the procedure off-pump or on-pump. (1) Patients were enrolled at 79 centers in 19 countries. The authors assessed quality of life and cognitive function at discharge, at 30 days, and at 1 year and clinical outcomes at 1 year. In a previous paper, the authors reported no significant difference at 30 days in the rate of a primary composite outcome of death, myocardial infarction, stroke, or new renal failure requiring dialysis between patients who underwent off-pump and on-pump CABG. (2) The current paper report results on quality of life and cognitive function and on clinical outcomes at 1 year.
At 1 year, there was no significant difference in the rate of the primary composite outcome between off-pump and on-pump CABG (12.1% and 13.3%, respectively; hazard ratio with off-pump CABG, 0.91; 95% confidence interval [CI], 0.77 to 1.07; P=0.24). The rate of the primary outcome was also similar in the two groups in the period between 31 days and 1 year (hazard ratio, 0.79; 95% CI, 0.55 to 1.13; P=0.19). The rate of repeat coronary revascularization at 1 year was 1.4% in the off-pump group and 0.8% in the on-pump group (hazard ratio, 1.66; 95% CI, 0.95 to 2.89; P=0.07). There were no significant differences between the two groups at 1 year in measures of quality of life or neurocognitive function.
The authors conclude that 1 year after CABG, there was no significant difference between off-pump and on-pump CABG with respect to the primary composite outcome, the rate of repeat coronary revascularization, quality of life, or neurocognitive function.
In the second study from Bad Neustadt, Germany (ClinicalTrials.gov number, NCT00719667), the authors randomly assigned a total of 2539 patients 75 years of age or older who were scheduled for elective first-time CABG to undergo the procedure either off-pump or on-pump. (3) The primary end point was a composite of death, stroke, myocardial infarction, repeat revascularization, or new renal-replacement therapy at 30 days and at 12 months after surgery.
At 30 days after surgery, there was no significant difference between patients who underwent off-pump surgery and those who underwent on-pump surgery in terms of the composite outcome (7.8% vs. 8.2%; odds ratio, 0.95; 95% confidence interval [CI], 0.71 to 1.28; P=0.74) or four of the components (death, stroke, myocardial infarction, or new renal-replacement therapy). Repeat revascularization occurred more frequently after off-pump CABG than after on-pump CABG (1.3% vs. 0.4%; odds ratio, 2.42; 95% CI, 1.03 to 5.72; P=0.04). At 12 months, there was no significant between-group difference in the composite end point (13.1% vs. 14.0%; hazard ratio, 0.93; 95% CI, 0.76 to 1.16; P=0.48) or in any of the individual components. Similar results were obtained in a per-protocol analysis that excluded the 177 patients who crossed over from the assigned treatment to the other treatment.
The authors conclude that in patients 75 years of age or older, there was no significant difference between on-pump and off-pump CABG with regard to the composite outcome of death, stroke, myocardial infarction, repeat revascularization, or new renal-replacement therapy within 30 days and within 12 months after surgery.
References:
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- Lamy A, Devereaux PJ, Prabhakaran D, Taggart DP, Hu S, Paolasso E, Straka Z, Piegas LS, Akar AR, Jain AR, Noiseux N, Padmanabhan C, Bahamondes JC, Novick RJ, Vaijyanath P, Reddy S, Tao L, Olavegogeascoechea PA, Airan B, Sulling TA, Whitlock RP, Ou Y, Ng J, Chrolavicius S, Yusuf S; CORONARY Investigators. Off-pump or on-pump coronary-artery bypass grafting at 30 days. N Engl J Med. 2012 Apr 19;366(16):1489-97.
- Diegeler A, Börgermann J, Kappert U, Breuer M, Böning A, Ursulescu A, Rastan A, Holzhey D, Treede H, Rieß FC, Veeckmann P, Asfoor A, Reents W, Zacher M, Hilker M; GOPCABE Study Group. Off-pump versus on-pump coronary-artery bypass grafting in elderly patients.N Engl J Med. 2013 Mar 28;368(13):1189-98.
- Alexander JH.Clinical-Outcome Trials in Cardiac Surgery - Have We Primed the Pump?N Engl J Med. 2013 Mar 28;368(13):1247-1248.