SAN FRANCISCO—In patients 75 years of age or older, there was no significant difference between on-pump and off-pump CABG in the composite outcome of death, stroke, MI, repeat revascularization or new renal-replacement therapy within 30 days and within one year after surgery, according to the late-breaking GOPCABE trial, presented March 11 at the American College of Cardiology (ACC) scientific session.
The GOPCABE (German Off-Pump Coronary Artery Bypass Grafting in Elderly Patients) study focused exclusively on patients 75 years of age or older who were scheduled for elective first-time CABG to undergo the procedure either without cardiopulmonary bypass (off-pump CABG) or with it (on-pump CABG).
Previous studies comparing the two techniques also found similar results for on-pump and off-pump CABG, but none of these focused exclusively on elderly patients. Considering the high incidence of comorbidities in this population, the study’s lead author Anno Diegeler, MD, PhD, head of the department of cardiovascular surgery at the Heart Center Bad Neustadt in Germany, said that he and his colleagues anticipated that this trial would clarify the potential benefit of off-pump CABG in high-risk patients.
The researchers randomized a total of 2,539 patients. 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 the composite outcome (7.8 vs. 8.2 percent) or four of the components (death, stroke, MI or new renal-replacement therapy). Repeat revascularization occurred more frequently after off-pump CABG than after on-pump CABG (1.3 vs. 0.4 percent).
At 12 months, there was no significant between-group difference in the composite endpoint (13.1 vs. 14 percent) 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.
“For surgeons who prefer off-pump surgery, our study confirms that off-pump CABG is safe and the quality is equal to on-pump surgery for elderly patients. At 12 months, we had a survival rate of 93 percent among our off-pump patients and 92 percent for on-pump,” Diegeler said. He added that the surgeon’s level of experience is critical in assessing the two techniques.
The “trial does not support the assumption that off-pump CABG can improve the early outcome in high-risk patients,” which is consistent with the American Heart Association scientific statement, the researchers wrote in the study’s publication in the New England Journal of Medicine. However, they also recognized that their data did not match up entirely. “In contrast to the ROOBY trial, our study did not show a significant between-group difference in survival or major adverse events at one year after surgery. This difference may be a consequence of the requirement for substantially greater experience with off-pump CABG in the GOPCABE trial than in the ROOBY trial.”
Study panelist Michael Mack, MD, complimented the study as “superb,” and questioned whether on-pump should be continued in clinical practice. “Is there any group at all that benefits from its use?”
Diegeler first pointed out the importance of training with off-pump surgery, but those experienced with off-pump appear to have the same results, even in the highest risk patients.
Diegeler also noted that the similar result from both techniques is beneficial to facilities and patients in developing countries, where the on-pump procedure may come at a higher cost since instruments used in off-pump CABG can be resterilized, but components of the machine used in on-pump cannot.
He also said that further research is needed to assess CABG outcomes in other special populations, including patients deemed high-risk for surgery.
Maquet provided funding for the study.