Do higher-risk patients benefit from off-pump coronary artery bypass grafting? Evidence from an ecologic analysis of randomized trials

Incidence of perioperative stroke in clampless aortic anastomosis during off-pump coronary artery bypass grafting

This study aimed to assess if clampless off-pump coronary artery bypass grafting (OPCAB) decreases the incidence of perioperative stroke (POS) rate and in-hospital mortality. The secondary aim was to evaluate 12-year rates of overall mortality. Between January 2003 to December 2015, data of 645 consecutive patients undergoing isolated CABG were retrospectively collected. 363 underwent aortic no-touch OPCAB (No-touch group) and 282 underwent OPCAB with the Heartstring device (HS group). In-hospital mortality and perioperative stroke rate as primary endpoint, as well as long-term follow-up outcome were analysed. In-hospital mortality was lower into No-touch group compared with HS group but without significant statistical difference (1.7 vs. 3.2%, p = 0.19, respectively); the rate of postoperative stroke was higher in No-touch group compared with HS group, although this difference did not reach statistically significance. Delirium was reported with higher presentation rate in HS group (3.9 vs. 0.8%, p = 0.01). Blood transfusions rate was higher in HS subjects (23.4 vs. 16.1%, p = 0.01). Intubation time, ICU, and hospital length of stay were increased in the HS group (p = 0.008, p = 0.001 and p = 0.003, respectively). Over a 12-year follow-up period, survival probabilities at 1, 5, and 10 years were 93.6 ± 1.3 vs. 93.2 ± 1.5, 80.4 ± 2.6 vs. 80.3 ± 2.2, and 57.9 ± 5 vs. 58.4 ± 3.8% in the No-touch and HS group, respectively (p = 0.97). In this retrospective study, clampless off-pump CABG lowers perioperative stroke rate whose incidence is, however, not inferior compared with No-touch technique, and no statistically significance was detected. Delirium has a higher presentation rate in clampless off-pump CABG.

Off-pump versus on-pump coronary-artery bypass grafting in elderly patients

BACKGROUND

The benefits of coronary-artery bypass grafting (CABG) without cardiopulmonary bypass in the elderly are still undetermined.

METHODS

We randomly assigned 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). 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.

RESULTS

A total of 2539 patients underwent randomization. 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.

CONCLUSIONS

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. (Funded by Maquet; GOPCABE ClinicalTrials.gov number, NCT00719667.).

Off-pump coronary artery bypass grafting--the current state

The optimal strategy for coronary revascularization remains controversial. Currently, most surgical revascularizations are performed with the use of cardiopulmonary bypass (ONCAB), yet over the past 20 years off-pump coronary artery bypass grafting (OPCAB) has been increasingly used because of the increased awareness of the deleterious effects of cardiopulmonary bypass (CPB) and aortic manipulation. Small, prospective, randomized controlled trials have lacked sufficient sample size to demonstrate differences in early and long-term outcomes. Larger observational studies that are better powered to statistically compare outcomes have shown more favorable in-hospital outcomes and equivalent long-term outcomes with OPCAB and ONCAB. The benefits of OPCAB techniques may be more apparent for patients at high risk for complications associated with CPB and aortic manipulation. Recent studies have demonstrated improved outcomes in higher-risk patients undergoing OPCAB, as well as improved neurological outcomes. The purpose of this review is to outline the recent literature comparing OPCAB with ONCAB, and to demonstrate efficacy of OPCAB as a useful technique for coronary revascularization.