Which aortic clamp strategy is better to reduce postoperative stroke and death: Single center report and a meta-analysis

Abstract

Background: Stroke is severe complication of coronary artery bypass grafting (CABG) which may be associated with clamp strategy, there are 2 strategies to clamp aorta including single aortic clamp (SAC) and partial aortic clamp (PAC). It is controversial that which clamping strategy is better to reduce the postoperative stroke and death, so this study aims to investigate which is better for reducing postoperative stroke and death within 30 days.

Methods: We collected 469 patients who had on-pump CABG in Fuwai Hospital during January 2014 to July 2015. The SAC group consisted of 265 patients while the PAC group included 204 patients. We compared the 2 group patient difference. At the same time, 12 studies were identified by systematic search. The odds ratio (OR) was used as effect index to compare SAC and PAC strategy by fix-effect modeling. We also tested heterogeneity and publication bias. The primary end point of study was occurrence of postoperative stroke within 30 days of operation, the second end point of study was the incidence of 30-day mortality.

Results: The single center retrospective study showed that the patients in the SAC group were older than those in the PAC group (62.5 ± 8.1 vs 60.3 ± 8.0 years, P = .01). The proportions of peripheral vascular disease and hypertension of SAC were higher than PAC (71 (26.8%) versus 36 (17.6%), P = .02; 183 (69.1%) versus 115 (56.4%), P = .01, respectively). Besides, the number of vascular anastomosis was more in the SAC group (3.29 ± 0.74 versus 2.97 ± 0.974, P < .001). The linear-regression analysis suggested that the time of cardiopulmonary bypass of SAC was shorter than the PAC group (93.2 ± 22.4 vs.103.4 ± 26.8 minutes, P-regression < .001) and postoperative death within 30-days was similar (1 (0.4%) vs. 2 (1.0%), P-regression = .47). There was no stroke occurring in both the groups. And the meta-analysis suggested the postoperative stroke and death within 30-days were similar between SAC group and PAC group (OR: 0.78, 95% CI: 0.58-1.06; OR: 0.82, 95% CI: 0.61-1.10; respectively). Moreover, subgroup meta-analysis also had the same results.

Conclusion: There was no significant difference between SAC and PAC clamping strategy on postoperative stroke and death within 30-days; however, SAC can reduce the usage time of cardiopulmonary bypass.

Figure 1

Flow chat of meta-analysis.

Figure 2

The merge effect of 12 studies: the OR for 30-day stroke was 0.78 (95% CI: 0.58–1.06, P = .10, I² = 0%) and the OR for 30-day death was 0.82 (95% CI: 0.61–1.10, P = .18, I² = 0%). OR = odds ratio, CI = confidence interval.

Figure 3

The merge effect of 5 RCTs: the ORs for 30 days stroke and death were that OR: 0.53, 95% CI: 0.19 to 1.45, P = .22, I² = 0%; OR: 0.46, 95% CI: 0.16 to 1.33, P = .15, I² = 0%, respectively. OR = odds ratio, CI = confidence interval, RCT = randomized controlled trial.

Figure 4

The merge effect of 7 retrospective studies: the merge result for 30 days stroke was that OR: 0.81, 95% CI: 0.60 to 1.10, P = .18, I² = 0%. The combined result for 30 days death was that OR: 0.86, 95% CI: 0.63 to 1.17, P = .33, I² = 0%. OR = odds ratio, CI = confidence interval.

Figure 5

Publication bias: Begg test: P = .24 > .05, Egger test: P = .11 > .05, respectively.