Effects of remote ischemic preconditioning on postoperative gastrointestinal function in patients undergoing off-pump coronary artery bypass grafting: a randomized controlled trial

Postoperative gastrointestinal function is one of the important factors influencing the prognosis of off-pump coronary artery bypass grafting (OPCAB) patients. Remote ischemic preconditioning (RIPC) is a noninvasive intervention that may offer multiorgan protection. This study aimed to evaluate the impact of preoperative RIPC on postoperative gastrointestinal function and clinical outcomes in OPCAB patients.

This prospective, assessor- and statistician-blinded, sham-controlled, randomized clinical trial included 106 patients scheduled to undergo elective OPCAB. They were randomly assigned to the RIPC (n = 53) or sham-RIPC (n = 53) group. The RIPC group received bilateral upper limb ischemia/reperfusion cycles (200 mmHg, 5-min ischemia/5-min reperfusion, repeated for 5 cycles) twice daily for 3 consecutive preoperative days. The primary outcome was the incidence of postoperative gastrointestinal intolerance (POGI), defined as an I-FEED score of 3–5 within 7 days postoperatively. The secondary outcomes included markers of intestinal injury (intestinal fatty acid-binding protein (I-FABP)), systemic inflammation (interleukin-6 (IL-6), C-reactive protein (CRP)), and S-100 protein beta subunit (S-100β). The exploratory outcomes comprised gut microbiota analysis and other clinical parameters.

The incidence of POGI was lower in the RIPC than in the sham-RIPC group (35.4% vs. 56.5%, P = 0.040). The postoperative serum levels of I-FABP, IL-6, CRP, and S-100β were also lower in the RIPC group. Moreover, the relative abundance of Gemella and Dorea decreased in the RIPC group postoperatively. Notably, the abundance of Gemella showed a positive correlation with the postoperative levels of I-FABP and IL-6, whereas that of Dorea exhibited a positive correlation with the postoperative I-FABP levels.

The preoperative application of RIPC was associated with a lower risk of POGI, with no observed safety concerns. This effect of RIPC may be related to attenuated intestinal mucosal injury, reduced systemic inflammation, and potential modulation of the gut microbiota.

This study was registered on May 30, 2024 (ChiCTR2400085044).