Loop isolation-based uploading preconditioning to protect heart from damage: a proof-of-concept study

Background Little is known on the role of indirect clamp releasing in coronary artery bypass grafting (CABG). Loop isolation-based uploading preconditioning (LiuPhD) was modified to protect the heart from damage and the question of whether this can attenuate reperfusion injury after global myocardial ischemia was examined. Methods A post-hoc comparative analysis was conducted of a prospective single-arm trial on the use of the LiuPhD strategy for 60 multivessel-disease patients undergoing isolated first-time elective on-pump CABG versus 1:1 propensity score-matched patients from the historical database of the same center. Results A total of 120 matched patients had a median age of 62.0 (interquartile range [IQR] 55.8–69.0) years, 27 (22.5%) women, 35 (29.2%) with left main disease, and median follow-up of 18.5 (10.9–35.4) months. The LiuPhD group had shorter post-bypass times than conventional controls (10 [6–13] vs 14 [10–19] mins; p = 0.003). The LiuPhD group had similar needs in terms of composite cardiac-specific interventions (38/60 vs 44/60; p = 0.29). At follow-up of safety, the risk for composite major adverse cardiac and cerebrovascular events was similar between groups (event-free survival: 82.3% vs 73.8%; hazard ratio 1.00 [0.39, 2.54], p log-rank test = 0.99). Conclusion The LiuPhD strategy is associated with short post-bypass times, comparable risk of myocardial injury, and similar safety compared with conventional direct clamp releasing.