Impact of Modified Anastomosis Sequence on Warm Ischemic Time and Clinical Outcomes in Orthotopic Heart Transplantation.

Abstract

Background and objectives: Prolonged ischemic time adversely affects outcomes after orthotopic heart transplantation (OHT). We implemented a modified anastomosis sequence to reduce warm ischemic time (WIT) and evaluated its impact on myocardial preservation and clinical outcomes.

Methods: We retrospectively analyzed 273 OHT recipients who underwent either a conventional (n=101) or modified (n=172) sequence between March 2009 and December 2020. In the modified group, the left atrial and aortic anastomoses were completed under aortic cross-clamping (ACC), followed by reperfusion and completion of the remaining anastomoses on a beating heart. Baseline imbalances were addressed using inverse probability of treatment weighting based on propensity scores, with additional adjustment for covariates that remained imbalanced after weighting.

Results: After adjustment, the modified anastomosis sequence was associated with shorter WIT (43.3±2.8 vs. 61.1±3.2 minutes; p<0.001) and lower postoperative myocardial injury markers, including creatine kinase-myocardial band and troponin-I. The modified sequence was also associated with lower odds of low cardiac output syndrome requiring extracorporeal membrane oxygenation support (odds ratio [OR], 0.07; 95% confidence interval [CI], 0.01-0.59; p=0.016) and left ventricular primary graft dysfunction (OR, 0.05; 95% CI, 0.00-0.53; p=0.014). Early mortality showed no statistically significant association with the anastomosis sequence. Findings were consistent in prespecified sensitivity analyses addressing transplant era.

Conclusions: The modified anastomosis sequence was associated with shorter WIT, lower myocardial injury markers, and a lower risk of early graft dysfunction. As a structured approach intended to reduce WIT through earlier ACC release, the modified sequence may be associated with more favorable early myocardial preservation and graft function after transplantation.