Relationship Between Left Ventricular Ejection Fraction and Ischemic Time on Heart Transplantation Survival Outcome

Abstract

<h3>Purpose</h3> The global donor shortage has encouraged many surgeons to expand the traditionally used donor eligibility criteria. One example is utilizing hearts with reduced left ventricular ejection fraction (LVEF), which many studies report to have an insignificant role in heart transplant (HTx) survival outcome. Despite this, previous investigations have found a deleterious effect in the culmination of multiple hits to donor ventricular function, specifically in the utilization of older donors with a prolonged ischemic time (IT). Therefore, our study seeks to explore the potential relationship between donor LVEF (dLVEF) and IT in HTx survival outcome. <h3>Methods</h3> We performed a retrospective investigation employing the UNOS database. Our study utilized 46,936 adult patients who had an orthotopic HTx. Donor LVEF values were categorized into 3 groups: <50%, 50-70%, and >70%. IT periods were stratified into 4 groups: 0-2hrs, 2.1-3hrs, 3.1-4hrs, and >4hrs. Long-term (10yr) survival outcome was assessed using Kaplan-Meier curves, log-rank tests, and multivariable Cox regression models. A p-value of <0.05 was considered significant. <h3>Results</h3> There was no significant survival difference between dLVEF groups in the 0-2hr and 2-3hr IT periods, while 3-4hr and >4hr IT intervals had a significantly different survival outcome between LVEF groups. Multivariable Cox regression found <50% dLVEF had significant findings when compared to the reference group of 50-70% in the 3.1-4hrs (HR=1.24; p-value=0.021) and >4hrs (HR=1.49; p-value<0.001). <h3>Conclusion</h3> Given the current organ shortage, it is imperative that every viable heart be used for transplantation using evidence-based organ eligibility criteria. Our investigation provides promising results in the utilization of donor hearts with reduced LVEF values, specifically when IT is <3hrs. By accepting and using these hearts in greater numbers, we can reduce the strain on the current organ shortage.