Warm Ischemic Time in Orthotopic Heart Transplantation: Is Faster Really Better?

Abstract

<h3>Purpose</h3> As donor criteria expand to meet increasing demand for transplantable hearts, increased focus has fallen on mitigating risk associated with extended criteria donors. It has been postulated that warm ischemic time may be as significant a factor as total ischemic time, and reduction is associated with better outcomes. This study investigates the impact of warm ischemic time on post-operative events and survival in orthotopic heart transplantation patients at a high-volume center. <h3>Methods</h3> From 2015 to 2020, patients who underwent heart transplantation were identified at a single institution in a prospectively maintained database with long-term clinical outcomes. After excluding heart-lung transplants and those with missing warm ischemic time, 388 patients were identified. Patients were classified in to three groups: < 45 minutes warm ischemic time (106), 45 ≥ warm ischemic time < 60 minutes (170), and ≥ 60 minutes warm ischemic time (112). Demographics and outcomes were analyzed by warm ischemic time group. A subgroup analysis of patients with over 4 hours total ischemic time was analyzed according to warm ischemic times. <h3>Results</h3> Between warm ischemic time groups, there were significant differences in recipient sex, age, and body mass index (BMI), all p < 0.05 (Table 1). Post-operative device requirements were similar between all groups, p > 0.05, as was 30-day freedom from PGD, 80.2% (85) vs 82.9% (141) vs 76.8% (86), 30-day survival, 98.1% (104) vs 98.2% (167) vs 97.3% (109), and one-year survival, 92.5% (98) vs 93.5% (159) vs 91.1% (102) (all p > 0.05). Warm ischemic time was not a predictor of one-year mortality, odds ratio (OR) 0.99 (95% CI, 0.97-1.02). In subgroup analysis with over 4 hours of total ischemic time, warm ischemic time was not a predictor of PGD, OR 0.94 (95% CI, 0.82-1.07), or one-year survival, OR 0.94 (95% CI, 0.82-1.07). <h3>Conclusion</h3> Although increased warm ischemic time did not predict increased adverse post-operative outcomes, continued emphasis on reducing total ischemic time is paramount.