Myocardial Stress During Donor Withdrawal Is Associated With Graft Dysfunction After Circulatory Death Heart...

We developed a physiologically grounded metric-the Delta Myocardial Stress Index (ΔMSI)-to estimate myocardial oxygen supply-demand imbalance during the donor agonal phase and evaluated its association with posttransplant graft dysfunction. We performed a retrospective single-center study of adult donation after circulatory death (DCD) heart transplants (February 2020-June 2025). High-resolution hemodynamic data from withdrawal to declaration of death (WTD) were analyzed. Delta Myocardial Stress Index, integrating myocardial oxygen supply-demand balance, was derived from available hemodynamic data. Associations between ΔMSI and severe primary graft dysfunction (PGD) were assessed. Among 191 cases (16 severe PGD events), ΔMSI trajectories were significantly elevated in donors who developed severe PGD ( p < 0.001). Two distinct ΔMSI trajectory phenotypes were identified; high ΔMSI was independently associated with severe PGD (odds ratio [OR]: 2.49, p = 0.02) and 90 day mortality (OR: 4.58, p = 0.03). The association between WTD and PGD operated primarily through cumulative ΔMSI burden ( p = 0.02), whereas WTD alone was not associated with PGD after accounting for ΔMSI ( p = 0.25). Delta Myocardial Stress Index provides a noninvasive quantification of myocardial stress during DCD withdrawal. Myocardial stress, rather than agonal duration alone, was associated with severe PGD. These findings support a shift from time-based thresholds toward physiologic assessment of donor myocardial resilience.