Vasoplegia as a distinct hemodynamic phenotype after heart transplantation: Prevalence, determinants, and clinical consequences despite preserved allograft function.

BACKGROUND

Vasoplegia is a recognized complication of cardiopulmonary bypass, yet its prevalence and clinical impact after heart transplantation (HT) remain incompletely defined, particularly when primary graft dysfunction is excluded. This study aims to characterize posttransplant vasoplegia using a consensus-based framework, identify perioperative risk factors, and quantify its impact on posttransplant outcomes.

METHODS

We conducted a single-center retrospective cohort study of 488 adults undergoing isolated HT between 2020 and 2025. Patients with moderate/severe primary graft dysfunction or cardiac index <2.2 L/min/m2 for 24 hours were excluded. Hourly hemodynamics and norepinephrine-equivalent dose were extracted for 48 hours. Vasoplegia was defined by concurrent hypotension (mean arterial pressure <65 mm Hg), low systemic vascular resistance (<800 dyn s cm-5), preserved cardiac index (≥2.2 L/min/m2), and elevated norepinephrine-equivalent dose (≥0.2 μg/kg/min) within the first 24 hours. A secondary 3-level phenotype (none, transient, sustained) was defined by duration over 48 hours. Elastic net regression with Firth refitting identified predictors. Inverse probability of treatment weighting was used to estimate the independent association of vasoplegia with postoperative outcomes.

RESULTS

Vasoplegia occurred in 85 of 488 patients (17.4%). Independent predictors included male sex, pretransplant left ventricular assist device support, greater pretransplant creatinine, longer allograft ischemic time, and prolonged cardiopulmonary bypass duration (model area under the curve, 0.74). After inverse probability of treatment weighting, vasoplegia remained independently associated with longer mechanical ventilation (+4.2 hours), greater odds of renal-replacement therapy (odds ratio, 2.72), requirement for ongoing hemodialysis at discharge (odds ratio, 2.97), and increased 30- and 90-day mortality (all P < .05). In the 3-level analysis, sustained vasoplegia (≥12 hours) demonstrated the greatest burden of renal injury, prolonged ventilation, and 1-year mortality.

CONCLUSIONS

Vasoplegia is frequent after HT, defines a high-risk phenotype, and is linked to renal dysfunction, prolonged resource use, and mortality, supporting its routine measurement and targeted prevention.