Early predictors and outcomes of mechanical circulatory support use during single lung transplant for secondary pulmonary hypertension: A large single-center experience

Background: Minimal data exists to predict the need for mechanical circulatory support (MCS) for patients with secondary pulmonary hypertension (SPH) undergoing single lung transplant (SLT). We aim to identify preoperative hemodynamic and echocardiographic variables that could predict MCS use and compare clinical outcomes for SLT with and without intraoperative MCS use. Methods: An institutional registry of SLT recipients with SPH between 2017 and 2021 were analyzed. Cohorts were separated by the use of intra-operative MCS and analyzed. Odds ratios and multivariable logistic regression were utilized to evaluate the likelihood of requiring intraoperative MCS during SLT. Results: We identified 293 patients, of which 44 (15.1%) required intraoperative MCS use, while 249 (84.9%) did not. Preoperative RV-PA coupling ratio or TAPSE/PASP ratio <0.3 was highly associated with intraoperative MCS use during SLT (OR4.09 (95% 2.06 - 8.14, p=<0.0001). PCWP, pre-operative PVR, transplant laterality, LAS and intraoperative PA Systolic Pressure were also independently associated with intraoperative MCS use. Length of stay was longer in the MCS-use group (29.8 vs 18.5 days, p= 0.007) whereas survival was similar at 30 (100% MCS vs 99.6% non-MCS, p=1) and 60 days (100% MCS vs 98% non-MCS, p=0.75). A Kaplan-Meier analysis showed no survival difference to 3 years (p=0.92). Conclusions: Assessment of preoperative RV-PA uncoupling using TAPSE/PASP ratio can help predict intraoperative MCS use during SLT. A preoperative TAPSE/PASP <0.3 confers a 4-fold increase in the likelihood of MCS use. The use of MCS during SLT does increase the length of stay, however, does not significantly change survival.