Pulmonary Artery Pulsatility Index Predicts Mechanical Circulatory Support Following Heart Transplantation

The incidence of MCS for early graft dysfunction (EGD) following heart transplantation varies from 2.3% - 28.2%. Low pulmonary pulsatility index (PAPi) is associated with higher mortality in advanced heart failure and cardiogenic shock. We hypothesised that a lower pulmonary pulsatility index following heart transplantation is associated with MCS use for EGD.
Methods Two-centre study of consecutive heart transplantation from May 2018 to December 2022. Haemodynamic parameters and Inotropic/Vasoconstrictor data were investigated on admission to intensive care unit (T0) and at six hours later (T6).
Results Of the 173 patients included in this study, 24 had MCS for EGD. PAPi in the group that required MCS were lower at T0 (1.21(0.84) vs 1.67(1.23), p=0.001) and T6 (0.77(0.52) vs 1.44(0.82), p=<0.001). There was no significant difference in recipient characteristics, donor characteristics (donor age and sex matching) and operative factors (warm/cold ischaemic time, total ischaemic time, cardiopulmonary bypass time) between the two groups. On multiple variable regression, PAPi at T6 was associated with delayed MCS independent of total donor organ ischaemic time and short term MCS bridge to transplantation (OR 0.1 (0.036-0.276), p= <0.001). ROC analysis showed an AUC of 0.694 for T0 PAPi and 0.832 for T6 PAPi; a cut-off T6 PAPi of 1.22 had sensitivity and specificity of 81% and 65% respectively.
Conclusions Lower PAPi at T6 (<1.22) is independently associated with MCS use for severe EGD post-heart transplantation.