Cardiac Power Output Index and Severe Primary Graft Dysfunction After Heart Transplantation.

OBJECTIVES: To evaluate the value of cardiac power output index (CPOi) in predicting severe primary graft dysfunction (PGD) after heart transplantation (defined as mechanical circulatory support [MCS] and/or mortality <30 days after transplant).

DESIGN: Observational cohort study.

SETTING: A heart transplant center in the United Kingdom.

PARTICIPANTS: Consecutive patients who underwent heart transplantation from January 2014 to December 2019 (n = 160). Twenty patients were excluded, as MCS was instituted immediately after transplant.

INTERVENTIONS: None.

MEASUREMENTS AND MAIN RESULTS: Hemodynamic data on return to the intensive care unit (time 0, T0) and at 6 hours (T6) were collected to calculate CPOi at both points in 140 consecutive patients-22 patients developed severe PGD. The CPOi at T0 correlated with donor-recipient predicted heart mass and inversely with inotrope score. Patients who developed severe PGD had significantly lower CPOi at T0 and T6. The areas under the receiver operating characteristic curve for CPOi at T0 and T6 for the development of severe PGD were 0.90 and 0.92, respectively. Adjusting for vasoactive-inotrope score did not improve discrimination. The probability of severe PGD if CPOi at T0 <0.34 W/m2 and T6 <0.33 W/m2 was 79%, but was only 2% if both CPOi at T0 and T6 were >0.34 W/m2 and >0.33 W/m2 , respectively. After adjusting for baseline differences, CPOi at T6 (odds ratio 0.78; 95% CI 0.67-0.91, p = .001) was significantly associated with severe PGD.

CONCLUSION: Low CPOi at T0 is associated with severe PGD. Serial assessment of CPOi increases the diagnostic probability of severe PGD.