Abstract 21298: Surveillance Invasive Hemodynamics in Pediatric Heart Transplant Patients: Utility or Futility?

Abstract

Introduction: Although first year survival after pediatric heart transplant is improving, late-onset rejection, cardiac allograft vasculopathy (CAV), and graft failure remain significant challenges. Patients routinely undergo endomyocardial biopsy with invasive hemodynamics as the gold standard for rejection surveillance and assessment of long-term graft performance. However, it remains unclear how hemodynamic measures contribute to the monitoring of rejection, CAV, and graft dysfunction. This study aims to assess changes in hemodynamics as the graft ages in patients with or without a history of rejection or CAV. Hypothesis: We hypothesize that abnormal hemodynamics, particularly elevated filling pressures, are associated with CAV, rejection and graft aging. Methods: A total of 2,764 patients from the Pediatric Heart Transplant Study database from 1995-2014 met study criteria of survival to 1 year after transplant with available surveillance biopsy and hemodynamics. Retrospective analyses of 16,489 hemodynamic sets were performed. Results: The median age at transplant was 4.89 years [0.73, 12.95]. Average follow up time was 4.05 years [2.04, 7.17]. Fifty-six percent of patients were male, and 46% had history of congenital heart disease. When comparing hemodynamics collected at the first annual catheterization to 10 years after transplant, those who never had rejection or CAV showed statistically significant increases in right atrial pressure (RAP) (p=<0.001), and pulmonary capillary wedge pressure (PCWP) (p = <0.001) with concomitant decrease in cardiac index (p=0.01). When comparing hemodynamics from patients with a history of CAV or rejection to those without such events, patients with history of CAV or rejection had higher RAP (p=<0.001) and PCWP (p = <0.001), and lower cardiac index (p=0.003) and systemic vascular resistance (p=0.0001). Conclusions: Despite freedom from CAV or rejection, RAP and PCWP increase and cardiac index decreases as the graft ages. Additionally, the diagnosis of CAV or rejection during the life of the graft leads to further derangement in graft performance, which can be detected in hemodynamics. Serial hemodynamic assessment may contribute to the ongoing monitoring of graft function in pediatric recipients.