Heart transplantation in children with markedly elevated pulmonary vascular resistance: impact of right ventricular failure on outcome.
BACKGROUND
Pulmonary hypertension causes increased morbidity and mortality in adults after heart transplantation. The effect of markedly elevated pulmonary vascular resistance (PVR) on post-transplant outcomes in children has not been well described.


METHODS
Outcomes were compared in a retrospective study between 58 children with an elevated PVR index (PVRI) ≥ 6 U/m(2) and 205 children with a PVRI < 6 U/m(2). Patients who did and did not respond to acute vasodilator testing and patients who underwent transplant before (pre-1995) and after (post-1995) the availability of inhaled nitric oxide (iNO) were compared.


RESULTS
The pre-transplant diagnoses, and cardiopulmonary bypass and donor ischemic times were similar between the high and low PVRI groups. High PVRI patients were older at transplant (12 ± 6.2 vs 8 ± 7.1 years, p = 0.002). The post-transplant inotrope score was higher in the high PVRI group (12 ± 12 vs 2 ± 2, p = 0.0001) and 1-year survival was worse (76% vs 81%, p = 0.03). The PVRI fell to < 6 U/m(2) with acute vasodilator testing in 21 of 49 (42%) high PVRI patients. RV failure occurred in 4 (19%) of the responders and in 14 (50%) of the non-responders (p = 0.037). One responder (5%) and 4 non-responders (14%) died of RV failure. In the period after 1995, the year iNO became clinically available, the select group of high PVRI patients who received iNO preemptively had a lower incidence of post-transplant RV failure than the group that did not receive preemptive iNO (13% vs 54%, p = 0.04).


CONCLUSIONS
Pre-transplant vasodilator testing identified patients at higher risk for RV failure. Patients who did not respond to vasodilator testing had an increased incidence of RV failure and death from RV failure. Preemptive use of iNO was associated with a decreased incidence of RV failure.
Division of Critical Care Medicine, Morgan Stanley Children's Hospital of New York, Columbia University College of Physicians and Surgeons, NY, USA. george.ofori@duke.edu
George
G
Ofori-Amanfo
Daphne
D
Hsu
Jacqueline M
JM
Lamour
Seema
S
Mital
Michael L
ML
O'Byrne
Arthur J
AJ
Smerling
Jonathan M
JM
Chen
Ralph
R
Mosca
Linda J
LJ
Addonizio
D000280:Administration, Inhalation; D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005260:Female; D006333:Heart Failure / Q000453:epidemiology / Q000209:etiology*; D016027:Heart Transplantation / Q000401:mortality / Q000502:physiology*; D006801:Humans; D006976:Hypertension, Pulmonary / Q000150:complications* / Q000503:physiopathology; D007223:Infant; D008297:Male; D009569:Nitric Oxide / Q000008:administration & dosage*; D012189:Retrospective Studies; D018570:Risk Assessment; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome; D014655:Vascular Resistance / Q000502:physiology*; D018497:Ventricular Dysfunction, Right / Q000453:epidemiology / Q000209:etiology*; D055815:Young Adult
D009569:Nitric Oxide