Risk stratification in post operative pulmonary hypertension: Insights from the the japanese association of congenital heart disease registry (JACPHR) members

I was interested to read the article on midterm follow up of post-operative pulmonary artery hypertension(PAH) in the Japanese association of congenital heart disease registry data by Sumitomo et al. in the recent issue of the journal. [1]. While the registry is a welcome addition towards unravelling the incompletely understood subject of postoperative PAH in shunt lesions; the proposed score seem potentially misleading. Mean follow up duration of 18 months does not qualify for a midterm duration of patients operated for shunt lesions at 11 years of age. Further, three deaths, three hospitalisation and 2 worsening of clinical status as the endpoints (assuming these are different patients) within 18 months duration would not occur in patients with PVRI of 4 units.m2 or with mean PA pressures of around 30 mmHg or so, but might result from severe Right ventricular failure in NYHA class 3 or class 4 patients with other comorbidities. As such, the univariate analysis of PVRI cut off 4, or PA mean pressure 30 mm was not statistically different in the survivors. The details of deaths are not known, but the small number of events might result in spurious statistical association. The authors themselves have suggested that the data might be considered as hypothesis generating only, but the emphasis on cut off of PVRI 4 units.m2 or PA mean pressure of 30 mmHg might be considered as overtly conservative. The survival and the quality of life in post operative shunt patients does not depend on the PVR or PA mean pressures only, but on the right ventricular functional adaptation to PAH, as well as the trajectory of the changes in PVRI on follow up. Thus the right ventricle of these patients is unlikely to respond so unfavourably to PA mean 30 mm or a PVRI of 4 units.m2 only to cause death or class 3 symptoms. Therefore, these 4 variables cannot be given equal status. A reasonable strategy might include a cutoff of PVRI of 6 units.m2 or more, and a PA mean 50 mmHg or more and other clinical variables denoting ventricular function like BNP etc.… I hope the registry data will help to continue to educate us in this mysterious area of persisting PAH in postoperative shunt patients.

CRediT authorship contribution statement

Shyam S. Kothari: Conceptualization, Writing – review & editing.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.