Journal of Pediatric Cardiology and Cardiac Surgery

Background: The definition of pulmonary hypertension (PH) in current European guidelines is a mean pulmonary arterial pressure (mPAP) of >20 mmHg, differing from the ≥25 mmHg threshold in the previous guidelines, because even mildly elevated mPAP (21–24 mmHg) is associated with poor prognosis in adults with PH. The impact of mild PH in children, nonetheless, remains unknown in terms of the outcomes and recommended treatments. We aimed to elucidate the characteristics and clinical courses of pediatric patients with mPAP of 21–24 mmHg.

Methods and Material: In this retrospective study, we found 57 pediatric patients with mild PH between January 2005 and December 2022 at our hospital in Japan. All patients exhibited mPAP of 21–24 mmHg. Of these, 13 were subsequently re-evaluated for cardiac catheterizations. They were divided into two groups based on the change in mPAP (an increase or a decrease) during the observation period.

Results: An increase in mPAP over time occurred in 23% (n=3) of patients. The 3 patients exhibited three distinguishing characteristics: 1) older at the time of diagnosis of mild PH, 2) pulmonary arterial wedge pressure (PAWP) that increased with age, and 3) PAWP ≥12 mmHg at the time of diagnosis of mild PH.

Conclusion: Mild PH improved with age in most of pediatric patients. Some exhibited worsening of PH, which coincided with elevated PAWP. Patients with elevated PAWP (≥12 mmHg) should be carefully followed up to prevent deterioration of PH.