The effects of standardized intravenous treprostinil in pulmonary arterial hypertension patients after total cavo-pulmonary connection procedure.

Objective: Total cavo-pulmonary connection (TCPC) is a palliative treatment for single ventricular malformations. For high-risk patients (preoperative mean pulmonary arterial pressure, mPAP > 15 mmHg), between the inhaled and oral targeted medications, the application of intravenous treprostinil as a bridge therapy to achieve "seamless" management is core postoperative treatment. This study intends to explore the effect of different administration regimens on early postoperative recovery.

Methods: This was a retrospective cohort study. High-risk pediatric patients (age ≤ 14 years) who underwent TCPC procedure in Fu Wai Hospital from 2015 to 2022 were included. Since the regimen of treprostinil was standardized in our center in 2021, the patients in 2020 and before were included in group 1, patients in 2021 and 2022 were included in group 2. The hemodynamic parameters were compared before and after the maintenance dose of treprostinil. The differences of demographic characteristics, surgical data and postoperative recovery were compared between the two groups.

Results: A total of 51 pediatric patients were included. Group 1 included 35 patients who received treprostinil at 1-3 postoperative days and an average dose of 12 ± 4 ng/(kg·min). Group 2 included 16 patients who received treprostinil within postoperative 1 day and an average dose of 22 ± 7 ng/(kg·min). There were no significant differences between the two groups in terms of age, weight, preoperative percutaneous oxygen saturation and mPAP,  heterotaxy syndrome, TCPC procedure type, other concurrent procedure, cardiopulmonary bypass time and aortic cross-clamp proportion (p > 0.05). After 24 h of treprostinil treatment, the mPAP in group 1 reduced from 17 ± 3 mmHg to 15 ± 2 mmHg (p < 0.001), and in group 2 from 17 ± 2 mmHg to 14 ± 2 mmHg (p < 0.001), with no difference between groups. In the postoperative recovery, patients in Group 2 exhibited a reduced duration of mechanical ventilation, 19 (11, 25) hours vs 69 (23, 189) hours, p = 0.001; a shorter stay in the ICU, 8 (6, 12) days vs 16 (9,26) days, p = 0.006; and a shorter postoperative length of stay, 27 (17,55) days vs 39 (29,58) days, p = 0.032. Patients in Group 2 also exhibited a lower incidence of thromboembolic events, 0 (0/26) vs 26% (9/35), p = 0.043; and the need for renal replacement therapy, 0 (0/26) vs 31% (11/35), p = 0.011.

Conclusion: Treprostinil reduces pulmonary artery pressure after TCPC procedure. The standardized application of treprostinil may improve the postoperative recovery which should be proven by randomized controlled trials or matched cohort studies in the future.