A63-49 Therapeutic Effect of Adding Inhaled Treprostinil to PDE5 Inhibitors in Patients With PH-ILD: A Series of Two Cases

Abstract Introduction Currently, there is no definitive treatment for pulmonary hypertension associated with interstitial lung disease (PH-ILD). Therefore, phosphodiesterase-5 inhibitors (PDE5 inhibitors) have been used as palliative treatment for patients with PH-ILD. Recently, inhaled treprostinil has been approved for the treatment of PH-ILD. Here, we present two cases of PH-ILD, in which patients improved with PDE5 inhibitors and exhibited additional therapeutic benefits from inhaled treprostinil. Case presentation Case 1 A 74-year-old female with idiopathic interstitial pneumonia developed dyspnea. Right heart catheterization (RHC) showed a mean pulmonary arterial pressure (mPAP) of 51 mmHg and pulmonary vascular resistance (PVR) of 10.1 WU, consistent with pulmonary hypertension (PH). Four months after starting tadalafil for PH-ILD, RHC revealed a decrease in mPAP to 26 mmHg. Despite this treatment, PVR remained high. Treprostinil was subsequently administered. After she began additional therapy, RHC showed a decrease in mPAP to 18 mmHg, and PVR to 3.9 WU, without side effects such as decreased oxygen saturation (SpO2) and hypotension. Furthermore, additional therapeutic effects were observed on exercise tolerance and hematological findings. The World Health Organization functional class (WHO-FC) improved from class IV to III, the 6-minute walk distance (6 MWD) improved from 75 to 99 m, and NT-proBNP improved from 1245 pg/mL to 638 pg/mL.Case 2: A 73-year-old male with combined pulmonary fibrosis and emphysema presented with dyspnea and peripheral edema. RHC revealed a mPAP of 41 mmHg and a PVR of 13.2 WU, consistent with PH. After 10 months of treatment with sildenafil for PH-ILD, mPAP decreased to 38 mmHg on RHC, but PVR remained high. Therefore, we administered treprostinil via inhalation. After he began additional therapy, RHC showed additional therapeutic efficacy, with mPAP decreasing to 31 mmHg and PVR to 6.4 WU, without side effects such as decreased SpO2 and hypotension. Moreover, additional therapeutic effects were observed on exercise tolerance and hematological findings. The WHO-FC improved from class III to II, 6 MWD improved from 168 to 180 m, and NT-proBNP improved from 4646 to 116 pg/mL. Discussion Addition of inhaled treprostinil to PDE5 inhibitors led to an improvement in exercise tolerance and pulmonary hemodynamics in patients with PH-ILD. Further cases are needed to confirm the efficacy and validity of this treatment for PH-ILD. This abstract is funded by: None