[Effects of iloprost combined with low dose tadalafil in adult congenital heart disease patients with severe pulmonary arterial hypertension: a single-center, open-label controlled study].

Objective: To evaluate the therapy efficacy of iloprost combined with low dose tadalafil in adult congenital heart disease (CHD) patients with severe pulmonary arterial hypertension (PAH).
Methods: Adult CHD patients with severe PAH were included and divided into the sequential combination therapy group [iloprost: 10 µg/inhalation, 6 times per day for 6 months, and then add oral tadalafil (5 mg/d) till 12 months, n = 32] and upfront combination therapy group [iloprost: 10 µg/inhalation, 6 times per day combined with oral tadalafil (5 mg) for 12 months, n = 36]. Data on 6 min walking test (6MWT), Borg dyspnea score, oxygen saturation measurement, WHO classification, and cardiac catheterization were obtained at baseline, 6 and 12 months.
Results: Seventy-two patients were enrolled in the study and 68 patients completed the study. Pulmonary vascular resistance (PVR) was significantly reduced in the sequential combination therapy group[ (12.96 ± 6.48 ) Wood U vs. (16.94 ± 8.11) Wood U, P < 0.05] and in the upfront combination therapy group [(12.45 ± 7.32) Wood U vs. (16.73 ± 9.28) Wood U, P < 0.05] while pulmonary blood flow [(6.77 ± 3.17) L/min vs. (5.08 ± 2.36) L/min, P < 0.05; (6.95 ± 3.32) L/min vs. (5.03 ± 2.32) L/min, P < 0.05], the 6 MWD were significantly increased [(458 ± 59) m vs. (427 ± 65) m, P < 0.05; (494 ± 59) m vs. (436 ± 62) m, P < 0.01], the Borg dyspnea score (2.04 ± 0.72 vs. 2.52 ± 0.79, P < 0.05; 1.72 ± 0.73 vs. 2.51 ± 0.77, P < 0.01) was significantly improved in both groups at 6 months compared to baseline levels. In the upfront combination therapy group, venous oxygen saturation [(68.4 ± 9.3)% vs. (62.9 ± 9.5)%, P < 0.05] and systemic oxygen saturation during exercise[ (87.2 ± 9.7)% vs. (83.1 ± 15.6)%, P < 0.05]at 6 months were also significantly improved compared to baseline. At month 12, significantly lowered pulmonary artery pressure, PVR, Rp/Rs and increased pulmonary blood flow and cardiac index were evidenced in both groups compared to baseline.
Conclusion: Iloprost combined with low dose tadalafil regimen can effectively reduce PVR, increase 6MWD, and improve cardiopulmonary function in adults CHD patients with severe PAH. Compared with the sequential therapy regimen, the upfront combination therapy regimen can more rapidly improve the clinical symptoms of patients.