Long-term effect of vasodilator therapy in pulmonary hypertension due to COPD: a retrospective analysis.

Purpose: Pulmonary hypertension (PH) due to COPD has dismal prognosis. We reviewed the long-term effect of PH-target therapy in severe PH-COPD.

Method: Patients attending our PH-clinic were reviewed for PH-COPD receiving PH-target therapy. Baseline characteristics, death/transplantation until 2014, therapy, NYHA functional class, 6 min walk distance (6MWD) and oxygen saturation (SpO(2)) at baseline, 3, 6, 12 and 24 months were analysed.

Results: Of 48 PH-COPD identified 21 were excluded (insufficient data, comorbidity). 27 patients (7 females, 21 smokers, 23 emphysema) with median (quartiles) baseline age 70 (60; 76) years, FEV1 60 (46; 78) %, FEV1/FVC 57 (51; 64) %, DLCO 42 (36; 59) %, mean pulmonary artery pressure 39 (32;44) mmHg under inhaled iloprost (10), subcutaneous prostanoids (2), intravenous prostanoids (3), endothelin receptor antagonists (15) and phosphodiesterase-5-inhibitors (25) were included. Under therapy, NYHA functional class improved from 3.5 (3; 4) to 3 (2; 4) after 3 months and 3 (2; 3.5) after 6 months (p = .02 and .008). The 6MWD improved from 373 (236; 452) to 395 (339; 472), 414 (285; 492) and 396 (308; 497)m at 3, 6 and 12 months (p = .005, .006 and .011) with unchanged resting-SpO(2) but decreased peak-exercise SpO(2). During median follow-up of 5.9 (2.3; 8.4) years, 10 died, 2 were transplanted and 2 were lost to follow-up. Transplant-free survival at 1,2,3 years was 92,69,54 % and was similar for GOLD stages 1-4, but worse for patients with mPAP ≥40 mmHg (p = .026), 6MWD <370 m (p = 0.008), resting SpO(2) <92 % (p = 0.02) and peak-walk SpO(2) <87 % (p = 0.012).

Conclusion: PH-target vasodilator therapy improved NYHA functional class and 6MWD up to one year in highly selected patients with severe PH-COPD. Poor exercise capacity, low SpO(2) and high mean pulmonary artery pressure at baseline but not airflow obstruction were associated with unfavourable outcome.