Effect of first‑month specific therapy determines long‑term clinical outcome in patients with pulmonary arterial hypertension (RCD code: II‑1A.4.o)

Background: Efficacy of pulmonary arterial hypertension (PAH)-specific therapy may differ among the patients depending on the PAH aetiology. Aim: To compare the real‑life efficacy of PAH‑specific therapy between non‑congenital heart disease (non‑CHD) and CHD groups of PAH patients and to determine whether an early clinical response has an impact on prognosis. Methods: Clinical data from 41 PAH patients, 21 non‑CHD and 20 CHD patients, were included in the study. The WHO functional class (WHO‑FC), 6‑minute walk distance (6MWD) and NT‑proBNP serum level were compared at baseline and after 1 and 7 months of PAH‑specific treatment. Only patients with unmodified PAH‑specific therapy during 7‑month follow‑up were enrolled in the study. Results: Baseline characteristics revealed higher WHO‑FC and increased [loge]NT‑proBNP levels (7.74 ±1.05 vs 6.51 ±1.48; p = 0.008) in non‑CHD vs. CHD patients; baseline 6MWD was similar in both groups (283.3 ±148.5 m vs 339.2 ±114.7 m). Clinical improvement by at least one WHO‑FC after 1‑month treatment was observed more frequently in non‑CHD (55%) when compared with CHD patients (25%, p = 0.04) and was comparable (50% vs 50%) after 7‑month observation. Non‑CHD patients, who did not improve within 1 month of treatment were unlikely to achieve improvement after 7 months. The 6MWD increased during the first month of treatment in non‑CHD (p=0.009) and in CHD patients (p=0.006) when compared to baseline values and remained at this level after 7 months of treatment. [Loge]NT‑proBNP levels markedly declined only in non‑CHD patients, who had an improvement in WHO‑FC (8.0 ±1.0 vs 7.4±1.1, p=0.04) in the first month. In CHD patients, the decrease in [loge]NT‑proBNP level was seen (6.5 ± 1.5 vs 6.1 ±1.5, p=0.04) only within a 1‑month observation. Conclusion: Efficacy of 1‑month PAH‑specific therapy is aetiology‑dependent and determines clinical outcome in patients with PAH. JRCD 2018; 3 (6): 199–204