The assessment of prognosis of patients with pulmonary arterial hypertension (PAH) is considered an important part of care and the current treatment strategy is based on systematic assessment of clinical response. The multiparametric risk stratification approach is utilised for defining a low, intermediate or high-risk status. The aim of this study was to determine the impact of drugs approved for PAH in modifying the risk score of treatment-naïve PAH patients.
This is a retrospective study of 371 newly diagnosed and treatment-naïve PAH type 1 patient (incident). Patients were enrolled in the REHAP registry between January 1, 2010 and December 31, 2017. Demographic, hemodynamic, clinical variables (WHO,heart failure symptoms), exercise (6MWT/CPET) and right ventricular function echo parameters were collected at the beginning of the treatment with specific treatment and at 3-12 months follow-up. Patients with suspicion or high probability of pulmonary veno-occlusive disease or uncorrected congenital heart disease were excluded.
65% was female, mean aged 54. The most frequent aetiology was idiopathic and hereditary PAH (38%) followed by scleroderma (30%). At baseline most of the patients were in intermediate risk (62%) and at follow up 40% remains the same. At baseline in low and intermediate risk the more frequent treatment is monotherapy and in the high risk the double combination. Survival rates were significantly higher in patients with lower risk, both at baseline and follow-up, and for those maintaining or achieving a low-risk profile at follow-up. Triple therapy was associated with poorer survival in patients who achieved/maintained a low-risk profile at follow-up.
Although the stratification strategy used found differences in survival rates according to risk of patients and demonstrated the benefit of achieving/maintaining a low-risk profile, we were unable to demonstrate the benefit of combination over monotherapy. Inability to properly discriminate the risk in populations with mixed aetiologies may account for this failure.