Guideline implementation and early risk assessment in pulmonary arterial hypertension associated with congenital heart disease: A retrospective cohort study.

Introduction: Current guidelines emphasize that accurate risk stratification is important for patients with pulmonary arterial hypertension (PAH), however, few suggestions have been specified for PAH associated with congenital heart disease (PAH-CHD).

Objectives: The aim of this study was to propose an accurate and simple system based on current guidelines for risk stratification in PAH-CHD patients during 12-month follow-up.

Methods: We reviewed 288 Chinese PAH-CHD patients between January 2014 and December 2016 in this retrospective cohort study. The low-risk criteria according to 2015 European Society of Cardiology guidelines and the adverse events (AEs) during follow-up were collected. The association between low-risk criteria and AEs was assessed with Cox regression, and a simplified risk stratification system was proposed.

Results: There were 105 PAH-CHD patients included in the final analysis. Twenty-nine patients had AEs defined as death, initiation of new or combined medication treatment, or re-hospitalisation because of the PAH worsening. Among the low-risk criteria, WHO/NYHA functional class, 6-minute walking distance (6MWD), NT-proBNP and SvO were significantly different between AE and AE-free groups. However, 6MWD (HR = 0.08, 95% CI: 0.03-0.19, P < 0.001) and NT-proBNP (HR = 0.35, 95% CI: 0.16-0.78, P = 0.01) were the only independent predictors of AEs in multivariable model. When taking them into a simplified system for risk stratification, the number of low-risk criteria at diagnosis discriminated the risk of AEs (P < 0.001).

Conclusions: Among the low-risk criteria proposed by current guidelines, 6MWD and NT-proBNP predicted AEs independently for PAH-CHD patients. Simplified risk stratification system by taking these two parameters numerically provides accurate prognostic information in PAH-CHD patients.