Value of right heart haemodynamics for risk stratification of patients with pulmonary arterial hypertension at follow-up

INTRODUCTION: ESC/ERS guidelines recommend risk stratification of prevalent patients with pulmonary arterial hypertension (PAH) using noninvasive parameters, whereas right heart haemodynamic parameters are left to the clinician's discretion if deemed necessary. The study aimed to define the possible contribution of invasive haemodynamic parameters in predicting both the risk of death from all causes and the risk of clinical worsening (CW) in patients with PAH categorized at follow-up by the noninvasive ESC/ERS 4-strata risk stratification model. METHODS: We evaluated incident patients with PAH enrolled in 11 Italian centres between 2005 and 2021 who had a first follow-up right heart catheterization within 6-12 months of diagnosis. In each noninvasive risk category, patients were subsequently stratified in a subgroup with a good haemodynamic profile if stroke volume index was ⩾38 mL/m2 and right atrial pressure was <8 mmHg and a subgroup with a poor haemodynamic profile if stroke volume index <38 ml/m2 and/or right atrial pressure ⩾8 mmHg. Median follow-up was 3.7 years (interquartile range 1.2-6.8) months. RESULTS: Among low-risk patients (n = 162) survival was similar, but the CW rate was better in the good haemodynamic compared with the poor haemodynamic subgroup (P = .033). Among patients at intermediate-low risk (n = 240), both survival and CW rates were significantly better in the good haemodynamic subgroup compared with the poor haemodynamic subgroup (P = .028 and P = .011, respectively). Among patients at intermediate-high risk (n = 339), the CW rate was similar but survival was significantly better in the good haemodynamic than in the poor haemodynamic subgroup (P = .015). In the high-risk group, only 1 out of 28 patients had a good haemodynamic profile. CONCLUSION: In prevalent patients with PAH, a good haemodynamic profile predicts better survival in intermediate-risk patients and, importantly, a lower CW rate in low-risk patients.