Right atrial and ventricular function in risk stratification of patients with pulmonary artery hypertension

Abstract Background Right atrial (RA) phasic function was proved to be impaired in individuals with pulmonary arterial hypertension (PAH), the awareness of the nonnegligible involvement of RA in the clinical course of PAH was raised. However, evidence for the clinical significance of the RA strain in prognostication and risk stratification for PAH patients was limited. Method Participants diagnosed with PAH from June 2013 to December 2022 in West China Hospital were prospectively and continuously recruited. The primary endpoint was all-cause mortality, and the second endpoint was a combination of all-cause mortality and heart failure-related repeat hospitalization. Cox regression analysis and Kaplan Meier survival analysis were performed to identify the association between variables and outcomes. C-index, 1-year mortality, and annual event rate were performed to confirm the value of RA strain in PAH patients’ risk stratification. Result A total of 283 participants (mean age, 38 ± 14 years, 84 male) were finally included, following a median follow-up duration of 31.5 months (interquartile range: 15.1-53.9 months). Significant decreases in RA reservoir (p<.001), conduit (p<.001), booster pump function (p<.001), right ventricular global longitudinal strain (RVGLS, p<.001), and free-wall longitudinal strain (RV-FWLS, p<.001) were observed in participants with all-cause mortality than those who survived. Using 16.1% and 23.6% as thresholds for RA reservoir strain, PAH patients could be divided into low-, intermediate, and high-risk groups well, with calculated 1-year mortality of 1.8%, 6.9%, and 21.4%. Moreover, RA reservoir strain presented with better 1-year mortality predictive performance than RV-FWLS (C-index, 0.82 [0.72-0.92] vs 0.72 [0.62-0.82], p<.001). The addition of RA reservoir strain had significantly increased the power of both REVEAL Lite2 and Comparative, Prospective Registry of Newly initiated Therapies for Pulmonary Hypertension (COMPERA) models (both p<.001). Conclusion RA reservoir strain was an independent predictor of all-cause mortality in individuals with pulmonary arterial hypertension and could be used to stratify participants into different risk stratification stratum.