Page 58 - Assessing right ventricular function and the pulmonary circulation in pulmonary hypertension Onno Anthonius Spruijt

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may limit their incremental values if considered together as covariates. The sex differences related to active RAEF will require further study and validation. The association that we found between SBP and outcome was consistent with the findings of the REVEAL registry and may reflect lower cardiac output or the use of prostanoid therapy. Our study has 3 main clinical implications. First, a simple right heart score can be useful for stratified randomization strategies in phase II clinical trials because matching based only on NYHA functional class may not capture the complexity of the disease process and all variables from the REVEAL registry may not be available. Second, a simple right heart score can serve as a “benchmark” against which the incremental value of novel biomarkers can be assessed. Third, empirically patients with higher scores could be monitored more closely clinically because they are at higher risk of clinical deterioration. However, it is important to mention that our study was not designed to provide a comparison with well-validated scores, such as the REVEAL registry score, and should by no means be considered interchangeable. Our study does however suggest, as did the study of Fine et al. [18], that quantitative assessment of right heart function and remodeling may simplify risk assessment in patients with PAH.
Study limitations
The small sample size limited the number of variables that we could consider in the multivariable model. The strong relationship with the REVEAL registry and NIH survival equation, however, brought indirect external validation to our findings, as did the validation cohort. Second, we did not include more complex imaging modalities, such as strain imaging, in our study. Finally, it is important to emphasize that our study focused on prevalent cases of patients with PAH, rather than incident treatmentnaive patients.
Conclusions
In this study, we showed that in patients with idiopathic, familial, or drug- and toxin-associated PAH, a simple right heart score combining indexes of right heart remodeling and function could predict longterm outcome. If further validated, this simple score may significantly improve the evaluation of novel biomarkers and help guide stratified randomization in clinical trials.
Acknowledgments
The authors thank the Vera Moulton Wall Center, Stanford Cardiovascular Institute, and Pai Chan Lee Research Fund at Stanford University for their support.