Risk Stratification in Pulmonary Arterial Hypertension: Perhaps Simple Is Not Best?

Competing Interests: Financial/Nonfinancial Disclosures The authors have reported to CHEST the following: R. L. B.’s institution has received grants from The American Heart Association, Bayer, The National Institutes of Health/National Heart, Lung, and Blood Institute (NIH/NHLBI), and United Therapeutics. T. T. and M. R. are employees of Actelion Pharmaceuticals US, Inc, a Janssen Pharmaceutical Company of Johnson & Johnson. C. F. received consulting fees from Janssen, outside of the submitted work, and grant from Pfizer and Novartis, outside of the submitted work. R. J. W. reports consulting with Merck, Bayer, and Altavant and research support from United Therapeutics, Merck, Bayer, Gossamer, and Altavant. None declared (R. R. V., R. B., C. D. V., S. L., A. D. E., and S. H. V.).