Left Ventricular Ejection Fraction Cut Point of 50% for Heart Failure With Preserved Ejection Fraction. CaoThong Huy 2019 To the Editor I read the article by Vanderpool et al1 published in JAMA Cardiology with great interest. The authors conducted a very valuable and interesting study on a large cohort of 10 023 participants, of whom 2587 (25.8%) had pulmonary hypertension associated with heart failure with preserved ejection fraction (HFpEF). The results in this study suggest that pulmonary hypertension associated with HFpEF is very common in the invasive hemodynamic assessment. In addition, transpulmonary gradient, pulmonary vascular resistance, and diastolic pulmonary gradient were associated with mortality and cardiac hospitalizations. However, the authors used a left ventricular ejection fraction (LVEF) cut point of 45% for HFpEF.1 Could the authors use an LVEF cut point of 50% for HFpEF based on the heart failure guidelines? According to the 2013 American College of Cardiology Foundation/American Heart Association guidelines2 and the 2016 European Society of Cardiology guidelines,3 the diagnosis of HFpEF is defined as an LVEF of 50% or greater. Patients with an LVEF in the range of 41% to 49% are classified into a borderline or intermediate group in the 2013 American College of Cardiology Foundation/American Heart Association guidelines2 and are considered to have heart failure with mid-range ejection fraction in the 2016 European Society of Cardiology guidelines.3 Using an LVEF cut point of 50% for HFpEF would keep this article up to date in the future and have a greater effect for this study.