Mildly Elevated Pulmonary Hypertension: Gray Zone or Already a Disease?

During the sixth World Symposium on Pulmonary Hypertension, the threshold of mean pulmonary arterial pressure (mPAP) for the definition of pulmonary hypertension (PH) has been lowered to a value of greater than 20 mmHg, measured by means of right heart catheterization at rest. In this review, we aim at describing the impact of the new definition of PH, analyzing the available data from the latest scientific literature concerning subjects with mPAP between 21 and 24 mmHg (defined as "mildly elevated PH"), discussing the impact of the new threshold for mPAP in the clinical practice, and highlighting the new perspectives in this field.