PDP1 and pulmonary arterial hypertension: While most data in the literature suggest that the inhibition of PDH, which prevents pyruvate from entering into TCA cycle and therefore diminishes oxidative phosphorylation, mediates the metabolic dysfunction in PAH [1], metabolomic studies in lungs from patients with severe PAH have indicated upregulated TCA cycle activity, disrupted glycolysis, and increased FAO [45].