Which of the following biomarkers has been shown to correlate best with pulmonary vascular resistance in patients with hea failure:

Answer is C (Endothelin-1) Endothelin-1 (ET-I) levels have been found to correlate best with pulmonary vascular resistance in patients with Hea Failure. Hea failure is associated with increase in plasma levels of Endothelin-1 (ET-1). Endothelin-1 (ET-I) is amongst the most potent endogenous vasoconstrictors. The pulmonary circulation is the primary source of expression of this neurohormone and ET-1 Levels have been found to correlate with pulmonary vascular resistance. 'Plasma ET-1 Levels correlate directly with pulmonary vascular resistance and it is thought that this peptide may play a role in mediating pulmonary hypeension in persons with hea failure'