Endothelin Receptor Blockade and Exacerbation of Heart Failure

To the Editor: We have read with interest the report by Luscher et al1 on the Heart Failure Endothelin A Receptor Blockade Trial (HEAT). Administration of an endothelin A receptor antagonist, darusentan (30, 100, or 300 mg/d), for 3 weeks significantly decreased systemic vascular resistance with concomitant increase in cardiac index in patients with chronic heart failure (HF). However, early exacerbation of HF was observed in 36.7% of the patients receiving 300 mg darusentan, in contrast to 12.1% in …