Prognostic Value of Hemodynamic vs Big Endothelin Measurements During Long-term IV Therapy in Advanced Heart Failure Patients

To compare hemodynamics and plasma big endothelin levels in patients awaiting heart transplantation who are receiving continuous IV therapy, and to establish their respective potency for predicting future cardiac events. A randomized, prospective trial of ambulatory continuous treatment with IV prostaglandin E1 (PGE1) vs dobutamine. A subanalysis was conducted of all patients who completed 4 weeks of follow-up in regard to treatment effects on hemodynamics and big endothelin plasma levels. Thirty-two listed heart transplant candidates who were refractory to oral treatment, 21 patients who were receiving PGE1, and 11 patients receiving dobutamine. Hemodynamics and plasma big endothelin levels were measured at baseline and after 4 weeks. The cardiac index increased significantly (PGE1 group, 1.7 ± 0.4 vs 2.5 ± 0.6 L/min/m2; dobutamine group, 1.8 ± 0.3 vs 2.3 ± 0.6 L/min/m2; p < 0.05), whereas the systemic vascular resistance index (SVRI) decreased significantly only in the PGE1 group (3,352 ± 954 vs 2,178 ± 519 dyne · s · cm−5/m2; p < 0.05). The plasma big endothelin level decreased significantly (PGE1 group, 7.6 ± 3.1 vs 4.7 ± 2.6 fmol/mL; dobutamine group, 6.5 ± 3.7 vs 5.0 ± 2.6 fmol/mL; p < 0.01 for the time effect). Plasma big endothelin (β = 0.393;χ 2 = 10.8; p = 0.001) and SVRI (β = 0.003;χ 2 = 6.9; p < 0.01), both measured after 4 weeks of continuous treatment, were the only independent predictors of future outcome. Continuous treatment over 4 weeks with either PGE1 or dobutamine in patients awaiting heart transplantation yields an improved hemodynamic state accompanied by a reduction of increased big endothelin levels. Plasma big endothelin measured after 4 weeks of continuous therapy provides prognostic information about future outcome.