Author + information
- Received March 22, 1996
- Revision received August 8, 1996
- Accepted August 19, 1996
- Published online December 1, 1996.
- Michael M. Givertz, MD,
- Joshua M. Hare, MD,
- Evan Loh, MD,
- Diane F. Gauthier and
- Wilson S. Colucci, MD, FACC⁎
- ↵⁎Address for correspondence: Dr. Wilson S. Colucci, Cardiomyopathy Program, Boston Medical Center, 1 Boston Medical Center Place, Boston, Massachusetts 02118.
Objectives To examine the feasibility of using milrinone to test pulmonary vascular reactivity in patients before heart transplantation, we tested the hypothesis that milrinone would lower pulmonary vascular resistance (PVR) in patients with severe heart failure.
Background Fixed pulmonary hypertension is a risk factor for right heart failure and death after orthotopic heart transplantation. Sodium nitroprusside, the agent used most commonly to test for reversibility of pulmonary hypertension before transplantation, requires dose titration and is frequently limited by hypotension. Milrinone is an intravenously active phosphodiesterase inhibitor that acts rapidly and exerts both positive inotropic and direct vasodilator effects in patients with heart failure. The ability of milrinone to lower PVR in patients with heart failure has not been tested.
Methods In 27 patients with New York Heart Association functional class III or IV heart failure referred for heart transplantation with a PVR ≥ 200 dynes-s-cm−5, we measured the hemodynamic response to a single intravenous bolus of milrinone (50 μg/kg body weight) infused over 1 min.
Results Milrinone decreased PVR in all patients. The effect was maximal 5 to 10 min after the bolus and persisted for at least 20 min. The reduction in PVR at 5 min ([mean ± SEM] 31 ± 4%) was associated with a 42 ± 4% increase in cardiac output and decreases of 12 ± 4% and 16 ± 5% in mean pulmonary artery and pulmonary artery wedge pressures, respectively, but no change in transpulmonary pressure gradient. Milrinone had no effect on heart rate or systemic arterial pressure. The magnitude of the decrease in PVR correlated inversely with the milrinone-induced increase in cardiac output.
Conclusions Bolus milrinone consistently decreases PVR in patients with pulmonary hypertension secondary to severe heart failure. This effect is rapid in onset and well tolerated, even by patients with low systemic arterial pressure. An intravenous bolus of milrinone can be used to test for the reversibility of pulmonary hypertension in patients with heart failure undergoing evaluation for heart transplantation.
This study was supported in part by Grants T32 HL07604 and HL52320 from the National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland.
- Received March 22, 1996.
- Revision received August 8, 1996.
- Accepted August 19, 1996.
- American College of Cardiology