Background: End-stage congestive heart failure (CHF) is associated with a high mortality rate and is often refractory to standard medical treatment. Although parenteral inotropes have been beneficial in hospitalized patients, their use in outpatients has been limited by toxicity and tachyphylaxis.
Methods and results: To determine whether patients with end-stage CHF could safely tolerate intermittent outpatient inotropic therapy and demonstrate both symptomatic and functional improvement with these agents, we studied the effects of low-dose, intermittent home infusions of the inotrope/vasodilator milrinone in 10 patients with end-stage CHF. After showing hemodynamic improvement with milrinone while hospitalized, central lines were placed and patients were given the drug at home with small portable infusion pumps, starting at 3 days a week for 6 hours at a time over a 3-month period. Patients tolerated the drug well, with no deaths and a fourfold decrease in hospitalizations during the study. Arrhythmias were minimal and angina decreased in two patients. Mean total, physical, and emotional scores on the Minnesota Living with Heart Failure Questionnaire reflected a general trend of symptomatic improvement throughout the infusion period. The mean number of reported hours of improvement after infusion progressively increased throughout the study, producing a mean of 25 hours of postinfusion improvement during the final week (p < 0.01). Repeat hemodynamic study at the end of the 3-month period showed trends toward improvement in cardiac function.
Conclusions: This is the first study to demonstrate safety, efficacy, hemodynamic, and functional improvement in patients receiving low-dose, intermittent outpatient milrinone therapy. We believe this improvement partly relates to a "training" effect on the heart or peripheral muscles and circulation. These promising results suggest that given appropriately, inotropes have an important therapeutic role in the outpatient treatment of end-stage CHF.