title: Effect of Milrinone Infusion on Pulmonary Vasculature and Stroke Work Indices: A Single-Center Retrospective Analysis in 69 Patients Awaiting Cardiac Transplantation.
abstract: BACKGROUND
  Although milrinone infusion is reported to benefit left ventricular function in chronic left heart failure, few insights exist regarding its effects on pulmonary circulation and right ventricular function.
  
  
  METHODS
  We retrospectively reviewed right heart catheterization data at baseline and during continuous infusion of milrinone in 69 patients with advanced heart failure and analyzed the effects on ventricular stroke work indices, pulmonary vascular resistance and pulmonary arterial compliance.
  
  
  RESULTS
  Compared to baseline, milrinone infusion after a mean 58 ± 61 days improved mean left ventricular stroke work index (1540 ± 656 vs. 2079 ± 919 mmHg·mL/m2, p = 0.0007) to a much greater extent than right ventricular stroke work index (616 ± 346 vs. 654 ± 332, p = 0.053); however, patients with below median stroke work indices experienced a significant improvement in both left and right ventricular stroke work performance. Overall, milrinone reduced left and right ventricular filling pressures and pulmonary and systemic vascular resistance by approximately 20%. Despite an increase in pulmonary artery capacitance (2.3 ± 1.6 to 3.0 ± 2.0, p = 0.013) and a reduction in pulmonary vascular resistance (3.8 ± 2.3 to 3.0 ± 1.7 Wood units), milrinone did not reduce the transpulmonary gradient (13 ± 7 vs. 12 ± 6 mmHg, p = 0.252), the pulmonary artery pulse pressure (25 ± 10 vs. 24 ± 10, p = 0.64) or the pulmonary artery diastolic to pulmonary capillary wedge gradient (2.0 ± 6.5 vs. 2.4 ± 6.0, p = 0.353).
  
  
  CONCLUSIONS
  Milrinone improved left ventricular stroke work indices to a greater extent than right ventricular stroke work indices and had beneficial effects on right ventricular net input impedance, predominantly via augmentation of left ventricular stroke volume and passive unloading of the pulmonary circuit. Patients who had the worst biventricular performance benefited the most from chronic milrinone infusion.
authors.affiliation: Division of Cardiology, University of Louisville, 201 Abraham Flexner Way Ste 1001, Louisville, KY, 40202, USA. DAbramov1@gmail.com.
authors.forename: Dmitry
authors.identifier: http://orcid.org/0000-0003-0571-3109
authors.initials: D
authors.lastname: Abramov
authors.affiliation: Heart Failure Center, University of Kansas Health System, Kansas City, KS, USA.
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Haglund
authors.affiliation: Division of Cardiology, Medical University of South Carolina, Charleston, SC, USA.
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Di Salvo
mesh_terms: D000328:Adult; D006328:Cardiac Catheterization / Q000639:trends; D005260:Female; D006333:Heart Failure / Q000503:physiopathology / Q000628:therapy; D016027:Heart Transplantation / Q000639:trends*; D006439:Hemodynamics / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D020105:Milrinone / Q000008:administration & dosage*; D012189:Retrospective Studies; D013318:Stroke Volume / Q000187:drug effects* / Q000502:physiology; D016896:Treatment Outcome; D014655:Vascular Resistance / Q000187:drug effects* / Q000502:physiology; D014665:Vasodilator Agents / Q000008:administration & dosage; D014850:Waiting Lists
chemical_list: D014665:Vasodilator Agents; D020105:Milrinone