Inotropes improve right heart function in patients undergoing aortic valve replacement for aortic stenosis.
The administration of inotropes after aortic valve replacement (AVR) for aortic stenosis (AS) is controversial. Issues include the risk of left ventricular (LV) systolic outflow obstruction (LVOTO) and the proper treatment of diastolic dysfunction for patients in whom LV systolic function is often preserved and subsequently improved. In this study, we assessed the hemodynamic benefits of inotropes for patients undergoing AVR for AS. Thirty-four patients were prospectively randomized to one of three groups: epinephrine, milrinone, or placebo. Hemodynamic and echocardiographic data were obtained before and immediately after cardiopulmonary bypass (CPB). Data were also obtained before and after increases in ventricular preload to assess the effects of inotropes on diastolic function. The use of inotropes was associated with significantly larger increases in right ventricular (RV) (placebo, 0.5%; epinephrine, +9%; milrinone, +8%; P < 0.01) and LV (placebo, +7%; epinephrine, +18%; milrinone, +20%; P = 0.07) ejection fractions (EF) and cardiac output after CPB. Changes in cardiac output and index were more strongly correlated with changes in RVEF (r = 0.56, P < 0.01; r = 0.47, P < 0.01, respectively) than with LVEF (r = 0.22, r = 0.08). Of all patients receiving epinephrine or milrinone, only one (1 of 22) had a decrease in RVEF, whereas 6 of 12 patients receiving placebo had a reduction in RVEF from pre-CPB to post-CPB. Correspondingly, for LVEF, 1 of 22 patients receiving inotropes had a decrease in LVEF, whereas 3 of 12 placebo patients had a reduction in LVEF from pre-CPB to post-CPB. No patient had evidence of LVOTO. Inotropes improved hemodynamics after AVR for AS. This was attributable more to improved RV function than to changes in LV function. Although there were no changes in diastolic function, it is possible that this study did not allow significant timing to observe benefits of inotropes on diastolic function in this setting.


CONCLUSIONS
Compared with placebo, both epinephrine and milrinone similarly improved biventricular performance after aortic valve replacement, with a greater impact on right ventricular function. Choice of either inotropic drug should be driven by blood pressure and hemodynamic goals in this setting.
Maslow
Andrew D
AD
From the Departments of Anesthesia and Surgery; Rhode Island Hospital, Providence Rhode Island; Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts.
Regan
Meredith M
MM
Schwartz
Carl
C
Bert
Arthur
A
Singh
Arun
A
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000368:Aged; D001021:Aortic Valve / Q000601:surgery*; D001024:Aortic Valve Stenosis / Q000601:surgery*; D006348:Cardiac Surgical Procedures; D002316:Cardiotonic Agents / Q000494:pharmacology*; D001026:Coronary Artery Bypass; D003324:Coronary Artery Disease / Q000601:surgery; D004311:Double-Blind Method; D004452:Echocardiography; D004837:Epinephrine / Q000494:pharmacology; D005260:Female; D006324:Heart Arrest, Induced; D019918:Heart Valve Prosthesis Implantation; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D020105:Milrinone / Q000494:pharmacology; D016277:Ventricular Function, Left / Q000187:drug effects; D016278:Ventricular Function, Right / Q000187:drug effects*
D000316:Adrenergic alpha-Agonists; D002316:Cardiotonic Agents; D020105:Milrinone; D004837:Epinephrine