Intravenous and Inhaled Milrinone in Adult Cardiac Surgery Patients: A Pairwise and Network Meta-Analysis

Abstract

Objective: To summarize the evidence on the hemodynamic, echocardiographic, and clinical effects of inhaled and intravenous milrinone (iMil and IvMil) in adult cardiac surgery patients. Design: Systematic review, pairwise and network meta-analysis. Setting: Multi-institutional. Participants: Adult cardiac surgery patients. Interventions: Comparison between iMil and IvMil versus other agents or placebo. Measurements and Main Results: The primary endpoints were mean pulmonary artery pressure (MPAP) and peripheral vascular resistance (PVR). Secondary endpoints included the following: (1) mean arterial pressure, heart rate, and cardiac index (CI); (2) echocardiographic data; and (3) clinical outcomes. Random model, leave-one-out-analysis, and meta-regression were used. Thirty studies (6 iMil and 24 IvMil) were included for a total of 1,438 patients (194 iMil and 521 IvMil). IvMil was associated with a lower MPAP, lower PVR, and higher CI compared to placebo (standardized mean difference [SMD] = –0.22 [95% CI = –0.48 to 0.05], SMD = –0.49 [95% CI = –0.71 to –0.27], and SMD = 0.94 [95% CI = 0.51 to 1.37]). No difference in any outcome was found between iMil and placebo. At network meta-analysis, significantly lower PVR and shorter hospital length of stay were found for IvMil compared to iMil (SMD = –0.82 [95% CI = –1.53 to –0.10] and SMD = –0.50 [95% CI = –0.95 to –0.05], respectively). Conclusion: These results support the clinical use of IvMil in cardiac surgery patients. No evidence at present supports the adoption of iMil.