A56-01 Efficacy and Safety of Dobutamine Versus Milrinone in Cardiogenic Shock: A Systematic Review and Meta-analysis With Meta-regression Analysis

Introduction Dobutamine and milrinone are key inotropes used in managing heart failure and myocardial infarction-related cardiogenic shock (CS). Dobutamine, a β₁-adrenergic agonist, enhances contractility with mild vasodilation at lower doses. Milrinone, a phosphodiesterase III inhibitor, offers inotropic and lusitropic effects but causes greater vasodilation and hypotension. Unlike dobutamine, it acts independently of β-receptors, reducing tachycardia risk. Renal function is crucial in choosing between them, as milrinone is renally cleared. Hypothesis We aimed to compare dobutamine and milrinone in terms of all-cause mortality, hospital length of stay, and ICU length of stay to determine which agent demonstrates superior outcomes. Methods We conducted a systematic review and meta-analysis to compare the efficacy and safety of dobutamine versus milrinone in patients with cardiogenic shock. A comprehensive search was performed across MEDLINE, Embase, and Scopus databases up to October 20, 2025, including both randomized controlled trials (RCTs) and observational studies. The primary outcome was all-cause mortality, while secondary outcomes encompassed hospital and intensive care unit (ICU) length of stay. Risk ratios (RR) were calculated for mortality, and mean differences (MD) for length-of-stay outcomes, with all effect estimates pooled using random-effects models. Heterogeneity was evaluated using I² statistics and τ². To explore sources of variability, meta-regression was conducted incorporating study-level covariates, including mean age, study design (single- vs. multi-center), sample size, and study type (RCT vs. observational). Results A total of sixteen studies were included in the final analysis. For all-cause mortality, data from 14 studies involving 24,731 patients on dobutamine and 8,691 on milrinone showed no significant difference between the two agents (RR 1.22, 95% CI 0.99-1.49, p = 0.057; I²=82.3%). Hospital length of stay, assessed in 12 studies (dobutamine n = 24,489; milrinone n = 9,109), was significantly shorter in patients receiving dobutamine by an average of 2.02 days (MD -2.02, 95% CI -3.80 to -0.24, p = 0.031; I²=74.9%). In contrast, ICU length of stay, reported in 7 studies (dobutamine n = 6,488; milrinone n = 3,254), showed no significant difference between groups (MD -0.33 days, 95% CI -1.68 to 1.02, p = 0.56; I²=78.5%).Meta-regression analysis did not identify any significant moderators of the mortality effect. Neither mean age (β = 0.024, p = 0.570), single-center versus multi-center design (β = 0.394, p = 0.198), sample size (β=-0.00002, p = 0.712), nor study type (RCT vs. observational; β=-0.555, p = 0.258) explained the observed heterogeneity. Conclusion Given milrinone’s renal clearance, dobutamine is often preferred in renal dysfunction. Further studies are needed to assess the impact of cardiac remodeling and cardiorenal syndromes on inotrope selection.