Background The randomized DOREMI (Dobutamine Compared to Milrinone) clinical trial evaluated the efficacy and safety of milrinone and dobutamine in patients with cardiogenic shock. Whether the results remain consistent when stratified by acute myocardial infarction remains unknown. In this substudy, we sought to evaluate differences in clinical management and outcomes of acute myocardial infarction complicated by cardiogenic shock (AMICS) versus non‐AMICS. Methods and Results Patients in cardiogenic shock (n=192) were randomized 1:1 to dobutamine or milrinone. The primary composite end point in this subgroup analysis was all‐cause in‐hospital mortality, cardiac arrest, non‐fatal myocardial infarction, cerebrovascular accident, the need for mechanical circulatory support, or initiation of renal replacement therapy (RRT) at 30‐days. Outcomes were evaluated in patients with (n=65) and without (n=127) AMICS. The primary composite end point was significantly higher in AMICS versus non‐AMICS (hazard ratio [HR], 2.21; 95% CI, 1.47–3.30; P =0.0001). The primary end point was driven by increased rates of all‐cause mortality, mechanical circulatory support, and RRT. No differences in other secondary outcomes including cardiac arrest or cerebrovascular accident were observed. AMICS remained associated with the primary composite outcome, 30‐day mortality, and RRT after adjustment for age, sex, procedural contrast use, multivessel disease, and inotrope type. Conclusions AMI was associated with increased rates of adverse clinical outcomes in cardiogenic shock along with increased rates of mortality and initiation of mechanical circulatory support and RRT. Contrast administration during revascularization likely contributes to increased rates of RRT. Heterogeneity of outcomes in AMICS versus non‐AMICS highlights the need to study interventions in specific subgroups of cardiogenic shock. Registration URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03207165.
Milrinone as Compared with Dobutamine in the Treatment of Cardiogenic Shock
AbstractAimsCardiogenic shock (CS) is a state of low cardiac output resulting in end-organ hypoperfusion. Despite high in-hospital mortality rates, little evidence exists regarding the optimal mean arterial pressure (MAP) target in CS. We therefore evaluated the relationship between achieved MAP and clinical outcomes in patients with CS.Methods and resultsWe performed a post hoc analysis of the CAPITAL DOREMI trial: a randomized, double-blind trial comparing dobutamine to milrinone in patients with CS. We divided patients into a high MAP group (average MAP ≥ 70 mmHg over the 36 h following randomization), and a low MAP group (average MAP < 70 mmHg). Our primary outcome included in-hospital all-cause mortality, resuscitated cardiac arrest, need for cardiac transplantation or mechanical circulatory support, non-fatal myocardial infarction, transient ischaemic attack or stroke, or initiation of renal replacement therapy. In total, 71 (37.0%) patients achieved an average MAP < 70 mmHg, and 121 (63.0%) achieved an average MAP ≥ 70 mmHg. The primary outcome occurred in 48 (67.6%) patients in the low MAP group and 51 (42.2%) patients in the high MAP group [adjusted relative risk (aRR) 0.70; 95% confidence interval (CI) 0.53–0.92; P = 0.01]. All-cause mortality occurred in 41 (57.8%) and 35 (28.9%) patients in the low and high MAP groups, respectively (aRR 0.56; 95% CI 0.40–0.79; P < 0.01). There were no significant differences in any secondary outcomes between each group.ConclusionsIn patients with CS treated with inotrope therapy, low MAP is associated with worse clinical outcomes. Randomized data evaluating optimal MAP targets in CS is needed to guide medical therapy.