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Milrinone or Dobutamine in Cardiogenic Shock?

Is your institution a milrinone shop or a dobutamine shop? Or do you have a mixed shop? It seems that most institutions are accustomed to use mostly one or the other in cardiogenic shock. Some argue that milrinone is better. Some argue that dobutamine is better. But do we know the answer? This was answered late in 2021 in the New England Journal of Medicine. Hat tip to the authors. Download the article for yourself as this is not medical advice. They randomized 192 patients in cardiogenic shock to either milrinone or dobutamine. Baseline characteristics were similar between the two groups.

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Articles of Interest

An Evidence-Based Approach to Pressors in Shock: Part II

Milrinone is a phosphodiesterase-3 (PDE3) inhibitor. PDE3 is present in cardiac myocytes and vascular smooth muscles; it ultimately leads to cardiac smooth muscle relaxation and peripheral vasoconstriction. Therefore, PDE3 inhibition results in potent inotropy, in addition to diastolic relaxation and vasodilation. This leads to reduced preload, afterload, and systemic vascular resistance (SVR). In addition to increased cardiac contractility, this results in improved cardiac output. Milrinone has no beta-adrenergic activity, resulting in minimal chronotropic effects.

Critical Care Alert: Milrinone vs. Dobutamine in the Treatment of Cardiogenic Shock

Selection of one inotrope over the other is often guided by physician and center preference, often based on the clinical scenario and theoretical benefits weighed against its adverse effects. For instance, milrinone is often preferred in patients with severe pulmonary hypertension because of a purported mechanism of reducing pulmonary-artery pressures and improving right ventricular function.

DoReMi Trial: Milrinone vs Dobutamine for Treatment of Cardiogenic Shock

There was no significant difference in the primary composite outcome between milrinone and dobutamine in patients with classic or deteriorating cardiogenic shock in this single-center trial with a small sample size. The lack of difference found in this trial could simply be because initiation of therapy may have been too late in the clinical course of illness as is seen by the high mortality rates in this population across both groups. The decision on which drug to use should be tailored to institutional availability, cost, nursing familiarity, the individual patient and their clinical condition.

Milrinone

effective in patients on b-blockers and with b-adrenoceptor downregulation (as occurs in chronic CHF). less increase in myocardial O2 consumption and tachycardia than b-agonists, with lower filling pressures and lower pulmonary vascular resistance (PVR).

Milrinone as Compared with Dobutamine in the Treatment of Cardiogenic Shock

In patients with cardiogenic shock, no significant difference between milrinone and dobutamine was found with respect to the primary composite outcome or important secondary outcomes.

Resources

Milrinone: Drug information

Continuous infusion: IV: Initial: 0.125 to 0.25 mcg/kg/minute; titrate based on clinical end point (eg, systemic perfusion or end organ perfusion); usual dosage range: 0.125 to 0.75 mcg/kg/minute. Note: IV bolus loading doses are not recommended due to risk of hypotension.

StatPearls

Milrinone is a medication indicated for cardiac support in patients with acute heart failure, pulmonary hypertension, or chronic heart failure. It is often used during cardiac surgeries, including coronary artery bypass graft surgery, cardiac transplantation, and other cardiac surgeries requiring cardiac support.