What is the treatment for hypotension in a patient with left heart ST-Elevation Myocardial Infarction (STEMI)?

From the Guidelines

In treating hypotension in left heart STEMI, the primary goal is to restore adequate perfusion while addressing the underlying myocardial infarction, and norepinephrine should be administered if the patient is markedly hypotensive, until systolic arterial pressure rises to at least 80 mm Hg. When managing hypotension in this context, it's crucial to consider the patient's overall hemodynamic status, including cardiac output, systemic arterial pressure, and left-sided filling pressure 1.

Key Considerations

• Initial assessment should focus on identifying the cause of hypotension, which could be due to left ventricular dysfunction, cardiogenic shock, or other factors.
• Fluid resuscitation may be necessary, but it should be done cautiously to avoid volume overload, which could worsen cardiac function.
• Vasopressors, such as norepinephrine, may be required to support blood pressure, with the goal of maintaining a systolic arterial pressure of at least 80 mm Hg 1.
• The use of ACE inhibitors is also recommended in patients with STEMI, particularly those with left ventricular dysfunction or heart failure, as they have been shown to improve outcomes 1.

Management Approach

• Norepinephrine should be the initial vasopressor of choice, starting at a dose of 0.01-0.3 mcg/kg/min, and titrated to achieve the desired blood pressure.
• Dobutamine may be added for patients with evidence of cardiogenic shock and reduced cardiac output, to help improve cardiac function.
• Continuous hemodynamic monitoring is essential, including blood pressure, heart rate, oxygen saturation, and urine output, to guide therapy and adjust as needed.
• The definitive treatment remains urgent coronary reperfusion through primary PCI or fibrinolysis if PCI is unavailable within 120 minutes, as this addresses the underlying cause of the myocardial infarction.

From the FDA Drug Label

Dopamine Hydrochloride in 5% Dextrose Injection, USP is indicated for the correction of hemodynamic imbalances present in shock due to myocardial infarction, trauma, endotoxic septicemia, open heart surgery, renal failure and chronic cardiac decompensation as in refractory congestive failure Hypotension: Low to moderate doses of dopamine, which have little effect on SVR, can be used to manage hypotension due to inadequate cardiac output At high therapeutic doses, dopamine's α-adrenergic action becomes more prominent and thus may correct hypotension due to diminished SVR.

Dopamine can be used to treat hypotension in left heart STEMI, particularly when due to inadequate cardiac output or diminished SVR 2.

• Low to moderate doses of dopamine can be used to manage hypotension due to inadequate cardiac output.
• High therapeutic doses of dopamine may correct hypotension due to diminished SVR. Alternatively, norepinephrine can also be used for blood pressure control in certain acute hypotensive states, including myocardial infarction 3.

From the Research

Treating Hypotension in Left Heart STEMI

• The management of ST-segment elevation myocardial infarction (STEMI) is complex and requires emergent treatment, with the primary goal of reperfusion as quickly as possible 4.
• In the context of cardiogenic shock, guidelines recommend the use of norepinephrine to reach the target mean arterial pressure (MAP) rather than epinephrine and dopamine 5.
• A meta-analysis comparing norepinephrine with dopamine found that patients receiving norepinephrine had a lower 28-day mortality, a lower risk of arrhythmic events, and a lower risk of gastrointestinal reaction 5.
• Another study found that the use of norepinephrine as a first-line vasopressor was not associated with reductions of in-hospital mortality or arrhythmia but could reduce the use of additional vasopressors in cardiogenic shock patients 6.
• A prospective, double-blind, multicenter, randomized study comparing epinephrine and norepinephrine in patients with cardiogenic shock after acute myocardial infarction found that the use of epinephrine was associated with a higher incidence of refractory shock 7.

Treatment Strategies

• Primary percutaneous coronary intervention (PCI) is the preferred reperfusion strategy in patients with STEMI, and if PCI cannot be performed within 120 minutes of STEMI diagnosis, fibrinolysis therapy should be administered 8.
• The initiation of networks to provide around-the-clock cardiac catheterization availability and the generation of standard operating procedures within hospital systems have helped to reduce the time to reperfusion therapy 8.
• New advances in antithrombotic therapy and preventive measures have resulted in a decrease in mortality from STEMI 8.

Vasopressor Agents

• Norepinephrine is associated with a lower 28-day mortality, a lower risk of arrhythmic events, and gastrointestinal reaction compared to dopamine 5.
• Epinephrine is associated with a higher incidence of refractory shock compared to norepinephrine in patients with cardiogenic shock after acute myocardial infarction 7.
• The use of norepinephrine as a first-line vasopressor can reduce the use of additional vasopressors in cardiogenic shock patients 6.