What is the best pressor or intervention for hypotension (low blood pressure) post-myocardial infarction (MI) and percutaneous coronary intervention (PCI) with poor cardiac output?

From the Guidelines

For hypotension post-MI and PCI with poor cardiac output, norepinephrine is generally the preferred vasopressor, typically started at 0.01-0.3 mcg/kg/min and titrated to maintain a mean arterial pressure of 65-70 mmHg. This approach is guided by the need to balance the maintenance of adequate coronary perfusion pressure with the risk of exacerbating myocardial oxygen demand, particularly in the post-MI setting 1.

Key Considerations

• The choice of vasopressor should be tailored to the patient's specific hemodynamic profile, with norepinephrine preferred due to its ability to maintain coronary perfusion pressure with less tachycardia than dopamine 1.
• In cases of cardiogenic shock, mechanical circulatory support such as an intra-aortic balloon pump or Impella device should be considered early, as revascularization is the only treatment proven to decrease mortality rates in this context 1.
• Dobutamine (2.5-10 mcg/kg/min) can be added if cardiac output remains inadequate despite adequate blood pressure, providing inotropic support without excessive chronotropy 1.
• Fluid resuscitation should be approached cautiously with small boluses (250-500 mL) while monitoring for pulmonary congestion, to avoid worsening cardiac function.

Additional Interventions

• Early revascularization, either PCI or CABG, is recommended for patients less than 75 years old with ST elevation or LBBB who develop shock within 36 hours of MI and are suitable for revascularization that can be performed within 18 hours of shock 1.
• Inotropes such as dopamine, dobutamine, and milrinone may be considered for patients with relative hypotension and intolerance or no response to vasodilators and diuretics, but their use portends a very poor prognosis and requires thorough hemodynamic assessment 1.

From the FDA Drug Label

For blood pressure control in certain acute hypotensive states (e.g., pheochromocytomectomy, sympathectomy, poliomyelitis, spinal anesthesia, myocardial infarction, septicemia, blood transfusion, and drug reactions). Restoration of Blood Pressure in Acute Hypotensive States Blood volume depletion should always be corrected as fully as possible before any vasopressor is administered.

The best pressor or intervention for hypotension post-myocardial infarction (MI) and percutaneous coronary intervention (PCI) with poor cardiac output is Norepinephrine (IV), as it is indicated for blood pressure control in certain acute hypotensive states, including myocardial infarction 2, 2.

• The dosage should be titrated according to the response of the patient, with an average maintenance dose ranging from 0.5 mL to 1 mL per minute (from 2 mcg to 4 mcg of base) 2.
• Blood volume depletion should always be corrected as fully as possible before any vasopressor is administered 2.
• The infusion should be continued until adequate blood pressure and tissue perfusion are maintained without therapy, and then reduced gradually, avoiding abrupt withdrawal 2.

From the Research

Best Pressor or Intervention for Hypotension Post-MI and PCI

The management of hypotension post-myocardial infarction (MI) and percutaneous coronary intervention (PCI) with poor cardiac output is crucial for patient outcomes. Several studies have investigated the best pressor or intervention for this condition.

Vasopressor Therapy

• Norepinephrine (NE) is considered a first-line vasopressor for patients with shock, including cardiogenic shock, due to its effectiveness in increasing arterial pressure with a lower risk of adverse events compared to other catecholamine vasopressors 3.
• The use of epinephrine compared to norepinephrine in patients with cardiogenic shock secondary to acute myocardial infarction was associated with similar effects on arterial pressure and cardiac index, but a higher incidence of refractory shock 4.
• Vasopressin or angiotensin II may be added to norepinephrine in patients who are not responsive to norepinephrine alone 3, 5.

Inotropic Support

• Dobutamine may be used as an inotrope to increase cardiac output in patients with poor cardiac output 3.
• Low doses of epinephrine or dopamine may be used for inotropic support, but high doses of these drugs carry an excessive risk of adverse events 3.

Mechanical Support

• Intra-aortic balloon pumping (IABP) is commonly used for initial hemodynamic stabilization in patients with cardiogenic shock, but its effectiveness is limited in patients with severe depression of left ventricular function 6, 7.
• Percutaneous left ventricular assist devices (LVAD) may be beneficial in patients with cardiogenic shock who do not respond to standard treatment, including IABP support 6.

Predictors of Mortality

• Age, vasopressor use, resuscitation before PCI, acute renal failure, and IABP implantation after PCI are independent predictors of in-hospital mortality in patients with cardiogenic shock due to acute myocardial infarction 7.