What is the role of push dose phenylephrine (phenyl) in heart failure (HF) with reduced ejection fraction?

From the Guidelines

Push-dose phenylephrine should be used with extreme caution in heart failure with reduced ejection fraction (HFrEF) when rapid blood pressure support is needed, due to its potential to worsen cardiac function by increasing myocardial oxygen demand and workload on an already compromised heart. The typical preparation involves diluting 1 mL of phenylephrine 10 mg/mL with 9 mL of normal saline to create a 1 mg/mL solution, administered in 50-200 mcg (0.05-0.2 mL) boluses every 1-5 minutes as needed. In HFrEF patients, start at the lower end of dosing (50 mcg) and carefully titrate based on response. Phenylephrine is a pure alpha-1 agonist that increases blood pressure through vasoconstriction without direct inotropic effects, which can be beneficial in HFrEF compared to mixed alpha/beta agonists. However, the increased afterload from vasoconstriction may worsen cardiac function in HFrEF patients by increasing myocardial oxygen demand and workload on an already compromised heart. Close hemodynamic monitoring is essential, including blood pressure, heart rate, and signs of worsening heart failure. If prolonged vasopressor support is needed, transition to a continuous infusion and consider more definitive management of the underlying cause of hypotension. Alternative agents like norepinephrine or dobutamine may be more appropriate for longer-term support in HFrEF patients. According to the most recent guidelines, the focus should be on optimizing guideline-directed medical therapy (GDMT) for HFrEF, which includes medications such as renin-angiotensin-aldosterone system (RAS) inhibitors, beta-blockers, mineralocorticoid-receptor antagonists, and sodium-glucose cotransporter-2 inhibitors 1.

Some key points to consider when using push-dose phenylephrine in HFrEF patients include:

• Starting with a low dose and titrating carefully to avoid excessive vasoconstriction and worsening cardiac function
• Monitoring hemodynamics closely, including blood pressure, heart rate, and signs of worsening heart failure
• Considering alternative agents for longer-term support, such as norepinephrine or dobutamine
• Optimizing GDMT for HFrEF, including medications such as RAS inhibitors, beta-blockers, and mineralocorticoid-receptor antagonists, as recommended by the most recent guidelines 1.

It is also important to note that the use of push-dose phenylephrine in HFrEF patients should be guided by the most recent and highest-quality evidence, and that the potential benefits and risks of its use should be carefully weighed in each individual patient. As stated in the 2021 update to the 2017 ACC expert consensus decision pathway for optimization of heart failure treatment, the treatment of HFrEF can feel overwhelming, and many opportunities to improve patient outcomes are being missed 1.

In terms of specific medications, the 2016 ESC guidelines for the diagnosis and treatment of acute and chronic heart failure recommend the use of ACE inhibitors, beta-blockers, and mineralocorticoid receptor antagonists in patients with symptomatic HFrEF 1. The 2020 guideline-directed medical therapy for heart failure also emphasizes the importance of optimizing medical therapy, including the use of neprilysin inhibitors, beta-blockers, and mineralocorticoid receptor antagonists, in patients with HFrEF 1.

Overall, the use of push-dose phenylephrine in HFrEF patients requires careful consideration of the potential benefits and risks, and should be guided by the most recent and highest-quality evidence.

From the FDA Drug Label

5 WARNINGS AND PRECAUTIONS

5.1 Exacerbation of Angina, Heart Failure, or Pulmonary Arterial Hypertension Because of its pressor effects, phenylephrine hydrochloride can precipitate angina in patients with severe arteriosclerosis or history of angina, exacerbate underlying heart failure, and increase pulmonary arterial pressure.

The use of phenylephrine in patients with heart failure (HF) with reduced ejection fraction may exacerbate underlying heart failure due to its pressor effects.

• Key consideration: Phenylephrine can increase pulmonary arterial pressure and precipitate angina in patients with severe arteriosclerosis or history of angina.
• Clinical decision: Use of phenylephrine in HF with reduced ejection fraction should be approached with caution, as it may worsen heart failure symptoms 2.

From the Research

Push Dose Phenyl in Heart Failure with Reduced Ejection Fraction

• There is no direct evidence in the provided studies regarding the use of "push dose phenyl" in heart failure with reduced ejection fraction (HFrEF) 3, 4, 5, 6, 7.
• However, the studies discuss various treatment strategies for HFrEF, including the use of beta-blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and mineralocorticoid receptor antagonists.
• Beta-blockers are recommended as foundational therapy for patients with HFrEF, as they have been shown to reduce morbidity and mortality 4, 5.
• The use of phenylephrine, a vasopressor, is not mentioned in the provided studies as a treatment for HFrEF.
• It is essential to note that the treatment of HFrEF should be guided by evidence-based guidelines and individualized to each patient's needs and circumstances.

Treatment Strategies for Heart Failure with Reduced Ejection Fraction

• The studies emphasize the importance of using evidence-based treatments for HFrEF, including beta-blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and mineralocorticoid receptor antagonists 3, 4, 5.
• The use of diuretics and digoxin may be necessary for symptom control, but they do not provide a mortality benefit 3.
• Device therapies, such as implantable cardioverter-defibrillators and biventricular pacemakers, may be beneficial in selected patients with HFrEF 3, 5.

Beta-Blockers in Heart Failure with Reduced Ejection Fraction

• Beta-blockers are a cornerstone of treatment for HFrEF, as they have been shown to reduce morbidity and mortality 4, 5.
• The studies discuss the importance of using beta-blockers in patients with HFrEF, unless there are specific contraindications 4, 5.
• The use of beta-blockers in patients with heart failure with preserved ejection fraction (HFpEF) is less clear, and further studies are needed to determine their effectiveness in this population 6, 7.