From the Guidelines
I strongly advise against using milrinone at 0.125 mcg/min in a patient with heart failure with reduced ejection fraction (HFrEF) at 20% who has atrial fibrillation (AF) with rapid ventricular response, and instead recommend prioritizing rate control of the AF using beta-blockers or non-dihydropyridine calcium channel blockers. The patient's condition requires careful management to prevent worsening of heart failure and arrhythmias. According to the 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation 1, the main goals of therapy for those with AF and HF are prevention of thromboembolism and control of symptoms. Key considerations for managing this patient include:
- Rate control of the AF to prevent further deterioration of heart function
- Evaluation for anticoagulation to prevent stroke
- Potential cardioversion once the patient is stabilized
- Consideration of alternative inotropes, such as dobutamine, if inotropic support is still needed The use of milrinone, a phosphodiesterase inhibitor, may worsen arrhythmias and potentially increase mortality in this setting, as noted in the provided evidence 1. In contrast, beta-blockers, such as metoprolol, and non-dihydropyridine calcium channel blockers, such as diltiazem, are preferred agents for achieving rate control in patients with HFrEF and AF, due to their favorable effect on morbidity and mortality 1. Additionally, digoxin may be considered for both rate control and mild inotropic effect, as suggested by the 2022 AHA/ACC/HFSa guideline for the management of heart failure 1. Overall, the priority should be to control the patient's heart rate and prevent further deterioration of heart function, rather than relying on milrinone, which may exacerbate arrhythmias and worsen outcomes.
From the FDA Drug Label
Milrinone lactate produces a slight shortening of AV node conduction time, indicating a potential for an increased ventricular response rate in patients with atrial flutter/fibrillation which is not controlled with digitalis therapy During therapy with milrinone lactate, blood pressure and heart rate should be monitored and the rate of infusion slowed or stopped in patients showing excessive decreases in blood pressure
The patient with HFrEF at 20% and AF with rapid response should be closely monitored during infusion of milrinone at 0.125 mcg/min. The infusion rate should be slowed or stopped if the patient shows excessive decreases in blood pressure or an increased ventricular response rate. 2 2
From the Research
Management of HFrEF with Atrial Fibrillation and Rapid Response
- The management of heart failure with reduced ejection fraction (HFrEF) in patients with atrial fibrillation (AF) and rapid ventricular response (RVR) is crucial for improving outcomes.
- A study published in 2019 3 compared the effects of metoprolol versus diltiazem in the acute management of AF with RVR in patients with HFrEF, and found that both medications achieved similar rate control with no increase in adverse events.
Considerations for Medication Dosage
- The dosage of medications such as beta-blockers and angiotensin-converting enzyme inhibitors (ACE-Is) or angiotensin receptor blockers (ARBs) is important in the management of HFrEF.
- A study published in 2020 4 found that higher body mass index (BMI) was associated with achieving upper-range doses of ACE-Is/ARBs, while pre-existing diabetes mellitus was associated with achieving upper-range doses of beta-blockers.
Combination Therapy
- The combination of beta-blockers and ACE-Is or ARBs is a common treatment strategy for HFrEF.
- However, a study published in 2020 5 highlighted the lack of evidence for the combination use of ARBs and beta-blockers in HFrEF, except for candesartan, and suggested that modern guidelines should emphasize this distinction.
Benefits and Adverse Effects of ACE Inhibitors
- ACE inhibitors are a cornerstone of treatment for HFrEF, but their benefits and adverse effects must be carefully considered.
- A systematic review and meta-analysis published in 2021 6 found that ACE inhibitors reduced all-cause mortality in HFrEF patients, but were also associated with adverse effects such as cough, hypotension, and hyperkalaemia.
New Pharmacotherapies
- New medications such as sacubitril/valsartan and dapagliflozin have shown benefits in mortality and can be used in addition to current therapies for HFrEF.
- A review published in 2020 7 highlighted the potential benefits of these new pharmacotherapies, but noted that more research is needed to fully understand their mechanisms of action and effects on disease modification.