Management of a Patient with LVEF Fluctuating Between 45% and 50%
For patients with LVEF fluctuating between 45% and 50%, they should be classified as having Heart Failure with Mildly Reduced Ejection Fraction (HFmrEF) and treated according to guideline-directed medical therapy for this category.
Understanding the Classification
The 2022 AHA/ACC/HFSA guidelines classify heart failure based on left ventricular ejection fraction as follows 1:
- HFrEF: LVEF ≤40%
- HFmrEF: LVEF 41%-49%
- HFpEF: LVEF ≥50%
- HFimpEF: Previous LVEF ≤40% and follow-up measurement >40%
A patient with LVEF fluctuating between 45% and 50% falls primarily in the HFmrEF category, though occasionally crosses into the HFpEF range.
Diagnostic Considerations
When LVEF is >40%, evidence of increased filling pressures is important for confirming the diagnosis of heart failure 1. This includes:
- Elevated natriuretic peptide levels
- Echocardiographic evidence of diastolic dysfunction
- Invasive hemodynamic measurements showing elevated filling pressures
Treatment Approach
First-line Medications
Beta-blockers: Recommended for patients with LVEF >40% to control heart rate and reduce symptoms 1
SGLT2 inhibitors: Should be considered for patients with HFmrEF as they have shown benefit in this population 1
Diuretics: Use as needed for symptom relief and volume management
Additional Therapies to Consider
For patients with LVEF in the 41-49% range:
ARNi (Angiotensin Receptor-Neprilysin Inhibitor): May be beneficial, particularly for those with LVEF closer to 40% 1
MRAs (Mineralocorticoid Receptor Antagonists): Should be considered, especially for those with LVEF closer to the lower end of the range 1
ACEi/ARBs: May be beneficial for symptom management and to prevent progression of heart failure 1
Special Considerations
Stability of LVEF Classification
Recent research shows that LVEF has considerable variability over time, with the HFmrEF category being particularly unstable 2. Patients with HFmrEF have a probability of less than 25% of remaining in that category after one year. This underscores the importance of regular monitoring and treatment adjustments.
Prognostic Implications
LVEF is a powerful predictor of cardiovascular outcomes in heart failure patients. Research shows that mortality risk increases by 39% for every 10% reduction in ejection fraction below 45% 3. However, once LVEF is above 45%, further increases do not significantly change cardiovascular risk assessment 3.
Treatment for Patients with Improved LVEF
If a patient previously had HFrEF (LVEF ≤40%) and has improved to 45-50%, they should be classified as having HFimpEF. In this case:
Guideline-directed medical therapy should be continued even if the patient becomes asymptomatic, to prevent relapse of heart failure and left ventricular dysfunction 1.
Monitoring and Follow-up
- Regular echocardiographic assessment (typically annual)
- Monitor for symptoms of heart failure
- Assess volume status at each visit
- Monitor renal function and electrolytes, especially if on diuretics, ACEi/ARB, or MRAs
- Evaluate for potential causes of LVEF fluctuation
Pitfalls to Avoid
Undertreatment: Don't withhold beneficial therapies just because LVEF occasionally rises above 50%
Overreliance on a single LVEF measurement: Given the variability of LVEF measurements (SD of within-person variance is 7.4% 2), treatment decisions should consider the overall clinical picture and trend of measurements
Premature discontinuation of therapy: If LVEF improves, continue guideline-directed medical therapy to prevent relapse 1
Failure to address comorbidities: Manage hypertension, coronary artery disease, and other conditions that may contribute to heart failure progression
By following these guidelines and considering the dynamic nature of LVEF, clinicians can optimize outcomes for patients with fluctuating LVEF between 45% and 50%.