From the Guidelines
Yes, an LVEF of 16% is significantly low and indicates heart failure with reduced ejection fraction (HFrEF), requiring immediate medical attention and comprehensive treatment. According to the most recent guidelines, an LVEF of 16% falls into the category of severely reduced heart function, with normal LVEF ranging from 55-70% and severe reduction being below 30% 1.
Classification of Heart Failure
The 2022 AHA/ACC/HFSA guideline for the management of heart failure classifies heart failure based on left ventricular ejection fraction (LVEF) into three categories: heart failure with reduced ejection fraction (HFrEF), heart failure with preserved ejection fraction (HFpEF), and heart failure with mildly reduced ejection fraction (HFmrEF) 1.
Management of HFrEF
Typical management of HFrEF includes medications such as:
- ACE inhibitors (like enalapril 2.5-20mg twice daily) or ARBs
- Beta-blockers (such as carvedilol 3.125-25mg twice daily)
- Mineralocorticoid receptor antagonists (spironolactone 25-50mg daily)
- Possibly SGLT2 inhibitors (dapagliflozin 10mg daily) Diuretics like furosemide are often needed to manage fluid overload. Patients with this severely reduced LVEF may also be candidates for device therapy such as an implantable cardioverter-defibrillator (ICD) or cardiac resynchronization therapy (CRT) 1.
Prognosis and Risk Factors
Reduced LVEF has been consistently demonstrated to be the strongest independent predictor of sudden cardiac death (SCD) 1. The low ejection fraction means the heart is only pumping out 16% of its blood volume with each contraction, significantly compromising cardiac output and potentially leading to symptoms like shortness of breath, fatigue, and fluid retention. When LVEF is severely depressed (<15–20%), the prevailing mode of cardiac death is non-sudden, or when sudden it is often related to bradyarrhythmias or electromechanical dissociation rather than ventricular tachyarrhythmias 1.
Key Considerations
- The trajectory of LVEF over time and the cause is important to evaluate
- Elevated natriuretic peptide levels are supportive of the diagnosis, but normal levels do not exclude a diagnosis of HFmrEF or HFpEF
- The clinical diagnosis of HF in these EF categories should be further supported by objective measures
- A significant reduction in LVEF over time is a poor prognostic factor 1.
From the Research
Left Ventricular Ejection Fraction (LVEF) of 16%
- An LVEF of 16% is considered low, indicating severe left ventricular dysfunction 2, 3.
- Studies have shown that patients with severe left ventricular dysfunction (LVEF < 30%) may benefit from revascularization procedures such as coronary artery bypass grafting (CABG) or percutaneous revascularization 2.
- The optimal approach to revascularization in patients with severe LV dysfunction is still a topic of debate, with some studies suggesting that CABG may be more effective in improving LV function and reducing cardiac events 2.
Treatment Options for Low LVEF
- Beta-blockers and inhibitors of the renin-angiotensin-aldosterone system (RAAS) are commonly used to treat heart failure with reduced ejection fraction (HFrEF) 4, 5, 6.
- These medications have been shown to improve survival and reduce morbidity in patients with HFrEF, but their effectiveness in patients with preserved ejection fraction (HFpEF) is less clear 5.
- A study found that achieving guideline-recommended target doses of both beta-blockers and RAAS inhibitors was associated with improved outcomes in patients with HFrEF 4.
Prognosis and Outcomes
- Patients with low LVEF (< 50%) have been shown to have worse outcomes, including increased mortality and hospitalization rates, compared to those with higher LVEF 3.
- A decline in LVEF can begin before aortic stenosis becomes severe, and LVEF < 60% in the presence of moderate aortic stenosis predicts further deterioration of LVEF 3.
- Treatment with beta-blockers, RAAS inhibitors, and other medications may help improve outcomes in patients with low LVEF, but more research is needed to determine the most effective treatment strategies 4, 5, 6.