What is the recommended management for a patient with mildly reduced right ventricular ejection fraction (RVEF) and slightly below normal left ventricular ejection fraction (LVEF)?

Management of Mildly Reduced Right Ventricular Ejection Fraction with Normal Left Ventricular Function

For a patient with mildly reduced right ventricular ejection fraction (RVEF 37%) and normal left ventricular ejection fraction (LVEF 59%), close monitoring with serial imaging is recommended, as there is no indication for specific heart failure therapy at this time.

Understanding the Clinical Significance

The cardiac MRI findings show:

• Normal LV size and wall thickness with LVEF of 59% (normal)
• Normal regional wall motion
• No evidence of myocardial fibrosis or infiltrative disease
• Mildly reduced RVEF of 37% (normal RVEF is typically ≥45%)

Classification Context

According to the 2022 AHA/ACC/HFSA Heart Failure Guidelines 1, heart failure classifications are primarily based on left ventricular function:

• HFrEF (reduced EF): LVEF ≤40%
• HFmrEF (mildly reduced EF): LVEF 41-49%
• HFpEF (preserved EF): LVEF ≥50%

The patient's LVEF of 59% places them in the normal/preserved category, not meeting criteria for left-sided heart failure.

Clinical Implications of Isolated RV Dysfunction

The prognostic significance of isolated RV dysfunction varies:

• Research shows that reduced RVEF can be an independent predictor of mortality in patients with non-ischemic cardiomyopathy 2, but this patient has no evidence of cardiomyopathy.
• In patients with normal LVEF, the anteroposterior component of RV motion may provide independent prognostic value 3.
• Impairment of RVEF can carry a higher risk of mortality independent of LVEF in certain cardiovascular conditions 4.

Management Approach

1. Baseline Assessment:

   • Evaluate for symptoms of right heart failure (peripheral edema, jugular venous distension, hepatomegaly)
   • Assess for potential causes of isolated RV dysfunction:
     • Pulmonary hypertension
     • Pulmonary embolism history
     • Sleep apnea
     • Congenital heart disease

2. Monitoring Strategy:

   • Serial cardiac imaging (echocardiography or CMR) at 6-12 month intervals to track RVEF
   • Monitor for development of symptoms

3. When to Consider Treatment:

   • If RVEF deteriorates further
   • If symptoms of right heart failure develop
   • If pulmonary hypertension is identified

Important Considerations

• The correlation between LVEF and RVEF is weak in patients with normal biventricular function 5, explaining why isolated RV dysfunction can occur.
• In patients with left-sided heart disease, there can be significant remodeling of the RV with preservation of RVEF in mild to moderate LV dysfunction 3.
• The absence of late gadolinium enhancement suggests no myocardial fibrosis or infiltrative disease, which is reassuring.

Pitfalls to Avoid

1. Don't overtreat: Avoid initiating heart failure medications based solely on mildly reduced RVEF with normal LV function, as current guidelines don't support this approach 1.

2. Don't underinvestigate: Ensure appropriate workup for potential causes of isolated RV dysfunction.

3. Don't ignore progression: If serial imaging shows worsening RVEF or development of LV dysfunction, reassess management strategy.

4. Don't miss pulmonary hypertension: Consider echocardiography with estimation of pulmonary artery pressures if not already performed.

In summary, while the mildly reduced RVEF warrants attention and follow-up, in the absence of symptoms and with normal LV function, specific heart failure therapy is not indicated at this time based on current guidelines.