Q&A: Determining systolic versus diastolic heart failure

Q: Is there a cut off for ejection fraction (EF) to determine if it is truly a systolic heart failure (HF) or diastolic HF?

A: This is a great question.

There are specified cut offs when determining the type of HF. There are parameters for systolic and diastolic dysfunction as well as the newer categories HFmrEF (HF with mildly reduced EF) and HFrecEF (HF with recovered EF). Below is the breakdown of each type.

HFpEF (diastolic): Typically categorized by the left ventricle’s muscle being too thick or stiff which results in the inability to properly or effectively fill. EF is greater than 50%. So, the pump works, it just doesn't have enough volume. On echo, mild left ventricular hypertrophy (LVH) and mild diastolic dysfunction are commonly described.

HFrEF (systolic): Typically characterized by the left ventricle failing to pump the amount of blood that the body needs. EF is less than 40%. Essentially, the pump doesn’t work well. Patients with an EF of less than 20% usually have an element of both diastolic and systolic dysfunction (not enough volume in the tank and a worn-out pump).

HFmrEF EF 41-49% (HF with mildly reduced EF): This is harder to diagnose, as the signs and symptoms are similar to HFpEF but the echo results are usually described on echo with diastolic dysfunction, left atrial enlargement and left ventricular hypertrophy. Per Coding Clinic, third quarter 2020, p. 32, when a patient’s HF is described in terms of mildly or midrange ejection fraction, assign a code for systolic HF (I50.2).

HFrecEF Heart failure with recovered EF (could also be documented as HFimpEF—HF with improved EF): Previous LVEF ≤40% and follow-up measurement of LVEF >40%. Improved EF usually is diagnosed after an intervention. This could be a change in medications and/or lifestyle changes or after a valve replacement. Per Coding Clinic, third quarter 2020, p. 32, this would code as chronic diastolic HF (I50.32). As it is defined as improved, this would never be captured as an acute condition.

For more detailed descriptions, diagnostics and treatment, the Journal or the American College of Cardiology has an extensive overview, which is available here: https://www.jacc.org/doi/10.1016/j.jacc.2021.12.012

Editor’s note: Kim Conner, BSN, CCDS, CCDS-O, CDI education specialist for ACDIS/HCPro based in Middleton, Massachusetts, answered this question. Contact her at kconner@acdis.org.