Relationship Between Left Ventricular Ejection Fraction and ICD-10 Codes Among Patients Hospitalized With Heart Failure

Introduction: While left ventricular ejection fraction (LVEF) represents an important means by which to classify patients with heart failure (HF), relatively little is known about the distribution of LVEFs among patients hospitalized for HF based on their International Classification of Disease (ICD)-10 code.

Methods: We performed a retrospective cross-sectional analysis of patients admitted to a large integrated health system within the western US between January 1, 2018 and October 1, 2022 with a principal diagnosis of HF (defined by ICD-10 codes: I50.2, systolic HF; I50.3, diastolic HF; I50.4, combined systolic and diastolic HF; I11.0, hypertensive heart disease with HF; and I13.0 and I13.2, hypertensive heart disease with HF and chronic kidney disease).

Results: Over nearly 5 years, 61,238 HF hospitalizations occurred, of which 49,772 (81%) had a LVEF available by echocardiography within the preceding 3 months. Whereas most patients hospitalized with systolic HF (n = 2220) as well as systolic and diastolic heart failure (n = 1582) had an LVEF ≤ 40% (86.2% and 74.8%, respectively), most patients hospitalized with diastolic HF (n = 1542) had an LVEF ≥ 50% (94.0%) (Figure). A much greater range of LVEFs were noted for those with hypertensive heart disease with HF (n = 18,092) and hypertensive heart disease with HF and CKD (n = 26,336) (Figure).

Conclusion: While there was relatively good concordance between LVEF and the ICD-10 code-defined HF type for systolic HF, diastolic HF, and systolic and diastolic HF, these codes represent a small subset (~10%) of total HF hospitalizations.