According to the American Heart Association, 6.5 million Americans currently have heart failure and over 670,000 cases are diagnosed every year.
The diagnosis of heart failure is, first and foremost, a clinical one, based on history and physical examination traditionally defined by the 1948 Framingham diagnostic criteria. The Framingham diagnostic standards identify major and minor criteria. For a diagnosis of heart failure, a patient should meet either two major criteria or one major criterion plus two minor criteria.
Major criteria include paroxysmal nocturnal dyspnea, orthopnea, elevated jugular venous pressure, S-3 gallop, pulmonary rales, and cardiomegaly or pulmonary edema on chest X-ray. Minor criteria include bilateral lower-extremity edema, nocturnal cough, dyspnea on ordinary exertion, hepatomegaly, pleural effusion, and tachycardia (≥120 beats/min).
The severity of heart failure may be determined by the New York Heart Association functional classification, stages I through IV (Table 1). Once heart failure has been clinically diagnosed, a number of studies, such as electrocardiogram, echocardiogram, B-type natriuretic peptide (BNP), and exercise testing, are typically conducted to further substantiate the diagnosis and investigate the cause.
Once the diagnosis is established, all cases of heart failure can be classified as systolic, diastolic, or combined systolic/diastolic in nature. Identifying the systolic versus diastolic nature of heart failure is crucial for clinical management and coding purposes. Without this information, correct therapeutic decisions cannot be made and code assignment will not reflect the patient's true severity of illness or costs of care. Quality and other performance measures can also be impacted adversely. The systolic/diastolic nature of heart failure should be documented in the record for every admission and included or updated on the problem list.
Identification of the systolic/diastolic nature of heart failure can be easily done with echocardiography. If heart failure has been diagnosed, an ejection fraction (EF) below normal (<55%) represents systolic heart failure. In diastolic heart failure, the EF is normal (55% to 70%) or elevated (>70%). The echocardiogram may identify other parameters of diastolic dysfunction. Combined systolic/diastolic heart failure is recognized by low EF (systolic dysfunction) together with some of these other diastolic parameters.
Newer descriptive terms are also acceptable for identifying and coding the systolic/diastolic distinction: heart failure with reduced ejection fraction (HFrEF) for systolic and heart failure with preserved ejection fraction (HFpEF) for diastolic. Other acceptable descriptions include heart failure “with low EF” or “with reduced systolic function” for systolic heart failure and “preserved systolic” or “preserved ventricular” function for diastolic heart failure. Similar descriptive terms are also acceptable for either systolic or diastolic function.
Establishing the acuity of heart failure is just as important as determining whether it is systolic or diastolic, but acuity will have no impact on coding if the systolic/diastolic nature is not documented. Always document clearly and consistently in the medical record if there has been an acute exacerbation or decompensation of chronic heart failure—even if mild.
Potential indicators suggesting decompensated heart failure may include any exacerbation of symptoms (e.g., increasing shortness of breath, weight gain, edema), use of an IV diuretic like furosemide (even one dose) or increased oral dosing, pulmonary rales, pulmonary congestion/edema on chest X-ray, new or increasing pleural effusion, need for supplemental oxygen, and a BNP level greater than 500 pg/mL or a pro-BNP level greater than 3,000 pg/mL.
In the absence of decompensation, stable asymptomatic chronic heart failure also contributes to severity and reimbursement even if no related treatment is required other than continuation of usual home medications. However, this is the case only if the systolic/diastolic nature of the patient's heart failure is identified.
Medicare's diagnosis-related group (DRG) payment system classifies many diagnoses (including heart failure) into DRGs with increasing levels of severity, expected lengths of stay (LOS), and reimbursement to cover higher costs of care based on the presence of certain comorbid conditions (CCs) or major comorbid conditions (MCCs). These comorbid conditions are statistically determined by CMS. A DRG with no CC or MCC has lower severity, shorter expected LOS, and lower reimbursement. A DRG with one or more MCCs has the highest severity, LOS, and reimbursement. DRGs with one or more CCs but no MCCs fall somewhere in between.
The International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM), identifies many types of heart failure (see examples in Table 2), but it is most important to specify acuity and the systolic/diastolic distinction. Unspecified heart failure (e.g., “CHF”) or simply “heart failure” without further description is assigned code I50.9, which makes no contribution to severity of illness classification.
Other types of heart failure that are identified by ICD-10-CM codes but have no significant severity of illness classification (non-CCs) include biventricular, right, end-stage, and high-output heart failure. Whenever these are diagnosed, the systolic/diastolic nature and acuity should also be documented. Peripartum heart failure is assigned an obstetrical code for peripartum cardiomyopathy with a high associated severity of illness (MCC).
Left ventricular (or left-heart) failure is assigned to a code that is a CC but does not have specificity for acuity. Therefore, when left-heart failure is acute, both its acuity and the systolic/diastolic nature should be documented. Unspecified valvular heart failure or disease is assigned to codes for endocarditis. Therefore, it is necessary to describe which valve is affected and whether there is stenosis or regurgitation or both to avoid misclassification. Rheumatic valvular heart failure or disease can be independently coded correctly.
All forms of heart failure documented in the record should be coded to capture a complete picture of the patient's condition. For example, documentation of acute diastolic right-heart failure would be assigned two codes: one for acute right-heart failure (non-CC) and another for acute diastolic heart failure (MCC).
For coding purposes, whenever a patient has both heart failure and hypertension, it is assumed to be hypertensive heart disease unless specifically stated otherwise by the clinician, and a combination code from category I11 (hypertensive heart disease) is assigned first, followed by codes for the type(s) of heart failure and hypertension. If the patient also has chronic kidney disease, the connection between it, hypertension, and heart failure is also assumed and a code from category I13 (hypertensive heart and chronic kidney disease) is assigned first, followed by codes for all three conditions.
As an example, for chronic diastolic heart failure and essential hypertension, the following codes are assigned in this order: I11.0 (hypertensive heart disease with heart failure), I50.32 (chronic diastolic heart failure), I10 (hypertension).
In summary, heart failure is a clinical diagnosis based on signs, symptoms, and physical findings. The diastolic/systolic nature and acuity of heart failure must be identified in all cases. In systolic heart failure, the EF is less than 55%; an EF of 55% and above is diastolic failure. HFrEF and HFpEF are acceptable descriptions of systolic and diastolic heart failure, respectively. Always identify and document any acute exacerbation or decompensation from the baseline state, even if mild.