What findings are sensitive and specific for congestive heart failure (CHF)?

From the Guidelines

Elevated B-type natriuretic peptide (BNP) levels and N-terminal probrain natriuretic peptide (NTproBNP) are highly sensitive and specific for heart failure diagnosis, particularly when used as a rule-out test at their respective lower cut-off thresholds, as shown in a meta-analysis published in the BMJ in 2015 1. The diagnosis of heart failure can be challenging due to non-specific symptoms and signs, and the mortality from acute heart failure remains high, at approximately 25% over one year. Several findings are sensitive and specific for heart failure diagnosis, including:

• Elevated BNP levels above 400 pg/mL or NT-proBNP above 450 pg/mL (age <50), 900 pg/mL (age 50-75), or 1800 pg/mL (age >75), which strongly suggest heart failure with specificity around 90%
• Echocardiographic evidence of reduced left ventricular ejection fraction (<40%) or preserved ejection fraction with diastolic dysfunction, as recommended by the European Society of Cardiology guidelines in 2016 1
• Physical examination findings with high specificity, such as jugular venous distention, third heart sound (S3 gallop), and hepatojugular reflux
• Chest X-ray findings of cardiomegaly, pulmonary vascular redistribution, and pleural effusions, which are moderately specific The combination of multiple findings significantly increases diagnostic accuracy, with the Framingham criteria providing a structured approach to diagnosis. Heart failure diagnosis is most accurate when combining history, physical examination, laboratory biomarkers, and imaging studies, rather than relying on any single finding, as recommended by the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines in 2009 1. Key laboratory evaluations include complete blood count, urinalysis, serum electrolytes, blood urea nitrogen, serum creatinine, fasting blood glucose, lipid profile, liver function tests, and thyroid-stimulating hormone. Imaging studies, such as two-dimensional echocardiography with Doppler and chest radiograph, are essential for assessing left ventricular ejection fraction, left ventricular size, wall thickness, and valve function. Coronary arteriography should be performed in patients with angina or significant ischemia, unless the patient is not eligible for revascularization of any kind. In clinical practice, the early use of a natriuretic peptide test to rule out acute heart failure can reliably exclude heart failure and allow more rapid investigation of other potential causes for a patient’s symptoms, as shown in the BMJ study in 2015 1. A negative test result may reduce or obviate the need to proceed to echocardiography or other cardiac imaging, allowing more efficient use of resources. In patients where the clinical assessment is difficult, the ability to rapidly raise the suspicion of acute heart failure when the result for natriuretic peptide is above the cut-off, will allow targeted, rapid investigation to confirm or refute the diagnosis. Earlier confirmation of the diagnosis of heart failure may facilitate more rapid initiation of specific treatment, potentially shortening hospital stay and reducing mortality.

From the Research

Sensitive and Specific Findings for Heart Failure

The diagnosis of heart failure is based on a combination of clinical symptoms, physical examination, and diagnostic tests. The following findings are sensitive and specific for heart failure:

• A displaced cardiac apex, a third heart sound, and chest radiography findings of venous congestion or interstitial edema are useful in identifying heart failure 2
• Echocardiography is the diagnostic standard to confirm systolic or diastolic heart failure through assessment of left ventricular ejection fraction 2, 3
• The presence of heart failure is highly unlikely in the absence of dyspnea and an abnormal chest radiograph or electrocardiogram 3
• B-type natriuretic peptide level is a useful marker in diagnosing heart failure, and a normal level makes systolic heart failure unlikely 2

Diagnostic Criteria

The European Society of Cardiology defines the diagnosis of heart failure based on three criteria:

• Symptoms compatible with heart failure at rest or on exercise
• Objective evidence of cardiac dysfunction at rest
• A favourable response following therapy for heart failure 4

Diagnostic Tests

The following diagnostic tests are used to confirm the diagnosis of heart failure:

• Echocardiography to assess left ventricular ejection fraction
• Chest radiography to evaluate venous congestion or interstitial edema
• Electrocardiography to evaluate cardiac rhythm and function
• Laboratory tests, such as B-type natriuretic peptide level, to evaluate cardiac function 2, 3, 4