What is the diagnosis for a patient presenting with shortness of breath (dyspnea), orthopnea, and congestive heart failure (CHF) with a brain natriuretic peptide (BNP) level within normal limits (<25)?

From the Guidelines

The patient's symptoms of dyspnea and orthopnea, combined with a BNP level below 25 pg/mL, make congestive heart failure unlikely as the primary cause, and alternative diagnoses such as pulmonary disease, anemia, deconditioning, or obesity should be considered. This conclusion is supported by the findings of 1, which highlights the importance of considering the clinical context and additional objective measures of cardiac dysfunction in diagnosing heart failure, especially in cases with mildly reduced or preserved ejection fraction. The low BNP level in this patient, as noted in 1, suggests that heart failure with reduced ejection fraction (HFrEF) is less likely, and other causes of symptoms should be explored.

Given the patient's presentation, a comprehensive evaluation is warranted, including:

• Pulmonary function tests to assess for pulmonary disease
• Chest imaging to evaluate for other respiratory or cardiac causes
• Complete blood count to check for anemia or other hematological abnormalities
• Assessment for obstructive sleep apnea, as it can contribute to symptoms of dyspnea and orthopnea

While awaiting further workup, symptomatic management with elevation of the head of the bed for orthopnea and appropriate activity pacing is reasonable, as suggested by 1. If respiratory symptoms are prominent, a trial of bronchodilators might be considered, depending on the results of pulmonary function tests and clinical assessment. The high negative predictive value of BNP levels under 100 pg/mL for excluding heart failure, with levels under 25 pg/mL making heart failure particularly unlikely, as discussed in 1, supports the decision to look beyond cardiac causes for the patient's symptoms.

Overall, the approach should prioritize identifying and addressing the underlying cause of the patient's symptoms, with a focus on improving morbidity, mortality, and quality of life outcomes.

From the Research

Presentation of Symptoms

• Dyspnea, orthopnea, and a CHF peptide level <25 can be indicative of various conditions, including heart failure and pulmonary diseases 2, 3, 4.
• Orthopnea, in particular, is a typical feature of patients with chronic heart failure (CHF), and is strongly correlated with increased diaphragmatic effort 5.

Diagnostic Approach

• A detailed history and physical examination should be the initial step in evaluating patients with dyspnea and orthopnea, with subsequent testing driven by the results 2, 3, 4.
• Initial tests may include chest radiography, electrocardiography, spirometry, complete blood count, and basic metabolic panel, as well as measurement of brain natriuretic peptide levels to help exclude heart failure 2, 3, 4.
• Further testing, such as echocardiography, cardiac stress tests, pulmonary function tests, and computed tomography scan of the lungs, may be necessary if no cause is identified initially 3.

Role of CHF Peptide Level

• A CHF peptide level <25 may help to exclude heart failure as a cause of symptoms, but should be interpreted in conjunction with other clinical findings and test results 2, 4.
• The measurement of serum brain natriuretic peptide has substantially improved the accuracy of diagnosis of heart failure, but should not be relied upon as the sole diagnostic criterion 6.

Treatment and Management

• Treatment of patients with dyspnea and orthopnea should be directed at the underlying cause of symptoms, and may involve a multidisciplinary approach 3, 6.
• For patients with CHF, therapy is directed at restoring normal cardiopulmonary physiology and reducing the hyperadrenergic state, with the cornerstone of treatment being a combination of an angiotensin-converting-enzyme inhibitor and slow titration of a beta blocker 6.