Heart Failure Misdiagnosis: Conditions That Mimic and the Claims That Follow

Heart failure is a complex clinical syndrome with a broad differential diagnosis. Allegations of misdiagnosis frequently arise when alternative conditions are overlooked, leading to delayed or inappropriate treatment. Such cases require rigorous scrutiny of clinical decision-making, adherence to diagnostic frameworks, and application of established legal tests. This article examines conditions that commonly mimic heart failure, the legal principles governing such claims, and the pivotal role of the cardiology expert witness.

Clinical Context: Recognising Heart Failure and Its Mimics

Heart failure is characterised by the heart’s inability to pump sufficient blood to meet the body’s metabolic demands, or to do so only at elevated filling pressures. It is typically classified by left ventricular ejection fraction (LVEF): heart failure with reduced ejection fraction (HFrEF), heart failure with mildly reduced ejection fraction (HFmrEF), and heart failure with preserved ejection fraction (HFpEF). The diagnosis relies on clinical assessment, imaging (primarily echocardiography), and biomarkers such as N-terminal pro-B-type natriuretic peptide (NT-proBNP).

Several conditions present with symptoms and signs that closely resemble heart failure, complicating the diagnostic process. These include:

• Chronic obstructive pulmonary disease (COPD): Dyspnoea, fatigue, and peripheral oedema are common to both conditions. Spirometry and chest imaging are essential to differentiate COPD from heart failure, particularly in patients with a smoking history.
• Pulmonary embolism (PE): Acute dyspnoea and hypoxia may mimic decompensated heart failure. D-dimer testing and computed tomography pulmonary angiography (CTPA) are critical in excluding PE, particularly in high-risk patients.
• Anaemia: High-output heart failure secondary to anaemia may present with fatigue and dyspnoea. Full blood count and iron studies are essential in such cases.
• Atrial fibrillation (AF) with rapid ventricular response: AF can cause dyspnoea and fatigue, which may be misattributed to heart failure. Rate control and rhythm assessment are necessary to clarify the clinical picture.
• Chronic kidney disease (CKD): Volume overload in CKD can present with oedema and elevated NT-proBNP, mimicking heart failure. Renal function tests and fluid balance assessment are key to distinguishing the two.
• Obesity and deconditioning: Exertional dyspnoea in obese patients may be attributed to heart failure, particularly when NT-proBNP is mildly elevated. Cardiopulmonary exercise testing can help clarify the diagnosis.
• Constrictive pericarditis and restrictive cardiomyopathy: These rare conditions present with signs of right heart failure, including elevated jugular venous pressure and peripheral oedema. Advanced imaging, such as cardiac magnetic resonance (CMR), is often required for accurate diagnosis.

NICE Guidance (NG106) on chronic heart failure in adults emphasises the importance of timely and accurate diagnosis, recommending echocardiography and NT-proBNP measurement within two weeks for patients with suspected heart failure. Failure to adhere to these pathways may form the basis of an allegation of breach of duty in clinical negligence claims.

Legal Relevance: Breach of Duty and Causation

In heart failure misdiagnosis claims, the legal framework centres on two key questions: whether there was a breach of duty, and whether that breach caused harm. The Bolam test, as refined by Bolitho, requires that the clinician’s actions be judged against those of a responsible body of medical opinion. The court must also be satisfied that the body of opinion is logically defensible and withstands scrutiny.

Breach of Duty

Allegations of breach of duty in heart failure misdiagnosis cases often focus on:

• Failure to investigate: Omission of echocardiography or NT-proBNP testing in patients presenting with symptoms suggestive of heart failure.
• Misinterpretation of investigations: Incorrect classification of LVEF or misattribution of symptoms to alternative diagnoses without adequate exclusion of heart failure.
• Delayed referral: Failure to refer patients with suspected heart failure to specialist services within recommended timeframes, as outlined in NICE Guidance.
• Inadequate follow-up: Lack of monitoring in patients with risk factors for heart failure, such as hypertension or diabetes.

The Montgomery test is also relevant, particularly where a patient’s individual risk factors or preferences were not adequately considered in the diagnostic process. For example, a patient with a strong family history of cardiomyopathy may require more extensive investigation than standard pathways suggest.

Causation

Establishing causation in heart failure misdiagnosis claims can be challenging. The claimant must demonstrate, on the balance of probabilities, that the alleged breach of duty resulted in harm. This may involve:

• Delayed diagnosis: Evidence that earlier diagnosis would have led to timely initiation of disease-modifying therapies, such as beta-blockers, ACE inhibitors, or mineralocorticoid receptor antagonists, which are known to improve prognosis in HFrEF.
• Inappropriate treatment: Administration of therapies that exacerbated the patient’s condition, such as non-steroidal anti-inflammatory drugs (NSAIDs) in undiagnosed heart failure, which can worsen fluid retention and renal function.
• Psychological harm: Anxiety or depression resulting from prolonged uncertainty or inappropriate management.

The legal principles established in Bailey v Ministry of Defence (2008) and Williams v Bermuda Hospitals Board (2016) are particularly relevant in cases where multiple factors contribute to the harm. The court may need to apportion responsibility where both the alleged breach and the underlying condition played a role in the outcome.

Common Pitfalls and Disputes in Heart Failure Misdiagnosis Claims

Several recurring themes emerge in cardiology medico-legal practice involving heart failure misdiagnosis:

Overreliance on Clinical Judgement Without Objective Testing

Clinical assessment alone is insufficient to diagnose or exclude heart failure. Symptoms such as dyspnoea and fatigue are non-specific, and signs like peripheral oedema can be misleading. Expert opinion may address whether the failure to perform objective tests, such as echocardiography or NT-proBNP measurement, fell below the standard expected of a competent clinician.

Misinterpretation of Echocardiography

Echocardiography is the cornerstone of heart failure diagnosis, but its interpretation requires specialist expertise. Common pitfalls include:

• Incorrect measurement of LVEF, leading to misclassification of heart failure subtype.
• Failure to identify regional wall motion abnormalities suggestive of ischaemic cardiomyopathy.
• Overlooking valvular heart disease, which may contribute to or mimic heart failure.

In such cases, expert witnesses may be instructed to review echocardiographic images and reports to determine whether the interpretation was reasonable and whether any errors were material to the diagnosis.

Failure to Consider Alternative Diagnoses

As outlined earlier, several conditions mimic heart failure. A common allegation is that clinicians failed to consider or adequately investigate alternative diagnoses, particularly in patients with atypical presentations. Expert witnesses may be asked to opine on whether the differential diagnosis was appropriately explored and whether the investigations performed were sufficient to exclude mimics.

Inadequate Documentation

Poor documentation can significantly weaken a clinician’s defence in misdiagnosis claims. Key omissions may include:

• Lack of a clear differential diagnosis in the medical records.
• Failure to record the rationale for excluding heart failure or alternative diagnoses.
• Incomplete follow-up plans or safety-netting advice.

Expert witnesses are often required to assess whether the documentation reflects a logical and thorough diagnostic process.

The Role of the Cardiology Expert Witness

In heart failure misdiagnosis claims, the cardiology expert witness plays a critical role in assisting the court to understand the clinical complexities and apply the legal tests of breach of duty and causation. The expert’s duties are governed by CPR Part 35, which requires that reports be independent, objective, and addressed to the court.

Key Areas of Expert Input

Expert witnesses may be instructed to address the following:

• Breach of duty: Whether the clinician’s actions fell below the standard expected of a reasonable body of medical opinion, and whether that opinion is logically defensible (Bolam/Bolitho).
• Causation: Whether the alleged breach of duty caused or materially contributed to the harm suffered by the claimant, applying the principles established in Bailey and Williams.
• Condition and prognosis: The likely trajectory of the claimant’s condition had the alleged breach not occurred, including life expectancy and quality of life.
• Quantum: The impact of the alleged breach on the claimant’s future care needs, employment prospects, and other heads of loss.

Preparing a CPR Part 35 Compliant Report

A robust expert report in heart failure misdiagnosis cases should:

• Clearly define the scope of the expert’s instruction and the issues to be addressed.
• Summarise the relevant clinical history, investigations, and management, with reference to the medical records.
• Apply the Bolam/Bolitho test to the facts of the case, explaining the standard of care expected and whether it was met.
• Assess causation, considering whether the harm was foreseeable and whether the breach materially contributed to the outcome.
• Provide a balanced and objective opinion, acknowledging areas of uncertainty or disagreement within the medical literature.

In cases involving multiple experts, the joint statement process (CPR Part 35.12) is critical in identifying areas of agreement and disagreement. The expert witness must approach this process with an open mind, focusing on the issues that are material to the court’s determination.

Practical Guidance for Solicitors

For solicitors handling heart failure misdiagnosis claims, the following considerations are essential:

Early Instruction of a Specialist Expert Witness

Heart failure misdiagnosis cases often hinge on complex clinical details and adherence to diagnostic pathways. Early instruction of a consultant cardiologist with expertise in heart failure and medico-legal practice can help to:

• Identify the key issues in the case, including potential breaches of duty and causation arguments.
• Review the medical records and investigations to determine whether the diagnostic process was reasonable.
• Advise on the strengths and weaknesses of the claim, including the likelihood of establishing breach and causation.

Focus on the Diagnostic Pathway

Solicitors should pay particular attention to:

• Whether the claimant’s symptoms and risk factors warranted investigation for heart failure, in line with NICE Guidance.
• Whether the investigations performed (e.g., echocardiography, NT-proBNP) were timely and appropriately interpreted.
• Whether alternative diagnoses were adequately considered and excluded.

Consider the Impact of Delay

In cases involving delayed diagnosis, solicitors should explore:

• Whether earlier initiation of disease-modifying therapies would have altered the claimant’s prognosis.
• The psychological impact of prolonged uncertainty or inappropriate management.
• The potential for accelerated disease progression due to the delay.

Prepare for the Joint Statement Process

The joint statement is a critical stage in clinical negligence claims. Solicitors should ensure that their expert is:

• Fully briefed on the issues to be addressed in the joint statement.
• Prepared to engage constructively with the opposing expert, focusing on areas of genuine disagreement.
• Able to provide clear and concise responses to the questions posed by the experts.

Conclusion

Heart failure misdiagnosis claims present unique challenges in both clinical and legal domains. The conditions that mimic heart failure are numerous, and the diagnostic process requires careful consideration of symptoms, investigations, and risk factors. In medico-legal practice, the role of the cardiology expert witness is pivotal in assisting the court to navigate these complexities and apply the relevant legal tests.

For solicitors, early instruction of a specialist cardiology expert witness can provide clarity on the strengths and weaknesses of a claim, ensuring that the case is built on a robust clinical and legal foundation. By focusing on the diagnostic pathway, the impact of delay, and the requirements of CPR Part 35, solicitors can effectively advocate for their clients in heart failure misdiagnosis claims.