Delayed Diagnosis Claims in Cardiology: How Lost Time Becomes Lost Damages

In cardiology medico-legal practice, delayed diagnosis claims present complex challenges at the intersection of clinical decision-making and legal liability. When a cardiac condition is not identified promptly, the consequences can range from prolonged morbidity to catastrophic outcomes. For solicitors acting in clinical negligence, personal injury, or inquest proceedings, understanding the clinical frameworks, legal tests, and expert methodologies is essential to assessing the merits of such claims.

Clinical Context: Time-Critical Pathways in Cardiology

Cardiology encompasses a spectrum of time-sensitive conditions where early intervention can significantly alter outcomes. Key areas where delayed diagnosis frequently arises include:

• Acute coronary syndromes (ACS): Including ST-elevation myocardial infarction (STEMI), non-ST-elevation myocardial infarction (NSTEMI), and unstable angina. Current NICE guidance (NG185) emphasises the role of high-sensitivity troponin pathways (0/1h or 0/3h algorithms) and risk stratification tools such as HEART, GRACE, or TIMI scores to guide timely intervention.
• Aortic dissection: A life-threatening emergency requiring immediate imaging, typically via CT aortogram. Delays in recognition or referral can result in aortic rupture or malperfusion syndromes.
• Heart failure: Particularly acute decompensated heart failure, where NICE guidance (NG225) outlines the importance of early echocardiography and natriuretic peptide testing to confirm diagnosis and initiate appropriate management.
• Arrhythmias: Including atrial fibrillation (AF) with high stroke risk, where anticoagulation decisions are guided by CHA₂DS₂-VASc scores, and ventricular arrhythmias associated with inherited cardiac conditions such as hypertrophic cardiomyopathy (HCM) or arrhythmogenic right ventricular cardiomyopathy (ARVC).
• Structural heart disease: Such as severe aortic stenosis or mitral regurgitation, where surveillance and timely intervention are critical to preventing irreversible cardiac damage.

In each of these scenarios, the clinical standard of care is underpinned by national and international guidelines, including those from NICE, the European Society of Cardiology (ESC), and the American College of Cardiology (ACC). Expert witnesses in delayed diagnosis claims must scrutinise whether the alleged index events deviated from these frameworks and, if so, whether such deviations resulted in harm.

Legal Relevance: Breach, Causation, and the Bolam/Bolitho Test

Delayed diagnosis claims in cardiology typically hinge on two key legal questions: whether there was a breach of duty, and whether that breach caused the claimant’s harm. The legal tests for these questions are well-established but require nuanced application in cardiac cases.

Breach of Duty

The Bolam test, as refined by Bolitho v City and Hackney Health Authority [1998], remains the cornerstone for assessing breach of duty. In cardiology, this involves evaluating whether the clinician’s actions fell below the standard of a reasonably competent practitioner in the same field. For example, in a claim involving missed ACS, the expert witness may consider:

• Whether the clinician adhered to NICE guidance on chest pain assessment and troponin testing.
• Whether the interpretation of electrocardiograms (ECGs) met the standard expected of a cardiologist or emergency physician, particularly in cases of subtle STEMI, posterior MI, or de Winter T-waves.
• Whether risk stratification tools were appropriately applied to guide referral or admission decisions.

The Bolitho refinement requires that the expert’s opinion must be logically defensible. For instance, if a clinician failed to refer a patient with chest pain for troponin testing, the expert must assess whether such a decision could be justified by a responsible body of medical opinion, even if it deviated from NICE guidance.

Causation

Causation in delayed diagnosis claims often turns on the “but for” test: would the claimant have suffered the same harm but for the alleged breach? In cardiology, this can be particularly complex due to the progressive nature of many cardiac conditions. Key considerations include:

• Lost chance of a better outcome: In Gregg v Scott [2005], the House of Lords held that a claimant cannot recover damages for the loss of a chance of a better outcome unless they can prove, on the balance of probabilities, that the breach caused the harm. In cardiology, this may arise where a delay in diagnosing heart failure or valvular disease resulted in irreversible cardiac remodelling or reduced life expectancy.
• Material contribution: In cases where multiple factors contributed to the harm, the principles in Bailey v Ministry of Defence [2008] and Williams v Bermuda Hospitals Board [2016] may apply. For example, if a delay in diagnosing ACS led to a larger myocardial infarction, the expert may need to assess whether the delay materially contributed to the extent of the damage.
• Eggshell skull rule: Under Smith v Leech Brain [1962], a defendant must take the claimant as they find them. In cardiology, this may be relevant where a patient with an underlying inherited cardiac condition (e.g., Long QT syndrome) suffered a fatal arrhythmia following a delay in diagnosis.

Expert witnesses must carefully analyse the clinical timeline, imaging, and laboratory results to determine whether the alleged delay altered the natural history of the disease. This often involves reconstructing the “what if” scenario: what treatment would have been offered had the diagnosis been made earlier, and how would this have impacted the claimant’s prognosis?

Common Pitfalls and Disputes in Delayed Diagnosis Claims

Delayed diagnosis claims in cardiology are frequently contested, with disputes arising in several key areas:

1. Interpretation of Investigations

Misinterpretation of diagnostic tests is a frequent allegation in delayed diagnosis claims. Common pitfalls include:

• ECG interpretation: Subtle changes such as posterior MI, Wellens syndrome, or hyperacute T-waves may be overlooked, particularly in non-cardiology settings. Expert witnesses must assess whether the ECG was reviewed by a clinician with appropriate expertise and whether the interpretation met the standard of care.
• Troponin testing: High-sensitivity troponin assays have transformed the diagnosis of ACS, but their interpretation requires adherence to specific pathways (e.g., 0/1h or 0/3h algorithms). Failure to follow these pathways, or misinterpretation of the results, can lead to delayed or missed diagnoses.
• Imaging: In cases of aortic dissection, the choice and timing of imaging (e.g., CT aortogram vs. transthoracic echocardiography) can be critical. Expert witnesses may need to assess whether the imaging modality selected was appropriate and whether the results were correctly interpreted.

2. Risk Stratification and Referral Decisions

Many delayed diagnosis claims involve allegations that a patient was inappropriately discharged or not referred for specialist assessment. Key considerations include:

• Chest pain triage: NICE guidance (NG12 and NG185) provides clear pathways for assessing patients with chest pain, including the use of risk scores and troponin testing. Expert witnesses must evaluate whether these pathways were followed and whether deviations were justifiable.
• Heart failure: NICE guidance (NG225) recommends natriuretic peptide testing and echocardiography for patients with suspected heart failure. Delays in performing these tests, or failure to act on abnormal results, can lead to allegations of substandard care.
• Inherited cardiac conditions: Patients with conditions such as HCM, ARVC, or Long QT syndrome may present with non-specific symptoms (e.g., palpitations, syncope). Expert witnesses may need to assess whether appropriate family screening or genetic testing was offered, particularly in cases where a sudden cardiac death (SCD) has occurred.

3. Documentation and Communication

Poor documentation or communication failures are often cited in delayed diagnosis claims. Examples include:

• Failure to record the rationale for clinical decisions, such as why a patient was discharged or not referred for further testing.
• Inadequate handover between clinicians, particularly in emergency or out-of-hours settings.
• Miscommunication of test results, such as troponin levels or imaging findings, leading to delays in diagnosis or treatment.

Expert witnesses must assess whether the documentation meets the standard expected of a reasonably competent clinician and whether any deficiencies contributed to the alleged harm.

4. Limitation and the Date of Knowledge

Under the Limitation Act 1980, claimants generally have three years from the date of knowledge to bring a claim. In delayed diagnosis cases, the date of knowledge may be contested, particularly where the claimant was unaware of the alleged breach or its causative link to their harm. Expert witnesses may be asked to provide opinions on when the claimant ought reasonably to have become aware of the potential claim, which can be pivotal in limitation disputes.

The Role of the Expert Witness in Delayed Diagnosis Claims

Expert witnesses play a critical role in delayed diagnosis claims, providing independent, CPR Part 35-compliant opinions on breach of duty and causation. Their responsibilities include:

1. Clinical Reconstruction

The expert must reconstruct the clinical timeline, reviewing all relevant medical records, investigations, and correspondence. This often involves:

• Analysing ECGs, echocardiograms, and imaging studies to assess whether the diagnosis was missed or delayed.
• Reviewing troponin results and other laboratory tests to determine whether they were interpreted correctly and acted upon appropriately.
• Assessing the clinical decision-making process, including the use of risk stratification tools and adherence to national guidelines.

2. Application of Legal Tests

The expert must apply the Bolam/Bolitho test to assess breach of duty and the “but for” test to assess causation. This requires a clear understanding of the legal principles and the ability to articulate how they apply to the specific facts of the case. For example:

• In a claim involving missed ACS, the expert may need to opine on whether the clinician’s decision not to admit the patient for troponin testing fell below the standard of care and, if so, whether this delay resulted in a larger myocardial infarction or other harm.
• In a case involving delayed diagnosis of heart failure, the expert may need to assess whether earlier intervention would have altered the claimant’s prognosis, taking into account factors such as left ventricular ejection fraction (LVEF) and New York Heart Association (NYHA) class.

3. Preparation of CPR Part 35-Compliant Reports

Expert reports in delayed diagnosis claims must comply with the requirements of CPR Part 35, including:

• A statement of the expert’s qualifications and experience.
• A declaration that the expert understands their duty to the court and has complied with it.
• A clear and concise summary of the facts and issues in the case.
• An analysis of the clinical evidence, including any areas of dispute or uncertainty.
• Opinions on breach of duty and causation, supported by reference to the clinical evidence and relevant guidelines.
• A statement of the expert’s fees and any conflicts of interest.

Expert witnesses must ensure that their reports are balanced, evidence-based, and free from advocacy. They must also be prepared to engage in the joint statement process, where they may be required to discuss areas of agreement and disagreement with the opposing expert.

4. Subspecialty Expertise

Cardiology is a broad field, and delayed diagnosis claims may require input from subspecialists. For example:

• Interventional cardiologists: May be required in cases involving delayed percutaneous coronary intervention (PCI) or complications arising from procedural delays.
• Electrophysiologists: May be needed in cases involving delayed diagnosis of arrhythmias or inherited cardiac conditions.
• Heart failure specialists: May be required in cases involving delayed diagnosis or management of heart failure.
• Paediatric cardiologists: May be needed in cases involving congenital heart disease or inherited cardiac conditions in children.

Solicitors should consider instructing experts with the appropriate subspecialty expertise to ensure that the clinical nuances of the case are fully addressed.

Practical Guidance for Solicitors

For solicitors acting in delayed diagnosis claims in cardiology, the following practical steps can help to strengthen the case:

1. Early Instruction of an Expert Witness

Instructing an expert witness at an early stage can provide valuable insights into the merits of the claim and help to identify key areas of dispute. Early expert input can also assist in:

• Identifying missing medical records or investigations that may be critical to the case.
• Assessing the strength of the claimant’s case on breach of duty and causation.
• Advising on the need for additional expert input, such as from a subspecialist or a life expectancy expert.

2. Thorough Review of Medical Records

A comprehensive review of the medical records is essential to identify potential breaches of duty and gaps in the clinical timeline. Key documents to review include:

• Emergency department records, including triage notes, clinical assessments, and discharge summaries.
• ECGs, echocardiograms, and imaging reports.
• Laboratory results, including troponin levels and natriuretic peptide tests.
• Correspondence between clinicians, including referrals, clinic letters, and multidisciplinary team meeting notes.
• Records of any previous cardiac investigations or interventions.

3. Consideration of Alternative Causes

In delayed diagnosis claims, defendants may argue that the claimant’s harm was caused by factors unrelated to the alleged breach. Solicitors should work with their expert witness to consider alternative explanations for the claimant’s presentation and prognosis. For example:

• In a claim involving missed ACS, the defendant may argue that the claimant’s myocardial infarction was inevitable due to the extent of their coronary artery disease.
• In a case involving delayed diagnosis of heart failure, the defendant may contend that the claimant’s prognosis was poor regardless of the timing of intervention.

Expert witnesses can help to assess the validity of these arguments and provide opinions on whether the alleged breach materially contributed to the harm.

4. Engagement in the Joint Statement Process

The joint statement process, governed by CPR Part 35, is a critical stage in delayed diagnosis claims. Solicitors should prepare their expert witnesses for this process by:

• Ensuring that the expert is familiar with the clinical evidence and the legal tests.
• Identifying key areas of agreement and disagreement with the opposing expert.
• Preparing a list of questions to be addressed in the joint statement, focusing on the most contentious issues in the case.

A well-prepared joint statement can help to narrow the issues in dispute and facilitate settlement negotiations.

5. Preparation for Inquests and Prevention of Future Deaths Reports

In cases involving fatal outcomes, delayed diagnosis claims may intersect with the coronial process. Solicitors should be aware of the potential for Prevention of Future Deaths (PFD) reports under regulation 28 of the Coroners (Investigations) Regulations 2013. Expert witnesses can play a key role in:

• Assisting the coroner in understanding the clinical context of the case.
• Identifying systemic issues that may have contributed to the delayed diagnosis.
• Providing recommendations to prevent future deaths, such as changes to clinical pathways or staff training.

Solicitors should consider instructing an expert witness with experience in coronial proceedings to ensure that the medico-legal aspects of the case are fully addressed.

Conclusion

Delayed diagnosis claims in cardiology present unique challenges, requiring a deep understanding of both clinical frameworks and legal principles. For solicitors acting in such cases, early instruction of a specialist cardiology expert witness can provide invaluable insights into the merits of the claim, the strength of the evidence, and the potential areas of dispute. By adhering to the standards set out in CPR Part 35 and engaging with the joint statement process, expert witnesses can help to clarify the issues and facilitate fair outcomes for all parties.

Specialist cardiology medico-legal assessment from an experienced consultant cardiologist expert witness can be pivotal in cases of this nature, ensuring that the clinical and legal complexities are fully addressed.