Aortic Dissection Misdiagnosis: The Hardest Cardiology Case to Spot in UK Medico-Legal Practice

Aortic dissection is a time-critical, life-threatening emergency that remains one of the most diagnostically challenging conditions in acute cardiology. Its presentation often mimics more common conditions, such as myocardial infarction or pulmonary embolism, leading to potential delays in recognition and treatment. In UK medico-legal practice, cases involving alleged aortic dissection misdiagnosis frequently hinge on subtle clinical nuances, adherence to diagnostic pathways, and the application of established legal tests for breach of duty and causation.

Clinical Context: Diagnostic Challenges in Aortic Dissection

Aortic dissection occurs when a tear in the aortic intima allows blood to enter the medial layer, creating a false lumen. The Stanford classification system is used: Type A involves the ascending aorta (requiring urgent surgical intervention), while Type B involves the descending aorta (often managed medically in stable cases). Mortality rates for untreated Type A dissections increase by approximately 1% per hour, making timely diagnosis critical.

The diagnostic challenge lies in the variable presentation. Classic symptoms include sudden-onset severe chest or back pain (described as tearing or ripping), but these are not universally present. Other features may include:

• Pulse deficits or blood pressure differentials between limbs
• Neurological symptoms (syncope or stroke-like deficits)
• New aortic regurgitation murmur
• Signs of malperfusion (mesenteric ischaemia or acute limb ischaemia)
• Widened mediastinum on chest X-ray (though neither sensitive nor specific)

Atypical presentations are common, particularly in patients with connective tissue disorders like Marfan syndrome. The absence of classic features can lead to misattribution of symptoms to conditions such as acute coronary syndrome or gastro-oesophageal reflux. UK studies report misdiagnosis rates of up to 30% in some series, reflecting the diagnostic uncertainty.

Legal Framework: Breach of Duty and Causation

UK clinical negligence claims involving aortic dissection misdiagnosis typically focus on two key questions: whether there was a breach of duty, and whether that breach caused or materially contributed to harm. The Bolam test (as refined by Bolitho) remains central to breach assessment. The court considers whether the clinician’s actions fell within a range of practices accepted by a responsible body of medical opinion, with the Bolitho addendum requiring logical analysis of the opinion.

Breach allegations may centre on:

• Failure to consider aortic dissection in differential diagnosis, particularly in high-risk patients
• Failure to perform timely CT aortography
• Misinterpretation of imaging findings
• Failure to escalate care to specialist centres

Causation is often contested. The claimant must establish, on the balance of probabilities, that the breach caused or materially contributed to harm. The Bailey v Ministry of Defence [2008] principle is frequently invoked, where material contribution to injury may establish liability even if other factors were involved. Expert evidence must address whether earlier diagnosis would have altered the outcome, considering dissection type, complications, and patient’s pre-morbid condition.

Key Medico-Legal Disputes

Risk Factor Consideration

Risk factors (hypertension, connective tissue disorders, bicuspid aortic valve) should heighten suspicion, but their absence does not exclude diagnosis. UK courts take a pragmatic approach, recognising that while risk factors are important, their absence does not absolve clinicians of considering the diagnosis in appropriate contexts.

Imaging Interpretation

Chest X-rays have limited utility, while CT aortography is the gold standard. Disputes may arise over:

• Whether subtle signs on CT should have been identified
• Whether failure to perform timely CT constituted breach
• Communication of urgent findings between radiologists and clinical teams

The duty to communicate critical findings in a timely manner is well-established in UK clinical practice and case law.

Timing of Surgical Intervention

In Type A dissections, surgical intervention is typically indicated to prevent complications. Disputes may arise over:

• Whether delay in surgery fell below acceptable standards
• Whether medical management was appropriate initially
• Whether patient’s haemodynamic status justified delay

Specialist Centre Transfer

The failure to transfer to a specialist centre may constitute breach. Disputes may focus on:

• Whether delay in transfer was clinically justified
• Whether patient’s condition permitted safe transfer
• Distance to nearest specialist centre and transport availability

Expert Witness Considerations

Expert evidence is pivotal in UK aortic dissection claims. The expert witness (typically a consultant cardiologist or cardiothoracic surgeon) must:

• Assess breach using Bolam/Bolitho principles
• Address causation, considering material contribution principles
• Provide condition and prognosis evidence where applicable
• Prepare CPR Part 35-compliant reports
• Engage constructively in joint statements

Subspecialty expertise is often required. A cardiologist with aortic disease expertise may address diagnosis and medical management, while a cardiothoracic surgeon may opine on surgical intervention timing.

Practical Guidance for UK Solicitors

Early Expert Instruction

Early instruction of a cardiology expert witness is advisable to:

• Identify key issues in dispute
• Review clinical records comprehensively
• Advise on claim merits

Clinical Record Review

A comprehensive review should include:

• Emergency department records (triage, assessments, investigations)
• Imaging reports (chest X-rays, CT scans, echocardiograms)
• Surgical records (operative notes, postoperative care)
• Correspondence between clinicians
• Pre-morbid records (GP notes, previous admissions)

Clinical Guidelines

While no specific NICE guidance exists for aortic dissection, relevant frameworks include:

• European Society of Cardiology guidelines on aortic diseases
• American Heart Association guidelines on thoracic aortic disease
• Local NHS protocols for acute chest pain management

The expert should comment on adherence to these guidelines and any clinically justified deviations.

Limitation Considerations

Aortic dissection claims may involve complex limitation issues under the Limitation Act 1980. Solicitors should consider:

• Three-year limitation period (may be extended in certain circumstances)
• Expert evidence on date of knowledge (section 14 of the Act)
• Whether the claim is in time

Inquest Preparation

In fatal cases, an inquest may be held. Solicitors should:

• Engage with the coronial process
• Instruct expert witnesses for inquest evidence
• Be prepared for Prevention of Future Deaths reports (regulation 28)

Inquest findings may be relevant to subsequent clinical negligence claims.

Conclusion

Aortic dissection misdiagnosis presents unique challenges in UK medico-legal practice. The condition’s variable presentation, time-critical nature, and high mortality rate make it a frequent source of clinical negligence claims. Early instruction of specialist cardiology expert witnesses is essential to navigate the complex clinical and legal issues. By understanding the clinical frameworks, legal principles, and practical considerations outlined in this article, solicitors can better position their clients for successful outcomes in these challenging cases.