Failure to Diagnose an Aortic Dissection: Medical Malpractice and Diagnostic Oversight

Failure to diagnose an acute thoracic aortic dissection (TAD) represents one of the most catastrophic errors in emergency medicine. Despite being a rare condition—with an estimated annual incidence of 3–4 cases per 100,000 people—its mortality rises by approximately 1–2% per hour after symptom onset if untreated. This white paper examines the intersection of clinical oversight and medical malpractice, focusing on failure to rule in or rule out an aortic dissection during initial emergency presentation. Drawing from clinical literature and legal precedent, it explores diagnostic standards, systemic failures, and medico-legal accountability.

Introduction

An aortic dissection occurs when a tear in the intimal layer of the aorta allows blood to enter the media, creating a false lumen and threatening rupture or organ ischemia. Early recognition is essential, as delayed or missed diagnosis accounts for up to 38% of pre-hospital deaths. In the context of medical malpractice, the failure to consider or exclude aortic dissection in the differential diagnosis of acute chest pain is among the most litigated errors in emergency care.

Understanding Aortic Dissection

Pathophysiology of Thoracic Aortic Dissection

Aortic dissection is typically precipitated by intimal injury in the presence of medial degeneration, often secondary to chronic hypertension, connective tissue disorders, or atherosclerosis. The false lumen that forms can extend proximally or distally, compromising branch vessel perfusion and leading to ischemia of vital organs including the brain, kidneys, and myocardium.

Classification Systems: Stanford and DeBakey

The Stanford classification divides dissections into:

• Type A: Involves the ascending aorta (surgical emergency)

• Type B: Confined to the descending aorta (managed medically unless complicated)

This classification guides both diagnosis and treatment urgency, underscoring why prompt identification is a critical aspect of meeting the standard of care.

The Diagnostic Challenge in the Emergency Department

Overlap of Symptoms with Common Conditions

Chest pain is among the most frequent reasons for ER visits. Unfortunately, the presentation of an aortic dissection often mimics that of myocardial infarction (MI) or pulmonary embolism (PE). The classic “tearing” pain radiating to the back is reported in less than half of cases. Many patients present with vague symptoms, leading clinicians to anchor prematurely on more common diagnoses like acute coronary syndrome.

Cognitive Errors in Emergency Medicine

Diagnostic errors often stem from anchoring bias (fixating on an initial impression), premature closure (ending the diagnostic process too soon), and availability bias (favoring recent or memorable cases). Studies have shown that over 60% of missed dissections result from cognitive rather than technical errors, emphasizing the importance of maintaining a high index of suspicion.

Standard of Care in Evaluating Acute Chest Pain

Role of History, Physical Exam, and Risk Factors

The standard of care mandates that emergency clinicians assess:

• Onset and character of pain (abrupt, tearing, radiating)

• Blood pressure discrepancies between arms

• Neurological findings (syncope, stroke-like symptoms)

• Risk factors such as hypertension, Marfan syndrome, or prior cardiac surgery

Failure to document or evaluate these findings may constitute a breach of duty.

Appropriate Diagnostic Testing

A reasonable physician should employ a tiered diagnostic approach:

• ECG and troponins to evaluate myocardial injury

• Chest X-ray for mediastinal widening or abnormal aortic contour

• D-dimer testing (useful for low-risk patients in conjunction with clinical scores)

• Definitive imaging via CT angiography (CTA), transesophageal echocardiography (TEE), or MRI when suspicion persists

When such imaging is omitted despite suggestive symptoms, malpractice risk escalates sharply.

Failure to Rule In or Rule Out Aortic Dissection

This is the core issue in malpractice litigation: the clinician’s failure to consider aortic dissection in the differential diagnosis and to order confirmatory imaging when indicated.

Missed or Delayed Imaging

In multiple legal cases, failure to obtain a CTA or inappropriate reliance on normal ECG/troponin results has been deemed negligent. A patient presenting with acute chest pain, pulse deficit, or neurological changes should prompt immediate imaging. The American College of Emergency Physicians (ACEP) guidelines state that “clinicians must not exclude aortic dissection solely based on the absence of classic features.”

Incomplete or Inaccurate Risk Stratification

The Aortic Dissection Detection Risk Score (ADD-RS) helps quantify risk. Failure to apply such validated tools, particularly when risk ≥1, is considered a deviation from accepted practice. The combination of ADD-RS + D-dimer can safely rule out dissection in low-risk patients; ignoring this evidence base has legal consequences.

Case Examples and Common Scenarios

• Case A: A 52-year-old hypertensive male with chest and back pain was misdiagnosed with gastritis; no CTA was ordered. Autopsy revealed a Type A dissection.

• Case B: A patient with transient neurological symptoms and hypertension was discharged without imaging. Fatal rupture occurred within hours.
  Both cases highlight the failure to rule in or rule out TAD — a central malpractice issue.

Legal Implications and Medical Malpractice

Elements of a Malpractice Claim

A successful malpractice claim must establish:

1. Duty: A physician-patient relationship existed.

2. Breach: The provider failed to meet the standard of care.

3. Causation: The breach directly caused harm or death.

4. Damages: The patient suffered measurable injury or loss.

In the context of missed dissection, breach usually lies in diagnostic omission, while causation is established by demonstrating that earlier recognition would have enabled life-saving surgery.

Expert Testimony and Standards of Proof

Medical experts—typically emergency physicians or cardiothoracic surgeons—testify on whether the clinician acted as a “reasonably prudent” practitioner would under similar circumstances. Failure to order imaging, ignoring red flags, or prematurely discharging a symptomatic patient are often cited as clear deviations.

Preventing Diagnostic Failure

Diagnostic Protocols and Decision Support Tools

Instituting clinical checklists and electronic decision support can reduce omission errors. Integration of ADD-RS calculators and CT imaging prompts into electronic health records has been shown to improve diagnostic yield.

Continuing Medical Education and Simulation Training

Simulation-based training helps physicians recognize atypical presentations. Incorporating case-based learning focused on missed dissections can enhance clinical vigilance.

Ethical and Policy Considerations

While excessive imaging may increase healthcare costs and radiation exposure, the ethical imperative to prevent avoidable death outweighs these concerns. Hospitals must balance stewardship with patient safety by employing evidence-based algorithms that minimize unnecessary scans without compromising care.

Conclusion

Aortic dissection remains a low-incidence but high-consequence diagnosis. The failure to rule in or rule out its presence in the emergency setting constitutes a serious breach of diagnostic duty. Through adherence to established protocols, cognitive awareness, and systemic safeguards, emergency departments can significantly reduce the incidence of missed dissections—and the devastating legal and human consequences that follow.

References

• American College of Emergency Physicians. “Clinical Policy: Evaluation of Chest Pain in the Emergency Department.”

• Hagan PG et al. JAMA, 2000;283(7):897–903.

• Nazerian P et al. Circulation, 2014;129(20):2511–2518.

• Trimarchi S et al. Ann Thorac Surg, 2010;90(6):2042–2046.

• U.S. Department of Health and Human Services. AHRQ Diagnostic Safety and Quality Reports.

Frequently Asked Questions (FAQs)

1. What makes a missed aortic dissection a case of malpractice?
When a clinician fails to include dissection in the differential diagnosis despite clear risk factors or symptoms, and this omission leads to harm, it can constitute malpractice.

2. How quickly should aortic dissection be diagnosed in the ER?
Ideally within hours of presentation. Mortality increases by 1–2% per hour after onset if untreated.

3. Can normal ECG or troponin results rule out dissection?
No. Up to 10% of dissections show ischemic ECG changes. Reliance on these alone violates diagnostic standards.

4. What imaging is best for detecting TAD?
CT angiography (CTA) is the gold standard due to its speed, accuracy, and availability.

5. Are emergency physicians legally required to use the ADD-RS tool?
Not mandated by law, but its non-use when available may be viewed as failure to follow evidence-based care.

6. How can hospitals prevent these diagnostic errors?
By implementing clinical pathways, EHR decision prompts, and simulation training to maintain awareness.

External Link:
For a review of risk stratification and diagnostic algorithms, visit the American Heart Association’s Clinical Guidelines on Aortic Dissection