Differential Diagnosis for ACS vs Chronic Coronary Syndrome on Catheterization

When differentiating Acute Coronary Syndrome (ACS) from chronic coronary syndrome on catheterization, several factors and diagnoses must be considered. Here's a breakdown of potential diagnoses categorized for clarity:

• Single Most Likely Diagnosis

  • ACS with significant coronary artery occlusion: This is the most likely diagnosis when there's evidence of acute plaque rupture, thrombus formation, or significant luminal narrowing in the context of clinical symptoms and electrocardiographic changes suggestive of acute myocardial ischemia or infarction. The justification lies in the direct visualization of the occlusion and the clinical context of acute presentation.

• Other Likely Diagnoses

  • Chronic coronary artery disease with stable angina: This diagnosis is considered when there are significant coronary artery stenoses without evidence of acute occlusion or thrombus, and the patient's symptoms are more consistent with stable angina. The justification is based on the presence of significant atherosclerotic disease without acute changes.
  • Variant (Prinzmetal’s) angina: Caused by coronary artery spasm, this condition can mimic ACS but typically occurs at rest and is associated with transient ST-segment elevation on ECG. Catheterization might show normal or near-normal coronary arteries with possible spasm induction during the procedure. The justification for considering this diagnosis is the episodic nature of symptoms and the potential for spasm to be induced during catheterization.

• Do Not Miss Diagnoses

  • Aortic dissection: Although less common, aortic dissection can present with chest pain similar to ACS and can be life-threatening if missed. The involvement of the coronary ostia can lead to myocardial ischemia. The justification for including this in the "do not miss" category is its high mortality rate if not promptly diagnosed and treated.
  • Coronary artery embolism: This can occur in the setting of atrial fibrillation, endocarditis, or paradoxical embolism, among other conditions. It's crucial to consider this diagnosis due to its potential for significant morbidity and mortality if not recognized and treated appropriately.

• Rare Diagnoses

  • Coronary artery vasculitis: Conditions like Kawasaki disease or other forms of vasculitis can cause coronary artery inflammation and potentially mimic ACS. These are rare and typically have other systemic symptoms or signs of inflammation. The justification for considering these diagnoses is their potential to cause significant coronary artery abnormalities, although they are much less common than atherosclerotic disease.
  • Spontaneous coronary artery dissection (SCAD): A rare cause of ACS, particularly in younger women without traditional cardiovascular risk factors. It involves a tear in the coronary artery wall, leading to dissection and potential occlusion. The justification for including SCAD is its potential to cause ACS in a demographic less likely to have traditional coronary artery disease.