ASA for ACS When the Patient has History of ACS?

A patient with a history of AAA repair two years ago presents with severe lower abdominal pain and concurrent chest pain with cardiac features. Vital signs show hypertension with equal bilateral pressures. In this situation, is ASA still appropriate for suspected ACS, or should it be withheld due to concern for a possible AAA related complication?

A previous AAA repair does not automatically contraindicate ASA. The key question is whether there is evidence of active or suspected bleeding today. Severe abdominal pain alone does not confirm rupture because patients with repaired aneurysms can have many non aneurysmal causes of pain. In an actual leak or rupture the physiologic pattern usually shifts toward hypotension, falling peripheral perfusion, tachycardia, or unequal limb pressures. Hypertension with symmetric pressures argues against acute hemorrhage and is more consistent with a pain driven sympathetic response.

ASA provides substantial benefit in suspected ACS by inhibiting thromboxane A2 and platelet aggregation. This benefit outweighs the risk unless active bleeding is suspected. In the presence of cardiac chest pain with ACS features and no clinical indicators of a leaking aneurysm, ASA is appropriate. You would only withhold ASA if the presentation showed hemodynamic instability or other findings that raise real concern for rupture.