Perioperative management of cardiac ischemia

• Highest risk period for MI is post-op day 3

Epidemiology

• Represents 1-6% of cardiac events

Etiology

• Bleeding (35%)
• Cardiac cause (44%), including MI, AV block, arrhythmias
• Other (21%), including PE, anaphylaxis, and hypoxemia

Pathophysiology

• Thrombosis
• Catecholamine surges from stress state
• Obstruction
• Infection or inflammation
• Increased demand, from tachycardia, fever, hypotension, anemia, and hypoxemia

Clinical Manifestations

• Myocardial infarction after non-cardiac surgery (MINS)
• STEMI is rare

Diagnosis

• Increased troponin with typical pattern
• Signs of ischemia, including Q waves on ECG or wall motion abnormalities on echocardiography

Management

• Treat underlying cause
• Add ASA and beta blocker, consider ACE inhibitor or nitrates

Preoperative assessment

• If surgery is emergent, proceed to OR
• If not emergent, then rule out ACS and treat this first
• If not having ACS, then risk stratify with AHA class or RCRI or NSQuIP
• Elective surgery should be delayed for:
  • Anticoagulation/antiplatelets
  • Electrolyte abnormalities
  • Infection, especially pneumonia
  • Obstructions in the vasculature (ACS or PE within the past month)
  • Unstable vitals

Prognosis

• 15-25% in-hospital mortality
• Outcomes are related to peak troponin (per VISION study)