What is the recommended management for a patient post ST-Elevation Myocardial Infarction (STEMI) Percutaneous Coronary Intervention (PCI), including when to start beta-blockers (BB) and Angiotensin-Converting Enzyme Inhibitors (ACEI) or Angiotensin Receptor Blockers (ARB), and what parameters to monitor?

Post-STEMI PCI Management Protocol

Beta-blockers and ACE inhibitors should be initiated within the first 24 hours after STEMI in most patients following PCI, with specific timing and parameters based on hemodynamic stability and risk factors.

Immediate Post-PCI Antithrombotic Management

• Dual Antiplatelet Therapy (DAPT):
  • Start immediately and continue for 12 months 1
  • Aspirin 75-100 mg daily + a P2Y12 inhibitor (ticagrelor or prasugrel preferred over clopidogrel) 1
  • Consider proton pump inhibitor for patients at high risk of gastrointestinal bleeding 1

Beta-Blocker Therapy

When to Start:

• Oral beta-blockers: Initiate within the first 24 hours in hemodynamically stable patients 1
• Timing: After patient is hemodynamically stable with no signs of:
  • Heart failure
  • Low-output state
  • Increased risk for cardiogenic shock
  • PR interval >0.24 seconds
  • Second or third-degree heart block
  • Active asthma or reactive airways disease 1

Parameters to Monitor:

• Heart rate (avoid if <60 bpm)
• Blood pressure (avoid if systolic BP <120 mmHg)
• Signs of heart failure
• PR interval on ECG

Contraindications:

• Absolute: Avoid IV beta-blockers in patients with hypotension, acute heart failure, AV block, or severe bradycardia 1
• Relative: Asthma, COPD, severe peripheral vascular disease

ACE Inhibitor/ARB Therapy

When to Start:

• Start within first 24 hours in patients with: 1
  • Anterior MI
  • Left ventricular ejection fraction ≤40%
  • Heart failure
  • Diabetes mellitus

Parameters to Monitor:

• Blood pressure (avoid if systolic BP <90 mmHg)
• Renal function (serum creatinine)
• Serum potassium

Contraindications:

• Hypotension (systolic BP <90 mmHg)
• Bilateral renal artery stenosis
• History of angioedema with ACE inhibitors
• Pregnancy
• Hyperkalemia

Aldosterone Antagonists

When to Start:

• Add for patients with:
  • LVEF ≤40% AND
  • Heart failure symptoms or diabetes mellitus 1
  • Already receiving ACE inhibitor and beta-blocker

Parameters to Monitor:

• Serum potassium (avoid if >5.0 mEq/L)
• Renal function (avoid if creatinine >2.5 mg/dL in men, >2.0 mg/dL in women) 1

Statin Therapy

• High-intensity statin: Start as early as possible after admission and continue long-term 1
• Target: LDL-C <1.8 mmol/L (70 mg/dL) or ≥50% reduction if baseline is 1.8-3.5 mmol/L 1

Special Considerations

Patients with LV Dysfunction:

• Beta-blockers are particularly beneficial in patients with LVEF <40% 2
• Research shows combination of beta-blockers with ACE inhibitors provides better outcomes than beta-blockers with ARBs in post-STEMI patients 3, 4

Patients with Normal LV Function:

• Beta-blocker therapy is still recommended for all patients without contraindications 5
• ACE inhibitors are reasonable for all STEMI patients without contraindications 1

Reassessment Timeline

• Beta-blockers: Patients with initial contraindications should be reassessed daily for eligibility 1
• ACE inhibitors/ARBs: Titrate dose over 24-48 hours as tolerated
• Follow-up echocardiography: Perform during hospitalization to assess LV function and detect complications 1

Pitfalls to Avoid

1. Avoid IV beta-blockers in hemodynamically unstable patients
2. Don't delay ACE inhibitors beyond 24 hours in eligible patients
3. Monitor renal function and electrolytes closely when starting ACE inhibitors or aldosterone antagonists
4. Reassess contraindications daily as patient stabilizes
5. Don't use glucocorticoids or NSAIDs for post-STEMI pericarditis 1, 6

Remember that the combination of beta-blockers with ACE inhibitors has shown better outcomes than beta-blockers with ARBs in reducing mortality and major adverse cardiac events in post-STEMI patients 7, 3.