Can metoprolol (beta blocker) and lisinopril (angiotensin-converting enzyme inhibitor) be given to a patient with post-myocardial infarction (post-MI) pericarditis?

Post-MI Pericarditis: Beta-Blocker and ACE Inhibitor Use

Yes, both metoprolol and lisinopril should be given to patients with post-MI pericarditis, as the benefits of these guideline-directed therapies for reducing mortality after myocardial infarction outweigh concerns about pericardial inflammation. The key is to use aspirin as first-line therapy for the pericarditis itself while continuing essential post-MI medications.

Beta-Blocker Therapy (Metoprolol)

Beta-blockers must be started and continued indefinitely in all post-MI patients unless contraindicated, regardless of pericarditis presence. 1

• The ACC/AHA guidelines recommend initiating beta-blocker therapy within the first 24 hours in patients without signs of heart failure, evidence of low-output state, or increased risk for cardiogenic shock 1
• Beta-blockers should be continued indefinitely in all patients who have had MI, with or without LV dysfunction 1
• The FDA label for metoprolol demonstrates significant mortality reduction (36% at 3 months) when started early after MI 2

Critical Contraindications to Monitor

Do not give beta-blockers if the patient has: 1

• Systolic blood pressure <120 mmHg
• Heart rate >110 bpm at presentation
• Signs of acute heart failure or cardiogenic shock
• Evidence of low-output state

ACE Inhibitor Therapy (Lisinopril)

ACE inhibitors should be administered within the first 24 hours to all post-MI patients with anterior location, heart failure, or ejection fraction ≤40%. 1

• For patients with LVEF <40%, hypertension, diabetes, or heart failure, ACE inhibitors are Class I recommendations and should be continued indefinitely 1
• Even in patients without these high-risk features, ACE inhibitors are reasonable for all post-MI patients (Class IIa) 1
• The GISSI-3 trial demonstrated an 11% reduction in mortality at 6 weeks with lisinopril started within 24 hours of MI 3

Dosing Considerations in Post-MI Pericarditis

Start lisinopril at 5 mg within 24 hours, then 5 mg after 24 hours, then 10 mg daily 3

• If systolic BP <120 mmHg at baseline, start with 2.5 mg 3
• Reduce dose or discontinue if severe hypotension develops 3

Management of the Pericarditis Component

Aspirin is the preferred first-line therapy for post-MI pericarditis pain, not NSAIDs or corticosteroids. 4, 5, 6

• Aspirin relieves pericardial discomfort within 48 hours in almost all patients 5
• NSAIDs should NOT be initiated and should be discontinued during hospitalization for acute coronary syndromes due to increased risk of major adverse cardiac events 1
• Corticosteroids must be avoided due to reported complications including impaired myocardial healing 4

Clinical Course and Monitoring

Post-MI pericarditis typically develops on day 2-3 after transmural MI and has a benign clinical course 4

• The presence of pericarditis does not alter the patient's prognosis from the MI itself 4
• Pericardial effusions occur in up to 28% of post-MI patients but do not absolutely contraindicate anticoagulation 4
• Most cases resolve with aspirin therapy alone 6

Critical Pitfalls to Avoid

Never withhold beta-blockers or ACE inhibitors solely because of pericarditis presence - the mortality benefit from these medications far exceeds any theoretical concern about pericardial inflammation 1

Do not use NSAIDs (indomethacin, ibuprofen) for pericarditis pain in the acute post-MI setting - these increase risk of MI complications including impaired infarct healing, myocardial rupture, and recurrent ischemic events 1, 4

Avoid corticosteroids - they are associated with increased complications including impaired ventricular remodeling and worse outcomes 4

Practical Treatment Algorithm

1. Confirm hemodynamic stability - check BP >100 mmHg systolic, HR <110 bpm, no signs of cardiogenic shock 1, 3

2. Initiate beta-blocker (metoprolol) within 24 hours if hemodynamically stable 1

3. Start ACE inhibitor (lisinopril) within 24 hours, using reduced dose if BP 100-120 mmHg 1, 3

4. Treat pericarditis pain with aspirin at doses of 650-1000 mg every 6-8 hours 5, 6

5. Continue both medications indefinitely as part of guideline-directed medical therapy for secondary prevention 1

The combination of metoprolol and lisinopril with aspirin for pericarditis represents optimal evidence-based care that addresses both the underlying MI and the pericardial complication simultaneously 1, 5.