Does a patient with a history of coronary artery bypass grafting (CABG) 1 month ago, who developed methicillin-resistant Staphylococcus aureus (MRSA) wound dehiscence and was treated with daptomycin (Cubicin), now presenting with multifocal pneumonia and congestive heart failure (CHF) exacerbation, and found to have staph bacteremia and moderate tricuspid regurgitation (TR) on echocardiogram, require cardiology consultation?

Cardiology Consultation is Necessary for Post-CABG Patient with Staph Bacteremia and Moderate TR

Yes, cardiology consultation is necessary for this patient with recent CABG, MRSA wound dehiscence, staph bacteremia, and moderate tricuspid regurgitation due to high risk of infective endocarditis.

Rationale for Cardiology Consultation

The European Society of Cardiology (ESC) and American College of Cardiology/American Heart Association (ACC/AHA) guidelines strongly recommend cardiology involvement in cases of suspected infective endocarditis (IE) 1. This patient has multiple high-risk features:

1. Recent cardiac surgery (CABG 1 month ago) - creates risk for prosthetic material infection
2. MRSA wound dehiscence - source of bacteremia
3. Staphylococcus bacteremia - S. aureus is highly virulent in IE
4. Moderate tricuspid regurgitation - could represent valvular involvement
5. Multifocal pneumonia - potential septic emboli

Diagnostic Approach

Echocardiography

• Transesophageal echocardiography (TEE) is strongly recommended as the first-line imaging modality in this scenario 1:
  • TEE is recommended for all patients with S. aureus bacteremia to diagnose possible IE 1
  • TEE has superior sensitivity for detecting vegetations, abscesses, and paravalvular complications compared to TTE 1
  • Particularly important given the moderate TR already documented

Blood Cultures

• Multiple sets of blood cultures should be obtained to document clearance of bacteremia 1
• Persistent bacteremia (>72 hours) despite appropriate antibiotics is concerning for endovascular infection 1

Antibiotic Management

The current antibiotic regimen of ceftaroline and levofloxacin appears appropriate for treating both pneumonia and bacteremia, but requires cardiology input:

• Daptomycin (previously prescribed) is not recommended for pneumonia due to risk of treatment failure and daptomycin-induced eosinophilic pneumonia 2
• Ceftaroline has shown efficacy in combination therapy for complicated MRSA bacteremia 3, 4
• If IE is confirmed, antibiotic duration would need to be extended to 4-6 weeks 1

Potential Complications Requiring Cardiology Management

1. Valvular dysfunction - The moderate TR could worsen with vegetation involvement
2. Heart failure exacerbation - Current CHF exacerbation may be related to valvular dysfunction
3. Paravalvular complications - Abscesses, fistulae, or dehiscence of surgical sites
4. Need for surgical intervention - Cardiology and cardiac surgery consultation is essential if any of the following develop:
   • Heart failure due to valve dysfunction
   • Uncontrolled infection despite antibiotics
   • Large vegetations with embolic risk
   • Abscess formation 1

Multidisciplinary Approach

The ESC guidelines specifically state: "The early involvement of a cardiologist and an infectious disease specialist to guide management is highly recommended" 1. The ACC/AHA guidelines similarly recommend that "patients with IE should be evaluated and managed with consultation with a multispecialty Heart Valve Team" 1.

Conclusion

This patient presents with multiple high-risk features for infective endocarditis, including recent cardiac surgery, MRSA bacteremia, and moderate tricuspid regurgitation. Cardiology consultation is not only beneficial but necessary for proper evaluation with TEE, determination of appropriate antibiotic duration, monitoring for complications, and assessment for potential surgical intervention.