Is coronary computed tomography angiography (CTA) safe in patients with rhabdomyolysis?

Safety of Coronary CTA in Rhabdomyolysis

Coronary computed tomography angiography (CTA) is not recommended in patients with rhabdomyolysis due to the risk of worsening renal function from iodinated contrast exposure in patients already at high risk for acute kidney injury.

Rationale for Contraindication

The 2024 ESC guidelines for management of chronic coronary syndromes specifically contraindicate coronary CTA in patients with severe renal failure (eGFR <30 mL/min/1.73 m²) 1. Rhabdomyolysis presents a significant risk for acute kidney injury due to:

• Myoglobin release from damaged muscle causing direct tubular toxicity
• Potential for existing renal impairment in rhabdomyolysis patients
• Additive nephrotoxic risk from iodinated contrast media

Mechanism of Risk

Rhabdomyolysis involves the breakdown of skeletal muscle with release of myoglobin into circulation, which can:

• Cause direct renal tubular damage
• Lead to tubular obstruction
• Result in vasoconstriction of renal vessels
• Produce acute kidney injury

Adding iodinated contrast to this scenario could potentially:

• Exacerbate existing renal dysfunction
• Increase risk of contrast-induced nephropathy
• Lead to more severe and potentially irreversible renal damage

Alternative Imaging Options

For patients with rhabdomyolysis requiring coronary assessment, the following alternatives should be considered:

1. Non-contrast cardiac imaging modalities:

   • Stress echocardiography (preferred for moderate to high pre-test probability of CAD) 1
   • Cardiac MRI without contrast (if available and patient can tolerate)

2. Delayed coronary assessment:

   • Postpone coronary CTA until after resolution of rhabdomyolysis and normalization of renal function
   • Monitor creatine kinase levels and renal function parameters to determine appropriate timing

3. For urgent cases requiring immediate assessment:

   • Consider stress echocardiography as first-line 1
   • If invasive assessment is necessary, minimize contrast use and ensure adequate hydration

Special Considerations

Severity Assessment

The risk of performing coronary CTA in rhabdomyolysis depends on:

• Creatine kinase levels (marker of muscle breakdown severity)
• Current renal function (eGFR)
• Presence of other risk factors for contrast-induced nephropathy

Rare Exception Scenario

In the extremely rare circumstance where coronary CTA is deemed absolutely necessary despite rhabdomyolysis:

• Ensure aggressive hydration before and after the procedure
• Use the minimum possible contrast dose
• Consider prophylactic renal replacement therapy in severe cases
• Monitor renal function closely following the procedure

Conclusion

The risk of worsening renal function and potentially causing permanent renal damage makes coronary CTA an inappropriate choice in patients with rhabdomyolysis. The 2024 ESC guidelines clearly state that coronary CTA "is not recommended in patients with severe renal failure" 1, and patients with rhabdomyolysis are at high risk for developing acute kidney injury. Alternative non-contrast imaging modalities should be utilized until the rhabdomyolysis has resolved and renal function has stabilized.