Functional assessment of intermediate coronary artery stenosis with 4-Fr catheters

Area of Science:

• Cardiology
• Medical Devices
• Diagnostic Imaging

Background:

• The 4-French (4-Fr) catheter is often avoided for invasive coronary artery stenosis assessment due to potential aortic waveform distortion.
• Accurate functional assessment is crucial for guiding revascularization decisions in intermediate coronary artery stenosis.

Purpose of the Study:

• To determine the incidence of aortic waveform distortion using a 4-Fr catheter.
• To identify a method for accurate coronary artery stenosis diagnosis with a 4-Fr catheter.

Main Methods:

• Retrospective analysis of 178 intermediate coronary artery stenosis lesions.
• Measurement of distal coronary pressure (Pd) and aortic pressure (Pa) with 4-Fr diagnostic and 6-Fr guiding catheters.
• Calculation of Pd/Pa and instantaneous wave-free ratio (iFR) before and after saline flush.

Main Results:

• Aortic waveform distortion significantly decreased from 42.0% to 1.8% after saline flush with the 4-Fr catheter (p < 0.001).
• The 6-Fr guiding catheter showed minimal distortion (3.0% pre-flush, 0% post-flush).
• Aortic waveform distortion impacted iFR measurements with the 4-Fr system.

Conclusions:

• Adequate saline flushing is essential when using a 4-Fr diagnostic catheter for functional coronary artery stenosis assessment.
• Saline flush mitigates aortic waveform distortion, allowing for reliable iFR and Pd/Pa measurements.
• This finding supports the feasible use of 4-Fr catheters with proper flushing techniques.