Influence of coronary calcification on hyperemic response during fractional flow reserve measurements

Area of Science:

• Cardiology
• Interventional Cardiology
• Vascular Physiology

Background:

• Maximal hyperemia is crucial during invasive fractional flow reserve (FFR) measurements, typically achieved with adenosine and nitrates.
• Severe coronary artery calcification (CAC) may potentially impair vasodilation, affecting hyperemic response.
• Understanding the relationship between CAC severity and hyperemic response is important for accurate FFR interpretation.

Purpose of the Study:

• To investigate the hyperemic response during invasive FFR in patients with severe versus mild coronary artery calcification.
• To determine if the severity of CAC influences vasodilation achieved with hyperemia-inducing agents.
• To assess the association between CAC score and the pressure gradient changes during FFR.

Main Methods:

• Retrospective analysis of 236 patients undergoing both CAC scoring and invasive FFR.
• FFR performed in 304 vessels with intermediate stenoses.
• Utilized Delta (Δ) FFR (pressure gradient before adenosine minus FFR after adenosine) to quantify hyperemic response.

Main Results:

• No significant difference in the mean pressure gradient before adenosine administration between severe and mild CAC groups.
• FFR values ≤0.80 were more frequent in vessels with severe CAC (p=0.045).
• No association found between Δ FFR and the severity of calcifications; regression analysis confirmed no link between CAC score and hyperemic response (p=0.49).

Conclusions:

• The severity of coronary artery calcification was not associated with the hyperemic response during invasive FFR.
• Vasodilation during FFR, as assessed by Δ FFR, appears independent of CAC severity.
• These findings suggest that severe CAC does not preclude achieving adequate hyperemia for accurate FFR assessment.