Collateral flow reserve and right coronary occlusion: evaluation during off-pump revascularization

Area of Science:

• Cardiovascular Medicine
• Interventional Cardiology
• Cardiac Surgery

Background:

• Three-vessel disease with chronic total occlusion presents complex revascularization challenges.
• Assessing functional significance of coronary collaterals is crucial for treatment decisions.
• Off-pump coronary artery bypass grafting is a surgical approach for complex coronary artery disease.

Purpose of the Study:

• To determine pressure-derived collateral fractional flow reserve (FFR(coll)) in patients with three-vessel disease and chronic right coronary artery occlusion.
• To compare preoperative FFR(coll) with Rentrop grade and left ventricular ejection fraction (LVEF).
• To evaluate the impact of left coronary artery revascularization on FFR(coll).

Main Methods:

• Retrospective analysis of eight patients undergoing off-pump coronary artery bypass grafting.
• Preoperative coronary angiography to assess collaterality (Rentrop grade).
• Measurement of FFR(coll) before (FFR(coll) 0) and after left coronary artery revascularization (FFR(coll) 1).

Main Results:

• No correlation was found between preoperative Rentrop grade and FFR(coll) 0.
• A significant linear correlation was observed between FFR(coll) 0 and LVEF (P<0.001).
• No significant change in FFR(coll) was noted after left coronary artery bypass grafting.

Conclusions:

• Coronary angiogram-derived collaterality (Rentrop grade) is a poor predictor of functional collateral flow.
• Left ventricular ejection fraction is a better indicator of functional collateralization.
• Revascularization of the occluded right coronary artery is justified despite left-sided grafting, as indicated by stable FFR(coll).