A novel equitation to predict the pressure derived collateral flow index in multiple sequential coronary stenoses

Area of Science:

• Cardiovascular Physiology
• Interventional Cardiology
• Biomedical Engineering

Background:

• Coronary collateral circulation is vital for myocardial blood supply during insufficient original flow.
• The pressure-derived collateral flow index (CFI) predicts outcomes in ischemic heart disease but requires coronary artery occlusion at maximum hyperemia, limiting its use.
• Assessing collateral function in complex coronary artery disease with sequential stenoses remains challenging.

Purpose of the Study:

• To validate a novel mathematical equation for calculating CFI in sequential coronary stenoses.
• To assess the accuracy of the derived equation in an in vitro coronary circulation model.
• To provide a method for evaluating collateral flow without inducing maximum hyperemia.

Main Methods:

• A mathematical equation was derived to calculate CFI in sequential stenoses: CFI = (FFRpre - FFRpost(1 - ∆FFR))/(FFRpre + ∆FFR - FFRpost).
• An in vitro experimental system simulating coronary circulation with sequential constrictors was utilized.
• Thirty different sequential stenoses were created, pressure data obtained, and predicted CFI compared against true CFI.

Main Results:

• A strong positive correlation (r=0.90, p<0.0001) was observed between the predicted CFI and the true CFI.
• The derived equation demonstrated high accuracy in the in vitro model.
• The study successfully validated the mathematical model for CFI calculation in sequential stenoses.

Conclusions:

• The novel equation accurately predicts coronary collateral flow index in sequential stenoses.
• This method offers a potential alternative for assessing collateral function without the need for maximal hyperemia.
• The findings support the clinical utility of this equation for patients with ischemic heart disease and complex coronary lesions.