Innovative Use of Adenosine-Free Constant Resistance Ratio to Evaluate Distal Blood Flow during Perfusion Balloon Dilation: A Case Report

Coronary interventional therapy effectively achieves myocardial reperfusion in coronary heart disease. New surgical instruments may enhance treatment selectivity and reduce discomfort. The constant resistance ratio (cRR) is a non-congestive measurement that directly assesses coronary function without vasodilators including adenosine, simplifying operations and minimizing drug side effects compared to fractional flow reserve (FFR). As a novel device in interventional treatment, the perfusion balloon (PB)'s ability to preserve distal blood flow during inflation is not been fully understood. The case aims to evaluate the extent of blood flow preservation by using cRR.