Research on New Technologies for the Diagnosis and Treatment of Cardiovascular Diseases-Multi-parameter Noninvasive Early Diagnosis of Coronary Microvascular Diseases Series I: Clinical Study Protocol for a New Method of Evaluating Coronary Microvessels Based on Coronary IMR Calculated from Coronary Angiography Images

This study was a retrospective, multicenter observational investigation and approved by the local Human Research Ethics Committee and conducted in accordance with the principles outlined in the Helsinki Declaration.Patients aged 18 years or older who had severe coronary calcification and underwent successful RA during PCI were eligible for inclusion in the study. Exclusion criteria included target vessel was chronic total occlusion, poor angiographic image quality, failed RA and RA not used for severe coronary calcification.

Angiography-derived index of microcirculatory resistance was measured in the target vessel treated with RA pre-PCI and post-PCI and blinded and performed by an independent core laboratory.The follow-up entailed the utilization of a multipronged approach, encompassing clinic visits, medical record reviews and telephone contacts.