The Use of Quantitative Flow Ratio for Decisions and Outcomes in Percutaneous Coronary Intervention Study

Background: This pilot study explores the impact of quantitative flow ratio (QFR) guidance on decision-making for angioplasty and post-intervention procedures in stable coronary artery disease. Aim: The primary aim was to evaluate the vessel-oriented composite endpoint (VOCE) at 6 months, encompassing cardiac death, vessel-related MI and ischaemia-driven target vessel revascularisation. Secondary objectives included assessing individual components of VOCE and the influence that the QFR had on decision-making before and after interventions. Methods: The pilot study was conducted from 1 January to 31 July 2023 and included all angiogram patients. Cardiologists used QFR readings for decision-making, with QFR >0.80 indicating non-significance and <0.80 denoting significant stenosis, prompting angioplasty. The lesions were re-evaluated post-angioplasty and QFR >0.90 indicated that no further intervention was necessary. Results: A total of 770 subjects were screened. Most of the patients in the post-percutaneous coronary intervention (PCI) without QFR group were Malaysian (36.1%), while there were more Chinese patients in the PCI with QFR group (49.2%). Hypertension was the primary risk factor for both groups (79.5% and 73%, respectively). Decision changes were more common in pre-intervention assessments (39%), with 34% of these opted not to proceed whereas 66% agreed to proceed. Post-PCI decision changes were less common (22%); 19% of these opted for further intervention and 81% accepted the angiographic results before the QFR reading. VOCE at 6-month follow-up showed one cardiac death in the PCI without QFR group and none in the PCI with QFR group (p=0.316). Conclusion: QFR readings demonstrated significant value in guiding pre-PCI decisions. This study underscores the potential for enhanced decision-making and improved patient outcomes by using QFR-guided interventions.