Impact of Post-Percutaneous Coronary Intervention Quantitative Flow Ratio of De Novo Coronary Artery Lesions Treated with Drug-coated Balloons: The QUADRIC Study

Background: Quantitative flow ratio (QFR) is a non-invasive modality that uses 3D coronary artery reconstruction and coronary fluid dynamics to estimate fractional flow reserve. The Quantitative Flow Ratio of De Novo Coronary Artery Lesion Treated with Drug-Coated Balloon (QUADRIC) study aims to assess the role of QFR in predicting major adverse cardiovascular events (MACE) in de novo coronary lesions treated with drug-coated balloons (DCBs). Methods: This study is an investigator-initiated real-world study involving 414 patients and 429 lesions. Patients aged 18 years and above who were admitted between January 2020 and December 2020 for percutaneous coronary intervention (PCI) with a DCB in a de novo lesion were included. The primary outcome was two-year MACE rate, and the secondary outcome was the clinically driven target lesion revascularisation rate at 24 months. Results: The mean age of patients was 61 years [SD 10.1]. In total, 234 (79.6%) patients were men, 188 (63.9%) had diabetes and 163 (55.4%) presented with acute coronary syndrome. The mean estimated lesion length was 32 mm (SD 20.1) and the mean vessel size was 2.5 mm (range: 2.0–4.0 mm; SD 0.4). The 2-year primary endpoint occurred in 8 (4.5%) patients in the QFR ≥0.90 group and in 14 (12.6%) patients in the QFR <0.90 group (p=0.011). Post-PCI QFR was significantly lower in patients with target lesion revascularisation during follow-up compared to those without it (p=0.032). Conclusion: In this study, a post-PCI QFR <0.90 could be used to predict MACE events in patients with de novo coronary artery lesions treated with DCB and improve patient outcomes within the first two years. However, a larger randomised trial is recommended.