Fractional Flow Reserve

The goal of this clinical trial is to find out whether a treatment strategy based on a drug-coated balloon (DCB) achieves coronary artery function at 6 months that is not worse than a strategy using only drug-eluting stents (DES) by more than a prespecified amount. The study will enroll adults undergoing percutaneous coronary intervention (PCI) for a new coronary artery narrowing (de novo lesion). The main questions are: 1. Is fractional flow reserve (FFR) at 6 months noninferior after DCB-based PCI compared with DES-only PCI? FFR is a pressure-based measure used to assess blood flow through a coronary artery. 2. Does the DCB-based strategy reduce the number and total length of stents implanted? 3. What cardiovascular events or medical problems, such as cardiovascular death, myocardial infarction, repeat coronary procedures, or bleeding, occur during follow-up? Investigators will randomly assign 100 participants to one of two treatment strategies. In the DCB-based group, the lesion will first be prepared with a balloon. A DCB will be used if lesion preparation produces a suitable result; a DES may be implanted if needed to achieve a safe and adequate result. In the DES-only group, the lesion will be treated with a DES. Participants will: 1. Receive treatment according to their assigned strategy. 2. Undergo follow-up coronary angiography and FFR measurement at approximately 6 months. For clinical reasons, this examination may take place up to 9 months after the procedure. 3. Be followed for cardiovascular events through 12 months after randomization.

For patients with atherosclerotic renal artery stenosis, the results of randomized controlled trials published in recent years have failed to demonstrate that renal artery stenting is superior to optimal medical therapy. However, these studies still have limitations. Fractional flow reserve (FFR) has been extensively studied in coronary artery disease, and it has been established that FFR-guided revascularization is superior to both angiography-guided percutaneous coronary intervention and medical therapy alone. Whether FFR can guide interventional treatment in patients with renal artery stenosis and hypertension is currently a hot topic in the field of renal artery stenosis research. Eligible patients meeting the inclusion criteria were enrolled. Pharmacologically induced FFR values were measured as the baseline. Patients with FFR ≥ 0.8 were randomly assigned to either the medical therapy group or the stenting group, while patients with FFR \< 0.8 underwent stent implantation. Changes in eGFR, 24-hour systolic blood pressure, and 24-hour diastolic blood pressure from baseline to 12 months were compared among the groups.

Quantitative Flow Ratio (QFR) has shown good diagnostic performance against Fractional Flow Reserve (FFR) in several meta-analyses, comparable or even superior to nonhyperemic pressure ratios. However, the reproducibility of QFR is modest and there is high inter- and intra-observer variability even when fairly experienced but non-core lab operators (at least 150 QFR procedure experience) are performing the analysis. Although smaller studies have demonstrated that non-core analysis and even paramedical user analysis can have good correlation with FFR, the concern about the diagnostic performance of QFR in real-world clinical practice by inexperienced users remains. The primary objective of "Dedinje FFR/QFR Registry" is to determine the feasibility and diagnostic performance of QFR analysis by vendor-certified inexperienced medical users in a real-world setting using FFR as the gold standard. All patients \>18 years old who present to the Institute for Cardiovascular Diseases "Dedinje" and undergo a planned or ad hoc FFR procedure will be asked to participate in the registry. FFR procedure is performed according to the standardized institutional protocol. QFR analysis will be subsequently performed offline according to a standard operating procedure.