Tehran University of Medical Sciences The Research in Heart Yield and Translational Medicine (RHYTHM) 3115-7270 19 1 2024 01 31 Long-Term Outcomes of Fractional Flow Reserve-Guided Percutaneous Coronary Intervention of Moderate Lesions in Patients with Chronic Coronary Syndrome 54 59 Hamid Khederlou Department of Cardiology, Zanjan University of Medical Sciences, Zanjan, Iran. Mehrdad Mohajeri Cardiovascular Diseases Research Institute, Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran. Houshang Bavandpour Karvane Cardiovascular Diseases Research Institute, Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran. Arash Jalali Cardiovascular Diseases Research Institute, Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran. Mojtaba Salarifar Cardiovascular Diseases Research Institute, Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran. 2023 07 28 2024 05 05 Background: Fractional flow reserve (FFR) is crucial to evaluating coronary artery stenosis in patients diagnosed with chronic coronary syndrome (CCS). By assessing the severity of stenosis, FFR assists in determining whether percutaneous coronary intervention (PCI) is necessary. Methods: Conducted at Tehran Heart Center from 2013 through 2017, this cohort study involved 52,248 CCS patients who underwent coronary angiography. Among them, 598 symptomatic individuals, despite receiving comprehensive medical treatment, underwent FFR assessment. Subsequently, 225 patients with positive FFR (≤0.80) underwent PCI, while 373 patients received solely medical treatment. The patients were monitored for 3 years to evaluate primary and secondary endpoints. Results: After 3 years, the PCI group demonstrated a lower incidence of the primary composite endpoint, consisting of all-cause mortality, nonfatal myocardial infarction, repeat target vessel/lesion revascularization (TVR/TLR), and coronary artery bypass graft surgery, than the medical treatment group (HR, 0.85; 95% CI, 0.74 to 0.98; P=0.012). Additionally, urgent TVR/TLR significantly decreased in the PCI group (HR, 0.56; 95% CI, 0.42 to 0.74; P<0.001). Conclusion: FFR-guided PCI demonstrated effectiveness in reducing long-term major adverse cardiac events, primarily by lowering the incidence of TVR/TLR. The results emphasize the significance of FFR-guided PCI in addressing stenosis rather than alleviating ischemia. https://rhythm.tums.ac.ir/index.php/jthc/article/view/1898