Fractional Flow Reserve Evaluation and Chronic Kidney Disease: Analysis From a Multicenter Italian Registry (the FREAK Study)

Matteo Tebaldi, Simone Biscaglia, Massimo Fineschi, Antonio Manari, Mila Menozzi, Gioel Gabrio Secco, Emilio Di Lorenzo, Fabrizio D'Ascenzo, Fabio Fabbian, Carlo Tumscitz, Roberto Ferrari, Gianluca Campo

Research output: Contribution to journalArticlepeer-review


Objectives: To establish if the presence of chronic kidney disease (CKD) influences fractional flow reserve (FFR) value in patients with intermediate coronary stenosis. Background: FFR-guided coronary revascularization reduces cardiac adverse events in patients with coronary artery disease. CKD impairs microcirculation and increases cardiovascular risk. Whether CKD presence may limit FFR accuracy is unknown. Methods: We used data from a multicenter prospective registry enrolling 1.004 patients undergoing FFR evaluation for intermediate stenosis. We assessed the relationship between clinical and angiographic variables and FFR measurement. CKD was defined as CrCl value ≤45 ml/min. FFR value was considered potentially flow-limiting, and therefore positive, if ≤0.80. The index of microcirculatory resistance (IMR) was calculated in 20 patients stratified according CrCl value (single-center substudy). Results: FFR measurement was positive in 395 (39%) patients. Overall, 131 (13%) patients had CKD. Patients with CrCl ≤45 ml/min showed significantly higher FFR values as compared to the others (0.84 ± 0.07 vs. 0.81 ± 0.08, p < 0.001). Positive FFR occurrence was lower in patients with CrCl ≤45 ml/min (27% vs. 41%, p < 0.01). After multivariable analysis, diabetes (HR 1.07, 95%CI 1.008–1.13, p = 0.03), left anterior descending (HR 1.35, 95%CI 1.27–1.43, p < 0.001) and CrCl ≤45 ml/min (HR 0.92, 95%CI 0.87–0.97, p = 0.005) emerged as independent predictors of FFR measurement. Accordingly, IMR values were higher in patients with CrCl ≤45 ml/min (32 U [28245] vs. 16 U [11220], p < 0.01). Conclusions: FFR and IMR measurements differ between CKD patients and those with normal renal function. Flow-limiting FFR is less frequent in patients with CrCl ≤45 ml/min.

Original languageEnglish
Pages (from-to)555-562
Number of pages8
JournalCatheterization and Cardiovascular Interventions
Issue number4
Publication statusPublished - Oct 1 2016
Externally publishedYes


  • coronary artery disease
  • microvascular function
  • renal failure

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging
  • Cardiology and Cardiovascular Medicine


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