Next Generation FFR Microcatheter Technology

2017 ◽  
Vol 12 (02) ◽  
pp. 2
Author(s):  
Katrina Mountfort ◽  
Keyword(s):  
Fractional Flow Reserve ◽  
Clinical Utility ◽  
Independent Predictor ◽  
Medical Systems ◽  
Fractional Flow ◽  
Flow Reserve ◽  
Pressure Wire ◽  
Percutaneous Coronary ◽  
The Difference ◽  
Standard Techniques

Fractional flow reserve (FFR) is the mainstay of functional haemodynamic assessment of coronary artery lesions, guiding decisions in percutaneous coronary interventions (PCI). The RXi® rapid exchange FFR system, featuring an ultrathin monorail pressure microcatheter (Navvus™) has the potential to simplify PCI procedures. Data from two studies sponsored by ACIST Medical Systems evaluating the clinical utility of the microcatheter system were presented at EuroPCR, which took place over 16–19 May 2017 in Paris. Early data from the FFR-Stent Evaluated at Rotterdam Cardiology Hospital (FFR-SEARCH) registry have indicated that post-PCI, almost half of patients have FFR values below 0.90 even when stent placement appears fine on angiography. This registry is noteworthy for including a high proportion of unstable patients. The Assessment of Catheter-based Interrogation and Standard Techniques for Fractional Flow Reserve measurement (ACIST-FFR) study has shown that the microcatheter system provides a modestly lower FFR value compared with the traditional pressure wire, and an independent predictor of a difference between the two is the physiological severity of the lesion as measured by the Navvus microcatheter, meaning that the clinical impact of the difference is minimal for most measurements. These findings add to the growing body of evidence in support of the microcatheter FFR system and have prompted further research into optimising procedures.

scholarly journals The Value of Pre- and Post-Stenting Fractional Flow Reserve for Predicting Mid-Term Stent Restenosis Following Percutaneous Coronary Intervention (PCI)

2015 ◽  
Vol 8 (7) ◽  
pp. 240 ◽  
Author(s):  
Alireza Rai ◽  
Mostafa Bahremand ◽  
Mohammad Reza Saidi ◽  
Zahra Jalili ◽  
Nahid Salehi ◽  
...  
Keyword(s):  
Percutaneous Coronary Intervention ◽  
Fractional Flow Reserve ◽  
Coronary Intervention ◽  
Cardiac Events ◽  
Fractional Flow ◽  
Stent Restenosis ◽  
Flow Reserve ◽  
Percutaneous Coronary ◽  
History Of ◽  
The Difference

<p>Measuring fractional flow reserve (FFR) in percutaneous coronary intervention (PCI) has predictive value for PCI outcome. We decided to examine the utility of pre- and post-stenting FFR as a predictor of 6-month stent restenosis as well as MACE (major adverse cardiac events). Pre- and post-stenting FFR values were measured for 60 PCI patients. Within 6 months after stenting, all patients were followed for assessment of cardiac MACE including myocardial infarction, unstable angina, or positive exercise test. Stent restenosis was also assessed. Cut-off values for pre- and post-stenting FFR measurements were considered respectively as 0.65 and 0.92.Stent restenosis was detected in 4 patients (6.6%). All 4 patients (100%) with restenosis had pre-stenting FFR of &lt; 0.65, while only 26 of 56 patients without restenosis (46.4%) had pre-stenting FFR value of &lt; 0.65 (P= 0.039). Mean pre-stenting FFR in patients with restenosis was significantly lower than in those without restenosis (0.25 ± 0.01 vs. 0.53 ± 0.03, P= 0.022). Although stent restenosis was higher in patients with post-stenting FFR of &lt; 0.92 (2 cases, 9.5%) than in those with FFR value of ≥ 0.92 (2 cases, 5.1%), the difference was not statistically (P= 0.510). Pre-stenting FFR, the use of longer stents, and history of diabetes mellitus can predict stent restenosis, but the value of post-stenting FFR for predicting restenosis was not explicit.</p>

scholarly journals The imortance of hyperemic contrast velocity assessment on image-based fractional flow reserve calculation

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
B Tar ◽  
A Uveges ◽  
Z Koszegi
Keyword(s):  
Fractional Flow Reserve ◽  
Three Dimensional ◽  
Microvascular Disease ◽  
Simple Calculation ◽  
Fractional Flow ◽  
Roc Curve Analysis ◽  
Flow Reserve ◽  
Myocardial Area ◽  
Pressure Wire ◽  
The Difference

Abstract Aims Image-based fractional flow reserve (FFR) calculations reported good agreement with FFR measured invasively. The purpose of this study was to perform a retrospective analysis of the cases of a previous study on less invasive FFR calculation (simple FFR: FFRsim) as a simple calculation from hyperemic contrast flow data and three-dimensional coronary parameters. Methods and results We aimed to analyze the relations between the pressure wire-based FFR (FFRmeas) and fixed FFRsim: calculated from the fixed hyperemic velocity, rest FFRsim: calculated using the non-hyperemic frame count data to extrapolate the hyperemic velocity (based on the database used in the FAVOR1 study) hyp FFRsim: the hyperemic velocity derived from the frame count assessment during vasodilation.To calculate the frame count reserve (CFRFC) the resting frame count was divided by the hyperemic frame count; this value was then used to determine the CFRFC/FFRmeas ratio as an indicator of microvascular function in the corresponding myocardial area of the measured coronary vessel. A total of 50 lesions with intermediate stenosis were investigated. Correlation between rest FFRsim (from the resting frame count extrapolated to the hyperemic velocity) and FFRmeas was lower than the correlation between hyp FFRsim and FFRmeas (r=0.761 vs. 0.824). Based on ROC curve analysis for predicting the abnormal FFR of ≤0.80 the AUC were significantly higher for the hyperemia-based parameter than those calculated from resting frame counts. Significantly higher AUC were detected by the hyp FFRsim than by the rest FFRsim: 0.936 (95% CI: 0.828 to 0.985) vs. 0.862 (CI: 0.734 to 0.943); p=0.011. Linear regression analyses between the FFRsim (either by fixed FFRsim or by rest FFRsim or by hyp FFRsim methods) and the FFRmeas showed higher intercepts and less steep of the slopes in the subgroups with presence of microvascular disease defined as CFRFC/FFRmeas &lt;2 than in those without microvascular disease (CFRFC/FFRmeas &gt;2); the difference reached significant level (p=0.019) when calculated by rest FFRsim. Conclusions Hyperemic challenge either by adenosine or regadenoson is required for exact image-based FFR calculation especially in cases of suspicion for microvascular coronary disease. Funding Acknowledgement Type of funding source: None

scholarly journals Fractional flow reserve derived from microcatheters versus standard pressure wires: a stenosis-level meta-analysis

Open Heart ◽  
2019 ◽  
Vol 6 (1) ◽  
pp. e000971 ◽  
Author(s):  
Henry Seligman ◽  
Matthew J Shun-Shin ◽  
Anushkumar Vasireddy ◽  
Christopher Cook ◽  
Yousif Y Ahmad ◽  
...  
Keyword(s):  
Fractional Flow Reserve ◽  
Meta Analysis ◽  
Medical Systems ◽  
Fractional Flow ◽  
Device Failure ◽  
Flow Reserve ◽  
Small Device ◽  
Standard Pressure ◽  
The Difference ◽  
Eden Prairie

AimsTo determine the agreement between sensor-tipped microcatheter (MC) and pressure wire (PW)-derived fractional flow reserve (FFR).Methods and resultsStudies comparing FFR obtained from MC (FFRMC, Navvus Microcatheter System, ACIST Medical Systems, Eden Prairie, Minnesota, USA) versus standard PW (FFRPW) were identified, and a meta-analysis of numerical and categorical agreement was performed. The relative levels of drift and device failure of MC and PW systems from each study were assessed. Six studies with 440 lesions (413 patients) were included. The mean overall bias between FFRMC and FFRPW was −0.029 (FFRMC lower). Bias and variance were greater for lesions with lower FFRPW (p<0.001). Using a cut-off of 0.80, 18 % of lesions were reclassified by FFRMC versus FFRPW (with 15 % being false positives). The difference in reported drift between FFRPW and FFRMC was small. Device failure was more common with MC than PW (7.1% vs 2%).ConclusionFFRMC systematically overestimates lesion severity, with increased bias in more severe lesions. Using FFRMC changes revascularisation guidance in approximately one out of every five cases. PW drift was similar between systems. Device failure was higher with MC.

A real-world comparison of outcomes between fractional flow reserve-guided versus angiography-guided percutaneous coronary intervention

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
C Wong ◽  
A Ng ◽  
C Ada ◽  
V Chow ◽  
W Fearon ◽  
...  
Keyword(s):  
Percutaneous Coronary Intervention ◽  
Fractional Flow Reserve ◽  
Primary Endpoint ◽  
Real World ◽  
Independent Predictor ◽  
Coronary Intervention ◽  
Funding Source ◽  
Fractional Flow ◽  
Flow Reserve ◽  
Percutaneous Coronary

Abstract Background Fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) has been shown to be superior to angiography-guided PCI in randomized controlled studies. However, real-world data on the use and outcomes of FFR-guided PCI remain limited. Purpose To investigate the outcomes of patients undergoing FFR-guided PCI compared to angiography-guided PCI in a large, state-wide unselected cohort. Methods All patients undergoing PCI between June 2017 and June 2018 recorded by the Centre for Health Record Linkage (CHeReL) were included in the study. The CHeReL database is one of the largest data linkage systems in Australia, capturing health data from ≥97% of all healthcare facilities in the state of New South Wales, which has a population of 7.5 million people. The PCI cohort was stratified into the FFR-guided group when a concomitant FFR procedure was performed, and the angiography-guided group when no FFR was performed. The primary endpoint was a combined endpoint of death or myocardial infarction (MI). Secondary endpoints included all-cause death, cardiovascular (CV) death, and MI. Results The cohort comprised 10,304 patients, of which 542 (5%) underwent FFR-guided PCI. There were no significant differences in age, gender, or comorbidities between the two groups. During a mean follow-up of 12±4 months, the FFR-guided PCI group had reduced occurrence of the primary endpoint (3% vs 8%, P&lt;0.001), all-cause death (1% vs 4%, P=0.001), CV death (1% vs 3%, P=0.01), and MI (2% vs 4%, P=0.01) (Figure). Multivariable Cox regression analysis demonstrated FFR-guidance to be an independent predictor of the primary endpoint (hazard ratio [HR] 0.47, 95% confidence interval [CI] 0.28–0.78, P=0.004), after adjusting for age, clinical presentation, comorbidities, and multi-vessel PCI. A sensitivity analysis was performed excluding patients that presented with acute MI, leading to a smaller cohort of 5,850 patients, of which 448 (8%) underwent FFR-guided PCI. FFR-guidance remained an independent predictor of the primary endpoint in this cohort of stable patients (HR 0.36, 95% CI 0.17–0.77, P=0.01). Conclusion In this real-world study of patients undergoing PCI, FFR-guidance was associated with improved clinical outcomes, driven by the lower hard endpoint of death or MI. The use of FFR-guided PCI remains limited worldwide, and efforts should be directed to increase adoption of this technique in future. Figure 1 Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): National Heart Foundation of Australia Health Professional Scholarship

Fractional Flow Reserve: Does a Cut-off Value add Value?

2016 ◽  
Vol 11 (1) ◽  
pp. 17
Author(s):  
Shah R Mohdnazri ◽  
◽  
◽  
◽  
Thomas R Keeble ◽  
...  
Keyword(s):  
Fractional Flow Reserve ◽  
Coronary Intervention ◽  
Grey Zone ◽  
Fractional Flow ◽  
Non Invasive ◽  
Invasive Test ◽  
Flow Reserve ◽  
A Value ◽  
Percutaneous Coronary ◽  
Value Add

Fractional flow reserve (FFR) has been shown to improve outcomes when used to guide percutaneous coronary intervention (PCI). There have been two proposed cut-off points for FFR. The first was derived by comparing FFR against a series of non-invasive tests, with a value of ≤0.75 shown to predict a positive ischaemia test. It was then shown in the DEFER study that a vessel FFR value of ≥0.75 was associated with safe deferral of PCI. During the validation phase, a ‘grey zone’ for FFR values of between 0.76 and 0.80 was demonstrated, where a positive non-invasive test may still occur, but sensitivity and specificity were sub-optimal. Clinical judgement was therefore advised for values in this range. The FAME studies then moved the FFR cut-off point to ≤0.80, with a view to predicting outcomes. The ≤0.80 cut-off point has been adopted into clinical practice guidelines, whereas the lower value of ≤0.75 is no longer widely used. Here, the authors discuss the data underpinning these cut-off values and the practical implications for their use when using FFR guidance in PCI.

scholarly journals A Computational Analysis of the Influence of a Pressure Wire in Evaluating Coronary Stenosis

Fluids ◽  
2021 ◽  
Vol 6 (4) ◽  
pp. 165
Author(s):  
Jie Yi ◽  
Fang-Bao Tian ◽  
Anne Simmons ◽  
Tracie Barber
Keyword(s):  
Coronary Stenosis ◽  
Severe Case ◽  
Patient Specific ◽  
Fractional Flow ◽  
Ideal Model ◽  
Coronary Pressure ◽  
Flow Reserve ◽  
Pressure Wire ◽  
Physical Presence ◽  
The Difference

Cardiovascular disease is one of the world’s leading causes of morbidity and mortality. Fractional flow reserve (FFR) was proposed in the 1990s to more accurately evaluate the functional severity of intermediate coronary stenosis, and it is currently the gold standard in cardiac catheterization laboratories where coronary pressure and flow are routinely obtained. The clinical measurement of FFR relies on a pressure wire for the recording of pressures; however, in computational fluid dynamics studies, an FFR is frequently predicted using a wire-absent model. We aim to investigate the influence of the physical presence of a 0.014-inch (≈0.36 mm) pressure wire in the calculation of virtual FFR. Ideal and patient-specific models were simulated with the absence and presence of a pressure wire. The computed FFR reduced from 0.96 to 0.93 after inserting a wire in a 3-mm non-stenosed (pipe) ideal model. In mild stenotic cases, the difference in FFR between the wire-absent and wire-included models was slight. The overestimation in severe case was large but is of less clinical significance because, in practice, this tight lesion does not require sophisticated measurement to be considered critical. However, an absence of the pressure wire in simulations could contribute to an over-evaluation for an intermediate coronary stenosis.

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