HeartFlowNXT - HeartFlow Analysis of Coronary Blood Flow Using Coronary CT Angiography (HFNXT)
To determine the diagnostic performance of FFRCT by coronary computed tomographic angiography (cCTA), as compared to cCTA alone, for non-invasive determination of the presence of a hemodynamically significant coronary lesion, using direct measurement of fractional flow reserve (FFR) during cardiac catheterization as a reference standard.
The Targeted Population is Subjects With Suspected CAD Who Are Referred for Non-emergent Clinically-indicated Invasive Coronary Angiography.
Device: Measured FFR
|Study Design:||Endpoint Classification: Efficacy Study
Intervention Model: Single Group Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Diagnostic
|Official Title:||HeartFlowNXT - HeartFlow Analysis of Coronary Blood Flow Using Coronary CT Angiography: NeXt sTeps|
- Primary Endpoint [ Time Frame: 1 day ] [ Designated as safety issue: No ]The area under the receiver operating characteristic curve (AUC of ROC) of a patient-based model intended to detect hemodynamically significant obstruction. FFR is used as the reference standard to determine the presence or absence of hemodynamically significant obstruction. cCTA stenosis will be calculated for each patient as the highest cCTA stenosis category for any vessel segment with diameter ≥2.0 mm. Only subjects with maximum cCTA stenosis in the range of 30 to 90% (as determined by the investigative site) in one or more vessel segments with diameter ≥2.0 mm will be included in the primary analysis.
|Study Start Date:||September 2012|
|Study Completion Date:||September 2013|
|Primary Completion Date:||September 2013 (Final data collection date for primary outcome measure)|
Experimental: single arm
Device: Measured FFR
Fractional Flow Reserve
Other Name: Fractional Flow Reserve
Recently, coronary Computed Tomography Angiography (cCTA) of 64-detector rows or greater has emerged as a novel non-invasive imaging modality that is capable of providing high-resolution images of coronary artery lesions (Budoff 2008; Miller 2008; Meijboom 2008). While cCTA demonstrates good diagnostic performance for detection and exclusion of anatomic coronary artery stenoses, numerous prior studies have revealed an unreliable relationship between detection of obstructive anatomic coronary artery stenoses by cCTA and hemodynamically (HD)-significant coronary artery disease (CAD), identified by myocardial perfusion SPECT or fractional flow reserve (FFR) (Di Carli 2007; Klauss 2007; Rispler 2007; van Werkhoven 2009). Individual subjects may have HD-significant CAD despite cCTA assessment demonstrating angiographically mild (<50%) maximal stenosis (Schuijf 2006). These findings emphasize the need for additional measures beyond anatomic stenosis severity for the detection and exclusion of HD-significant CAD.
Measurement of FFR during invasive cardiac catheterization represents the "gold standard" for assessment of the hemodynamic significance of coronary artery lesions (Kern 2010). Anatomic coronary artery stenosis assessment by quantitative coronary angiography (QCA) also correlates very poorly with FFR Melikian 2010). This was highlighted by the results of the FAME study in which FFR-guided coronary revascularization improved healthcare and economic outcomes compared to the conventional angiographically guided strategy (Pijls 2010; Tonino 2009; Tonino 2010).
The major disadvantage of FFR is that it has to be measured invasively. HeartFlow, Inc. ('HeartFlow') has recently developed a non-invasive method to determine FFR which computes the hemodynamic significance of CAD (FFRCT) from subject-specific cCTA data using computational fluid dynamics under rest and simulated maximal coronary hyperemic conditions. Preliminary results in subjects suggest that FFRCT accurately predicts the hemodynamic significance of coronary lesions when compared to directly-measured FFR during invasive cardiac catheterization (Koo 2011).