Clinical trial NCT01747031: Determination of Instantaneous Wave-Free Ratio by Computed Tomography
Official title: Diagnostic Performance of Instantaneous Wave-Free Ratio From Computed Tomography
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: NA
Conditions: Coronary Artery Disease
Keywords: iFR
FFR
instantaneous wave-free ratio
fractional flow reserve
Lead sponsor: Shanghai 10th People's Hospital
Sponsor class: OTHER
First posted: 2012-12-11
Enrollment: 100
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: DIAGNOSTIC

Brief summary: The iFRCT study is a prospective, multicenter study to evaluate the diagnostic performance of iFRCT with the use of ≥64-detector row CT scanners for the detection and exclusion of significant obstructive coronary artery disease, defined by invasive fractiona flow reserve (FFR) as the reference standard.

Detailed description: Noninvasive fractional flow reserve (FFR) computed from CT (FFRCT) is a novel method for determining the physiologic significance of coronary artery disease (CAD), and several clinical trials have revealed that the FFRCT has a good correlation with invasive FFR, also use of noninvasive FFRCT plus Computed Tomography (CT ) among stable patients with suspected or known CAD was associated with improved diagnostic accuracy and discrimination vs CT alone for the diagnosis of hemodynamically significant CAD.

The cornerstone of FFR is the linear relationship between pressure and flow under conditions of constant (and minimized) intracoronary resistance, so is FFRCT. Under such conditions, pressure and flow are assumed to be directly proportional, and a decrease in pressure across a stenosis reflects a decrease in blood flow to the dependent myocardium. However, even after administration of potent pharmacologic agents such as adenosine, intracoronary resistance is not static, but instead fluctuates in a phasic pattern throughout the cardiac cycle. In addition, for patients who are allergic to pharmacologic agents or with sever lesions which response little to pharmacologic agents, the measurement of FFR is challenging and the lesion are always underestimated. The ADVISE trial revealed that intracoronary resistance is naturally constant and minimized during the wave-free period. The instantaneous wave-free ratio calculated over this period produces a drug-free index of stenosis severity comparable to FFR. But whether iFR calculated from Computed Tomography(iFRCT) is comparable to FFRCT or FFR, and its diagnostic performance remains unknown. Thus the investigators conduct this trial to assess the diagnostic performance of Instantaneous Wave-Free Ratio for diagnosis of hemodynamically significant coronary stenosis.

Instantaneous Wave-Free Ratio calculated from reconstructed heart model.Wave-intensity analysis identified a wave-free period in which intracoronary resistance at rest is similar in variability and magnitude.The investigators define the resting distal-to-proximal pressure ratio during this period as the instantaneous wave-free ratio (iFR).

Eligibility criteria: Inclusion Criteria:

* Coronary computed tomographic angiography(CCTA) with over 50 percent stenosis in a major coronary artery over 2mm diameter
* Undergoing clinically indicated invasive coronary angiography with FFR

Exclusion Criteria:

* A history of CABG surgery
* Prior percutaneous coronary intervention with suspected instent restenosis
* Suspicion of or recent acute coronary syndrome
* Complex congenital heart disease
* Prior pacemaker or defibrillator
* Prosthetic heart valve
* Significant arrhythmia
* heart rate \>100 beats/min
* systolic blood pressure≤90 mmHg
* contraindication to beta blockers, nitroglycerin or adenosine
* Serum creatinine level greater than 1.5 mg per dL
* Allergy to iodinated contrast
* Pregnant state
* Body mass index greater than 35
* Evidence of active clinical instability or lifethreatening disease
* Canadian Cardiovascular Society class IV angina
* nonevaluable CCTA as determined by the CCTA core laboratory
* Inability to adhere to study procedures

Primary outcomes:
measure: Diagnostic Accuracy of iFRCT
timeFrame: 1 day
Secondary outcomes:
measure: Diagnostic accuracy of iFRCT at the subject level
timeFrame: 1 day
measure: Diagnostic accuracy of iFRCT at the vessel level
timeFrame: 1 day
measure: FFR Numerical Correlation
timeFrame: 1 day
measure: FFRCT Numerical Correlation
timeFrame: 1 day
measure: Predicted Post-PCI FFR Measurement
timeFrame: 1 day
Other outcomes:
Locations:
city: Shanghai
country: China
facility: Department of Cardiology, Shanghai Tenth People's Hospital
Study officials:
affiliation: Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine
name: Ya-Wei Xu, MD, FACC
role: PRINCIPAL_INVESTIGATOR
References:
citation: Sen S, Escaned J, Malik IS, Mikhail GW, Foale RA, Mila R, Tarkin J, Petraco R, Broyd C, Jabbour R, Sethi A, Baker CS, Bellamy M, Al-Bustami M, Hackett D, Khan M, Lefroy D, Parker KH, Hughes AD, Francis DP, Di Mario C, Mayet J, Davies JE. Development and validation of a new adenosine-independent index of stenosis severity from coronary wave-intensity analysis: results of the ADVISE (ADenosine Vasodilator Independent Stenosis Evaluation) study. J Am Coll Cardiol. 2012 Apr 10;59(15):1392-402. doi: 10.1016/j.jacc.2011.11.003. Epub 2011 Dec 7.