Diagnostic Performance and Prognostic Ability of the QFR

The Catholic Imaging and Functional Research Cohort (C-iFR)

1. The primary technical endpoint was the diagnostic performance of the QFR against the FFR.
2. The primary clinical endpoint was target vessel failure (TVF) between two groups distributed by a QFR cut-off value of 0.8

Study Overview

• Status: Completed
• Conditions: Ischemic Heart Disease
• Intervention / Treatment: Diagnostic test: QFR assessment

Detailed Description

The quantitative flow ratio (QFR) is a novel angiography-based tool used to assess functional ischemia caused by coronary stenosis. Computation of the fractional flow reserve (FFR) from coronary angiography is based on 3D reconstruction and fluid dynamics algorithms using a modified frame count; therefore, we do not need to induce hyperemia or perform invasive procedures with a pressure wire to measure it. During the past few years, the diagnostic accuracy of the QFR was investigated and showed favorable outcomes. However, data for patients with acute coronary syndrome are lacking. In addition, no data are available for the performance of the QFR in predicting clinical outcomes. We aim to evaluate the diagnostic performance of the QFR versus the FFR and their predictive abilities for clinical outcome in a real-world all-comer population.

The Catholic imaging and Functional Research (C-iFR) Cohort was designed to evaluate the diagnostic performance and clinical outcome predictive ability of the QFR in consecutive patients undergoing CAG and the FFR at 4 major cardiac centers in Korea from January 2012 to May 2018. All hospitals (Seoul St. Mary's Hospital, Seoul; St. Paul's Hospital, Seoul; Incheon St. Mary's Hospital, Incheon; Uijeongbu St. Mary's Hospital, Uijeongbu) perform a high volume of percutaneous coronary intervention (PCI) procedures, with more than 800 PCI procedures performed per year. This QFR registry includes demographic characteristics, clinical information, laboratory data, QFR findings, and FFR findings, with clinical outcome data collected over 4 years (a median of 2 years)

• Study Type: Observational
• Enrollment (Actual): 915

Contacts and Locations

Study Locations

• Korea, Republic of
  • Seochogu
    • Seoul, Seochogu, Korea, Republic of, 06591
      • Seoul Saint Mary's Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: N/A
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

915 patients with suspected ischemic heart disease including stable angina, or acute coronary syndrome including unstable angina, acute myocardial infarction with non-culprit stenotic lesion who underwent FFR measurement and were able to analyze QFR

Description

Inclusion Criteria:

• subject ≥18 years
• Patients suspected with ischemic heart disease
• All-comer patients with SA, UA and AMI whose CAG results showed intermediate stenosis (50-70%) indicative of physiologic lesions
• Patients whose target vessels were able to analyze QFR

Exclusion Criteria: Patients with insufficient CAG data due to reasons below

• CAG data uploading error
• 2 projection angles <25 degrees apart
• only 1 projection angle image exists
• images with suboptimal contrast filling
• images with too much panning or too much magnification
• containing an ostial lesion of the left main coronary artery or right coronary artery
• anatomical vessel problems including severe overlap, severe tortuosity, foreshortening, diffuse lesions, additional far distal lesion

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Retrospective

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
QFR group; 915 patients with suspected ischemic heart disease including stable angina, or acute coronary syndrome including unstable angina, acute myocardial infarction with non-culprit stenosis who underwent FFR measurement and were able to analyze QFR.	Diagnostic test: QFR assessment; The quantitative flow ratio (QFR) is a novel angiography-based method for noninvasive functional assessment of intermediate coronary lesions.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Diagnostic accuracy, sensitivity, specificity, negative predictive value, positive predictive value of QFR	the diagnostic accuracy, sensitivity, specificity, negative predictive value, positive predictive value of the QFR≤0.80 for identifying an FFR≤0.8 as the reference standard	follow up of 4 years (anticipated median duration : 2 years)
Target vessel failure	target vessel failure (TVF) between two groups distributed by a QFR cut-off value of 0.8	follow up of 4 years (anticipated median duration : 2 years)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Diagnostic accuracy, sensitivity, specificity, negative predictive value, positive predictive value of QFR in subgroups with a borderline FFR (≥0.75, ≤0.85)	the sensitivity, specificity, negative predictive value, positive predictive value of the QFR≤0.80 for identifying an FFR≤0.8 as the reference standard in subgroups with a borderline FFR (≥0.75, ≤0.85)	follow up of 4 years (anticipated median duration : 2 years)
Diagnostic accuracy, sensitivity, specificity, negative predictive value, positive predictive value of QFR in subgroups with complicated coronary lesions	the sensitivity, specificity, negative predictive value, positive predictive value of the QFR≤0.80 for identifying an FFR≤0.8 as the reference standard in subgroups with complicated coronary lesions, such as bifurcation lesions, a large intraluminal plaque volume, a low mean flow rate, a long lesion length, calcification, tandem lesions, and a previous history of coronary intervention	follow up of 4 years (anticipated median duration : 2 years)
All-cause death, cardiac death, nonfatal myocardial infarction, TLR and stroke	all-cause death, cardiac death, nonfatal myocardial infarction, TLR and stroke between two groups distributed by a QFR cut-off value of 0.80	follow up of 4 years (anticipated median duration : 2 years)

Collaborators and Investigators

• Sponsor: Seoul St. Mary's Hospital
• Collaborators: National Research Foundation of Korea; Seoul Saint Mary's Hospital; Incheon Saint Mary's Hospital; Seoul Saint Paul's Hospital; Uijeongbu Saint Mary's Hospital
• Investigators: Principal Investigator: Kiyuk Chang, MD, PhD, Seoul Saint Mary's Hospital

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2012
• Primary Completion (Actual): May 31, 2018
• Study Completion (Actual): June 14, 2019

Study Registration Dates

• First Submitted: September 15, 2019
• First Submitted That Met QC Criteria: September 23, 2019
• First Posted (Actual): September 25, 2019

Study Record Updates

• Last Update Posted (Actual): September 25, 2019
• Last Update Submitted That Met QC Criteria: September 23, 2019
• Last Verified: September 1, 2019

More Information

Terms related to this study

• Keywords: QFR; quantitative flow ratio
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Vascular Diseases; Arteriosclerosis; Arterial Occlusive Diseases; Coronary Disease; Heart Diseases; Coronary Artery Disease; Myocardial Ischemia
• Other Study ID Numbers: XC18REDI0035

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No