Instantaneous Wave-free Ratio (iFR) Correlates With Fractional Flow Reserve (FFR) Assessment of Coronary Artery Stenosis in Children and Young Adults

Doan, Tam

Instantaneous Wave-free Ratio (iFR) Correlates With Fractional Flow Reserve (FFR) Assessment of Coronary Artery Stenosis in Children and Young Adults

Wednesday, May 22, 2019

Belmont Ballroom 2-3 (The Cosmopolitan of Las Vegas)

Tam Doan, MD , Baylor College of Medicine/Texas Children's Hospital, Houston, TX

James C Wilkinson, MD , Baylor College of Medicine/Texas Children's Hospital, Houston, TX

Hitesh Agrawal, M.D. , University Of Tennessee /Le Bonheur Children's Medical Center, Memphis, TN

Silvana Molossi, MD, PhD , Baylor College of Medicine/Texas Children's Hospital, Houston, TX

Mahboob Alam, M.D., FSCAI , Baylor College of Medicine, Sugarland, TX

Carlos Mery, MD, MPH , The University of Texas at Austin/Dell Children's Medical Center, Austin, TX

Athar M. Qureshi, M.D., FSCAI , Baylor College of Medicine/Texas Children's Hospital, Houston, TX

Background
Fractional flow reserve (FFR) with adenosine-induced hyperemia (FFR_h) and diastolic FFR with dobutamine (FFR_d) have been recently used in children to evaluate coronary artery stenoses. In adults, instantaneous wave-free ratio (iFR)-guided revascularization is non-inferior to FFR-guided revascularization. There is no study validating the utility of iFR in children.

Methods
We performed a retrospective review of cases in which both FFR and iFR were performed at Texas Children’s Hospital from 7/2016-11/2018. Patients with anomalous aortic origin of the coronary artery (AAOCA), myocardial bridges (MB), congenital heart disease (CHD) and Kawasaki disease (KD) were included. FFR ≤ 0.8 and iFR ≤ 0.89 were considered significant.

Results
A total of 19 coronary arteries were assessed in 17 patients, median age 13 (4 - 21) years, weight 47 (19 - 110) kg. FFR_h was used to assess fixed lesions (5 post-surgical CHD, 4 post-surgical AAOCA, 1 KD) and FFR_d was used in 9 MBs. iFR correlated with both FFR_h and FFR_d (Table) and agreed with FFRin all but 1 patient. Transient ST depression occurred in 3/19 (15.8%). There was 1 major adverse event (death) in a patient with Noonan syndrome due to cerebral hemorrhage, secondary to underlying vasculopathy and hypertension.

Conclusions
In this preliminary experience, iFR correlated with FFR in the assessment of coronary artery stenoses in children and young adults. iFR does not require administration of pharmacologic agents, thus it may reduce procedural time, cost, complications, and result in more widespread adoption of invasive assessment of coronary artery lesions in young patients.