Prognostic implication of thermodilution coronary flow reserve in patients with indeterminate pressure-bounded coronary flow reserve. (15th June 2018)

• Record Type: Journal Article
• Authors: Lee, Joo Myung; Rhee, Tae-Min; Hwang, Doyeon; Park, Jonghanne; Kim, Chee Hae; Choi, Ki Hong; Shin, Eun-Seok; Nam, Chang-Wook; Doh, Joon-Hyung; Koo, Bon-Kwon
• Is Part Of: International journal of cardiology. Volume 261(2018)
• Page Start: 24
• Page End: 27
• Publication Date: 2018-06-15
• Subjects: Coronary flow reserve -- Fractional flow reserve -- Pressure-bounded coronary flow reserve -- Prognosis; Cardiology -- Periodicals; Electronic journals; 616.12
• DOI: 10.1016/j.ijcard.2018.02.008
• Languages: English
• ISSNs: 0167-5273

Abstract

Abstract: Background: Recently, the concept of pressure-bounded coronary flow reserve (PB-CFR) has been introduced. However, using pressure-only data, a substantial proportion of patients could not be classified into high or low PB-CFR and remained as indeterminate PB-CFR. The current study evaluated the prognostic implication of thermodilution-based CFR (thermo-CFR) in patients with indeterminate PB-CFR. Methods: Among 199 patients (211 lesions) with indeterminate PB-CFR, 170 patients (179 lesions) with deferral of revascularization were analyzed for the current study. The rates of patient-oriented composite outcomes (POCO, a composite of all-cause mortality, any myocardial infarction, and any ischemia-driven revascularization) were compared according to thermo-CFR. All patients underwent fractional flow reserve (FFR) and thermo-CFR measurements. Thermo-CFR ≤ 2.0 was classified as low thermo-CFR. The median follow-up duration was 1350.0 (Q1-Q3 1252.0–1468.0) days. Results: Mean angiographic percent diameter stenosis, FFR, and thermo-CFR were 42.3 ± 13.9, 0.84 ± 0.06, and 3.10 ± 1.15, respectively. Among 170 patients, 36 patients (21.2%) showed low thermo-CFR. Patients with low thermo-CFR showed significantly higher rate of POCO compared to those with high thermo-CFR (30.6% vs. 3.0%, HR 12.117, 95% CI 3.854–38.091, p < 0.001). Adding thermo-CFR to a prediction model with FFR significantly increased discrimination and reclassification index for the risk of POCO (c-index 0.545 vs. 0.766, p = 0.002, category-free net reclassification index 1.169, p < 0.001, relative integrated discrimination index 31.828, p < 0.001). Conclusions: Patients with low thermo-CFR showed a significantly higher risk of POCO compared to those with high thermo-CFR among patients with indeterminate PB-CFR. Thermo-CFR showed additional prognostic implication, in addition to FFR, in patients with indeterminate PB-CFR. Highlights: Recently, the concept of pressure-bounded coronary flow reserve (PB-CFR) has been introduced. However, using pressure-only data, a substantial proportion of patients could not be classified into high or low PB-CFR and remained as indeterminate PB-CFR. The current study sought to evaluate the prognostic implication of thermodilution-based CFR (thermo-CFR) in patients with indeterminate PB-CFR. Among 170 patients (179 lesions) who were classified into indeterminate PB-CFR and deferred revascularization, patients with low thermo-CFR showed significantly higher rate of POCO compared to those with high thermo-CFR. Furthermore, adding thermo-CFR to a prediction model with FFR significantly increased discrimination and reclassification index for the risk of POCO. The current results support the importance of comprehensive physiologic assessment in patients with coronary artery disease beyond pressure only measurements and reflect the complex mechanisms of myocardial ischemia.