Coronary Flow Reserve and Microcirculatory Resistance in Patients With Intermediate Coronary Stenosis

Joo Myung Lee; Ji-Hyun Jung; Doyeon Hwang; Jonghanne Park; Yongzhen Fan; Sang-Hoon Na; Joon-Hyung Doh; Chang-Wook Nam; Eun-Seok Shin; Bon-Kwon Koo

doi:10.1016/j.jacc.2015.12.053

Coronary Flow Reserve and Microcirculatory Resistance in Patients With Intermediate Coronary Stenosis

J Am Coll Cardiol. 2016 Mar 15;67(10):1158-1169. doi: 10.1016/j.jacc.2015.12.053.

Authors

Affiliations

¹ Department of Internal Medicine and Cardiovascular Center, Seoul National University Hospital, Seoul, South Korea.
² Department of Cardiology, Xiangtan Central Hospital, Xiangtan, China.
³ Department of Internal Medicine and Emergency Medical Center, Seoul National University Hospital, Seoul, South Korea; Institute of Aging, Seoul National University, Seoul, South Korea.
⁴ Department of Medicine, Inje University Ilsan Paik Hospital, Goyang, South Korea.
⁵ Department of Medicine, Keimyung University Dongsan Medical Center, Daegu, South Korea.
⁶ Department of Cardiology, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, South Korea.
⁷ Department of Internal Medicine and Cardiovascular Center, Seoul National University Hospital, Seoul, South Korea; Institute of Aging, Seoul National University, Seoul, South Korea. Electronic address: bkkoo@snu.ac.kr.

PMID: 26965536
DOI: 10.1016/j.jacc.2015.12.053

Abstract

Background: The prognostic impact of microvascular status in patients with high fractional flow reserve (FFR) is not clear.

Objectives: The goal of this study was to investigate the implications of coronary flow reserve (CFR) and the index of microcirculatory resistance (IMR) in patients who underwent FFR measurement.

Methods: Patients with high FFR (>0.80) were grouped according to CFR (≤2) and IMR (≥23 U) levels: group A, high CFR with low IMR; group B, high CFR with high IMR; group C, low CFR with low IMR; and group D, low CFR with high IMR. Patient-oriented composite outcome (POCO) of any death, myocardial infarction, and revascularization was assessed. The median follow-up was 658 days (interquartile range: 503.8 to 1,139.3 days).

Results: A total of 313 patients (663 vessels) were assessed with FFR, CFR, and IMR. Correlation (r = 0.201; p < 0.001) and categorical agreement (kappa value = 0.178; p < 0.001) between FFR and CFR were modest. Low CFR was associated with higher POCO than high CFR (p = 0.034). There were no significant differences in clinical and angiographic characteristics among groups. Patients with high IMR with low CFR had the highest POCO (p = 0.002). Overt microvascular disease (p = 0.008), multivessel disease (p = 0.033), and diabetes mellitus (p = 0.033) were independent predictors of POCO. Inclusion of a physiological index significantly improved the discriminant function of a predictive model (relative integrated discrimination improvement 0.467 [p = 0.037]; category-free net reclassification index 0.648 [p = 0.007]).

Conclusions: CFR and IMR improved the risk stratification of patients with high FFR. Low CFR with high IMR was associated with poor prognosis. (Clinical, Physiological and Prognostic Implication of Microvascular Status; NCT02186093).

Keywords: coronary artery disease; coronary flow reserve; fractional flow reserve; index of microcirculatory resistance; microvascular function.

Publication types

Clinical Trial
Multicenter Study
Research Support, Non-U.S. Gov't

MeSH terms

Coronary Angiography
Coronary Circulation / physiology*
Coronary Stenosis / diagnostic imaging
Coronary Stenosis / physiopathology*
Coronary Vessels / diagnostic imaging
Coronary Vessels / physiopathology*
Female
Follow-Up Studies
Fractional Flow Reserve, Myocardial / physiology*
Humans
Male
Microcirculation / physiology*
Middle Aged
Prognosis
Retrospective Studies
Severity of Illness Index
Vascular Resistance / physiology*

Associated data

ClinicalTrials.gov/NCT02186093