Prognostic Impact of Coronary Flow Reserve in Patients With Reduced Left Ventricular Ejection Fraction
Authors: Joh Hyun Sung , Shin Doosup , Lee Joo Myung , Lee Seung Hun , Hong David , Choi Ki Hong , Hwang Doyeon , Boerhout Coen K. M. , de Waard Guus A. , Jung Ji‐Hyun , Mejia‐Renteria Hernan , Hoshino Masahiro , Echavarria‐Pinto Mauro , Meuwissen Martijn , Matsuo Hitoshi , Madera‐Cambero Maribel , Eftekhari Ashkan , Effat Mohamed A. , Murai Tadashi , Marques Koen , Doh Joon‐Hyung , Christiansen Evald H. , Banerjee Rupak , Kim Hyun Kuk , Nam Chang‐Wook , Niccoli Giampaolo , Nakayama Masafumi , Tanaka Nobuhiro , Shin Eun‐Seok , Chamuleau Steven A. J. , van Royen Niels , Knaapen Paul , Koo Bon Kwon , Kakuta Tsunekazu , Escaned Javier , Piek Jan J. , van de Hoef Tim P. , van de Hoef Tim P. , Lee Joo Myung , Choi Ki Hong , Hong David , Lee Seung Hun , Shin Doosup , Hoshino Masahiro , Murai Tadashi , Kakuta Tsunekazu , Koo Bon Kwon , Hwang Doyeon , Boerhout Coen K. M. , Piek Jan J. , de Waard Guus A. , Chamuleau Steven A. J. , Marques Koen , Knaapen Paul , Jung Ji‐Hyun , Mejia‐Renteria Hernan , Escaned Javier , Echavarria‐Pinto Mauro , Meuwissen Martijn , Matsuo Hitoshi , Madera‐Cambero Maribel , Eftekhari Ashkan , Christiansen Evald H. , AEffat Mohamed , Doh Joon‐Hyung , Banerjee Rupak , Kim Hyun Kuk , Nam Chang‐Wook , Niccoli Giampaolo , Nakayama Masafumi , Tanaka Nobuhiro , Shin Eun‐Seok , Royen Niels 
Published: July 2022

Background
Intracoronary physiologic indexes such as coronary flow reserve (CFR) and left ventricular ejection fraction (LVEF) have been regarded as prognostic indicators in patients with coronary artery disease. The current study evaluated the association between intracoronary physiologic indexes and LVEF and their differential prognostic implications in patients with coronary artery disease.

Methods and Results

A total of 1889 patients with 2492 vessels with available CFR and LVEF were selected from an international multicenter prospective registry. Baseline physiologic indexes were measured by thermodilution or Doppler methods and LVEF was recorded at the index procedure. The primary outcome was target vessel failure, which was a composite of cardiac death, target vessel myocardial infarction, or clinically driven target vessel revascularization over 5 years of follow‐up. Patients with reduced LVEF <50% (162 patients [8.6%], 202 vessels [8.1%]) showed a similar degree of epicardial coronary artery disease but lower CFR values than those with preserved LVEF (2.4±1.2 versus 2.7±1.2,
P
<0.001), mainly driven by the increased resting coronary flow. Conversely, hyperemic coronary flow, fractional flow reserve, and the degree of microvascular dysfunction were similar between the 2 groups. Reduced CFR (≤2.0) was seen in 613 patients (32.5%) with 771 vessels (30.9%). Reduced CFR was an independent predictor for target vessel failure (hazard ratio, 2.081 [95% CI, 1.385–3.126],
P
<0.001), regardless of LVEF.

Conclusions
CFR was lower in patients with reduced LVEF because of increased resting coronary flow. Patients with reduced CFR showed a significantly higher risk of target vessel failure than did those with preserved CFR, regardless of LVEF.

Registration

URL:
https://www.clinicaltrials.gov
; Unique identifier: NCT04485234.