Coronary endothelial dysfunction is associated with inflammation and vasa vasorum proliferation in patients with early atherosclerosis.

Abstract

OBJECTIVE: Endothelial dysfunction is an early manifestation of atherosclerosis.

Inflammation and vasa vasorum play a pivotal role in the pathophysiology of

plaque initiation, development, and complications. Optical coherence tomography

allows high-resolution imaging of tissue microstructure. Therefore, the aim of

this study was to test the hypothesis that segments with endothelial dysfunction

show macrophages and vasa vasorum in patients with early coronary artery disease.

APPROACH AND RESULTS: Optical coherence tomography images were obtained from 40

patients with mild coronary atherosclerosis who underwent coronary endothelial

function assessment. Optical coherence tomography findings, including macrophages

and microchannels, were evaluated in 76 coronary segments corresponding to those

in endothelial response to acetylcholine. Coronary artery diameter change in

response to acetylcholine was more severe in segments showing macrophages

(-17.7+/-14.7% versus -6.3+/-13.9%; P<0.01) and microchannels (-15.9+/-15.9%

versus -6.4+/-13.5%; P<0.01) than those without. There were increasing trends of

the prevalence of macrophages and microchannels with endothelial dysfunction as

stratified by quartiles of coronary artery diameter change (P<0.01 and P=0.02 for

trend, respectively). In particular, segments with both macrophages and

microchannels (n=12) tended to have worse endothelial function than those with

macrophages alone (n=15) and microchannels alone (n=15; -22.1+/-14.6% versus

-10.9+/-15.6% and -10.9+/-15.6%; P=0.07 and P=0.06, respectively). CONCLUSIONS:

Epicardial endothelial dysfunction was associated with optical coherence

tomography -identified macrophages and microchannels in mild coronary

atherosclerosis. The current study further supports the role of inflammation and

vasa vasorum proliferation in the early stage of coronary atherosclerosis.