Prognostic value of gray matter to white matter ratio in hypoxic and non-hypoxic cardiac arrest with non-cardiac etiology.
OBJECTIVE
This study evaluated the prognostic performance of the gray to white matter ratio (GWR) on brain computed tomography (CT) in out-of-hospital cardiac arrest (OHCA) survivors with a noncardiac etiology and compared the prognostic performance of GWR between hypoxic and nonhypoxic etiologies.


METHODS
Using a multicenter retrospective registry of adult OHCA patients treated with targeted temperature management, we identified those with a noncardiac etiology who underwent brain CT within 24 hours after restoration of spontaneous circulation. Attenuation of the gray matter and white matter (at the level of the basal ganglia, centrum semiovale, and high convexity) were measured and GWRs were calculated. The primary outcome was neurologic outcome.


RESULTS
Of 164 patients, 145 (88.4%) were discharged with a poor neurologic outcome. Lower GWR was associated with a poor neurologic outcome. The sensitivities of this marker were markedly low (9.7%-43.5%) at cutoff values, with 100% sensitivity. The cutoff values of the GWR for hypoxic arrest showed higher sensitivities than those for nonhypoxic arrest. The area under the curve (AUC) values of the GWR for the caudate nucleus/posterior limb of the internal capsule, putamen/corpus callosum, and basal ganglia were significant in the hypoxic group, whereas the AUC of the putamen/corpus callosum was the only significant GWR in the nonhypoxic group.


CONCLUSIONS
A low GWR is associated with poor neurologic outcome in noncardiac etiology OHCA patients treated with targeted temperature management. Gray to white matter ratio can help to predict the neurologic outcome in a cardiac arrest with hypoxic etiology rather than a nonhypoxic etiology.
Department of Emergency Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea.
Byung Kook
BK
Lee
Department of Emergency Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
Won Young
WY
Kim
Department of Emergency Medicine, Seoul National University Boramae Medical Center, Seoul, Republic of Korea.
Jonghwan
J
Shin
Department of Emergency Medicine, School of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
Joo Suk
JS
Oh
Department of Emergency Medicine, School of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
Jung Hee
JH
Wee
Department of Emergency Medicine, Wonju College of Medicine, Yonsei University, Wonju, Republic of Korea.
Kyoung Chul
KC
Cha
Department of Emergency Medicine, College of Medicine, Yonsei University, Seoul, Republic of Korea.
Yooseok
Y
Park
Department of Emergency Medicine, College of Medicine, Soonchunhyang University, Cheonan, Chungcheongnam-do, Republic of Korea.
Jae Hyung
JH
Choi
Department of Emergency Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea. Electronic address: neoneti@hanmail.net.
Kyung Woon
KW
Jeung
D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D066128:Gray Matter / Q000000981:diagnostic imaging*; D006801:Humans; D000860:Hypoxia / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D059906:Neuroimaging / Q000379:methods*; D058687:Out-of-Hospital Cardiac Arrest / Q000097:blood / Q000139:chemically induced* / Q000150:complications; D011379:Prognosis; D012042:Registries; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D066127:White Matter / Q000000981:diagnostic imaging*