Conductive channels identified with contrast-enhanced MR imaging predict ventricular tachycardia in systolic heart failure.
OBJECTIVE
This study evaluated whether the conductive channel (CC) identified by late gadolinium enhanced-cardiac magnetic resonance (LGE-CMR) is associated with ventricular tachycardia (VT) in patients with systolic heart failure (HF).


BACKGROUND
One recent study demonstrated that the CC formed by heterogeneous tissue within the core scar could be detected by LGE-CMR and that the CC is responsible for clinical VT. We hypothesized that the CC could help identify HF patients at risk for VT.


METHODS
A total of 63 patients from a CMR database with left ventricular ejection fraction (LVEF) below 50% and with hyperenhancement on LGE-CMR were included. The cine and LGE images were analyzed to derive the LV function and scar characteristics, and to identify the CC. The outcomes, including VT, ventricular fibrillation (VF), and total mortality, were obtained by reviewing medical records.


RESULTS
After a median 1,379 (interquartile range: 271 to 1,896) days of follow-up, 8 patients had VT/VF attacks and 14 patients died. Among the CMR-measured parameters, only the probability of identifying the CC by LGE-CMR was higher in patients with VT/VF than those without VT/VF (75.0% vs. 16.4%, p < 0.001). The probability of identifying the CC was also higher in the total mortality group than the survival group (50.0% vs. 16.3%, p = 0.004). The other LGE-CMR variables were not significantly different between the 2 groups. A univariate Cox regression model showed that CC identification was positively associated with VT/VF attacks (hazard ratio [HR]: 27.032, 95% confidence interval [CI]: 3.291 to 222.054, p = 0.002) and excess total mortality (HR: 4.766, 95% CI: 1.643 to 13.824, p = 0.004). The LVEF was inversely associated with VT/VF attacks (HR: 0.119, 95% CI: 0.015 to 0.977, p = 0.048) and excess total mortality (HR: 0.491, 95% CI: 0.261 to 0.925, p = 0.028) during follow-up.


CONCLUSIONS
We demonstrated that CC identification using LGE-CMR can help identify HF patients at risk for VT/VF.
Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
Lian-Yu
LY
Lin
Mao-Yuan M
MY
Su
Jien-Jiun
JJ
Chen
Ling-Ping
LP
Lai
Juey-Jen
JJ
Hwang
Chuen-Den
CD
Tseng
Yih-Sharng
YS
Chen
Hsi-Yu
HY
Yu
Wen-Yih I
WY
Tseng
Jiunn-Lee
JL
Lin
D000328:Adult; D000368:Aged; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006329:Heart Conduction System / Q000473:pathology* / Q000503:physiopathology; D054143:Heart Failure, Systolic / Q000150:complications / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D053208:Kaplan-Meier Estimate; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D013318:Stroke Volume; D017180:Tachycardia, Ventricular / Q000209:etiology* / Q000401:mortality / Q000473:pathology / Q000503:physiopathology; D013997:Time Factors; D014693:Ventricular Fibrillation / Q000209:etiology / Q000401:mortality / Q000473:pathology / Q000503:physiopathology; D016277:Ventricular Function, Left
D003287:Contrast Media; D019786:Gadolinium DTPA
CC; CMR; EAVM; HF; LGE-CMR; LV; LVEF; MI; PSIR; SI; VF; VT; cardiac magnetic resonance; conductive channel; congestive heart failure; electroanatomical voltage mapping; heart failure; late gadolinium enhanced–cardiac magnetic resonance; left ventricle/ventricular; left ventricular ejection fraction; magnetic resonance image; myocardial infarction; phase-sensitive inversion recovery; signal intensity; ventricular fibrillation; ventricular tachycardia