QTc Heterogeneity in Rest Magnetocardiography is Sensitive to Detect Coronary Artery Disease: In Comparison with Stress Myocardial Perfusion Imaging.
BACKGROUND
Stress nuclear myocardial perfusion imaging (MPI) is an established method for diagnosis and prognosis of coronary artery disease (CAD). However, radiation exposure limits its clinical application. Magnetocardiography (MCG) has been proposed as a non-contact, rapid and non-radiation technique with high reproducibility. The aim of the study was to evaluate the diagnostic efficacy of rest MCG in CAD comparing to stress MPI.


METHODS
We prospectively enrolled 55 patients with suspected CAD (64 ± 10 years) who were scheduled for coronary angiography (CA). MCG, stress (201)Tl MPI and CA were performed within 3 months. The spatial distribution maps of QTc interval (21 × 21 in resolution) were derived from a 64-channel MCG system (KRISS, Korea). T-wave propagation mapping, repolarization heterogeneity index with QTc dispersion and smoothness index of QTc (SI-QTc) were analyzed, and the diagnostic criteria for CAD were developed based on the receiver operating characteristic (ROC) curve analysis.


RESULTS
Patients with significant CAD (≥ 70% luminal stenosis, n = 36) had higher QTc dispersion and SI-QTc than controls (both p < 0.05). The diagnostic sensitivity and specificity were 0.8330, 0.6842 for QTc dispersion ≥ 79 ms; 0.7778, 0.6842 for SI-QTc ≥ 9.1 ms; and 0.8611, 0.6842 for combination. There was no difference of area under ROC curve by using criteria of QTc dispersion ≥ 79 ms, SI-QTc ≥ 9.1 ms or combination (0.7588, 0.7310, 0.7727, p = NS), and non-inferior to stress MPI (p = NS).


CONCLUSIONS
The QTc heterogeneity parameters of rest MCG yield a good sensitivity and acceptable specificity for detection of CAD, and may provide an alternative to stress MPI without stress and radiation.


BACKGROUND
Coronary artery disease (CAD); Magnetocardiography (MCG); Myocardial perfusion imaging (MPI); Repolarization.
Department of Nuclear Medicine; ; Cardiology Division of Cardiovascular Medical Center, Far Eastern Memorial Hospital, New Taipei City; ; Departments of Internal Medicine; ; Departments of Nuclear Medicine, National Taiwan University Hospital; ; National Yang-Ming University School of Medicine, Taipei;
Yen-Wen
YW
Wu
Departments of Internal Medicine;
Lung-Chun
LC
Lin
E-Da Hospital, Kaohsiung;
Wei-Kung
WK
Tseng
Departments of Internal Medicine;
Yen-Bin
YB
Liu
Departments of Internal Medicine;
Hsian-Li
HL
Kao
Departments of Internal Medicine;
Mao-Shin
MS
Lin
Departments of Internal Medicine;
Huei-Chun
HC
Huang
Department of Nuclear Medicine;
Shan-Ying
SY
Wang
Institute of Electro-optical Science and Technology, National Taiwan Normal University;
Herng-Er
HE
Horng
Department of Physics;
Hong-Chang
HC
Yang
Departments of Internal Medicine; ; Department of Primary Care Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan.
Chau-Chung
CC
Wu