Risk factors of non-sustained ventricular tachycardia by technetium-perfusion imaging in patients with coronary artery lesions caused by Kawasaki disease.

BACKGROUND: Sudden death can occur in some patients with non-sustained ventricular tachycardia (NSVT) after myocardial infarction (MI) in those with coronary artery lesions (CAL) caused by Kawasaki disease (KD). The aim of this study was to determine the risk factors for NSVT in the late period after KD by technetium-99m-tetrofosmin myocardial perfusion imaging (MPI).

METHODS: We retrospectively analyzed the relation between the appearance of NSVT and the findings in MPI single-photon-emission computed tomography (SPECT) in 75 patients (55 males and 20 females) who had had CAL caused by KD. All the patients had undergone MPI and 24-h Holter electrocardiogram at the same time between 2003 and 2012. The age at MPI ranged from 2 to 44 years (median 19 years), and the time from the onset of KD to MPI ranged from 1 to 44 years (median 18 years). We evaluated extent score (ES), summed rest score (SRS), summed stress score (SSS), summed difference score (SDS), and left ventricular ejection fraction (LVEF) by quantitative gated SPECT software. We analyzed which factors related to NSVT using multivariate logistic regression. Further, we calculated the cut-off point for NSVT using receiver operating characteristic curve.

RESULTS: The affecting factors were ES (OR, 0.63, 95%CI, 0.35-0.92, p=0.013) and the interval from the onset of KD to MPI (OR, 0.82, 95%CI, 0.69-0.96, p=0.004). The cut-off points for ES and the interval from the onset of KD were 11% (AUC, 0.931, p<0.001) and 18 years (AUC, 0.732, p=0.007), respectively.

CONCLUSIONS: ES is the strongest parameter for predicting NSVT in the late period. In patients with post-KD, adolescence and young adults with ES ≥11% are at risk of fatal ventricular arrhythmia.