原著
負荷心筋パーフュージョンMRIにおける脾臓信号強度比を用いたアデノシン系薬物の負荷適正性確認および薬剤差の検討
2020 年 40 巻 1 号 p. 7-13
詳細
2020 年 40 巻 1 号 p. 7-13
Background : During stress cardiac MRI (CMR), if there is sufficient adenosine, a splenic switch-off phenomenon (SSO) occurs. In Japan, adenosine triphosphate (ATP) is more commonly used as a stressor drug than adenosine.
Aims : We aimed to examine whether the effect of these drugs was adequate and whether there is a difference between adenosine and ATP with respect to changes in splenic blood flow and signals of stress and rest (stress/rest splenic signal intensity ratio ; SIR).
Methods : We visually analyzed stress perfusion CMR scans in a total of 71 patients. In total 33 patients were administered adenosine (0.12 mg/kg/min), and 38 patients with ATP (0.16 mg/kg/min) underwent stress/rest perfusion CMR examination after intravenous injection of 0.1 ml/kg of 38% meglumine gadoterate at 4.0 ml/sec. After comparing coronary angiogram (CAG) findings performed within 2 months of CMR and stress CMR images, we divided the patients into 3 groups ; positive CAG and CMR (true positive), both negative (true negative), and CAG positive CMR negative (false negative). SIR was then compared across all groups.
Results : No SSO was identified in 25% of patients (adenosine 21%, ATP 29%). The optimal threshold for SIR as an indicator of SSO was 0.87 AUC 0.957 for adenosine (0.888-1.000 95%CI, p=0.003) and 0.96 AUC 0.806 for ATP (0.659-0.954 95%CI, p=0.012). In patients administered adenosine, the SIR for the false negative group was significantly higher than in the true positive group and the true negative group (0.50±0.20, vs 0.58±0.36 vs 1.24±0.35* : p=0.001). In patients administered ATP, there was a trend towards an increase in SIR in the false negative group compared to the true positive group, but there was no statistically significant difference among the three groups (0.79±0.20 vs 0.86±0.32 vs 1.06±0.24 : p=0.074).
Conclusion : In stress CMR, SIR is a useful indicator stressor effectiveness. In addition, SIR was found to be different between patients administered adenosine or ATP, which suggests a difference in the coronary vasodilator effect. Assessment of CMR after ATP requires more caution than with adenosine.
