The ATI score (Age-Thrombotic burden-Index of microcirculatory resistance) determined during primary percutaneous coronary intervention predicts final infarct size in patients with ST elevation myocardial infarction: a cardiac magnetic resonance validation study.
De Maria GL., Alkhalil M., Wolfrum M., Fahrni G., Borlotti A., Gaughran L., Dawkins S., Langrish J., Lucking A., Choudhury R., Porto I., Crea F., Dall'Armellina E., Channon K., Kharbanda R., Banning A.
AIMS: The age-thrombus score-index of microcirculatory resistance (ATI) score is a diagnostic tool able to predict suboptimal myocardial reperfusion before stenting, in patients with ST elevation myocardial infarction (STEMI). We aimed to validate the ATI score against cardiac magnetic resonance imaging (cMRI). METHODS AND RESULTS: The ATI score was calculated prospectively in 80 STEMI patients. cMRI was performed within 48 hours in all patients and in 50 patients at six months follow up to assess the extent of infarct size (IS%) and microvascular obstruction (MVO%). The ATI score was calculated using Age ( >50 = 1 point), pre-stenting index of microcirculatory resistance (IMR) (>40 and <100 = 1 point; ≥100 = 2 points) and angiographic thrombus score (4=1 point; 5=3 points). ATI score was closely related to final IS% (ATI0-1: 16.5% [8.7 - 22.9], ATI2-3: 28.5% [15.5 - 35.0], ATI4-5-6: 35.5% [22.2 - 44.4], p: 0.001) and with MVO% (ATI0-1: 0.0% [0.0-0.9], ATI2-3: 0.7% [0.0-2.5] and ATI4-5-6: 4.1% [1.2-10.7], p< 0.001). Furthermore, ATI score predicted final IS% at six months follow up (ATI0-1: 12.7% [4.1 - 18.0], ATI2-3-: 16.30% [8.0 - 24.7], ATI4-5-6: 29.5% [19.9 - 49.5], p: 0.02). CONCLUSIONS: The ATI score performed prior to stenting in patients with STEMI, can predict the likelihood of MVO% and IS% both acutely and at six months follow up cMRI.