Improved cardiac risk stratification in individuals with high risk plaque features using the perivascular fat attenuation index on CCTA by Kotanidis, CP, Oikonomou, EK, Marwan, M, Kluener, L, Thomas, KE, Alashi, A, Antonopoulos, AS, Shirodaria, C, Neubauer, S, Channon, KM, Achenbach, S, Desai, MY, Antoniades, C