Table 3.

Volume (mL), normalized volumes (a.u.) and mean intensity (HU) of InFAT and its subcomponents, stratified by study groups

	Total (N = 80)	Paroxysmal AF (N = 30)	Persistent AF (N = 30)	Controls (N = 20)	P-valuea
Volumes (mL)
InFAT	0.405 (0.245, 0.720)	0.415 (0.252, 0.593)	0.460 (0.350, 1.045)	0.275 (0.198, 0.375)	0.008
Dense InFAT	0.130 (0.057, 0.230)	0.130 (0.090, 0.215)	0.195 (0.110, 0.397)	0.050 (0.028, 0.118)	0.001
Fat-myocardial admixture	0.265 (0.170, 0.450)	0.280 (0.150, 0.432)	0.335 (0.233, 0.505)	0.210 (0.165, 0.290)	0.059
Normalized volumes (a.u.)
InFAT (LA volume-normalized)	0.0040 (0.0024, 0.0066)	0.0038 (0.0022, 0.0060)	0.0052 (0.0031, 0.0096)	0.0035 (0.0019, 0.0056)	0.043
Dense InFAT (LA volume-normalized)	0.0012 (0.0006, 0.0022)	0.0012 (0.008, 0.0019)	0.0019 (0.0010, 0.0037)	0.0006 (0.0003, 0.0015)	0.003
Fat-myocardial admixture (LA volume-normalized)	0.0030 (0.0017, 0.0044)	0.0029 (0.0013, 0.0042)	0.0033 (0.0021,0.0054)	0.0025 (0.0017, 0.0041)	0.180
InFAT (segmented wall volume-normalized)	0.039 (0.024, 0.052)	0.040 (0.023, 0.049)	0.042 (0.030, 0.068)	0.034 (0.019, 0.042)	0.080
Dense InFAT (segmented wall volume-normalized)	0.011 (0.006, 0.017)	0.011 (0.007, 0.015)	0.015 (0.009, 0.029)	0.007 (0.003, 0.012)	0.004
Fat-myocardial admixture (segmented wall volume-normalized)	0.026 (0.017, 0.038)	0.026 (0.015, 0.034)	0.026 (0.020, 0.039)	0.023 (0.017, 0.033)	0.487
Mean intensity (HU)
InFAT	−39.455 (−46.009, −34.636)	−38.621 (−46.639, −34.892)	−43.125 (−48.665, −38.430)	−34.862 (−39.281, −27.927)	<0.001
Dense InFAT	−77.145 (−80.847, −73.278)	−76.285 (−82.155, −70.593)	−78.665 (−81.755, −75.998)	−73.665 (−79.130, −71.382)	0.034
Fat-myocardial admixture	−23.465 (−24.000, −22.400)	−23.190 (−23.695, −22.667)	−23.710 (−24.378, −23.175)	−22.955 (−23.758, −20.975)	0.014

^aReported P-value refers to Kruskall–Wallis test between the three sub-group of interest; P-values < 0.05 are reported in bold.

AF, atrial fibrillation; LA, left atrial.