F8 and coronary artery disorder: In their study, linear-regression analysis showed a significant negative correlation between FVIII levels and aPTT in CAD patients (R2 = 10%, P < 0.0001), with each 1% increase in FVIII level associated with a 0.013-s reduction in aPTT [95% confidence interval (CI), −0.019 to −0.007] (2).