Operated valvular heart disease patients with AF had significantly lower mean TTR and PINRR (TTR: 55.7% (14.2) vs. 60.1% (14.6); p = 0.002, respectively, PINRR: 47.4% (13.5) vs. 51.6% (13.7); p = 0.002, respectively), and a lower proportion of TTR ≥ 70%, despite a similar number of INR tests compared to those without AF. Here, TTR is linked to atrial fibrillation.