Time in therapeutic range and major adverse outcomes in atrial fibrillation patients undergoing percutaneous coronary intervention : the Atrial Fibrillation Undergoing Coronary Artery Stenting (AFCAS) registry

Background: Combination of oral anticoagulation (OAC) and antiplatelets is used in atrial fibrillation (AF) patients undergoing percutaneous coronary intervention and stent (PCI-S) procedure but is associated with increased bleeding when triple antithrombotic therapy (TAT) is used. Our aim was to analyze the impact of time in therapeutic range (TTR) on outcomes, in patients prescribed with TAT. Methods: Ancillary analysis from the AFCAS registry in patients assigned to TAT. TTR was calculated with Rosendaal method. Outcomes were analyzed according to TTR tertiles (T1 [≤56.8%] vs. T2 [56.9-93.8%] vs. T3 [≥93.9%]). Major bleeding was the primary outcome. Results: Of 963 patients enrolled, 470(48.8%) were prescribed with TAT at discharge and qualified for this analysis. Median [IQR] TTR was 80.0% [45.3-100%]. After 359 [341-370] days, major bleeding rates were progressively lower with increasing TTR tertiles (T1 vs. T2 vs. T3: 10.3% vs. 4.7% vs. 2.3%, P=.006). Kaplan-Meier analysis demonstrated a progressively lower risk for major bleeding across tertiles (P=.006). Patients in the highest TTR tertile had a non-significant lower risk for major adverse coronary and cerebrovascular events (MACCE) (log-rank: 4.905, P=.086). Cox regression analysis showed that T2 and T3 were inversely associated with major bleeding (hazard ratio [HR]:0.39, P=.050 and HR: 0.21, P=.005). Continuous TTR was inversely associated with major bleeding (HR: 0.98, P<.001). For MACCE, adjusted Cox analysis found a non-significant lower risk for T3 (HR: 0.64, P=.128). Conclusions: In AF patients undergoing PCI-S prescribed TAT, good quality anticoagulation control (as reflected by TTR) was closely related to bleeding outcomes during follow-up. Despite some suggestive trends for an inverse relationship between TTR and MACCE, no definitive conclusions can be drawn, and further large studies are needed.