Resumption of anticoagulant therapy after major bleeding and recurrence of hemorrhagic complications in patients with atrial fibrillation with a high risk of stroke and thromboembolism (based on the results of 20 years of observation)

Aim. To analyze the frequency of resumption of anticoagulant therapy (ACT) after major and clinically significant bleeding among AF patients who received oral anticoagulants and were observed in the Department of clinical problems of atherothrombosis from 1999 to 2019 within the retro-prospective register «Regata-2», and to search for clinical factors associated with recurrence of hemorrhagic complications among patients who resumed anticoagulant therapy after a bleeding episode.

Materials and methods. In cohort study of patients with high-risk AF with absolute indications for ACT we enrolled 290 AF patients (130 women and 160 men) aged 32 to 85 years (the average age was 65.18±8.89 years). During the follow-up period, 92 patients developed hemorrhagic complications, and 73 of them resumed ACT. 35 of the 73 patients who resumed ACT developed a relapse of major/clinically significant bleeding.

Results. The frequency of resuming ACT after the first hemorrhagic complication increased over time from 75% in the period from 1999–2003 to 90% in the period 2015–2019. We were not able to establish an exact relationship between the presence of concomitant pathology and the decision to resume the ACT after bleeding. The only reliable reason for refusing to resume the ACT was the patient’s categorical reluctance. Among patients who had recurrent hemorrhagic complications, the total score on the Charleson comorbidity scale was significantly higher (4.23±2.01 vs 3.52±1.43; p=0.0425). Patients with recurrent bleeding were significantly more likely to suffer from CKD with a decrease in GFR less than 60 ml/min/1.73 sq. m, and also had a history of erosive and ulcerative lesions of the gastrointestinal tract. There was also a significant Association of recurrent bleeding with the use of proton pump inhibitors. Subgroups of patients who switched from warfarin to taking direct oral anticoagulants after the first bleeding and subsequent recurrent bleeding did not differ in basic clinical characteristics from patients without bleeding after changing the anticoagulant. According to multiple regression analysis, NSAIDs showed a tendency to develop a relapse of B/C bleeding on the background of direct oral anticoagulants in patients who underwent GO on the background of warfarin therapy (b=0.4524, p=0.0530).

Conclusion. During the 20-year follow-up, the frequency of all major and clinically significant bleeding was 2.6/100 patients-years, the frequency of first bleeding was 5.86/100 patients-years, while the frequency of repeated hemorrhagic complications was 7.06/100 patients-years. Patients with a high thromboembolic risk should receive anticoagulants, provided that the modifiable risk factors for bleeding are carefully corrected.