Anticoagulation in renal impairment: Indications, clinical profiles, and complications from a colombian high-complexity hospital

Anticoagulation in patients with renal impairment (RI) carries an increased risk of complications. This study aimed to assess clinical and therapeutic differences among anticoagulated patients across stages of renal dysfunction. An observational study was conducted in patients receiving anticoagulation with creatinine clearance <60 mL/min. Based on creatinine clearance, patients were classified as G3a, G3b, G4, or G5. Baseline characteristics, treatment regimens, and complications were evaluated. A total of 802 patients were included in the study (median age 79.5 years [IQR 70.1–86.5]; 53.2 % female): G3a (n = 418), G3b (n = 244), G4 (n = 100), and G5 (n = 40). Among atrial fibrillation (AF) patients (n = 314), direct oral anticoagulants (DOAC) were preferred, with apixaban the most frequently used therapy; reduced-dose regimens predominated in advanced RI (G4: 65.8 %, G5: 94.4 %). In venous thromboembolism (VTE) patients (n = 294), low-molecular-weight heparin (LMWH) was the predominant therapy (70.6 % in G5). For other indications (n = 181), LMWH and warfarin were the most frequently used. Hemorrhagic events occurred in 78 patients (10.1 %), including 36 patients with major bleeds (4.5 %), numerically higher rates in were found in G4–G5. Thromboembolic events were observed in 36 patients (4.9 %), mainly cerebral ischemia. The overall cohort showed a median HASBLED score of 3, consistent with a high bleeding risk. In RI patients, DOAC were preferred in the AF group, often at reduced doses in advanced stages, whereas LMWH was mostly used for VTE. This elderly, multimorbid population showed high bleeding and thrombotic event rates, underscoring the need for individualized anticoagulant strategies and close monitoring. • Renal impairment increases hemorrhagic and thrombotic risk in anticoagulated patients. • This is one of the first Latin American studies on anticoagulation in renal impairment. • Elderly patients with cancer and comorbidities showed high bleeding and thrombotic risk. • DOAC predominated in AF, while LMWH was preferred for VTE; reduced doses in severe RI. • Anticoagulant choice should reflect renal stage, comorbidities, and complication risks.