[Morbidity and mortality in patients treated with oral anticoagulants]

Abstract

Introduction and objectives: The number of patients receiving oral anticoagulant therapy has increased markedly in recent years, with the consequence that monitoring must be decentralized. The aim of this study was to provide reference values for the quality of care in patients receiving oral anticoagulants at large specialized Spanish centers for use in future comparative analyses.

Methods: The records of 20,347 outpatients who were receiving oral anticoagulants between January and December 2003 at four large Spanish centers were assessed. Databases at the four hospitals were searched for severe adverse events.

Results: In total, 211,987 regular check-ups were carried out, 72.7% of which gave international normalized ratios (INRs) within the range 2-4. Overall, 2369 hemorrhagic events were observed, 190 (8%) of which were severe, with 20 deaths (0.1 per 100 patient-years). In addition, there were 299 thromboembolic events, with 11 deaths (0.05 per 100 patient-years). The frequency of these events was greater in patients with a cardiac prosthesis, who required more intense anticoagulation. The incidence of death with different diagnoses was also greater in anticoagulated patients with a cardiac prosthesis, and the highest probability of death (1 in 3) was associated with episodes of cerebral hemorrhage. The incidence of hemorrhage increased as the INR increased. In contrast, thrombotic events occurred principally when the INR was below 2, and were not observed with INRs over 6.

Conclusions: The incidence of adverse events in patients receiving oral anticoagulant therapy at large Spanish centers was similar to that observed in other European countries.