RESUMO
BACKGROUND: Oral anticoagulation therapy (OAT), which aims to prevent thromboembolism in patients with atrial fibrillation (AF), is underused in subjects who are over the age of 80 yr because of the associated bleeding risk. The aim of this study was to evaluate the efficacy and safety of OAT with low (2.0) vs. standard (2.5) PT/international normalised ratio (INR) targets in patients over the age of 80. MATERIALS AND METHODS: Of 233 patients aged 80 yr or older with AF on OAT, 58 had unstable PT/INR values and achieved reduced targets. These patients were enrolled as a group (A) in a case-control study and were treated with a low (2.0) PT/INR target. They were compared with a second group (B) of 58 additional patients who were matched for age and CHADS scores and treated with a standard (2.5) PT/INR target. Group A OAT parameters were also compared before and after the PT/INR reduction. The time in the therapeutic range (TTR%), PT/INR values >5, haemorrhages and strokes were prospectively evaluated in the two groups after 2 yr of follow-up. RESULTS: Of the 116 enrolled patients, 55 group A and 57 group B patients were evaluated. The TTR was 72.59% in group A and 64.43% in group B (P < 0.01). The percent of PT/INR values >5 was 0.68% for group A and 1.42% for group B (P < 0.05). Haemorrhages and thromboses occurred only in group B patients. The before and after analysis in group A showed that a low INR target produced an increase in the TTR (53.05% vs. 72.59%; P < 0.0001) and a reduction in the PT/INR values > 5 (1.72% vs. 0.68%; P < 0.001). CONCLUSIONS: A low PT/INR target seems effective and safe in Italian patients with AF over the age of 80. Further trials are needed to confirm the hypothesis generated by this study.