Oral Anticoagulation in the Elderly: New Oral Anticoagulants-Innovative Solution for an Old Problem?

Direct oral anticoagulants emerge as the most innovative and promising drug toward preventing and treating cardiovascular disease, raising great interest among the scientific community. Numerous studies and meta-analysis generated much data clarifying clinicians' doubts; however, uncertainties remain regarding their use in particular groups such as patients with prosthetic valves, in valvular atrial fibrillation (defined as atrial fibrillation related to mitral rheumatic heart disease or prosthetic heart valves), among the elderly, in paraneoplastic thromboembolism, in pulmonary embolism with hemodynamic compromise, and scarcity of specific antidotes. This review article intends to condense the vast scientific production addressing new oral anticoagulants by focusing on their advantages and disadvantages when used on the elderly.

Low incidence of post-thrombotic syndrome in patients treated with new oral anticoagulants and percutaneous endovenous intervention for lower extremity deep venous thrombosis

Post-thrombotic syndrome (PTS) is a common complication of deep venous thrombosis (DVT) of the iliofemoral venous system leading to significant morbidity and high health care costs. It has been recently shown that percutaneous endovenous intervention (PEVI) can effectively reduce the incidence of PTS. The role of new oral anticoagulants (NOACs) in combination with PEVI in the reduction of PTS has not been previously studied. This report sought to evaluate the role of PEVI plus NOACs in the reduction of PTS in acute symptomatic femoropopliteal and iliac DVT. We studied 127 patients with acute lower extremity DVT who had undergone PEVI plus administration of NOACs. All had received a minimum of 3 months of anticoagulation with a NOAC following PEVI. The mean follow-up was 22±5 months. The patients were evaluated for development of PTS, bleeding, recurrent venous thromboembolism (VTE), duration of hospitalization and mortality. There was no in-hospital bleeding. The mean duration of hospitalization was 46±9 hours. DVT occurred in two patients who had been later switched to warfarin. There were four non-VTE-related deaths. PTS developed in five patients (3%), two of whom were those who had been switched to warfarin. Their mean Villalta score was 6.2±0.9. We conclude that the combination of PEVI plus NOAC and low dose aspirin is associated with a very low rate of PTS with the severity being only mild. This approach leads to very low rates of bleeding and recurrent VTE and promotes early discharge.

A novel stearic acid-modified hirudin peptidomimetic with improved pharmacokinetic properties and anticoagulant activity

A novel hirudin isoform 3 mimetic peptide, named peptide S2, has been prepared by introduction of a stearic acid modification. Peptide S2 exhibited superior inhibitory activity to hirulog-1 (Bivariludin) and showed significantly higher anticoagulant potency in vivo. Peptide S2 elevated the thrombin time, prothrombin time and activated partial thromboplastin time of rat and human plasma more efficiently than hirulog-1 and the unmodified form of peptide S2 (peptide 1). Furthermore, peptide S2 inhibited arterial thrombosis and inferior vena cava in rat model 8 h after administration, and was 10-fold more potent than hirulog-1 300 min after administration of 0.1 μmol/kg peptide. The enhanced antithrombotic activity could be attributed to its long half-life (T_1/2 = 212.2 ± 58.4 min), which was 13.1 and 14.7-fold longer than those of hirulog-1 (T_1/2 = 15.1 ± 1.3 min) and peptide 1 (T_1/2 = 13.5 ± 2.6 min), respectively. Further enzymatic degradation and binding assay with human serum albumin (HSA) demonstrated that the longer duration time should be originated from the slowing of trypsin or thrombin–mediated degradation, as well as its binding to HSA. The improved pharmacokinetic properties observed for peptide S2 has made it a promising therapeutic agent for the treatment of thrombi-related diseases.