[Acute coronary syndrome: Is there a place for direct oral anticoagulants?] / Syndrome coronaire aigu : y a-t-il une place pour les anticoagulants oraux directs ?

Venous thromboembolism and atrial fibrillation are two important indications of direct oral anticoagulants. Acute coronary syndrome is another potential indication of prolonged antithrombotic therapy in addition to antiplatelet therapy. Phase 2 and 3 studies were conducted with different molecules at different doses in acute coronary syndrome in addition to dual antiplatelet therapy. Studies have not shown a reduction of ischemic events for dabigatran and apixaban, but an excess of bleeding complications was observed. A reduction of ischemic events and stent thrombosis was observed with low dose of rivaroxaban taken twice a day but with an increased risk of major bleeding complications. This data was used to obtain a European marketing authorization but the positioning of the molecule remains difficult. A new study is currently being conducted to test rivaroxaban in association with a P2Y12 inhibitor without aspirin. Direct oral anticoagulants can also be used after percutaneous coronary intervention in patients requiring long-term oral anticoagulants. Dedicated studies are currently being conducted to confirm the optimal doses and the ideal association of antithrombotic drugs.

Real-time atrial wall imaging during radiofrequency ablation in a porcine model.

BACKGROUND: Real-time monitoring of radiofrequency (RF) ablation remains challenging. OBJECTIVE: We used intravascular ultrasound (IVUS) to describe atrial wall changes during RF ablation and to assess the extent of RF-induced lesions. METHODS: In 9 piglets, RF and IVUS catheters were coupled and introduced into the right atrium. RF applications were performed along the intercaval line. Corresponding IVUS images were analyzed. Wall thickness was correlated with electrogram (EGM) changes (n = 9) and histology (n = 5). RESULTS: There were 66 RF applications performed in 57 sites. IVUS provided real-time imaging of the atrial wall during RF application in all but 2 sites. IVUS demonstrated significant (>20%) and immediate increase in atrial wall thickness in 71.4% of RF applications. It showed epicardial or intramyocardial effusion in 30% of cases, 2 steam pops, 1 intramural hematoma, and 1 thrombus. EGM amplitude decreased and thickness increased after RF application than at baseline (2.20 ± 1.11 to 0.99 ± 0.62 mV and 1.34 ± 0.53 to 1.93 ± 0.80 mm, respectively; P < .001 for each). However, EGM and thickness changes were poorly correlated (r = 0.43; P < .05). Histologically and echographically measured thicknesses were correlated (r = 0.71; P = .004), but echographic thickness change was not related to histological lesion transmurality. CONCLUSION: An IVUS probe coupled to an RF catheter can provide relevant real-time imaging of the atrial wall during ablation. Although thickness change does not appear as a good predictor of the transmural extent, direct visualization and monitoring of RF application may provide new information to guide and secure RF ablation.