ObjectiveThe study objective was to analyze the effects of chronic oral anticoagulation on long-term outcomes after repair of type A acute aortic dissection and its influence on false lumen fate. MethodsWe studied 188 patients (median age, 62 years; 74% were male) who underwent repair of type A aortic dissection; patients receiving postoperative chronic oral anticoagulation (n = 59) were compared with those receiving antiplatelet therapy alone (n = 129). ResultsMedian age was similar: 60 years (18-79 years; OAC group) versus 64 years (22-86; no-OAC group) (P = .11); patients taking anticoagulants were more frequently male (88% vs 67%, P = .003). After a median follow-up of 8.4 years (2 months to 30 years), 58 patients died, 18 of aortic-related causes, and 37 patients underwent aortic reintervention. After multivariable adjustment, anticoagulation showed no significant effect on long-term survival (hazard ratio, 0.85; 95% confidence interval, 0.41-1.76; P = .66) or risk of reintervention (hazard ratio, 0.55; 95% confidence interval, 0.27-1.15; P = .11). Analysis of 127 postoperative computed tomography scans showed a patent false lumen in 53% of anticoagulated patients versus 38% of nonanticoagulated patients (P = .09): partially thrombosed in 8% versus 28% (P = .01) and thrombosed in 39% versus 34% (P = .63), respectively. In patients with a control computed tomography, there were 6 late aortic-related deaths, 1 among anticoagulated patients and 5 in those who were not. ConclusionsChronic anticoagulation after repair of type A acute aortic dissection favors persistent late false lumen patency, which is not a risk factor for late mortality or reoperation. Chronic anticoagulation can be administered safely to patients with repaired type A acute aortic dissection regardless of its specific indication.