Symptomatic primary aortic mural thrombus: Findings after 6 months of oral anticoagulation

Primary aortic mural thrombus (PAMT) is defined by an aortic thrombus in the absence of underlying aortic disease. Management relies on anticoagulation, with or without surgery, but optimal treatment duration remains uncertain. We evaluated clinical and radiological outcomes of symptomatic PAMT after 6 months of oral anticoagulation.

We performed a retrospective cohort study (2011-2022) reviewing all consecutive cases of aortic thrombosis. Inclusion criteria were symptomatic PAMT without prior anticoagulation. Patients treated surgically, without imaging follow-up, or lost to follow-up were excluded. Clinical, biological, and imaging data were collected. Radiological evolution was independently assessed by four physicians.

Of 101 screened cases, 29 were included. Median age was 57 years (IQR 49-67), 66% were men, and cardiovascular risk factors were frequent (current and former smokers 86%, hypertension 55%, dyslipidemia 41%). Thrombi were mainly infrarenal (55%), followed by thoracic descending (21%), suprarenal abdominal (14%), and aortic arch (10%). Presentations included acute limb ischemia (76%) and organ infarction (21%). After a median of 180 days (IQR 167-208) of anticoagulation, thrombus evolution showed complete resolution in 17%, partial improvement in 48%, stability in 31%, and progression in 3%. Two embolic recurrences (7%) occurred, including one requiring thrombectomy. At extended follow-up (median 268 days), one major and three clinically relevant nonmajor bleeding events occurred; three deaths were unrelated to PAMT.

Six months of anticoagulation in symptomatic PAMT achieves low recurrence and thrombus regression in most patients with acceptable safety. Prolonging anticoagulation beyond 6 months did not improve outcomes.