Abstract Body (Do not enter title and authors here): Background: Patients with aortic intramural hematoma (IMH) often present with cardiac tamponade. However, factors associated with the precipitating pericardial effusion remain to be elucidated.
Hypothesis: Morphologic factors affect IMH-associated pericardial effusion.
Aims: To identify factors associated with pericardial effusion and compare outcomes of conservative therapy vs urgent surgery in acute type A IMH.
Methods: Included in the study were 195 patients hospitalized for IMH within 48 hours of onset. They were identified from among 803 consecutive patients with acute type A aortic syndrome treated at 2 aortic centers between 2009 and 2022, with 213 (27%) having IMH. Study 1: Per on-admission CT data, correlation between maximum pericardial effusion width and ascending aortic diameter or hematoma thickness was assessed. Factors associated with massive pericardial effusion (>12.6 mm, upper quartile) and cardiac tamponade (systolic blood pressure <80 mmHg with pericardial effusion, n=49) were assessed by multivariable analysis. Study 2: Outcomes were compared between patients who underwent conservative therapy (n=57) and those who underwent surgery (n=138). Conservative therapy was principally performed if certain conditions were met: ascending aortic diameter <50 mm, hematoma thickness <11 mm, absence of pericardial effusion.
Results: Study 1: Pericardial effusion width was found to correlate with ascending aortic diameter (r=0.268, p<0.001) but not with hematoma thickness (r=-0.053, p=0.46). Association was found between dissection extending to the abdominal aorta and massive pericardial effusion (p=0.010, OR=0.41) and between ascending aortic diameter and tamponade (p=0.048, OR=1.053). Study 2: Median age (73 vs. 73.5 years, p=0.74), sex, and comorbidities were similar between the conservative therapy group and the surgery group. Five (9%) conservative therapy group patients underwent surgery for expansion of the aorta or hematoma within 30 days of onset, with no hospital death resulting. Thirty-day mortality (10.5% vs. 5.8%, p=0.25) and 5-year survival (81.1% vs. 84.2%, p=0.33) did not differ. However, the 5-year aortic event (surgery, redissection, aortic or sudden death) rate was increased in the conservative therapy group (27.3% vs. 12.6%, p=0.003).
Conclusions: Extent of dissection and aortic diameter are associated with pericardial effusion and cardiac tamponade in type A IMH. Aortic events are of increased likelihood with conservative therapy.