Impact of pulmonary artery intramural hematoma on patients with acute type A aortic dissection.

Objectives: To investigate the short-term/long-term impact of pulmonary artery intramural hematoma (PA-IMH) in patients with acute Stanford type A aortic dissection (ATAAD) following surgical repair.

Materials And Methods: Consecutive patients with ATAAD who received surgical repair at Beijing and Yunnan Fuwai Hospital in 2010-2021 were retrospectively reviewed. Patients with hemorrhage extending along the PA were identified as the PA-IMH group. Multivariable logistics regression was used to obtain the odds ratio (OR), and the Kaplan-Meier method was used to estimate the survival rate.

Results: Of the 2046 ATAAD patients, 324 (15.8%) patients were identified with PA-IMH, and 1722 (84.2%) were without PA-IMH. PA-IMH had a higher prevalence in patients with older age, female gender, aortic IMH, and type II aortic dissection. PA-IMH patients incurred excess early mortality compared with non-PA-IMH patients (9.3% vs. 5.6%, OR = 1.86, 95%CI 1.19-2.91, p = 0.006). The results were stable in the subgroup analysis, with an increased risk in older (> 70 years) or DeBakey type II ATAAD patients. Notably, an increase in the degree and extent of PA-IMH exacerbated the risk of early mortality. However, after landmark analysis at 30-day postsurgery, no significant difference was noted in the long-term outcomes between PA-IMH and non-PA-IMH groups (p = 0.440). The 5-year survival rates were 87.1% (95%CI: 83.3%, 91.1%) and 90.1% (95%CI: 88.5%, 91.7%), respectively.

Conclusions: The presence of PA-IMH in ATAAD patients is common and is independently associated with increased early mortality after surgical repair, especially in those with older age (> 70) or type II dissection. However, such detrimental effects do not persist in the long-term follow-up among patients who survived hospital discharge.

Clinical Relevance Statement: We confirmed that PA-IMH significantly increases early postoperative mortality in patients with acute type A aortic dissection, especially in older patients or DeBakey type II dissection. This should prompt further investigation of the incremental role of PA-IMH in this pathology.

Key Points: Acute type A aortic dissection mortality gets worse when pulmonary artery intramural hematoma is present. Pulmonary artery-intramural hematoma increased the risk of early mortality but not affect long-term prognosis. Further research should investigate the effects of pulmonary artery intramural thrombus on aortic dissection.