International Heterogeneity in Diagnostic Frequency and Clinical Outcomes of Ascending Aortic Intramural Hematoma

Background Differing diagnostic frequencies and management strategies for intramural hematoma (IMH) have been described in North American (NA)/European and Japanese/Korean studies. Methods All publications including type-A aortic IMH were reviewed for details on patient demographics, treatment strategy, and clinical outcomes. Publications were stratified by the geographic region (NA/Europe or Japan/Korea). Results IMH, as a percentage of aortic dissection, occurs more frequently in Japan/Korea versus NA/Europe (31.7% vs 10.9%, P < .0001). The proportion of patients treated with early medical therapy is greater in Japanese/Korean studies (77.9% vs 48.8% in NA/Europe, P < .0001). However, the overall mortality is significantly lower in Japan/Korea compared with NA/Europe (9.4% vs 20.6%, odds ratio = 2.80, P = .003) in part because of the lower mortality with early medical therapy (7.8% vs 33.3%, P < .0001). Conclusion There is significant international heterogeneity in the diagnosis and clinical outcomes of ascending IMH. IMH is diagnosed more frequently and has better overall outcomes in Japan/Korea.