Outcomes of Asian and Caucasian patients with type A aortic intramural haematoma: a multicentre registry analysis

Background Outcomes of aortic intramural haematoma (IMH) have shown disparities between Asian and Caucasian patients. We evaluated the heterogeneity of treatment effects in Asian and Caucasian patients with type A IMH. Methods This multicentre registry included individual patient data from 485 patients with type A IMH, collected from eight institutions (five Asian and three Western). Overall mortality was the primary outcome. Results Compared with their Asian counterparts, Caucasian patients (n=147) were older (69.3 vs 66.8 years) and had a higher prevalence of bicuspid aortic valve (4.1% vs 0.6%), visceral ischaemia (6.1% vs 1.5%), limb ischaemia (3.4% vs 0.3%) and shock (21.1% vs 6.8%), thicker haematoma (12.5±4.8 vs 10.5±5.2 mm) and larger ascending aortas (51.5±7.8 vs 47.7±7.2 mm). Urgent surgery was performed in 129 patients (26.6%), while 356 patients (73.4%) received medical treatment. Initial medical treatment was more common in Asian patients (85.5% vs 45.6%). During follow-up (median, 6.9 years), 121 deaths occurred. After adjustment for potential confounding factors, there was no significant difference regarding long-term mortality between Asian and Caucasian (HR, 1.38; 95% CI 0.73 to 2.60; p=0.32). Age (HR 1.42; 95% CI 1.17 to 1.72; p<0.001), ascending aorta diameter (HR 1.05; 95% CI 1.02 to 1.09; p<0.001) and medical treatment due to prohibitive surgical risk (HR 3.00; 95% CI 1.45 to 6.22; p<0.003) were independent predictors for long-term mortality. Conclusions In patients with type A IMH, race was not associated with long-term mortality. The initial clinical presentation and imaging characteristics were the primary determinants of clinical outcomes.