Five Year Results of Endovascular Versus Medical Therapy in Acute Type B Aortic Intramural Haematoma: Meta-Analysis of Reconstructed Time to Event Data

OBJECTIVE:To evaluate outcomes in the follow up of thoracic endovascular aortic repair (TEVAR) vs. medical therapy in patients with acute type B aortic intramural haematoma (IMH). DATA SOURCES:The following sources were searched for articles meeting the inclusion criteria and published by July 2023: PubMed/MEDLINE, EMBASE, CENTRAL/CCTR (Cochrane Controlled Trials Register). REVIEW METHODS:This systematic review with pooled meta-analysis of time to event data followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines, and its protocol was registered on the public platform PROSPERO (CRD42023456222). The following were analysed: overall survival (all-cause mortality), aortic related mortality, and restricted mean survival time. Certainty of evidence was evaluated through the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) tool. RESULTS:Eight studies met the eligibility criteria, including a total of 1 015 patients (440 in the TEVAR group and 575 in the medical therapy group). All studies were observational, and the pooled cohort had a median follow up of 5.1 years. Compared with patients who received medical therapy alone, those who underwent TEVAR had a significantly lower risk of all-cause death (HR 0.44, 95% CI 0.30 - 0.65; p < .001; GRADE certainty: low), lower risk of aortic related death (HR 0.04, 95% CI 0.01 - 0.31; p = .002; GRADE certainty: low) and lifetime gain (restricted mean survival time was overall 201 days longer with TEVAR; p < .001). CONCLUSION:Thoracic endovascular aortic repair may be associated with lower risk of all-cause and aortic related death when compared with medical therapy in patients with acute type B IMH; however, the underlying data are not strong enough to draw robust clinical conclusions. Randomised controlled trials with large sample sizes and longer follow up are warranted to elucidate this question.