Bedside-focused transthoracic echocardiography in acute atraumatic thoracic aortic syndrome: a systematic review and meta-analysis of diagnostic accuracy.

The objective of this review was to assess the diagnostic accuracy of bedside-focused transthoracic echocardiography (TTE) in acute atraumatic thoracic aortic syndrome in adults. We performed a systematic review and meta-analysis of publications that described the use of bedside-focused TTE on adults presenting to emergency care settings with suspected atraumatic thoracic aortic syndrome. Studies were identified using keyword and MeSH on relevant databases as well as grey literature, followed by abstract screening and study selection by two independent reviewers. Sixteen studies over six decades were included in the meta-analysis ( n  = 4569 patients). The prevalence of type A thoracic aortic dissection was 11% (range 1.4-45.7%) and type B dissection was 7% (range 1.8-30.55%). Pooled sensitivity and specificity for type A dissection (through direct TTE visualisation of an intimal flap) were 89% [95% confidence interval (CI), 82-94%] and 92% (95% CI, 88-95%), respectively. For type B dissection, pooled sensitivity was 65% (95% CI, 45-80%) and specificity was 100% (95% CI, 0.69-100%). Regarding indirect TTE signs, pooled sensitivities and specificities were 64% (5.2-98.2%) and 94% (92-96.1%), respectively for aortic valve regurgitation, 92% (54-99.2%) and 87% (62-97%) for thoracic aortic aneurysm and 39% (33.8-45%) and 94% (92-95%) for pericardial effusion. In this systematic review and meta-analysis, bedside-focused TTE has high specificity for type A and B dissection, a moderate to high sensitivity for type A but poor for type B, and unclear diagnostic accuracy for intramural haematoma and penetrating aortic ulcer.