High Risk Clinical Features for Acute Aortic Dissection: A Case–Control Study

Background Acute aortic dissection ( AAD ) is a rare condition with a high mortality that is often missed. The objective of our study was to assess the diagnostic accuracy of clinical and laboratory findings for AAD , in confirmed cases of AAD and in a low‐risk control group. Methods This was a historical matched case–control study: participants were adults > 18 years old presenting to two tertiary care emergency departments ( ED s) or one regional cardiac referral center. Cases were patients with new ED or in‐hospital diagnosis of nontraumatic AAD confirmed by computed tomography or echocardiography. Controls were patients with a triage diagnosis of truncal pain (<14 days) and an absence of a clear diagnosis on basic investigation. Cases and controls were matched in a 1:4 ratio by sex and age. A sample size of 165 cases and 660 controls was calculated based on 80% power and confidence interval of 95% to detect an odds ratio of greater than 2. Results Data were collected from 2002 to 2014 yielding 194 cases of AAD and 776 controls (mean ±  SD age = 65 ± 14.1 years; 66.7% male). Absence of abrupt‐onset pain (sensitivity = 95.9%, negative likelihood ratio = 0.07 [0.03–0.14]) can help rule out AAD . Presence of tearing/ripping pain (specificity = 99.7%, positive likelihood ratio [ LR +] = 42.1 [9.9–177.5]), aortic aneurysm (specificity = 97.8%, LR + = 6.35 [3.54–11.42]), hypotension (specificity = 98.7%, LR + = 17.2 [8.8–33.6]), pulse deficit (specificity = 99.3, LR + = 31.1 [11.2–86.6]), neurologic deficits (specificity = 96.9%, LR + = 5.26 [2.9–9.3]), and a new murmur (specificity = 97.8%, LR + = 9.4 [5.5–16.2]) can help rule in the diagnosis of AAD . Conclusions Patients with one or more high‐risk feature should be considered high risk, whereas patients with no high‐risk and multiple low‐risk features are at low risk for AAD .