CME Information: Clinical Examination for Acute Aortic Dissection: A Systematic Review and Meta-analysis

Objectives: Acute aortic dissection is a life-threatening condition due to a tear in the aortic wall. It is difficult to diagnose and if missed carries a significant mortality. Methods: We conducted a librarian-assisted systematic review of PubMed, MEDLINE, Embase, and the Cochrane database from 1968 to July 2016. Titles and abstracts were reviewed and data were extracted by two independent reviewers (agreement measured by kappa). Studies were combined if low clinical and statistical heterogeneity (I-2<30%). Study quality was assessed using the QUADAS-2 tool. Bivariate random effects meta analyses using Revman 5 and SAS 9.3 were performed. Results: We identified 792 records: 60 were selected for full text review, nine studies with 2,400 participants were included (QUADAS-2 low risk of bias, = 0.89 [for full-text review]). Prevalence of aortic dissection ranged from 21.9% to 76.1% (mean +/- SD=39.1%+/- 17.1%). The clinical findings increasing probability of aortic dissection were 1) neurologic deficit (n=3, specificity=95%, positive likelihood ratio [LR+]=4.4, 95% confidence interval [CI]=3.3-5.7, I-2=0%) and 2) hypotension (n=4, specificity=95%, LR+=2.9 95% CI=1.8-4.6, I-2=42%), and decreasing probability were the absence of a widened mediastinum (n=4, sensitivity=76%-95%, negative likelihood ratio [LR-]=0.14-0.60, I-2=93%) and an American Heart Association aortic dissection detection (AHA ADD) risk score<1 (n=1, sensitivity=91%, LR-=0.22, 95% CI=0.15-0.33). Conclusions: Suspicion for acute aortic dissection should be raised with hypotension, pulse, or neurologic deficit. Conversely, a low AHA ADD score decreases suspicion. Clinical gestalt informed by high- and low-risk features together with an absence of an alternative diagnosis should drive investigation for acute aortic dissection.