A study estimates that an appropriate clinical setting, suspicion for acute aortic dissection should be raised when patients present with findings that have high specificity and high positive likelihood ratio (hypotension, pulse deficit, or neurologic deficit). The study was published in the Journal of Academic Emergency Medicine. 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.
The study suggests that, conversely, findings with a high sensitivity and low negative likelihood ratio (a low American Heart Association aortic dissection detection score) decrease likelihood of aortic dissection in patients with chest pain. The authors propose that clinical gestalt informed by high- and low-risk features together with an absence of an alternative diagnosis should drive investigation for acute aortic dissection.
Studies were combined if low clinical and statistical heterogeneity (I2 < 30%). Study quality was assessed using the QUADAS?2 tool. Bivariate random effects meta-analyses using Revman 5 and SAS 9.3 were performed. They identified 792 records: 60 were selected for full-text review, nine studies with 2,400 participants were included (QUADAS?2 low risk of bias, κ = 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, I2 = 0%) and 2) hypotension (n = 4, specificity = 95%, LR+ = 2.9 95% CI = 1.8–4.6, I2 = 42%).
The author recommends that further investigation for acute aortic dissection should be guided by evidence-informed clinical suspicion and through a shared decision-making process with patients. Suspicion for acute aortic dissection should be raised with hypotension, pulse, or neurologic deficit. Conversely, a low AHA ADD score decreases suspicion.
A decreasing probability were the absence of a widened mediastinum (n = 4, sensitivity = 76%?95%, negative likelihood ratio [LR–] = 0.14–0.60, I2 = 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). Clinical gestalt informed by high? and low?risk features together with an absence of an alternative diagnosis should drive investigation for acute aortic dissection.