Karin Grimm, Simone Vanni, Francesca Giachino, Sibilla Anna Teresa Salvadeo, Bernd A Leidel, Stefano Grifoni, Emanuele E Pivetta, Peiman Nazerian, Enrico Lupia, Alexandre de Matos Soeiro, Christian Mueller, Múcio T Oliveira, Fulvio Morello
Background -Acute aortic syndromes (AAS) are rare and severe cardiovascular emergencies with unspecific symptoms. For AAS, both misdiagnosis and over-testing are key concerns, and standardized diagnostic strategies may help physicians to balance these risks. D-dimer (DD) is highly sensitive for AAS, but is inadequate as a standalone test. Integration of pre-test probability assessment (PPA) with D-dimer (DD) testing is feasible, but the safety and efficiency of such diagnostic strategy are currently unknown. Methods -In a multicenter prospective observational study involving 6 hospitals in 4 countries from 2014 to 2016, consecutive outpatients were eligible if they had ≥1 of the following: chest/abdominal/back pain, syncope, perfusion deficit, and if AAS was in differential diagnosis. The tool for PPA was the aortic dissection detection risk score (ADD-RS, 0 to 3), per current guidelines. DD was considered negative (DD-) if <500 ng/ml. Final case adjudication was based on conclusive diagnostic imaging, autopsy, surgery or on 14-day follow-up. The outcomes were the failure rate and efficiency of a diagnostic strategy ruling-out AAS in patients with ADD-RS=0/DD- or ADD-RS≤1/DD-. Results -1850 patients were analyzed. 438 (24%) patients had ADD-RS=0, 1071 (58%) patients had ADD-RS=1, and 341 (18%) had ADD-RS>1. 241 (13%) patients had AAS: 125 had type A aortic dissection, 53 had type B aortic dissection, 35 had intramural aortic hematoma, 18 had aortic rupture, and 10 had penetrating aortic ulcer. A positive DD test result had an overall sensitivity of 96.7% (95% CI 93.6-98.6%) and a specificity of 64% (95% CI 61.6-66.4%) for diagnosis of AAS; 8 patients with AAS had DD-. Within 294 patients with ADD-RS=0/DD-, 1 case of AAS was observed. This yielded a failure rate of 0.3% (95% CI 0.1-1.9%) and efficiency of 15.9% (95% CI 14.3-17.6%) for the ADD-RS=0/DD- strategy. Within 924 patients with ADD-RS≤1/DD-, 3 cases of AAS were observed. This yielded a failure rate of 0.3% (95% CI 0.1-1%) and efficiency of 49.9% (95% CI 47.7-52.2%) for the ADD-RS≤1/DD- strategy. Conclusions -Integration of ADD-RS (both =0 or ≤1) with DD may be considered to standardize diagnostic rule-out of AAS. Clinical Trial Registration -URL: http://www.clinicaltrials.gov. Unique identifier: NCT02086136.