D-dimer as a Rule-Out for Aortic Dissection

Introduction Acute aortic dissection (AAD) represents a significant diagnostic challenge with a high mortality rate if not treated promptly. This challenge arises from the diverse clinical presentations of AAD, and its symptom overlap with other medical conditions. Although both helical CT and transesophageal echocardiography are reliable diagnostic tools for AAD, they are not feasible for every suspected case. Furthermore, limited research on D-dimer's utility in ruling out AAD has been conducted due to the condition's rarity. Methods This study utilizes the TriNetX database (https://trinetx.com/), encompassing data from 54 healthcare organizations across the United States over the past two decades from 85 million patients. The objective is to evaluate the sensitivity of an elevated D-dimer level in diagnosing AAD across a much larger patient cohort than previously studied. Results Retrospectively analyzing this dataset, there were 1,319 patients identified with a confirmed AAD who had undergone D-dimer testing within a day of diagnosis. Of these, 1,252 patients exhibited D-dimer levels exceeding 400 ng/ml while 1,227 had levels surpassing 500 ng/ml. Notably, a D-dimer cutoff of 400 ng/ml demonstrated a sensitivity of 0.949 while a 500 ng/ml cutoff yielded a sensitivity of 0.930. Conclusion This large retrospective cohort study demonstrates that a blood D-dimer level is highly sensitive in assaying for AAD. The D-dimer levels analyzed showed a remarkable sensitivity in ruling out AAD, avoiding the need for more invasive testing in low-risk patients.