Association of dilated aortic root on point-of-care ultrasound with aortic aneurysm and dissection.

OBJECTIVES

Thoracic aortic dissection (TAD) is a life-threatening condition with a mortality rate of 1-2 % per hour, highlighting the importance of prompt diagnosis. Thoracic aortic aneurysm (TAA) is associated with TAD and can be detected by point-of-care ultrasound (POCUS). We sought to evaluate the diagnostic accuracy of POCUS in detecting TAA and the prevalence of TAD in patients with TAA by POCUS. We hypothesized that a dilated aortic root on POCUS would be strongly associated with TAA and TAD.

METHODS

Patients with a dilated aortic root measurement of ≥4.5 cm on transthoracic cardiac POCUS between 2013 and 2023 who received either chest CT or cardiology echocardiogram (c-echo) were retrospectively selected by querying a POCUS database (QpathE) from three EDs in our system. Comprehensive demographic, clinical, and imaging data were retrieved from electronic medical records. For both CT and c-echo, aortic measurements of ≥4 cm were considered aneurysmal, using the largest reported measurement. If both CT and c-echo were performed, the largest CT measure was used. We also investigated how many patients with TAA also had TAD. Statistical analysis was performed using IBM SPSS version 29.

RESULTS

Our cohort included 304 patients with TAA (≥4.5 cm) on POCUS, with a median age of 67.5 years (IQR:58-80) of which 247 (81.3 %) were male. 227 (74.6 %) had CT performed, and 77 (25.3 %) had a c-echo without CT. There was a significant positive correlation between POCUS measurements and those of CT and c-echo (r = 0.62, p < 0.001). Comparing the measurements on POCUS with those derived from our ground truths, the mean difference for the Bland-Altman plot was 0.13 cm (95 % confidence interval; -0.71 to 0.97), with the average POCUS measure being slightly higher. Overall, the positive predictive value (PPV) of POCUS for TAA was 96 % (95 % CI, 93.8 %-98 %). TAD was present in 45 (15.4 %) of patients with TAA.

CONCLUSION

Although POCUS measurement tended to be slightly higher than that of CT or c-echo on average, it demonstrated a high accuracy and predictive value for TAA. More than one in seven patients with TAA on POCUS had TAD. Our results underscore the efficacy of POCUS for the prompt detection of thoracic aortic aneurysm and dissection.