Rethinking Aortic Risk: The Potential Impact of Novel, Adjusted, and Combined Aortic Measures in the Prediction of Aortic Dissection.

BACKGROUND

Indications for pre-emptive aortic surgery are based on ascending aortic diameter. In this study we assessed the diagnostic test properties of novel unadjusted, adjusted, and combined measures of aortic geometry.

METHODS

This study comprised an international multicentre analysis of patients undergoing contrast-enhanced computed tomography angiography (CTA) before acute type A aortic dissection (ATAAD). A historical cohort of nonaneurysmal patients and patients with known aneurysmal disease (TAA) were included as a control group. Receiver operating characteristic (ROC) curves were applied to evaluate the aortic measures' diagnostic accuracy (for [un]adjusted aortic diameter, length, and volume), with sensitivity analyses performed in a matched sample. Clinically intuitive measures, such as the number needed to reclassify (NNR) to identify an additional patient at risk of ATAAD, were calculated.

RESULTS

Eighty patients underwent CTA before ATAAD occurred, in 5 centres in The Netherlands and Germany. The control group encompassed 333 patients. The specificity of all measures was 98.8%, 97.0%, and 94.9% at contemporary diameter thresholds of 55 mm, 52 mm, and 50 mm. The sensitivity of diameter, length, or volume was 4.1%, 6.8%, and 14.9% at the 98.8% specificity threshold (NNR volume vs diameter: 9.3, P = 0.008). The combination of diameter, length, and volume as a new criterion resulted in an increased sensitivity at the 55-mm and 52-mm thresholds (18.9%, NNR = 6.8, P = 0.001; 23.0%, NNR = 9.3, P = 0.008). Results were consistent in matched samples.

CONCLUSIONS

These newly introduced aortic measures seem promising to identify patients at risk of ATAAD, but their net benefit needs to be validated in real-world cohorts.