Can We Better Differentiate Type A Dissections: Evaluating the Role of Aortic Ratios

Varun J Sharma; Miae Kang; Jegatheesan Saravana Ganesh; David J McCormack; Minesh Prakash; Richard Moore; Nishith N Patel; Adam El-Gamel

doi:10.1016/j.hlc.2022.03.011

Can We Better Differentiate Type A Dissections: Evaluating the Role of Aortic Ratios

Heart Lung Circ. 2022 Aug;31(8):1126-1133. doi: 10.1016/j.hlc.2022.03.011. Epub 2022 May 19.

Authors

Varun J Sharma¹, Miae Kang², Jegatheesan Saravana Ganesh³, David J McCormack⁴, Minesh Prakash³, Richard Moore⁵, Nishith N Patel⁴, Adam El-Gamel⁴

Affiliations

¹ Department of Cardiothoracic Surgery, Waikato District Health Board, Hamilton, New Zealand; Department of Surgery, Melbourne Medical School, University of Melbourne, Melbourne, Vic, Australia; Waikato Institute of Surgical Education and Research (WISER), Hamilton, New Zealand. Electronic address: sharma.varun.j@gmail.com.
² Department of Cardiothoracic Surgery, Waikato District Health Board, Hamilton, New Zealand; Department of Surgery, Melbourne Medical School, University of Melbourne, Melbourne, Vic, Australia.
³ Department of Cardiothoracic Surgery, Waikato District Health Board, Hamilton, New Zealand; Waikato Institute of Surgical Education and Research (WISER), Hamilton, New Zealand.
⁴ Department of Cardiothoracic Surgery, Waikato District Health Board, Hamilton, New Zealand; Waikato Institute of Surgical Education and Research (WISER), Hamilton, New Zealand; Department of Surgery, University of Auckland, Hamilton, New Zealand.
⁵ Department of Cardiothoracic Surgery, Waikato District Health Board, Hamilton, New Zealand.

PMID: 35597706
DOI: 10.1016/j.hlc.2022.03.011

Abstract

Objectives: Type A aortic dissection (ATAAD) is hypothesised as a progression of aneurysmal dilation, but 60% of patients in the International Registry of Acute Aortic Dissection (iRAD) registry had a maximum aortic diameter (MAD)<55 mm. We aim to demonstrate that size ratios and aortic wall stress, assessed using a simplified markers, are unique to aortic patients who have had adverse events (ATAAD) compared to those who have not (thoracic aortic aneurysm [TAA]).

Methods: A retrospective cohort analysis of patients who underwent aortic intervention at Waikato Hospital, New Zealand between 2015-2020, comparing dissection (ATAAD) to TAA patients. MAD; ratio of MAD to standardised-points within the aorta; and MAD-to-height collected from computed tomography (CT)-scans of all patients was undertaken. Receiver operating characteristic (ROC)-analysis to determine cut-off point for each marker was undertaken together with multivariable logistic regression comparing both cohorts, cross-validated by propensity-score matched analysis.

Results: Cohort of 215 patients, 78 (36.3%) ATAAD and 137 (63.7%) TAA; median age at intervention 63.3 years, 52 (24.2%) females, both cohorts matched for size. Using the entire cohort, the MAD: sinus of Valsalva (SoV) ratio>1.06 (cut-off value) had 4.5-times greater association with ATAAD (95%CI 1.46-13.8) and a 0.1-unit increased conferred 1.45-times greater association with ATAAD (95%CI 1.00-2.08). MAD>55 mm only seen in 33.3% of ATAAD (n=26/78), and not associated with ATAAD (OR 1.88, 95%CI 0.64-5.51). Compared to MAD, MAD:SoV ratio had greater sensitivity (33% vs 73%), lower number-needed-to-treat (17.9 vs 2.7) and superior discrimination (area under the curve [AUC] 0.54 vs 0.71). Findings were consistent with propensity score matched analysis.

Conclusions: MAD:SoV ratio significantly correlates with ATAAD (4.5 times), with superior sensitivity, discrimination, and attributable-risk-percentage compared to MAD alone.

Keywords: Aortic Diameter; Aortic Dissection; Aortic wall stress; Haemodynamic; Tension.

MeSH terms

Acute Disease
Aorta / diagnostic imaging
Aortic Aneurysm, Thoracic* / diagnosis
Aortic Dissection* / diagnosis
Female
Humans
Male
Retrospective Studies
Treatment Outcome