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Efforts to screen for ascending aortic enlargement in the general population may be improved using a new prediction model based on common clinical variables easily gathered from medical records, researchers found.

The AORTA clinical score was found to correlate with measured ascending aortic diameters in development from a large U.K. Biobank cohort and externally validation in two other cohorts, according to Patrick Ellinor, MD, PhD, of the Broad Institute of MIT and Harvard in Cambridge, Massachusetts, and colleagues.

Notably, modeling suggested that a fixed-score threshold would require up to 10 flagged individuals to be imaged further to confirm one person of with an ascending aortic diameter of 4 cm or greater, they reported in .

"These findings are remarkable because more than 15 patients meeting the currently approved USPSTF [U.S. Preventive Services Task Force] screening guidelines for abdominal aortic aneurysm need to be imaged to identify a single patient with an aneurysmal abdominal aorta," commented Philip Goodney, MD, MS, of Dartmouth Health in Lebanon, New Hampshire, and Grace Wang, MD, MSCE, of the University of Pennsylvania in Philadelphia.

Aortic dissection and rupture are morbid consequences of thoracic aortic disease that often progresses silently. Adherence to screening guidelines is nonetheless low, as the focus on men, ages 65-75, who have ever smoked has been found to be of moderate net benefit, they noted in an .

The AORTA score explained approximately 30% of the variance in ascending aortic diameter across three validation cohorts, though the model significantly overestimated or underestimated aortic diameter in extreme cases.

"Collectively, these findings suggest that the AORTA score can efficiently identify asymptomatic individuals who could benefit from screening for ascending aortic enlargement based on simple data elements assimilated from electronic health records," Goodney and Wang said.

"As the aging population increases, our ability to repair aneurysms with endovascular technologies has grown. Our need to better identify individuals who can undergo elective repair is of utmost importance," they emphasized.

AORTA currently includes the simple variables of age, BMI, heart rate, blood pressure, diabetes, hypertension, and hyperlipidemia. More work is needed to optimize the model -- perhaps incorporating polygenic scores -- and assess whether it improves outcomes in a prospective trial, Ellinor's group said.

The authors reported the process of the AORTA model's derivation and validation:

• Developed from a training cohort of over 30,000 U.K. Biobank participants, ages 44 to 82
• Internally validated in another nearly 6,700 individuals in the U.K. Biobank
• Externally validated in 1,367 participants from the Framingham Heart Study offspring cohort who had undergone CT scans
• Externally validated further in over 50,000 individuals who had undergone transthoracic echocardiography in a retrospective hospital-based cohort of longitudinal primary care patients

The training cohort was 52% women with a median age of 65.1. Average ascending aortic diameters were 3.04 cm for women and 3.32 cm for men.

A moderately enlarged or greater ascending aorta measuring 4 cm or larger was found in 2.3% of this cohort.

Ellinor and colleagues warned that the AORTA score estimates aortic diameter at just one imaging plane; therefore, it does not capture variation up and down the entire ascending aorta.

Goodney and Wang stressed that if this tool is to be implemented in the real world, it would first need to be carefully evaluated for clinical use.

"Checks and balances will need to be established to ensure that sweeping through the electronic health record to find patients with aortic aneurysms does not unnecessarily identify patients with small aortic aneurysms, which are unlikely to rupture, as patient anxiety, overdiagnosis, and low-value tests and procedures would undoubtedly follow," they said.

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