Earlier prophylactic surgery preferable in selective nonsyndromic patients with thoracic aortic aneurysms: JAMA

The study of a large sociodemographically diverse cohort of patients with thoracic aortic aneurysm (TAA) found a low absolute risk of aortic dissection that increased with larger aortic sizes after adjusting for potential confounders and competing risks.

There is no proper understanding of the risk of adverse events from ascending thoracic aorta aneurysms (TAA), but it drives clinical decision-making. Considering this, Matthew D. Solomon, Division of Research, Kaiser Permanente Northern California, Oakland, and colleagues aimed to investigate the association of thoracic aortic aneurysm (TAA) size with outcomes in nonsyndromic patients in a large non–referral-based health care delivery system.

The Kaiser Permanente Thoracic Aortic Aneurysm (KP-TAA) cohort study, a retrospective cohort study at Kaiser Permanente Northern California, a fully integrated health care system insuring and providing care for more than 4.5 million persons. The study included nonsyndromic patients from a regional TAA safety net tracking system. Merging imaging data with electronic health records (EHR) and comprehensive death data was done to obtain comorbidities, demographic characteristics, laboratory values, medications, vital signs, and subsequent outcomes.

Calculating unadjusted rates was done, and the association of TAA size with outcomes was investigated in multivariable competing risk models that classified TAA size as a baseline and time-updated variable and considered potential confounders.

Of 6372 patients with TAA (mean age, 68.6 years; 32.2% were females and 67.8%, mean initial TAA size was 4.4 cm (828 individuals had an initial TAA size of 5.0 cm or larger and 280 5.5 cm or larger).

Key findings of the study include:

• AD rates were low across a mean of 3.7 years of follow-up (44 individuals [0.7% of cohort]; incidence of 0.22 events per 100 person-years).
• In multivariable models, a larger initial aortic size was associated with higher AD risk and all-cause death risk, with an inflection point in risk at 6.0 cm.
• Estimated adjusted AD risks within 5 years were 0.3%, 0.6%, 1.5%, 3.6%, and 10.5% in patients with TAA size of 4.0 to 4.4 cm, 4.5 to 4.9 cm, 5.0 to 5.4 cm, 5.5 to 5.9 cm, and 6.0 cm or larger, respectively, in time-updated models.
• Rates of the composite outcome of AD and all-cause death were higher than for AD alone, but a similar inflection point for increased risk was observed at 6.0 cm.

"Our findings support consensus guidelines recommending surgical intervention at 5.5 cm in nonsyndromic individuals with TAA; given the minor risks linked with aortic surgery, earlier prophylactic surgery should be performed selectively in the nonsyndromic population," the researchers concluded.

Reference:

Solomon MD, Leong T, Sung SH, et al. Association of Thoracic Aortic Aneurysm Size With Long-term Patient Outcomes: The KP-TAA Study. JAMA Cardiol. Published online October 05, 2022. doi:10.1001/jamacardio.2022.3305