December 9, 2020

Expanding Current AAA Screening Recommendations Could Identify a Greater Number of Patients With AAA

December 9, 2020—Investigators analyzing abdominal aortic aneurysm (AAA) screening criteria in the United States have determined that expanding the current criteria could aid in early detection and elective treatment. Matthew L. Carnevale, MD, et al performed a retrospective cohort analysis to identify the number of patients who would have met criteria for AAA screening using both the United States Preventive Services Task Force (USPSTF) and Society for Vascular Surgery (SVS) guidelines. Patients who underwent elective, urgent, and emergent open AAA repair and endovascular aneurysm repair (EVAR) were identified using the SVS Vascular Quality Initiative (VQI) data set. Those with a history of prior abdominal aortic surgery were excluded from analysis. Results of the analysis have been published in the Journal of Vascular Surgery (2020;72:1917-1926).

Key Findings

Fewer than one-third of patients would have been identified using USPSTF criteria (32% EVAR and 33% open repair).
With the addition of SVS and expanded SVS criteria, the rate of patients identified increased by 6% and 34% for EVAR, respectively, and 12% and 33% for open repair, respectively.
28% of patients who underwent AAA repair did not meet any screening criteria.
In patients who did not meet any screening criteria, 93% of patients aged < 65 years had a history of smoking, whereas smoking history was nonexistent in those aged > 65 years.
Ruptured AAA was twice as prevalent in patients who did not meet any screening criteria as compared with those who did (8.5% vs 4.4%; P ≤ .001).

As background, the USPSTF AAA screening guidelines recommend a one-time abdominal ultrasound examination in men aged 65 to 75 years with a smoking history. The SVS recommends a one-time abdominal ultrasound in men and women aged 65 to 75 years with a smoking history, and in addition to this criterion, the SVS expanded criteria recommend an abdominal screening ultrasound in those aged ≥ 65 years with a family history of AAA (first-degree relative) and those > 75 years with a smoking history.

Patients were stratified into four groups based on which screening guideline criteria they met: group 1 by USPSTF criteria, group 2 by SVS criteria, group 3 by SVS expanded criteria, and group 4 that met no screening criteria. Preoperative demographic information (ie, past medical history, family history of AAA, tobacco use) and postoperative outcomes (ie, mortality, postoperative complications, postoperative discharge status) were analyzed. Patient groups were evaluated using descriptive statistics, and univariate analyses were performed using the chi-square test, Fisher’s exact test, and Wilcoxon rank-sum test.

From the VQI database, 55,197 patients met inclusion criteria. Of 44,602 patients who underwent EVAR, 14,480 (32.46%) met USPSTF criteria, 2,895 (6.49%) met SVS criteria, 14,969 (33.56%) met SVS expanded criteria, and 12,072 (27.06%) did not meet any screening criteria. Of the 10,595 patients who underwent open AAA repair, 3,498 (33.02%) met USPSTF criteria, 1,249 (11.78%) met SVS criteria, 2,265 (21.37%) met SVS expanded criteria, and 3,521 (33.23%) did not meet any screening criteria.

Additional analysis was performed on the group that did not meet any screening criteria. Fifty-two percent of patients were aged < 65 years, and the majority (93%) had a history of heavy tobacco use. However, patients aged > 65 years had no smoking history. These findings were similar in the open AAA repair group. Ruptured AAA was more prevalent in patients who did not meet any screening criteria as compared with those who did (8.5% vs 4.4%; P ≤ .001).

The investigators noted that applying all expanded SVS recommendations to screening practices in this particular patient cohort would have increased the number of AAA patients identified to 72%. However, as this was a cohort extrapolated from the VQI database, it was unknown how AAA was diagnosed and whether screening took place. In addition, this analysis did not include patients who were observed and managed expectantly, and the amount of tobacco use was not quantified in the VQI, thus making any dose-dependent associations with AAA impossible, noted the investigators.

ENDOVASCULAR TODAY ASKS…

We asked lead author Matthew Carnevale, MD, who is at Montefiore Medical Center and The Albert Einstein College of Medicine in Bronx, New York:

What are the practicalities and potential downsides of screening expansion?

Dr. Carnevale: Expanding the currently used guidelines would identify more patients with AAA who require treatment. This is especially beneficial because many of the patients who do not meet any of the screening criteria end up presenting with ruptured AAA, which is a life-threatening condition. Perhaps the most obvious downside of expanding any screening program is the increase in associated costs. Another potential downside may be identifying AAA in patients who would have never otherwise required treatment, as this knowledge may cause emotional distress.

What happens next? How might your findings affect future screening criteria?

Dr. Carnevale: We hope that our paper generates renewed interest in expanding the screening guidelines put forth by the USPSTF. We look forward to further investigating the groups not meeting any screening criteria to identify if there are any similarities that may be worth considering in the future when deciding whether to screen for AAA.

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