Repair of Small Ruptured AAA in the VQI Vincent J. Noori, MD, Christopher T. Healey, MD, Jens Eldrup-Jorgensen, MD, Elizabeth Blazick, MD, Andres Schanzer, MD, Mahmoud B. Malas, MD, Marc L. Schermerhorn, MD, and Brian W. Nolan, MD, MS on behalf of the Vascular Quality Initiative Thank you for the opportunity to present today. Ill be presenting the data on small ruptured AAA repairs in the VQI.

No conflict of interest to declare.

Introduction Current SVS guidelines for elective AAA repair.* >5.5-cm in males, > 5.0-cm in females Saccular AAA Rapidly expanding fusiform AAA (>0.5cm over 6 mo.) Surveillance imaging for smaller AAAs. Some AAA below this threshold will rupture (rAAA). Current SVS clinical practice guidelines* recommend: Elective repair of a fusiform AAA >5.5cm in males and 5.0-5.4cm in females Elective repair for patients with a saccular AAA And elective repair of rapidly expanding fusiform aneurysm >0.5cm over 6 mo period. Surveillance imaging is recommended for smaller aneurysms. Despite these criteria, some AAAs below this threshold size will rupture * Chaikof et al. The society for vascular surgery practice guidelines on the care of patients with an abdominal aortic aneurysm. J Vasc Surg 2018;67:2-77

Study Aim To describe incidence and clinical outcomes of small rAAA in the VQI and identify risk factors predictive of small AAA rupture. Primary endpoint: in-hospital mortality. Secondary endpoints: major adverse events (MAE) and 5-year survival. The aim of this study was to describe the incidence and clinical outcomes of small rAAAs in the VQI and identify risk factors predictive of small AAA rupture. Our Primary endpoint was in-hospital mortality. Our Secondary endpoints are major adverse events (MAE) and 5-year survival.

Total AAA Repairs in VQI Guideline Size AAAs 33,454 (64%) Sample Total AAA Repairs in VQI (n = 52,186) Small AAAs* 18,732 (36%) Guideline Size AAAs 33,454 (64%) We performed a Retrospective cohort analysis of all rupture AAA repairs in the VQI performed from 2003-2018. Of 52000 AAA repairs, 33400 were for guideline size AAAs while 18700 were for small AAAs. Small AAAs made up 36% of the sample. Elective 16,876 (90%) Ruptured 484 (3%) Elective 26,714 (80%) Ruptured 3,498 (10%) Symptomatic 1,372 (7%) Symptomatic 3,238 (10%) * <5.5cm in males and <5.0cm in females

Sample 12% of rupture repairs for small AAAs Total AAA Repairs in VQI Guideline Size AAAs 33,454 (64%) Of guideline size AAAs, 3500 of those were ruptured AAAs and of the 18700 small AAAs, 484 of those were ruptured AAAs. ____________ (click animate) Of all RUPTURED AAA repairs in the VQI (both guideline size and small AAAs), 12% were for small AAAs. 484/3498 = 12% Elective 16,876 (90%) Ruptured 484 (3%) Elective 26,714 (80%) Ruptured 3,498 (10%) Symptomatic 1,372 (7%) Symptomatic 3,238 (10%) * <5.5cm in males and <5.0cm in females

Patient Demographics Guideline Size rAAA Small rAAA p-value Age 73 71 0.005 Any smoking history 80% 78% 0.374 EVAR used 56% 70% 0.001 Current smoker 57% 0.592 Beta blocker 45% 48% 0.098 Statin 42% 0.009 Aspirin 40% 0.017 CKD 35% 32% 0.189 History of COPD 31% 29% 0.363 Repair within 90-min of admission 26% 27% 0.300 History of MI or angina 22% 23% 0.913 Female 18% 0.045 Any DM 15% 17% 0.038 Non-white race 11% 0.003 History of any CHF 12% 0.344 Positive stress test 1% 3% Notable demographics from our sample showed an overall younger cohort in the small AAA group with more being repaired with EVAR than guideline size ruptured AAAs. More often patients with small aneurysms were on statins than guideline size rAAAs. Small rAAAs also tended to be more often of non white race and more often had a positive stress test.

Results p = 0.001 p = 0.001 There was a notably lower in-hospital mortality and any major adverse event rate for repair of small rAAA than for guideline size ruptured AAAs.

Long-Term Outcomes p = 0.047 75% 66% 63% 54% Years In this kaplan meyer curve looking at long term outcomes, you can see that small ruptured AAA repair patients tended to have better 5 year survival than guideline size ruptured AAA repair patients. Years Guideline Size rAAA Small rAAA

Multivariate Predictors of Small rAAA   O.R. 95% C.I. p-value Age < 60 1.7 1.2 2.4 0.002 Age 60 to 69 1.5 1.1 1.9 Age 70 to 79 1.3 1.0 0.020 Positive stress 2.1 3.6 0.010 NWR 1.4 1.8 0.006 Any statin Statistically significant multivariate predictors associated with rupture of small AAAs included younger age, a positive stress test, non-white race, and any use of statins.

Summary 12% of rAAA repairs are for small AAAs. Small rAAA more frequently repaired with EVAR than large rAAA. Lower mortality and MAE rate for repair of small rAAA. Predictors of small rAAA include younger age, positive stress test, non-white race and statin use. In summary, 12% of rAAA repairs in the VQI are for small AAAs. - Small rAAA are more frequently repaired with EVAR than large rAAA. - There is a Lower mortality rate and major adverse event rate for repair of small rAAA. - And Predictors of small rAAA include younger age, positive stress test, non-white race and statin use.

Conclusion Small AAAs rupture and outcomes better for small rAAA than large rAAA. Demographic risk factors could help identify patients at higher risk of small rAAA. Relationship to statin use should be further investigated. In conclusion, while we tend to focus our clinical decision making on aneurysm size alone, Small AAAs do in fact rupture - Outcomes tended to be better for small rAAA than guideline size rAAA. - Demographic risk factors could help identify patients that may be at higher risk of rupture of a small AAAs and should be considered. - And the Relationship between ruptured small AAAs to statin use should be further investigated.

Thank You 13 POSSIBLE QUESTIONS: 1) Was stress test done immediately preop? Could they get cardiac intervention prior to AAA repair? Stress test was only done at some point. these were ruptures (not symptomatic) so couldn't be intervened upon 2) Why difference in 5 year (long term) survival? Prob because of age (tend to be younger), also comorbidities 3) How do you account for rupture AAA below threshold that are saccular? Unfortunately we could not account for this and it is a limitation to this study. 4) Why do you think statin use has correlation with negative outcomes with repair of small rAAA? Its hard to say, some postulated theories could include possible cofounders, possible bias or could be real: Maybe there is a confounder that we could not account for Could be bias because people are put on statin for having aneurysm alone (no HLD) and no other reason to be on it. Could be negatively affected Or maybe there truly is something about statin use that is detrimental, there was a recent basic science paper published suggesting increased inflammatory response to perivascular fat; also, Could be that statins reduce risk of aneurysms to rupture but may have less of an effect on small AAAs; While data out there suggests its protective, this data suggests it may be less protective in smaller aneurysms Goal of paper: is to Draw awareness to fact that small AAAs do rupture and there are risk factors that can predict which patients with small aneurysms can rupture and this should be considered. 13