Clinical Follow-Up
There were significant interquartile differences in rates of clinical follow-up (new or previously established) with a cardiologist or cardiac surgeon following diagnosis of ATAA aneurysm (p<0.001 and p=0.002, respectively), shown in Figure 1 . Patients in the top three quartiles (Q1-Q3) were significantly more likely to have previously established follow-up with a cardiologist for their ATAA aneurysm, compared to those in Q4 (p<0.001). In addition, among those who were not already established with a cardiologist, rates of new encounters were similar between Q1, Q2, and Q3, at 36.3% (N=16), 46.3% (N=25), and 29.8% (N=17), respectively. However, only 16% (N=18) of previously unestablished patients in Q4 were seen by a cardiologist during the study period (p<0.001).
23.4% (N=109) of patients had previously established or new follow-up with a cardiac surgeon during the study period. ADI quartile was also significantly associated with follow-up with a cardiac surgeon (p<0.002), with statistically significant differences between the least disadvantage quartile (Q1) and most disadvantaged quartile (Q4) on pairwise testing (Q1: 33% vs. Q4: 16%).
47 (10.1%) patients underwent aortic repair surgery during the study period, at an average ATAA size of 5.0 (4.6, 5.2) cm (Table 2 ). There were no significant interquartile differences in ATAA size at time of surgery, but 92% (N=12) of patients in the most disadvantaged quartile were symptomatic at presentation for surgery, compared to only 25% (N=3) patients in the least disadvantage quartile (p<0.001).