Table 2. Unadjusted Outcomes of Death, Aortic Dissection, and Aortic Surgery by Initial Thoracic Aortic Aneurysm (TAA) Size and Time-Updated TAA Size.
| No. (%) | Total event-free person-years, No. | Deaths, No. (%) | Aortic dissection or rupture, No. (%) | Aortic surgical procedures, No. (%) | Rate of aortic dissection per 100 person-years (95% CI)b | Rate of aortic dissection or all-cause death per 100 person-years (95% CI)b | |
|---|---|---|---|---|---|---|---|
| Outcomes by initial TAA size, cm | |||||||
| <4.0 | 726 (11.4) | 2700 | 121 (16.7) | 0 | 38 (5.2) | 0.00 (0.00-0.00) | 4.41 (3.68-5.28) |
| 4.0-4.4 | 3120 (49.0) | 10 005 | 514 (16.5) | 15 (0.5) | 237 (7.6) | 0.15 (0.09-0.25) | 4.96 (4.54-5.42) |
| 4.5-4.9 | 1698 (26.7) | 5436 | 324 (19.1) | 18 (1.1) | 313 (18.4) | 0.33 (0.21-0.53) | 5.63 (5.04-6.30) |
| 5.0-5.4 | 548 (8.6) | 1380 | 136 (24.6) | 6 (1.1) | 225 (41.1) | 0.43 (0.20-0.97) | 8.48 (7.07-10.16) |
| 5.5-5.9 | 156 (2.5) | 334 | 40 (25.6) | 1 (0.6) | 78 (50.0) | 0.30 (0.04-2.12) | 11.06 (8.01-15.27) |
| ≥6.0 | 124 (2.0) | 182 | 47 (37.9) | 4 (3.2) | 64 (51.6) | 2.19 (0.82-5.84) | 21.36 (15.61-29.24) |
| Outcomes by time-updated TAA size, cma | |||||||
| <4.0 | NA | 3039 | 146 | 0 | 40 | 0.00 (0.00-0.00) | 4.48 (3.78-5.30) |
| 4.0-4.4 | NA | 9808 | 486 | 11 | 209 | 0.11 (0.06-0.20) | 4.79 (4.38-5.25) |
| 4.5-4.9 | NA | 5169 | 311 | 13 | 281 | 0.25 (0.15-0.43) | 5.77 (5.15-6.46) |
| 5.0-5.4 | NA | 1479 | 130 | 8 | 249 | 0.54 (0.27-1.08) | 7.78 (6.48-9.34) |
| 5.5-5.9 | NA | 348 | 47 | 4 | 97 | 1.15 (0.43-3.06) | 12.62 (9.39-16.96) |
| ≥6.0 | NA | 194 | 62 | 8 | 79 | 4.11 (2.05-8.21) | 27.21 (20.79-35.62) |
Abbreviation: NA, not applicable.
a
Patients were classified into TAA size bins based on each new imaging study across follow-up, and outcomes of aortic dissection or death were attributed to the most recent TAA size prior to the event. The time at risk within each aortic size bin began at the date of each new imaging study and extended until the next imaging study or censoring event. Sample size not populated as patients changed categories over time. Percentages were not calculated for death, aortic dissection or rupture, or aortic surgery due to lack of relevant denominator.
b
Rate of aortic dissection and rate of aortic dissection or all-cause death were censored at aortic surgery for those who underwent surgery.