Table 3.
Reclassification Based on Whether the Individual Does or Does not Develop Atrial Fibrillation in 10 Years.
| Without echocardiographic variables | With echocardiographic variables | |||
|---|---|---|---|---|
| <5% | 5–15% | >15% | Total | |
| Participants who do not develop atrial fibrillation | ||||
| <5% | 3216 (65.3) | 232 (4.7) | 1 (0.02) | 3449 (70.1) |
| 5–15% | 244 (5.0) | 891 (18.1) | 98 (2.0) | 1233 (25.1) |
| >15% | 0 (0.0) | 68 (1.4) | 172 (3.5) | 240 (4.9) |
| Total | 3460 (70.3) | 1191 (24.2) | 271 (5.5) | 4922 (100.0) |
| Participants who developed atrial fibrillation | ||||
| <5% | 59 (22.7) | 17 (6.5) | 2 (0.8) | 78 (30.0) |
| 5–15% | 14 (5.4) | 76 (29.2) | 20 (7.7) | 110 (42.3) |
| >15% | 0 (0.0) | 13 (5) | 59 (22.7) | 72 (27.7) |
| Total | 73 (28.1) | 106 (40.8) | 81 (31.2) | 260 (100.0) |
Individuals in the shaded diagonal boxes did not change classification with echocardiography; those above the diagonal had improved reclassification with echocardiography; those below the diagonal echocardiography worsened reclassification.
The net reclassification improvement was 0.04 (95% CI −0.02–0.10, p=0.18). Among individuals who did not develop AF in 10 years follow-up, echocardiographic variables up-classified 331 and down-classified 312 individuals. Among those participants who developed AF, 39 were up-classified and 27 were down-classified with echocardiography.