Table 1.
Baseline clinical characteristics for the discovery and validation cohorts
| Discovery | Validation | Between-cohort P value | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Total (N=556) | No PoAF (N=391) | PoAF (N=165) | P value | Total (N=1164) | No PoAF (N=828) | PoAF (N=336) | P value | ||
| Age (years) | 62±11 | 60±11 | 66±10 | <0.001 | 64±10 | 63±10 | 68±10 | <0.001 | <0.001 |
| Sex (male) | 402 (72%) | 272 (70%) | 130 (79%) | 0.03 | 952 (82%) | 676 (82%) | 276 (82%) | 0.84 | <0.001 |
| Previous AF | 58 (10%) | 15 (3.8%) | 43 (26%) | <0.001 | 50 (4.3%) | 21 (2.5%) | 29 (8.6%) | <0.001 | <0.001 |
| PR interval | 165 [164–168] | 162 [160–165] | 173 [170–176] | <0.001 | 170 [168–172] | 167 [166–168] | 176 [172–180] | <0.001 | 0.001 |
| Diabetes | 200 (36%) | 136 (35%) | 64 (39%) | 0.37 | 329 (28%) | 242 (29%) | 87 (26%) | 0.25 | 0.001 |
| Hypertension | 444 (80%) | 300 (77%) | 144 (87%) | 0.005 | 873 (75%) | 603 (73%) | 270 (80%) | 0.007 | 0.03 |
| LVEF<40% | 107 (19%) | 67 (17%) | 40 (24%) | 0.05 | 132 (11%) | 86 (10%) | 46 (14%) | 0.11 | <0.001 |
| Pre-op beta blockers | 351 (63%) | 254 (65%) | 97 (59%) | 0.17 | 910 (78%) | 648 (78%) | 262 (78%) | 0.92 | <0.001 |
| Post-op beta blockers | 487 (88%) | 347 (89%) | 140 (85%) | 0.20 | 1103 (95%) | 776 (94%) | 327 (97%) | 0.01 | <0.001 |
Age presented as mean ± standard deviation. PR interval presented as median [bootstrap 95% confidence interval] in milliseconds. AF: atrial fibrillation. PoAF: post-operative atrial fibrillation. LVEF: left ventricular ejection fraction. P values were calculated for differences between PoAF and no PoAF with chi-square for nominal variables and Mann-Whitney U test for continuous variables. Between-cohort P values reflect differences between the 2 entire cohorts, irrespective of PoAF status.