Table 1.
Presenting Characteristics According to the Occurrence of Postoperative AF
| Variables*,* | Overall Population (N=17 262) | Derivation Cohort (n=12 938) | Validation Cohort (n=4324) | |||||
|---|---|---|---|---|---|---|---|---|
| No AF (n=12 701) | AF (n=4561) | P Value | No AF (n=9515) | AF (n=3423) | No AF (n=3186) | AF (n=1138) | P Value* | |
| Age, y, % | 65.1±10.8 | 69.7±8.9 | <0.001 | 65.1±10.7 | 69.7±9.1 | 65.1±11.1 | 69.8±8.4 | 0.48 |
| <60 | 28.3 | 13.1 | <0.001 | 28.4 | 13.3 | 27.9 | 12.5 | 0.25 |
| 60 to 69 | 35.4 | 33.1 | 35.5 | 33.1 | 35.3 | 33.3 | ||
| 70 to 79 | 32.5 | 44.1 | 31.3 | 43.6 | 32.1 | 45.8 | ||
| ≥80 | 4.8 | 9.7 | 4.9 | 10.1 | 4.7 | 8.4 | ||
| Male, % | 76.2 | 72.1 | <0.001 | 76.3 | 71.7 | 75.6 | 73.1 | 0.85 |
| BMI, kg/m2 | 27.3±4.3 | 27.1±4.5 | 0.17 | 27.2±4.3 | 27.1±4.5 | 27.2±4.3 | 27.1±4.4 | 0.47 |
| BMI >40 kg/m2, % | 0.7 | 1.0 | 0.15 | 0.8 | 1.0 | 0.6 | 1.0 | 0.62 |
| Cardiac presentation, % | ||||||||
| Emergency | 2.8 | 4.8 | <0.001 | 2.8 | 4.7 | 2.5 | 5.3 | 0.94 |
| IABP | 0.7 | 2.0 | <0.001 | 0.7 | 1.9 | 0.8 | 2.0 | 0.49 |
| Previous cardiac surgery | 3.7 | 3.7 | 0.91 | 3.5 | 3.9 | 4.1 | 3.1 | 0.62 |
| Prior AMI | 36.2 | 36.4 | 0.81 | 36.4 | 36.8 | 35.4 | 35.2 | 0.16 |
| LVEF | 55.5±11.3 | 53.4±12.2 | <0.001 | 55.6±11.3 | 53.7±12.2 | 55.3±11.4 | 52.7±12.2 | 0.53 |
| LVEF <30, % | 3.3 | 5.2 | <0.001 | 3.3 | 5.3 | 3.2 | 4.8 | 0.57 |
| Comorbidities, % | ||||||||
| Hypertension | 64.9 | 68.7 | <0.001 | 64.8 | 69.1 | 65.2 | 67.4 | 0.94 |
| Diabetes | 20.0 | 21.7 | 0.012 | 19.9 | 21.5 | 20.1 | 22.2 | 0.69 |
| COPD | 5.2 | 8.4 | <0.001 | 5.4 | 8.3 | 4.5 | 8.8 | 0.26 |
| PVD | 9.7 | 11.5 | <0.001 | 9.8 | 11.8 | 9.4 | 10.7 | 0.25 |
| CVD | 7.3 | 9.1 | <0.001 | 7.3 | 9.6 | 7.1 | 7.5 | 0.13 |
| eGFR, mL/min per 1.73 m2 | 66.8±22.0 | 63.9±23.8 | <0.001 | 66.8±21.9 | 63.9±25.2 | 66.7±22.3 | 63.6±18.9 | 0.53 |
| eGFR <15 mL/min per 1.73 m2 or dialysis, % | 0.4 | 0.7 | 0.003 | 0.5 | 0.9 | 0.6 | 1.1 | 0.22 |
| Additive EuroSCORE, n | 4.0±2.8 | 5.4±3.1 | <0.001 | 4.0±2.8 | 5.5±3.0 | 4.0±2.8 | 5.4±3.1 | 0.89 |
| Preoperative drug regimen, % | ||||||||
| β‐Blockers | 54.8 | 52.9 | 0.17 | 53.7 | 53.7 | 53.0 | 50.3 | 0.16 |
| Calcium antagonists | 21.0 | 22.8 | 0.11 | 21.1 | 23.1 | 20.7 | 22.1 | 0.61 |
| ACE inhibitors | 38.8 | 40.1 | 0.32 | 38.9 | 38.5 | 38.5 | 40.6 | 0.21 |
| Statins | 57.8 | 58.6 | 0.44 | 57.8 | 58.1 | 57.9 | 59.9 | 0.55 |
| Operative data | ||||||||
| CPB time, min | 76.9±53.1 | 88.8±56.1 | <0.001 | 76.8±52.4 | 89.4±55.8 | 76.9±55.1 | 87.0±56.9 | 0.55 |
| ACC time, min | 51.6±39.5 | 59.9±42.5 | <0.001 | 51.6±39.6 | 60.3±41.8 | 51.4±39.3 | 59.0±44.5 | 0.44 |
| Use of CPB, % | 66.4 | 74.0 | <0.001 | 66.2 | 74.0 | 67.0 | 74.2 | 0.33 |
| Valve surgery, % | 29.0 | 41.5 | <0.001 | 28.9 | 41.7 | 29.1 | 41.1 | 0.88 |
| IABP, % | 1.1 | 2.9 | <0.001 | 1.1 | 3.1 | 1.2 | 2.1 | 0.42 |
| Postoperative data | ||||||||
| Ventilation, h | 6 (4 to 11) | 8.5 (5 to 17) | <0.001 | 6 (4 to 11) | 8 (5 to 17) | 6 (4 to 11) | 9 (5 to 17) | 0.39 |
| ICU time, h | 24 (23 to 48) | 43 (23 to 72) | <0.001 | 24 (23 to 48) | 44 (23 to 72) | 25 (23 to 48) | 36 (23 to 72) | 0.73 |
| CVA, % | 1.7 | 4.5 | <0.001 | 1.8 | 4.5 | 1.7 | 4.4 | 0.79 |
| AKI, % | 3.4 | 10.5 | <0.001 | 3.4 | 10.5 | 3.5 | 10.4 | 0.94 |
| RRT, % | 0.8 | 2.6 | <0.001 | 0.8 | 2.5 | 0.8 | 3.0 | 0.85 |
| Blood transfusion, % | 37.7 | 51.0 | <0.001 | 37.5 | 51.4 | 38.5 | 49.9 | 0.88 |
| Hospital outcome | ||||||||
| Length of stay, d | 7 (6 to 8) | 8 (7 to 12) | <0.001 | 7 (6 to 8) | 8 (7 to 12) | 7 (6 to 8) | 8 (7 to 11) | 0.86 |
| Mortality, % | 1.2 | 3.0 | <0.001 | 1.1 | 3.2 | 1.3 | 2.4 | 0.77 |
AF indicates atrial fibrillation; BMI, body mass index; IABP, intra‐aortic balloon pump; AMI, acute myocardial infarction; LVEF, left ventricular ejection fraction; COPD, chronic obstructive pulmonary disease; PVD, peripheral vascular disease; CVD, cardiovascular disease; eGFR, estimated glomerular filtration rate; ACE, angiotensin‐converting enzyme; CPB, cardiopulmonary bypass; ACC, aortic cross‐clamp; ICU, intensive care unit; CVA, cerebrovascular accident; AKI, acute kidney injury; RRT, renal replacement therapy.
For continuous variables, mean±SD or median (25th to 75th percentile); for categorical variables, %.
Other variables considered for the final model and not reported: body surface area, prior percutaneous coronary intervention, left mainstem stenosis, right coronary artery disease, left atrial diameter, dyslipidemia, basal hemoglobin, basal creatinine, creatinine values >2.0 mg/dL, angiotensin receptor blockers.
Test comparing the prevalence of risk factors between the entire derivation and entire validation cohorts.