TABLE 1.
Demographic, selected preoperative clinical and blood pressure dynamical characteristics of study groups.
| Variable | All | Short ICU LOS | Long ICU LOS | p value |
|---|---|---|---|---|
| N = 378 | N = 198 | N = 180 | ||
| Age (yrs) | 67 [59–75] | 65 [57–72] | 69 [61–77] | < 0.001 |
| Sex: Male | 271 (72%) | 152 (77%) | 119 (66%) | 0.022 |
| Body Mass Index (kg/m2) | 28.3 [25.4–32.0] | 28.7 [25.6–32.0] | 28.2 [25.3–32.5] | 0.574 |
| Hematocrit (%) | 39.3 [35.7–42.3] | 40.1 [ 36.0–42.6] | 38.2 [35.2–41.7] | 0.013 |
| Creatinine Clearance MDRD (ml/min/1.73 m2) | 72.6 [58.2–85.5] | 75.5 [61.6–90.4] | 68.3 [52.7–82.5] | < 0.001 |
| Albumin (g/dL) | 4.1 [3.8–4.5] | 4.2 [3.9–4.5] | 4.1 [3.8–4.4] | 0.005 |
| EuroSCORE II (%) | 1.95 [1.15–4.38] | 1.69 [1.01–2.96] | 2.82 [1.41–5.67] | < 0.001 |
| STS Morbidity/Mortality (%)* | 12.0 [7.9–20.1] | 11.0 [7.0–16.4] | 14.5 [9.0–25.0] | < 0.001 |
| Surgery type | 0.118 | |||
| CABG | 196 (52%) | 109 (55%) | 87 (48%) | |
| CABG + Valve | 65 (17%) | 26 (13%) | 39 (22%) | |
| Valve | 79 (21%) | 45 (23%) | 34 (19%) | |
| Other | 38 (10%) | 18 (9%) | 20 (11%) | |
| NYHA | 0.974 | |||
| I | 43 (11%) | 23 (12%) | 20 (11%) | |
| II | 168 (44%) | 88 (44%) | 80 (44%) | |
| III | 112 (30%) | 57 (29%) | 55 (31%) | |
| IV | 55 (15%) | 30 (15%) | 25 (14%) | |
| BPF (%) | 62.4 [56.2–67.8] | 60.6 [54.4–65.9] | 64.2 [57.5–70.6] | < 0.001 |
| Mean SBP (mmHg) | 136 [122–152] | 135 [122–151] | 138 [122–153] | 0.541 |
| SD (mmHg) | 7.24 [5.85–9.26] | 7.16 [5.85–9.02] | 7.34 [5.85–9.43] | 0.909 |
| CV | 0.053 [0.043–0.066] | 0.053 [0.043–0.066] | 0.054 [0.042–0.065] | 0.703 |
| ARV (mmHg) | 2.97 [2.25–3.86] | 2.94 [2.21–3.76] | 2.99 [2.26–4.08] | 0.264 |
| DFA ⍺1 | 1.11 [0.92–1.27] | 1.14 [0.96–1.31] | 1.07 [0.86–1.25] | 0.009 |
The values for continuous variables are the median and [inter-quartile range]. Values for binary variables are number of participants and (their percentage) in the population/sub-populations. Statistically significant p value are highlighted in bold. Abbreviations: ARV, average real variability; BPF, blood pressure fragmentation; CABG, coronary artery bypass graft; CV, coefficient of variation; DFA, detrended fluctuation analysis; EuroSCORE, European System for Cardiac Operative Risk Evaluation; ICU, intensive care unit; LOS, length of stay; MDRD, modification of diet in renal disease equation; NYHA, New York Heart Association; SBP, systolic blood pressure; SD, standard deviation; and STS, Society of Thoracic Surgeons.
*The STS Morbidity/Mortality risk score was calculated for all patients who qualified.