Table 1. Characteristics of participants categorized by MHR.
| Characteristics | low MHR group (<60 bpm) | high MHR group (≥60 bpm) | P |
|---|---|---|---|
| N | 840 | 1,191 | – |
| Age, years | 69.76±12.73 | 66.64±14.47 | <0.001 |
| Male | 542 (64.52) | 757 (63.56) | 0.656 |
| Private insurance | 276 (32.85) | 446 (37.44) | 0.025 |
| White | 520 (61.90) | 749 (62.88) | 0.652 |
| Weight, kg | 80.09±18.99 | 81.35±20.18 | 0.149 |
| SAPS score | 18.1±6.13 | 16.21±6.02 | <0.001 |
| SOFA score | 3.00 (1.00–6.00) | 3.00 (1.00–5.00) | 0.156 |
| Elixhauser score | 0.00 (0.00–5.00) | 0.00 (0.00–5.00) | 0.060 |
| Sedatives | 260 (30.95) | 401 (33.66) | 0.198 |
| Ventilation | 300 (35.71) | 438 (36.77) | 0.624 |
| Vasopressor | 259 (30.83) | 413 (34.67) | 0.070 |
| Heart rate, bpm | 78.31±18.02 | 89.46±15.98 | <0.001 |
| MAP, mmHg | 85.02±18.29 | 85.73±17.68 | 0.365 |
| Temperature, °C | 36.24±1.05 | 36.42±0.90 | <0.001 |
| Hypertension | 496 (59.04) | 671 (56.33) | 0.224 |
| AF | 233 (27.73) | 277 (23.25) | 0.022 |
| CHF | 310 (36.90) | 468 (39.29) | 0.275 |
| Valvular disease | 110 (13.09) | 181 (15.19) | 0.183 |
| Stroke | 50 (5.95) | 48 (4.03) | 0.047 |
| Diabetes | 215 (25.59) | 322 (27.03) | 0.468 |
| Sepsis | 181 (21.54) | 221 (18.55) | 0.096 |
| Renal disease | 74 (8.80) | 88 (7.38) | 0.244 |
| Liver disease | 44 (5.23) | 36 (3.02) | 0.011 |
| COPD | 78 (9.28) | 114 (9.57) | 0.828 |
| Malignancy | 47 (5.59) | 81 (6.80) | 0.271 |
| WBC, K/μL | 12.36±5.82 | 12.92±5.41 | 0.028 |
| Platelet, K/μL | 226.29±100.13 | 230.56±90.50 | 0.317 |
| Hemoglobin, g/dL | 11.71±2.08 | 11.75±2.14 | 0.663 |
| Creatinine kinase, U/L | 250.50 (51.00–964.06) | 462.00 (85.00–999.85) | <0.001 |
| Creatinine, mg/dL | 1.00 (0.80–1.40) | 0.90 (0.70–1.30) | <0.001 |
| Chloride, mg/dL | 104.83±5.05 | 104.75±4.88 | 0.718 |
| Sodium, mg/dL | 138.05±3.98 | 137.65±3.74 | 0.022 |
| Potassium, md/dL | 4.18±0.69 | 4.26±0.71 | 0.015 |
| BUN, mg/dL | 25.62±18.87 | 22.65±15.68 | <0.001 |
| Bicarbonate, mg/dL | 22.91±4.31 | 23.08±3.89 | 0.354 |
| 30-day mortality | 173 (20.59) | 130 (10.91) | <0.001 |
| 1-year mortality | 250 (29.76) | 230 (19.31) | <0.001 |
For each variable, mean ± standard deviation, median (interquartile range), or number (percent) was reported (as appropriate). Participants were divided into two groups, a low MHR group (MHR <60 bpm) and a high MHR group (MHR ≥60 bpm). Between these two groups, continuous variables were compared using either the Student t-test or the rank-sum test (as appropriate). The Chi-square test was employed to compare differences in the categorical variables. MHR, minimum heart rate; SAPS, simplified acute physiology score; SOFA, sequential organ failure assessment; MAP, mean arterial pressure; AF, atrial fibrillation; CHF, congestive heart failure; COPD, chronic obstructive pulmonary disease; WBC, white blood cell count; BUN, blood urea nitrogen; bpm, beats per minute.