Table 1. Baseline and procedural characteristics of patients in the hydration and non-hydration groups.
| Characteristics | Total (N = 17139) | Hydration (N = 7901) | Non-hydration (N = 9238) | P value |
|---|---|---|---|---|
| Age (years) | 60.33 ± 10.38 | 60.24 ± 10.31 | 60.41 ± 10.44 | 0.285 |
| Age >75 years, n (%) | 1139 (6.8) | 505 (6.5) | 634 (7.0) | 0.228 |
| Female, n (%) | 6117 (35.7) | 2829 (35.8) | 3288 (35.6) | 0.783 |
| Weight (kg) | 69.16 ± 10.71 | 70.05 ± 11.02 | 68.41 ± 10.38 | <0.0001 |
| Previous history | ||||
| History of hypertension, n (%) | 9528 (55.6) | 4619 (58.5) | 4909 (53.1) | <0.0001 |
| History of diabetes mellitus, n (%) | 3441 (20.1) | 1778 (22.5) | 1663 (18.0) | <0.0001 |
| Prior MI, n (%) | 1187 (6.9) | 646 (8.2) | 541 (5.9) | <0.0001 |
| Pre-existing renal disease, n (%) | 239 (1.4) | 185 (2.3) | 54 (0.6) | <0.0001 |
| Family history of CAD, n (%) | 1185 (6.9) | 660 (8.4) | 525 (5.7) | <0.0001 |
| Prior cardiac catheterization, n (%) | 1749 (10.2) | 864 (10.9) | 885 (9.6) | 0.003 |
| Systolic blood pressure (mmHg) | 134.20 ± 18.46 | 135.04 ± 18.66 | 133.47 ± 18.25 | <0.0001 |
| Diastolic blood pressure (mmHg) | 80.21 ± 11.48 | 81.31 ± 11.75 | 79.27 ± 11.16 | <0.0001 |
| Preoperative metformin, n (%) | 319 (1.9) | 168 (2.1) | 151 (1.6) | 0.018 |
| LVEF < 35%, n (%) | 158 (0.9) | 70 (0.9) | 88 (1.0) | 0.628 |
| LVEF <45%, n (%) | 717 (4.2) | 302 (3.8) | 315 (4.6) | 0.025 |
| Clinical presentation | ||||
| STEMI, n (%) | 1890 (11.0) | 1023 (12.9) | 867 (9.4) | <0.0001 |
| NSTEMI, n (%) | 833 (4.9) | 375 (4.7) | 458 (5.0) | 0.521 |
| Unstable angina, n (%) | 8689 (50.7) | 4610 (58.3) | 4079 (44.2) | <0.0001 |
| Stable angina, n (%) | 2039 (11.9) | 628 (7.9) | 1411 (15.3) | <0.0001 |
| Others, n (%) | 3912 (22.8) | 1388 (17.6) | 2524 (27.3) | <0.0001 |
| TC (mmol/L) | 4.51 ± 1.17 | 4.57 ± 1.17 | 4.46 ± 1.17 | <0.0001 |
| TG (mmol/L) | 1.69 ± 0.95 | 1.72 ± 0.98 | 1.66 ± 0.91 | <0.0001 |
| Contrast dose (mL) | 124.80 ± 72.88 | 140.38 ± 80.59 | 111.49 ± 62.57 | <0.0001 |
| Coronary artery features | ||||
| Normal, n (%) | 3044 (17.8) | 1036 (13.1) | 2008 (21.7) | <0.0001 |
| Single-vessel disease, n (%) | 6756 (39.4) | 2943 (37.2) | 3813 (41.3) | <0.0001 |
| Multi-vessel disease, n (%) | 7339 (42.8) | 3922 (49.6) | 3417 (37.0) | <0.0001 |
| Left main disease, n (%) | 1456 (8.5) | 809 (10.2) | 647 (7.0) | <0.0001 |
| Left anterior descending branch, n (%) | 11,142 (65.0) | 5434 (68.8) | 5708 (61.8) | <0.0001 |
| Left circumflex artery, n (%) | 6478 (37.8) | 3354 (42.5) | 3124 (33.8) | <0.0001 |
| Right coronary artery, n (%) | 6534 (38.1) | 3359 (42.5) | 3175 (34.4) | <0.0001 |
| Stents implanted, n (%) | 8287 (48.4) | 4078 (51.6) | 4209 (45.6) | <0.0001 |
| Number of stents implanted | 1.68 ± 0.76 | 1.69 ± 0.76 | 1.67 ± 0.76 | 0.302 |
Abbreviations: MI, myocardial infarction; CAD, coronary artery disease; LVEF, left ventricular ejection fraction; STEMI, acute ST segment elevation myocardial infarction; NSTEMI, non-ST segment elevation acute myocardial infarction; TC, total cholesterol; TG, total triglyceride.