Table 1.
Clinical characteristics of the study population.
| Parameter | Total (N = 160) | High IMR (N = 54) | Low IMR (N = 106) | P value |
|---|---|---|---|---|
| Clinical characteristics | ||||
| Age (years) | 56 ± 11 | 60 ± 11 | 54 ± 11 | 0.001 |
| Male, n (%) | 141 (88.1%) | 45 (83.3%) | 96 (90.6%) | 0.281 |
| Current smoking, n (%) | 115 (71.9%) | 36 (66.7%) | 79 (74.5%) | 0.353 |
| BMI | 24.6 [22.9–26.6] | 25.0 [21.9–26.9] | 24.6 [23.4–26.5] | 0.734 |
| SBP (mmHg) | 134.9 ± 23.8 | 137.7 ± 25.3 | 133.5 ± 23.1 | 0.299 |
| DBP (mmHg) | 84.4 ± 16.2 | 85.3 ± 17.2 | 84.0 ± 15.7 | 0.637 |
| HR (beats/min) | 76.8 ± 15.7 | 73.7 ± 15.6 | 78.4 ± 15.6 | 0.075 |
| Killip class | 0.053 | |||
| I | 122 (76.2%) | 35 (64.8%) | 87 (82.1%) | |
| II | 32 (20.0%) | 16 (29.6%) | 16 (15.1%) | |
| III | 6 (3.8%) | 3 (5.6%) | 3 (2.8%) | |
|
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| Medical history, n (%) | ||||
| Hypertension | 77 (48.1%) | 31 (57.4%) | 46 (43.4%) | 0.131 |
| Diabetes mellitus | 49 (30.6%) | 20 (37.0%) | 29 (27.4%) | 0.283 |
| Dyslipidemia | 68 (42.5%) | 21 (38.9%) | 47 (44.3%) | 0.624 |
|
| ||||
| Time to reperfusion, min | ||||
| DTB, min | 68.0 [57.0–80.0] | 69.5 [52.0–83.0] | 68.0 [59.0–80.0] | 0.779 |
| SHT, min | 120.0 [60.0–210.0] | 144.0 [71.0–360.0] | 95.0 [60.0–174.0] | 0.003 |
| SBT, min | 188.5 [125.5–293.0] | 235.0 [159.0–397.0] | 162.0 [115.0–265.0] | 0.001 |
|
| ||||
| Echocardiographic analysis | ||||
| LVEDD (mm) | 49.0 [46.0–51.0] | 48.0 [45.0–51.0] | 49.0 [46.0–51.0] | 0.664 |
| LVESD (mm) | 36.0 [33.0–38.0] | 34.0 [32.0–39.0] | 36.0 [33.0–38.0] | 0.489 |
| LVEF (%) | 46.5 ± 7.0 | 44.7 ± 6.8 | 47.3 ± 7.0 | 0.028 |
| E/e' | 10.1 [8.4–11.9] | 10.5 [9.3–12.5] | 9.8 [8.0–11.2] | 0.024 |
| WMSI | 1.6 [1.2–1.8] | 1.7 [1.3–1.8] | 1.5 [1.2–1.8] | 0.040 |
| LV mass (g) | 188.1 [158.2–213.6] | 193.5 [147.8; 220.6] | 188.1 [158.8; 207.3] | 0.690 |
| LV mass index (g/m2) | 104.8 [88.9; 116.7] | 107.9 [89.2; 119.3] | 103.4 [88.9; 114.5] | 0.424 |
|
| ||||
| Cardiac biomarkers | ||||
| CK peak, IU/L | 2373.0 [774.0–4276.0] | 3102.0 [1406.0–5580.0] | 2020.0 [729.0–3897.0] | 0.028 |
| CK-MB peak, ng/mL | 224.9 [78.2–370.0] | 289.4 [129.0–465.9] | 188.0 [73.0–334.0] | 0.010 |
| Troponin-I peak, ng/mL | 82.7 [21.0–148.4] | 100.0 [47.0–250.0] | 66.0 [17.4–122.5] | 0.084 |
| NT-proBNP, pg/mL | 70.0 [23.0–255.5] | 106.0 [36.0–293.5] | 51.5 [21.0–186.0] | 0.054 |
|
| ||||
| Renal function | ||||
| BUN, mg/dL | 15.3 [12.9–18.3] | 14.9 [12.2–18.5] | 15.4 [13.3–18.1] | 0.582 |
| Creatinine, mg/dL | 1.0 [0.9–1.2] | 1.0 [0.9–1.2] | 1.0 [0.9–1.1] | 0.543 |
| eGFR (ml/min/1.73 m2) | 77.5 [68.0–91.1] | 72.0 [62.7–91.2] | 79.5 [71.3–91.1] | 0.081 |
| eGFR < 60 ml/min/1.73 m2, n (%) | 18 (11.2%) | 9 (16.7%) | 9 (8.5%) | 0.184 |
BMI, body mass index; BUN, blood urea nitrogen; CK, creatine kinase; CK-MB, creatine kinase muscle/brain; DBP, diastolic blood pressure; DTB, door to balloon time; eGFR, estimated glomerular filtration rate; HR, heart rate; IMR, index of microcirculatory resistance; LV, left ventricle; LVEDD, left ventricular end-diastolic diameter; LVEF, left ventricular ejection fraction; LVESD, left ventricular end-systolic diameter; NT-proBNP, N-terminal prohormone of brain natriuretic peptide; SBP, systolic blood pressure; SBT, symptom onset to balloon time; SHT, symptom onset to hospital time; WMSI, wall motion score index.