Table 2.
Pooled odds ratio or standardized mean difference of risk factors
| Risk factors | No. of study | OR/SMD (95% CI) | Z value | p value | I2% (p) | Egger’s test, p |
|---|---|---|---|---|---|---|
| Preoperative risk factors | ||||||
| Demographics | ||||||
| Age (years) | 8 | 1.10 (0.62–1.59) | 4.46 | < 0.001 | 0.0 (0.811) | 0.658 |
| Male | 9 | 0.92 (0.79–1.08) | − 1.01 | 0.313 | 1.9 (0.419) | 0.367 |
| Female | 9 | 1.08 (0.93–1.27) | 1.01 | 0.313 | 1.9 (0.419) | 0.367 |
| BMI (kg/m2) | 3 | − 0.03 (− 0.10 to 0.04) | − 0.82 | 0.412 | 0.0 (0.956) | 0.262 |
| Clinical characteristics | ||||||
| Mg++ (mg/dL) | 2 | − 0.37 (− 0.84 to 0.10) | − 1.55 | 0.121 | 74.9 (0.046) | NA |
| Ca++ (mg/dL) | 2 | − 0.91 (− 0.30 to 0.12) | − 0.86 | 0.398 | 0.0 (0.528) | NA |
| Serum Cr (mg/dL) | 3 | 0.12 (0.05–0.19) | 3.39 | 0.001 | 0.0 (0.826) | 0.636 |
| Hemoglobin (mg/dL) | 3 | − 0.10 (− 0.17 to − 0.03) | − 2.71 | 0.007 | 0.0 (0.846) | 0.825 |
| LVEF (%) | 6 | − 0.43 (− 0.43 to − 0.27) | − 3.43 | 0.001 | 71.4 (0.004) | 0.553 |
| Beta-blockers | 8 | 0.89 (0.68–1.17) | − 0.83 | 0.405 | 35.9 (0.142) | 0.260 |
| ACEi | 3 | 1.05 (0.91–1.21) | 0.62 | 0.535 | 0.0 (0.927) | 0.375 |
| ACEi/ARB | 2 | 0.43 (0.12–1.54) | − 1.30 | 0.195 | 65.4 (0.089) | NA |
| Nitrates | 2 | 1.63 (0.86–3.02) | 1.54 | 0.124 | 0.0 (0.528) | NA |
| Diuretics | 2 | 1.33 (0.69–2.55) | 0.86 | 0.390 | 0.0 (0.912) | NA |
| Statin | 2 | 1.02 (0.57–1.82) | 0.05 | 0.959 | 0.0 (0.367) | NA |
| CCB | 4 | 1.22 (0.92–1.61) | 1.37 | 0.171 | 19.8 (0.291) | 0.310 |
| Comorbidities | ||||||
| MI | 5 | 1.37 (0.96–1.96) | 1.71 | 0.088 | 39.8 (0.156) | 0.326 |
| Essential hypertension | 8 | 1.33 (1.62–1.52) | 4.13 | < 0.001 | 0.0 (0.581) | 0.359 |
| Diabetes | 8 | 1.23 (0.96–1.56) | 1.67 | 0.095 | 37.9 (0.127) | 0.308 |
| COPD | 5 | 1.66 (1.13–2.43) | 2.59 | 0.010 | 0.0 (0.494) | 0.759 |
| Renal failure | 3 | 1.70 (1.14–2.55) | 2.60 | 0.009 | 0.0 (0.928) | 0.766 |
| Dyslipidemia | 4 | 1.47 (0.78–2.76) | 1.20 | 0.232 | 82.2 (0.001) | 0.225 |
| Stroke | 2 | 1.08 (0.58–2.00) | 0.24 | 0.813 | 0.0 (0.708) | NA |
| CVD | 2 | 1.60 (0.93–2.75) | 1.68 | 0.628 | 0.0 (0.428) | NA |
| Intraoperative risk factors | ||||||
| Number of grafts | 5 | − 0.09 (− 0.29 to 0.11) | − 0.86 | 0.393 | 49.3 (0.096) | 0.500 |
| Cross-clamp time (min) | 4 | 0.06 (− 0.08 to 0.20) | 0.82 | 0.415 | 1.1 (0.387) | 0.946 |
| Off-pump | 2 | 1.37 (0.67–2.80) | 0.87 | 0.386 | 56.1 (0.131) | NA |
| CPB time (min) | 3 | 0.20 (0.04–0.36) | 2.39 | 0.017 | 12.5 (0.319) | 0.422 |
| Postoperative risk factors | ||||||
| IV inotrope | 2 | 1.74 (1.50–2.02) | 7.37 | < 0.001 | 0.0 (0.551) | NA |
| Infection | 3 | 2.45 (0.78–7.66) | 1.54 | 0.123 | 68.38 (0.042) | 0.877 |
| Renal failure | 3 | 3.94 (1.70–9.16) | 3.19 | 0.001 | 0.0 (0.771) | 0.582 |
| Re-operation | 2 | 6.41 (1.75–23.42) | 2.81 | 0.005 | 0.0 (0.485) | NA |
| Mechanical ventilation (h) | 2 | 0.26 (− 0.03 to 0.54) | 1.78 | 0.076 | 0.0 (0.606) | NA |
ACEi, angiotensin-converting enzyme inhibitor; ARB, angiotensin receptor blocker; BMI, body mass index; CCB, Ca++ channel blocker; CI, confidence interval; COPD, chronic obstructive pulmonary diseases; Cr, creatinine; CVD, cerebrovascular disease; IV, intravenous; LVEF, left ventricle ejection fraction; MI, myocardial infarction; NA, not available; OR, odds ratio; SMD, standardized mean difference