The HbA1c level (P = 0.025), CTO of any target vessel (P = 0.009) and surgical time (P = 0.068) were associated with early VGF in univariable analysis. Therefore, these three variables were included in a multivariable analysis. Results of the multivariable analysis showed that only the HbA1c level was significantly associated with early VGF (P = 0.013) (Table 3). However, according to a restricted cubic spline, a non-linear (J-shaped) relationship was shown between the HbA1c levels and risk of early VGF (Fig. 2).
Table 3:
Multivariable logistic regression analysis results for early VGF
| Variable | Odds ratio (95% CI) | P-value |
|---|---|---|
| HbA1c level (per unit increase) | 1.30 (1.06–1.60) | 0.013 |
| CTO of any target vessel | 1.83 (0.95–3.53) | 0.073 |
| Surgical time (per minute increase) | 1.00 (1.00–1.01) | 0.073 |
| Variable | Odds ratio (95% CI) | P-value |
|---|---|---|
| HbA1c level (per unit increase) | 1.30 (1.06–1.60) | 0.013 |
| CTO of any target vessel | 1.83 (0.95–3.53) | 0.073 |
| Surgical time (per minute increase) | 1.00 (1.00–1.01) | 0.073 |
CI: confidence interval; CTO: chronic total occlusion; HbA1c: haemoglobin A1c; VGF: vein graft failure.
Table 3:
Multivariable logistic regression analysis results for early VGF
| Variable | Odds ratio (95% CI) | P-value |
|---|---|---|
| HbA1c level (per unit increase) | 1.30 (1.06–1.60) | 0.013 |
| CTO of any target vessel | 1.83 (0.95–3.53) | 0.073 |
| Surgical time (per minute increase) | 1.00 (1.00–1.01) | 0.073 |
| Variable | Odds ratio (95% CI) | P-value |
|---|---|---|
| HbA1c level (per unit increase) | 1.30 (1.06–1.60) | 0.013 |
| CTO of any target vessel | 1.83 (0.95–3.53) | 0.073 |
| Surgical time (per minute increase) | 1.00 (1.00–1.01) | 0.073 |
CI: confidence interval; CTO: chronic total occlusion; HbA1c: haemoglobin A1c; VGF: vein graft failure.
Figure 2:
Non-linear relationship between the haemoglobin (Hb) A1c level and risk of early vein graft failure according to restricted cubic spline with four knots (5.2, 5.8, 6.7 and 9.2%). The odds ratio was adjusted for the surgical time and chronic total occlusion of any target vessel. The reference was set at HbA1c = 6.1%, which corresponded to the lowest odds ratio.
