Table 3.
Morphometric Parameters and Graft Failure Due to Endothelial Decompensation Proportional Hazards Regression Multivariate Analyses
| Covariate | N | Hazard Ratio* | 95% Confidence Interval | P-value |
|---|---|---|---|---|
| Model 1 | 68 | |||
| Preoperative (baseline) VF-ECD | 1.06 | 0.87 – 1.28 | 0.56 | |
| Preoperative (baseline) CV | 1.10 | 0.19 – 6.43 | 0.92 | |
| Preoperative (baseline) HEX | 0.94 | 0.33 – 2.70 | 0.91 | |
| Model 2** | 46 | |||
| VF-ECD at 6 months | 1.20 | 1.04 – 1.38 | 0.01 | |
| CV at 6 months | 0.79 | 0.13 – 4.66 | 0.79 | |
| HEX at 6 months | 2.57 | 1.20– 5.50 | 0.02 | |
| Model 3*** | 72 | |||
| Most recent VF-ECD (time dependent) | 1.28 | 1.13 – 1.46 | <0.001 | |
| Most recent CV (time dependent) | 1.08 | 0.51 – 2.28 | 0.85 | |
| Most recent HEX (time dependent) | 0.99 | 0.62 – 1.59 | 0.98 |
VF = variable frame; ECD = endothelial cell density; CV = coefficient of variation; HEX = percent hexagonal cells
A hazard ratio value > 1.0 denotes increased graft failure with lower VF-ECD values, higher CV values and lower HEX values. The hazard ratio is calculated per 100 cells/mm2 change in ECD, 0.10 change in CV and 10% change in HEX. Morphometric values are treated as continuous variables in all models.
Cox model is conditional on graft survival at 6 months. Excluded subjects include graft failure prior to 6 months (N=1) or missing 6-month morphometric values (N=25).
Cox model fitted with all three morphometric parameters as time-dependent covariates. Most recent covariate is the last morphometric value prior to graft failure or last exam date.
Note: Results were similar when the morphometric ECD was used instead of variable frame ECD in all models presented in this table.