Table 4. Table 4A. Cox Regression with Multiple Predictor Variables Including Location and Type of Mutations and their Interaction for First Cardiac Event.
| Hazard Ratio | 95% Confidence Interval | P Value | ||
|---|---|---|---|---|
| 1. Mutation Location by Type | ||||
| Transmembrane pore (S5-loop-S6) / C-terminus (reference) | ||||
| Missense mutations | 2.87 | 2.03 | 4.07 | <0.001 |
| Non-missense mutations | 1.13 | 0.65 | 1.95 | 0.663 |
| N-terminus / C-terminus (reference) | ||||
| Missense mutations | 1.86 | 1.25 | 2.78 | 0.002 |
| Non-missense mutations | 0.77 | 0.50 | 1.17 | 0.220 |
| Transmembrane non-pore (S1-S4) / C-terminus (reference) | ||||
| Missense mutations | 1.19 | 0.59 | 2.39 | 0.632 |
| Non-missense mutations | 0.46 | 0.18 | 1.17 | 0.103 |
| 2. Mutation Type by Location | ||||
| Non-missense / Missense (reference) | ||||
| C-terminus location | 2.00 | 1.33 | 3.00 | 0.001 |
| Other locations (N-terminus, S1-S4, S5-loop-S6) | n.s. | |||
| 3. Interaction Between Mutation Location and Type* | --- | --- | --- | 0.008 |
| Table 4B. Cox Regression with Multiple Predictor Variables Including Location and Type of Mutations and their Interaction for Aborted Cardiac Arrest / LQT-Death | ||||
| Hazard Ratio | 95% Confidence Interval | P Value | ||
| 1. Mutation Location by Type | ||||
| Transmembrane pore (S5-loop-S6) / C-terminus (reference) | ||||
| Missense mutations | 1.65 | 0.93 | 2.91 | 0.085 |
| Non-missense mutations | 0.57 | 0.19 | 1.74 | 0.324 |
| N-terminus / C-terminus (reference) | ||||
| Missense mutations | 1.95 | 0.99 | 3.83 | 0.052 |
| Non-missense mutations | 0.80 | 0.37 | 1.73 | 0.575 |
| Transmembrane non-pore (S1-S4) / C-terminus (reference) | ||||
| Missense mutations | 1.94 | 0.61 | 6.20 | 0.264 |
| Non-missense mutations | 0.55 | 0.12 | 2.56 | 0.446 |
| 2. Mutation Type by Location | ||||
| Non-missense / Missense (reference) | ||||
| C-terminus location | 1.75 | 0.85 | 3.61 | 0.131 |
| Other locations (N-terminus, S1-S4, S5-loop-S6) | n.s. | |||
| 3. Interaction Between Mutation Location and Type* | --- | --- | --- | 0.208 |
Note: Items 1, 2, and 3 identify risk factors from the same model. The model adjusted for enrolling site, gender X age, QTc, and time-dependent beta-blockers as in Table 3. When family members who experienced LQTS-related SCD without being genotyped were omitted from the analyses, the hazard ratios, confidence intervals, and p-values for location and type of mutation were similar to those values in the above table, but the significance for the interaction between mutation location and type was reduced from p=0.008 to p=0.09.
The interaction between mutation location and type measures whether the cardiac event risk for a location relative to the C-terminus varies significantly between missense and non-missense mutations. The hazard ratio and confidence intervals are not provided for this interaction since the p-value is an overall significance level for three interaction terms.
See note in Table 4A. Model adjusted for enrolling site, gender X age, QTc, and time-dependent syncope and beta-blockers as in Table 3.
The interaction between mutation location and type measures whether the cardiac event risk for a location relative to the C-terminus varies significantly between missense and non-missense mutations. The hazard ratio and confidence intervals are not provided for this interaction since the p-value is an overall significance level for three interaction terms.