Table 3 Integrated Discrimination Improvement (IDI) and Net Reclassification Improvement (NRI) for ECG metrics added to clinical predictors of SCD and nonSCD outcomes (age, sex, race, coronary heart disease, stroke, hypertension, diabetes)
Outcome | Prediction model | Reclassification index | 1–90 days (high risk ≥25%) | 91–180 d (high risk ≥25%) | 181–365 d (high risk ≥25%) | 365–730 d (high risk ≥10%) | 731–1825 d (high risk ≥10%) | > 5 years (high risk ≥10%) |
|---|---|---|---|---|---|---|---|---|
Sudden cardiac death | Clinical + QTc, ms | Absolute IDI (P-value) | 0.063(0.109) | 0.007(0.437) | 0.001(0.695) | 0.004(0.236) | 0.001(0.020) | 0.0003(0.424) |
Event Reclassified Up | 2/11(18%) | 0 | 2/47(4.3%) | 3/84(3.6) | 11/495(2%) | 0 | ||
Category-free NRI (P-value) | 0.331(0.106) | −0.049(0.473) | 0.057(0.114) | 0.011(0.677) | 0.005(0.226) | −0.003(0.432) | ||
Clinical + QRS, ms | Absolute IDI (P-value) | 0.012(0.430) | 0.004(0.785) | 0.013(0.097) | 0.003(0.215) | 0.002(0.00006) | 0.001(0.070) | |
Event Reclassified Up | 0 | 0 | 0 | 3/84(3.6%) | 19/495(3.8%) | 1/320(0.3%) | ||
Category-free NRI (P-value) | −0.023(0.839) | − 0.015(0.853) | 0.058(0.018) | 0.003(0.919) | 0.009(0.032) | −0.009(0.198) | ||
Clinical + heart rate, bpm | Absolute IDI (P-value) | 0.00004(0.978) | 0.026(0.244) | 0.020(0.030) | 0.0003(0.664) | −0.0002(0.402) | 0.0005(0.410) | |
Event Reclassified Up | 0 | 0 | 4/47(8.5%) | 3/84(3.6%) | 11/495(2.2%) | 3/320(1%) | ||
Category-free NRI (P-value) | 0(1.0) | −0.067(0.420) | 0.029(0.671) | 0.034(0.109) | 0.003(0.433) | −0.004(0.630) | ||
Clinical+ Area QRS-T angle, ° | Absolute IDI (P-value) | 0.001(0.784) | 0.066(0.046) | 0.0001(0.852) | 0.005(0.195) | 0.005(< 0.00001) | 0.002(0.029) | |
Event Reclassified Up | 0 | 1/16(6.3%) | 0 | 2/84(2.4%) | 46/495(9.6%) | 1/320(0.3%) | ||
Category-free NRI (P-value) | 0(1.0) | −0.032(0.801) | −0.006(0.317) | 0.035(0.118) | 0.021(0.003) | −0.006(0.308) | ||
Clinical+ Peak QRS-T angle, ° | Absolute IDI (P-value) | 0.032(0.328) | 0.048(0.083) | −0.00001(0.986) | 0.007(0.084) | 0.007(< 0.00001) | 0.001(0.045) | |
Event Reclassified Up | 2/11(18%) | 1/16(6.3%) | 0 | 5/84(6.0) | 52/495(10.5%) | 1/320(0.3%) | ||
Category-free NRI (P-value) | 0.216(0.246) | −0.101(0.420) | −0.012(0.157) | 0.041(0.252) | 0.021(0.006) | −0.015(0.067) | ||
Clinical+ Area SVG azimuth, ° | Absolute IDI (P-value) | 0.012(0.607) | 0.007(0.651) | 0.002(0.665) | 0.020(0.001) | 0.002(0.004) | −0.0002(0.0008) | |
Event Reclassified Up | 2/11(18%) | 0 | 1/47(2.1%) | 7/84(7.1%) | 21/495(4.2%) | 0 | ||
Category-free NRI (P-value) | 0.277(0.068) | −0.050(0.541) | 0.023(0.398) | 0.055(0.152) | 0.003(0.578) | 0.0002(0.083) | ||
Clinical+ Peak SVG azimuth, ° | Absolute IDI (P-value) | 0.015(0.608) | 0.045(0.141) | −0.0001(0.880) | 0.017(0.005) | 0.003(0.00005) | −0.0001(0.568) | |
Event Reclassified Up | 2/11(18%) | 0 | 0 | 5/84(6%) | 27/495(5.5%) | 0 | ||
Category-free NRI (P-value) | 0.277(0.068) | −0.133(0.221) | −0.006(0.564) | 0.020(0.598) | 0.004(0.538) | 0.0009(0.003) | ||
Clinical + Area SVG elevation, ° | Absolute IDI (P-value) | 0.002(0.735) | 0.050(0.063) | 0.004(0.398) | −0.00001(0.990) | 0.0001(0.576) | −0.0004(0.045) | |
Event Reclassified Up | 0 | 1/16(6.3%) | 0 | 3/84(3.6%) | 11/495(2.2%) | 0 | ||
Category-free NRI (P-value) | 0.038(0.317) | −0.118(0.349) | 0.018(0.257) | 0.037(0.093) | 0.001(0.847) | 0.0004(0.034) | ||
Clinical + Peak SVG elevation, ° | Absolute IDI (P-value) | 0.003(0.663) | 0.046(0.112) | 0.002(0.463) | 0.0004(0.879) | 0.0002(0.387) | −0.0003(0.023) | |
Event Reclassified Up | 0 | 0 | 0 | 5/84(6%) | 7/495(1.4%) | 0 | ||
Category-free NRI (P-value) | 0.038(0.317) | −0.084(0.276) | 0.006(0.564) | 0.070(0.017) | −0.004(0.240) | 0.0005(0.020) | ||
Clinical + SAI QRST,mV*ms | Absolute IDI (P-value) | 0.0001(0.755) | 0.023(0.339) | 0.002(0.522) | 0.012(0.040) | 0.002(0.0004) | 0.001(0.061) | |
Event Reclassified Up | 0 | 0 | 0 | 1/84(1.2%) | 23/495(4.6%) | 1/320(0.3%) | ||
Category-free NRI (P-value) | 0(1.0) | −0.151(0.151) | 0.006(0.564) | 0.007(0.778) | 0.013(0.005) | 0.0005(0.909) | ||
Clinical + SVG magnitude, μV | Absolute IDI (P-value) | 0.015(0.566) | −0.0002(0.954) | 0.0002(0.884) | 0.0009(0.188) | −0.0002(0.00003) | 0.00007(0.764) | |
Event Reclassified Up | 0 | 0 | 0 | 2/84(2.4%) | 0 | 0 | ||
Category-free NRI (P-value) | −0.023(0.839) | − 0.052(0.083) | − 0.012(0.157) | 0.018(0.318) | 0.0001(0.371) | − 0.002(0.516) | ||
Clinical + Peak SVG mag, μV | Absolute IDI (P-value) | 0.001(0.748) | 0.0003(0.959) | 0.0002(0.869) | 0.0006(0.095) | −0.00006(0.676) | −0.0002(0.189) | |
Event Reclassified Up | 0 | 0 | 0 | 3/84(3.6%) | 7/495(1.4%) | 0 | ||
Category-free NRI (P-value) | 0(1.0) | −0.052(0.180) | − 0.012(0.157) | 0.032(0.135) | 0.004(0.144) | 0.0003(0.102) | ||
Non-Sudden cardiac death | Clinical + QTc, ms | Absolute IDI (P-value) | 0.069(0.170) | 0.006(0.667) | 0.015(0.200) | 0.0001(0.843) | 0.003(< 0.00001 | 0.001(0.040) |
Event Reclassified Up | 0 | 0 | 2/47(2.3%) | 0 | 46/711(6.5%) | 10/394(2.5%) | ||
Category-free NRI (P-value) | 0.200(0.059) | 0(1.0) | −0.006(0.880) | −0.011(0.225) | 0.002(0.749) | 0.016(0.064) | ||
Clinical + QRS, ms | Absolute IDI (P-value) | 0.028(0.467) | 0.187(0.001) | −0.002(0.702) | 0.0007(0.623) | 0.002(0.0001) | 0.001(0.051) | |
Event Reclassified Up | 0 | 2/16(12.5%) | 0 | 0 | 34/711(4.8%) | 10/394(2.5%) | ||
Category-free NRI (P-value) | −0.011(0.919) | 0.136(0.230) | 0.014(0.561) | 0.011(0.225) | 0.004(0.395) | 0.009(0.337) | ||
Clinical + heart rate, bpm | Absolute IDI (P-value) | 0.060(0.160) | −0.0001(0.981) | 0.0005(0.909) | 0.0003(0.779) | 0.005(< 0.00001) | 0.002(0.010) | |
Event Reclassified Up | 0 | 0 | 1/47(2.1%) | 0 | 89/711(12.5%) | 14/394(3.6%) | ||
Category-free NRI (P-value) | 0.200(0.059) | 0(1.0) | 0.037(0.158) | −0.0002(0.990) | 0.014(0.060) | 0.014(0.207) | ||
Clinical+ Area QRS-T angle, ° | Absolute IDI (P-value) | 0.053(0.272) | 0.012(0.625) | 0.059(0.002) | 0.007(0.120) | 0.010(< 0.00001) | 0.004(0.0004) | |
Event Reclassified Up | 1/11(9%) | 0 | 4/47(8.5%) | 0 | 108/711(15%) | 19/394(4.8%) | ||
Category-free NRI (P-value) | 0.120(0.411) | −0.049(0.499) | 0.060(0.286) | 0.084(0.0003) | 0.017(0.034) | 0.021(0.097) | ||
Clinical+ Peak QRS-T angle, ° | Absolute IDI (P-value) | 0.169(0.026) | 0.077(0.030) | 0.072(0.0004) | 0.005(0.180) | 0.009(< 0.00001) | 0.005(0.00002) | |
Event Reclassified Up | 1/11(9%) | 0 | 6/47(12.8%) | 0 | 114/711(16%) | 24/394(6.1%) | ||
Category-free NRI (P-value) | 0.120(0.411) | −0.084(0.276) | 0.01(0.167) | 0.052(0.006) | 0.017(0.033) | 0.034(0.011) | ||
Clinical+ Area SVG azimuth, ° | Absolute IDI (P-value) | 0.183(0.003) | 0.123(0.010) | 0.014(0.093) | 0.0008(0.534) | 0.003(< 0.00001) | 0.003(0.0006) | |
Event Reclassified Up | 1/11(9%) | 0 | 1/47(2.1%) | 0 | 57/711(8.0%) | 13/394(3.3%) | ||
Category-free NRI (P-value) | 0.200(0.202) | −0.049(0.574) | −0.005(0.899) | − 0.0002(0.994) | 0.009(0.109) | 0.06(0.112) | ||
Clinical+ Peak SVG azimuth, ° | Absolute IDI (P-value) | 0.164(0.015) | 0.005(0.740) | 0.007(0.315) | 0.0003(0.642) | 0.003(< 0.00001) | 0.003(0.001) | |
Event Reclassified Up | 1/11(9%) | 0 | 2/47(2.3%) | 0 | 45/711(6.3%) | 17/394(4.3%) | ||
Category-free NRI (P-value) | 0.240(0.138) | 0.017(0.317) | −0.008(0.840) | −0.002(0.782) | 0.003(0.600) | 0.027(0.019) | ||
Clinical + Area SVG elevation, ° | Absolute IDI (P-value) | 0.025(0.398) | 0.058(0.057) | 0.007(0.370) | 0.0008(0.356) | 0.0005(0.015) | 0.0006(0.044) | |
Event Reclassified Up | 0 | 0 | 4/47(8.5%) | 0 | 16/711(2.3%) | 9/394(2.3%) | ||
Category-free NRI (P-value) | −0.051(0.608) | 0(1.0) | 0.114(0.007) | −0.007(0.549) | − 0.005(0.216) | 0.018(0.025) | ||
Clinical + Peak SVG elevation, ° | Absolute IDI (P-value) | 0.039(0.273) | 0.017(0.193) | 0.018(0.081) | 0.0005(0.703) | 0.002(0.00007) | 0.0004(0.081) | |
Event Reclassified Up | 1/11(9%) | 0 | 4/47(8.5%) | 0 | 34/711(4.8%) | 4/394(1.0%) | ||
Category-free NRI (P-value) | 0.189(0.319) | 0.017(0.317) | 0.068(0.210) | 0.014(0.221) | −0.002(0.743) | 0.009(0.065) | ||
Clinical + SAI QRST,mV*ms | Absolute IDI (P-value) | 0.040(0.422) | 0.018(0.528) | 0.027(0.059) | 0.019(0.022) | 0.004(< 0.00001) | 0.0006(0.093) | |
Event Reclassified Up | 0 | 0 | 4/47(8.5%) | 1/84(1%) | 49/711(6.9%) | 3/394(0.8%) | ||
Category-free NRI (P-value) | 0.109(0.392) | −0.084(0.251) | 0.054(0.290) | 0.098(0.003) | 0.002(0.770) | 0.003(0.580) | ||
Clinical + SVG magnitude, μV | Absolute IDI (P-value) | 0.028(0.332) | −0.002(0.886) | −0.002(0.480) | 0.026(0.004) | 0.0008(0.00008) | 0.0002(0.00008) | |
Event Reclassified Up | 0 | 0 | 0 | 1/84(1%) | 10/711(1.4%) | 0 | ||
Category-free NRI (P-value) | 0.029(0.799) | 0(1.0) | 0.006(0.317) | 0.090(0.021) | −0.004(0.178) | −0.0004(0.059) | ||
Clinical + Peak SVG mag, μV | Absolute IDI (P-value) | 0.027(0.355) | 0.020(0.433) | −0.0004(0.907) | 0.016(0.032) | 0.0002(< 0.00001) | 0.0003(0.067) | |
Event Reclassified Up | 0 | 0 | 0 | 1/84(1%) | 2/711(0.3%) | 3/394(0.8%) | ||
Category-free NRI (P-value) | 0.029(0.799) | −0.067(0.348) | 0(1.0) | 0.098(0.005) | −0.001(0.473) | 0.004(0.482) |