Electrocardiography score based on the Minnesota code classification system predicts cardiovascular mortality in an asymptomatic low-risk population

Figures

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  Figure 1.. Associations between ECG findings and the risk of CV death in univariate models. ST depression, T-wave flattening, major and minor ST-T wave abnormalities, atrial fibrillation and high amplitude in the left and right precordial leads, left axis deviation, left anterior fascicular block, tachycardia and PR ≥ 70 bpm are associated with an increased risk of CV death. HR: hazard ratio; CI: confidence interval; PR: pulse rate

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  Figure 2.. Nomogram of the multivariate Cox proportional hazard model and the C-statistics of the prediction scores. A) The maximum value of the nomogram was set to 100. The numbers on the scales of individual predictors indicate the normalized coefficient of the predictors. The points were rounded to the closest integers. B) The scores ranged between 0 and 167. The survival ROC curve analysis showed a gradual decrease in the C-statistics over time during the follow-up.

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  Figure 3.. Goodness of fit of the ECG score model for predicting CV death. A) Participants were divided into groups based on their ECG scores (Group 1 [black], <30 points; Group 2 [red], 30–59 points; Group 3 [blue], ≥60 points). The cumulative incidence of CV death increased with the ECG scores. The solid lines represent the observed cumulative incidence of CV death, and the broken lines represent the cumulative incidence of CV death predicted using the ECG score. The HRs for CV death were 2.00 and 5.58 in Group 2 and 3, compared with that in Group 1. B) The predicted incidences of CV deaths agreed well with the observed incidences of CV deaths throughout the follow-up period. The intraclass correlation coefficient (ICC) between the predicted and observed incidences of CV deaths was 0.989 (95% CI, 0.978–0.995). The agreement level was lower in Group 3 than in the other groups. C) Hosmer–Lemeshow tests showed that the observed incidences agreed well with the predicted incidences throughout the follow-up duration.

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  Figure 4.. Predictive performances of the combined ECG score. A) The combined ECG score comprised the ECG score, age, the presence of diabetes and current smoking. B) The C-statistics of the combined ECG score gradually increased while remain >0.820 throughout the follow-up period. T = N indicates the time of the observation (Months) and the numbers indicate C-statistics and the 95% confidence intervals of the C-statistics. C) The risk of CV death markedly diverged with the groups divided based on the combined ECG score (Group 1 [black], <50 points; Group 2 [red], 50–99 points; Group 3 [blue], ≥100 points). The observed rates (solid lines) and predicted rates (broken lines) of CV deaths appeared to be closely approximated. D) The combined ECG score showed an excellent goodness of fit between the observed and predicted cumulative incidences of CV deaths. The intraclass correlation coefficient (ICC) was approaching 1 between the observed and predicted incidences of CV deaths.