Electrocardiographic ST-T Area Assessed by a Computerized Quantitative Method and Its Relation to Cardiovascular Events: The J-HOP Study

BACKGROUND: Although many studies have reported that the presence of minor or major ST-T change of electrocardiography (ECG) was associated with a risk of cardiovascular events, it is not clear whether there is a difference in the prognostic power depending on the summation of ST-T area (ST-Tarea) assessed by a quantitative method. METHODS: Electrocardiograms were performed in 834 clinical patients with one or more cardiovascular risks. ST-Tarea was assessed as the area enclosed by the baseline from the end of the QRS complex to the end of the ST-T segment using a computerized quantitative method. We used the lower magnitude of ST-Tarea in the V5 or V6 lead for the analysis. RESULTS: After a mean follow-up 8.4 ± 2.9 years (7,001 person-years), there were 92 cardiovascular events. With adjustment for covariates, the results from Cox proportional hazards models (Model 1) suggested that the lowest quartile of ST-Tarea was associated with a higher risk for cardiovascular outcome compared with the remaining quartile groups (hazard ratio, 2.08; 95% confidence interval, 1.36-3.16, P < 0.01). Even when adding the ECG left ventricular hypertrophy by Cornell voltage (Model 2) and Cornell product (Model 3) to Model 1, the significance remained (both P < 0.01). When we used ST-Tarea as a continuous variable substitute for the lowest quartile of ST-Tarea, these associations were similar in all models (all P < 0.01). CONCLUSION: The lower summations of ST-T area assessed by a computerized quantitative method were associated with increased risk of cardiovascular disease incidence in a clinical population.