Abstract Body (Do not enter title and authors here): Background: ST changes in the lateral leads, which reflect ischemic changes, are associated with cardiovascular events. However, quantitative assessment of the ST–T area and its association with cardiovascular events remains unclear.
Hypothesis: Electrocardiographic ST–T areas in lateral leads (V5 and V6) quantitatively assessed by machine analysis were associated with cardiovascular events.
Methods: We enrolled 4,654 subjects from the Cardiovascular Prognostic Coupling Study in Japan (Coupling Registry), who had one or more cardiovascular risk factors. The primary endpoint was composite (cardiovascular death, myocardial infarction, stroke), and the secondary endpoints were myocardial infarction and stroke. ST–T area 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–T area in the V5 or V6 lead for the analysis. The endpoints were compared between the lowest quartile of ST–T area (Q4) and the others (Q1–3).
Results: The mean follow-up period was 53 ± 17 months. The composite endpoint was 159 cases, myocardial infarction in 27 cases and cerebral infarction in 72 cases. The lowest quartile of ST–T area (N= 1,162) had significantly more cardiovascular events than the other Q1–3 groups (N= 3,492, hazard ratio [HR] 2.25, 95% confidence interval [CI] 1.64–3.10) after adjusting for age, gender, and other covariates. The onset of myocardial infarction did not reach statistical difference (HR 2.05, 95% CI 0.94–4.46, p=0.072), but the lowest quartile of ST–T area significantly more ischemic stroke than the other Q1–3 groups (HR 2.37, 95% CI 1.48–3.75 p<0.001)
Conclusions: The lower summations of ST–T area assessed by a computerized quantitative method were associated with increased risk of cardiovascular disease, especially ischemic stroke, in patients with one or more cardiovascular risk factors.