Prognostic value of myocardial injury-related findings on resting electrocardiography for cardiovascular risk in the asymptomatic general population: the 12-year follow-up report from the Ansan-Ansung cohort

Abstract

Background: We investigated the predictive values of myocardial injury-related findings (MIFs) including ST-T wave abnormalities (STA) and pathologic Q waves (PQ) in electrocardiography for long-term cardiovascular outcomes in an asymptomatic general population.Methods: We observed 8444 subjects without cardiovascular diseases and related symptoms biennially over a 12-year period. Major cardiovascular adverse events (MACEs) were defined as a composite of cardiovascular death, myocardial infarction, coronary artery disease and stroke.Results: MACEs occurred more frequently in subjects with STA (9.1% vs. 5.2%, p < .001) and in those with anterior PQ (11.5% vs. 5.2%, p = .001) than in those without any MIFs, whereas anterolateral/posterior PQ were not associated with a higher incidence of MACEs. Multivariate Cox regression analyses showed that STA and anterior PQ were independently associated with the risk of MACEs. However, survival receiver operating characteristic curve analysis showed that the composite of STA and anterior PQ did not improve the predictive power of the conventional cardiovascular risk estimators when added to the models.Conclusions: The presence of STA or anterior PQ was associated with worse cardiovascular outcomes in the asymptomatic general population. However, the addition of MIFs to the conventional risk estimators was of limited value in the prediction of MACEs.Key MessagesMyocardial injury-related findings including ST-T wave abnormalities and anterior pathologic Q waves in resting electrocardiography predict long-term cardiovascular outcomes in an asymptomatic low-risk population.However, ST-T wave abnormalities and anterior pathologic Q waves add only limited value to conventional cardiovascular risk estimators in the prediction of cardiovascular outcomes.

Keywords: Electrocardiography; ST-T wave abnormality; cardiovascular risk; low-risk populations; pathologic Q wave.

Figure 1.

The frequencies and the intersection of MIFs on ECG. (A) STAs were more frequent than PQ waves. T-wave flattening was the most frequent MIF among STAs, while the posterior wall was the most frequent location of PQ waves. (B) STAs and PQ waves were simultaneously present in only a small portion (5.9%) of participants with MIFs.

Figure 2.

The cumulative incidences and the risk of the MACEs according to the MIFs on ECG. STAs and PQ waves in the anterior leads were associated with the risk of MACEs, whereas PQ waves in the other leads were not. The risk of MACEs did not differ between subjects with T-wave flattening and those with T-wave inversion. *All p values were derived from a log-rank test against group A.

Figure 3.

Cox proportional hazard models for the association between various MIFs and the risk of MACEs. In both univariate and multivariate Cox proportional hazard models, STA, T-wave inversion, T-wave flattening and anterior PQ waves were significantly associated with an increase in the risk of MACEs. A backward variable selection process was performed to simplify the models (cut-off point <0.05). Covariates included age, sex, DM, hypertension, dyslipidemia, eGFR, low-density lipoprotein cholesterol level, log-transformed CRP level, current smoking, BMI, waist-to-hip ratio and the presence of ECG-LVH.