Association of major and minor ECG abnormalities with coronary heart disease events

A negative T-wave in electrocardiogram at 50 years predicted lifetime mortality in a random population-based cohort

Background

Severe electrocardiographic (ECG) abnormalities in asymptomatic subjects correlate with cardiovascular risk.

Hypothesis

The role of minor ECG abnormalities is less well‐known. We evaluated the association between a negative T‐wave and mortality, as a possible marker for prognosis.

Methods

A prospective, population‐based cohort, examined at 50 years, and followed until death. Time to death (event rates) and predictive role of a negative T‐wave (Cox regression) were analyzed.

Results

Participants (n = 839) with a negative T‐wave (7.3%) had significantly higher blood pressure (BP) (mean systolic 157.9 mmHg vs 136.8 mmHg without negative T‐wave, P = <.0001). A negative T‐wave correlated with elevated risk (hazard ratio [HR] [95% CI] [confidence interval]) for all‐cause and cardiovascular (CV) death (1.59 (1.20‐2.11) P = .0012 vs 1.91 (1.34‐2.73) P = .0004). The association remained after excluding coexisting Q/QS patterns and ST‐junction/segment depression ECG abnormalities (1.66 [1.13‐2.44] P = .0098 for all‐cause vs 1.87 [1.13‐3.09] P = .015 for CV death). Death from other causes was not associated with a negative T‐wave. A major negative T‐wave carried higher risk than a minor (2.17 [1.25‐3.76] P = .0062 vs 1.78 [1.13‐2.79] P = .012) for CV death.

Conclusion

A negative T‐wave at 50 years, in asymptomatic individuals, carried an increased risk of all‐cause and CV death during lifetime follow‐up.

Do sex differences in the prevalence of ECG abnormalities vary across ethnic groups living in the Netherlands? A cross-sectional analysis of the population-based HELIUS study

OBJECTIVES

Major ECG abnormalities have been associated with increased risk of cardiovascular disease (CVD) burden in asymptomatic populations. However, sex differences in occurrence of major ECG abnormalities have been poorly studied, particularly across ethnic groups. The objectives were to investigate (1) sex differences in the prevalence of major and, as a secondary outcome, minor ECG abnormalities, (2) whether patterns of sex differences varied across ethnic groups, by age and (3) to what extent conventional cardiovascular risk factors contributed to observed sex differences.

DESIGN

Cross-sectional analysis of population-based study.

SETTING

Multi-ethnic, population-based Healthy Life in an Urban Setting cohort, Amsterdam, the Netherlands.

PARTICIPANTS

8089 men and 11 369 women of Dutch, South-Asian Surinamese, African Surinamese, Ghanaian, Turkish and Moroccan origin aged 18-70 years without CVD.

OUTCOME MEASURES

Age-adjusted and multivariable logistic regression analyses were performed to study sex differences in prevalence of major and, as secondary outcome, minor ECG abnormalities in the overall population, across ethnic groups and by age-groups (18-35, 36-50 and >50 years).

RESULTS

Major and minor ECG abnormalities were less prevalent in women than men (4.6% vs 6.6% and 23.8% vs 39.8%, respectively). After adjustment for conventional risk factors, sex differences in major abnormalities were smaller in ethnic minority groups (OR ranged from 0.61 in Moroccans to 1.32 in South-Asian Surinamese) than in the Dutch (OR 0.49; 95% CI 0.36 to 0.65). Only in South-Asian Surinamese, women did not have a lower odds than men (OR 1.32; 95% CI 0.96 to 1.84). The pattern of smaller sex differences in ethnic minority groups was more pronounced in older than in younger age-groups.

CONCLUSIONS

The prevalence of major ECG abnormalities was lower in women than men. However, sex differences were less apparent in ethnic minority groups. Conventional risk factors did not contribute substantially to observed sex differences.

The Association and Predictive Ability of ECG Abnormalities with Cardiovascular Diseases: A Prospective Analysis

Aims

To examine whether electrocardiography (ECG) could provide additional values to the traditional risk factors for cardiovascular disease (CVD) risk prediction among different cardiovascular risk subgroups.

Methods

A total of 7,872 community residents aged ≥40 years were followed up for a median of 4.5 years. A 12-lead resting ECG was examined for participants at baseline. CVD events including myocardial infarction, stroke and cardiovascular mortality were collected. Cox proportional hazards models were used and models of traditional risk factors with and without ECG were compared.

Results

At baseline, 2,470 participants (31.3%) had ECG abnormalities. During follow-up, 464 participants developed CVD events. ECG abnormalities were associated with an increased risk of CVD after adjustment for the traditional risk factors in participants with a 10-year atherosclerotic CVD (ASCVD) risk ≥10% (hazard ratio, HR: 1.45; 95% confidence interval, CI: 1.11, 1.91). Adding ECG abnormalities to the traditional CVD risk factors improved reclassification for those who did not experience events [net reclassification index: 8.0% (95% CI: 2%, 19.5%)], discrimination (integrated discrimination improvement: 0.7% (95% CI: 0.1%, 1.9%), and calibration (goodness of fit P value from 0.600 to 0.873) in participants with a 10-year ASCVD risk ≥10%. However, no significant association and improvement were found in participants with a 10-year ASCVD risk <10%.

Conclusions

ECG screening might provide a marginal improvement in CVD risk prediction in adults at high risk. However, ECG should not be recommended in adults at low risk.

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

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.

The UK Biobank imaging enhancement of 100,000 participants: rationale, data collection, management and future directions

UK Biobank is a population-based cohort of half a million participants aged 40-69 years recruited between 2006 and 2010. In 2014, UK Biobank started the world's largest multi-modal imaging study, with the aim of re-inviting 100,000 participants to undergo brain, cardiac and abdominal magnetic resonance imaging, dual-energy X-ray absorptiometry and carotid ultrasound. The combination of large-scale multi-modal imaging with extensive phenotypic and genetic data offers an unprecedented resource for scientists to conduct health-related research. This article provides an in-depth overview of the imaging enhancement, including the data collected, how it is managed and processed, and future directions.

Improvement of electrocardiographic diagnostic accuracy of left ventricular hypertrophy using a Machine Learning approach

The electrocardiogram (ECG) is the most common tool used to predict left ventricular hypertrophy (LVH). However, it is limited by its low accuracy (<60%) and sensitivity (30%). We set forth the hypothesis that the Machine Learning (ML) C5.0 algorithm could optimize the ECG in the prediction of LVH by echocardiography (Echo) while also establishing ECG-LVH phenotypes. We used Echo as the standard diagnostic tool to detect LVH and measured the ECG abnormalities found in Echo-LVH. We included 432 patients (power = 99%). Of these, 202 patients (46.7%) had Echo-LVH and 240 (55.6%) were males. We included a wide range of ventricular masses and Echo-LVH severities which were classified as mild (n = 77, 38.1%), moderate (n = 50, 24.7%) and severe (n = 75, 37.1%). Data was divided into a training/testing set (80%/20%) and we applied logistic regression analysis on the ECG measurements. The logistic regression model with the best ability to identify Echo-LVH was introduced into the C5.0 ML algorithm. We created multiple decision trees and selected the tree with the highest performance. The resultant five-level binary decision tree used only six predictive variables and had an accuracy of 71.4% (95%CI, 65.5-80.2), a sensitivity of 79.6%, specificity of 53%, positive predictive value of 66.6% and a negative predictive value of 69.3%. Internal validation reached a mean accuracy of 71.4% (64.4-78.5). Our results were reproduced in a second validation group and a similar diagnostic accuracy was obtained, 73.3% (95%CI, 65.5-80.2), sensitivity (81.6%), specificity (69.3%), positive predictive value (56.3%) and negative predictive value (88.6%). We calculated the Romhilt-Estes multilevel score and compared it to our model. The accuracy of the Romhilt-Estes system had an accuracy of 61.3% (CI95%, 56.5-65.9), a sensitivity of 23.2% and a specificity of 94.8% with similar results in the external validation group. In conclusion, the C5.0 ML algorithm surpassed the accuracy of current ECG criteria in the detection of Echo-LVH. Our new criteria hinge on ECG abnormalities that identify high-risk patients and provide some insight on electrogenesis in Echo-LVH.

Impact of the Location of ST-T Abnormalities Accompanying Minor Q-Waves on the Definition of Prior Myocardial Infarction

According to the Fourth Universal Definition of myocardial infarction (MI), the likelihood of a previous MI is increased when ST-T abnormalities exist with minor Q-waves in the same leads. Therefore, we examined whether differences in location of ST-T abnormalities in relation to minor Q-waves as part of the old MI definition impact the prevalence and prognostic significance of MI. This analysis included 7,878 participants with available baseline electrocardiogram (ECG) and follow-up data from the third National Health and Nutrition Examination Survey. Two ECG MI definitions were utilized; both were based on the standards of the Minnesota Code (MC) ECG Classification, and both incorporated major Q-waves but differed in whether major ST-T abnormalities and minor Q waves, as part of the definition, were in the same lead group (Standard MC-MI) or not (Fourth Universal MI). All-cause mortality and cardiovascular disease mortality were ascertained during 14 years (median). We found no difference between baseline prevalence of Standard MC-MI (3.48%; n = 274) and Fourth Universal MI (3.27%; n = 258), p = 0.46. Also, Standard MC-MI and Fourth Universal MI were similarly associated with increased risk of all-cause mortality (hazard ratio [95% confidence interval] 1.64 [1.42 to 1.90] and 1.61 [1.38 to 1.87], respectively; p value for differences in associations = 0.86), and cardiovascular disease mortality (hazard ratio [95% confidence interval] 1.99 [1.61 to 2.48] and 1.94 [1.56 to 2.42], respectively; p value for differences in associations = 0.84). In conclusion, the location of ST-T abnormalities accompanying minor Q-waves does not impact the prevalence or prognostic significance of a prior MI which raise doubts about the clinical impact of considering the location of ST-T in relation to minor Q-waves when defining an old MI.

Interpretations of and management actions following ECGs in programmatic cardiovascular care in primary care: A retrospective dossier study

Background

The usefulness of routine electrocardiograms (ECGs) in cardiovascular risk management (CVRM) and diabetes care is doubted.

Objectives

To assess the performance of general practitioners (GPs) in embedding ECGs in CVRM and diabetes care.

Methods

We collected 852 ECGs recorded by 20 GPs (12 practices) in the context of CVRM and diabetes care. Of all abnormal (n = 265) and a sample of the normal (n = 35) ECGs, data on the indications, interpretations and management actions were extracted from the corresponding medical records. An expert panel consisting of one cardiologist and one expert GP reviewed these 300 ECG cases.

Results

GPs found new abnormalities in 13.0% of all 852 ECGs (12.0% in routinely recorded ECGs versus 24.3% in ECGs performed for a specific indication). Management actions followed more often after ECGs performed for specific indications (17.6%) than after routine ECGs (6.0%). The expert panel agreed with the GPs’ interpretations in 67% of the 300 assessed cases. Most often misinterpreted relevant ECG abnormalities were previous myocardial infarction, R‑wave abnormalities and typical/atypical ST-segment and T‑wave (ST-T) abnormalities. Agreement on patient management between GP and expert panel was 74%. Disagreement in most cases concerned additional diagnostic testing.

Conclusions

In the context of programmatic CVRM and diabetes care by GPs, the yield of newly found ECG abnormalities is modest. It is higher for ECGs recorded for a specific reason. Educating GPs seems necessary in this field since they perform less well in interpreting and managing CVRM ECGs than in ECGs performed in symptomatic patients.

Electronic supplementary material

The online version of this article (10.1007/s12471-020-01376-3) contains supplementary material, which is available to authorized users.

Association between resting painless ST-segment depression with sudden cardiac death in middle-aged population: A prospective cohort study

BACKGOUND

Silent electrocardiographic ST change predicts future coronary heart disease (CHD) incidence and mortality, but the prognostic significance of painless ST-segment depression (STD) with respect to sudden cardiac death (SCD) in subjects without apparent CHD remain unclear. This study sought to test the association between non-ischemic resting STD and risk of SCD in the general population.

METHODS

A total of 14,935 middle-aged subjects from the prospective, population-based Atherosclerosis Risk in Communities (ARIC) study were included in this analysis. Cox models were used to estimate the hazard ratios (HRs) adjusted for possible confounding factors. STD was defined as ST-segment depression of ≥0.05 mV in two or more contiguous leads.

RESULTS

A total of 626 sudden cardiac death occurred during the mean follow-up of 20.4 years. Compared with those without STD, subjects with resting painless STD of at least 0.05 mV had a significantly increased risk of developing SCD (adjusted HR, 1.45; 95% CI, 1.20 to 1.76), and those with STD ≥ 0.1 mV had even higher risk of SCD (adjusted HR, 1.90; 95% CI, 1.25 to 2.88). Significant interactions were present between gender and STD (P = .03), and between race and STD (P = .01). STD was significantly predictive of SCD in males (adjusted HR, 1.57; 95% CI, 1.22-2.01) and in whites (adjusted HR, 1.65; 95% CI, 1.27-2.14). STD in lateral leads and global leads were strong predictors of SCD.

CONCLUSIONS

Resting painless STD was an independent predictor of SCD in the middle-aged population without previously diagnosed CHD.

Prevalence and risk factors of prolonged QT interval and electrocardiographic abnormalities in persons living with HIV

OBJECTIVE

Abnormal ECGs are associated with increased risk of arrhythmias and sudden cardiac death. We aimed to investigate the prevalence and associated risk factors of prolonged QTc and major ECG abnormalities, in persons living with HIV (PLWH) and uninfected controls.

DESIGN

PLWH aged at least 40 years were recruited from the Copenhagen comorbidity in HIV infection (COCOMO) study and matched on sex and age to uninfected controls from the Copenhagen General Population Study.

METHODS

ECGs were categorized according to Minnesota Code Manual of ECG Findings definition of major abnormalities. A QT interval corrected for heart rate (QTc) greater than 440 ms in men and greater than 460 ms in women was considered prolonged. Pathologic Q-waves were defined as presence of major Q-wave abnormalities.

RESULTS

ECGs were available for 745 PLWH and 2977 controls. Prolonged QTc was prevalent in 9% of PLWH and 6% of controls, P = 0.052. Pathologic Q-waves were more common in PLWH (6%) than in controls (4%), P = 0.028. There was no difference in prevalence of major ECG abnormalities between PLWH and controls, P = 0.987.In adjusted analyses, HIV was associated with a 3.6 ms (1.8-5.4) longer QTc interval, P < 0.001, and HIV was independently associated with prolonged QTc [adjusted odds ratio: 1.59 (1.14-2.19)], P = 0.005. HIV was borderline associated to pathologic Q-waves after adjusting, P = 0.051.

CONCLUSION

HIV was associated with higher odds ratio of prolonged QTc after adjustment for cardiovascular risk factors, but analyses were not adjusted for QT-prolonging medication. Although evidence indicated more pathologic Q-waves in PLWH, the risk seemed to be associated mainly with an adverse risk profile.

Incidental abnormal ECG findings and long-term cardiovascular morbidity and all-cause mortality: A population based prospective study

BACKGROUND

The additional prognostic value of resting electrocardiogram (ECG) in long-term cardiovascular disease (CVD)-risk-assessment is unclear. We evaluated the association of incidental abnormal ECG findings with long-term CVD-risk and all-cause mortality, and assessed the additional prognostic value of ECG as a screening tool in adults without known CVD.

METHODS

A cohort of 2601 Israeli men and women without known CVD were actively followed from 1976 to 1982 for 23-year cumulative CVD-incidence, and until May 2017 for all-cause mortality. At baseline and follow-up, participants underwent interviews, physical examinations, blood tests and ECG.

RESULTS

At baseline, 1199 (46.1%) had incidental abnormal ECG findings (exposed-group). CVD cumulative incidence reached 31.6% among the 930 survivors who participated in the active follow-up (294/930). During a 31-year median follow-up, 1719 (66.1%) of the total cohort died. Incidental abnormal ECG findings were associated with 46% greater CVD-risk (odds ratio = 1.46, 95%CI = 1.09-1.97). The net reclassification improvement (NRI) of CVD-risk was 7.4% (95%CI_NRI = 1.5%-13.3%, p = 0.01) following the addition of ECG findings, but the C-index improvement was not statistically significant [C-index = 0.656 (0.619-0.694) vs. C-index = 0.666 (0.629-0.703), p = 0.14]. Multivariable Cox regression demonstrated an all-cause mortality hazard ratio (HR) of 1.18 (95%CI = 1.07-1.30) for exposed vs. unexposed individuals. Non-specific T-wave changes and left-axis deviation are the incidental ECG abnormalities that were associated with all-cause mortality [HR = 1.18 (95%CI = 1.05-1.33) and HR = 1.19 (95%CI = 1.00-1.42), respectively].

CONCLUSION

Incidental abnormal ECG findings, mainly non-specific T-wave changes and left-axis deviation, were associated with increased long-term CVD-risk and all-cause mortality among individuals without known CVD, and demonstrated net reclassification improvement for CVD-risk.

Electrocardiographic screening in primary care for cardiovascular disease risk and atrial fibrillation

Electrocardiograms (ECGs) are frequently recorded in primary care for screening purposes. An ECG is essential in diagnosing atrial fibrillation, and ECG abnormalities are associated with cardiovascular events. While recent studies show that ECGs adequately reclassify a proportion of patients based on the clinical risk score calculations, there are no data to support that this also results in improved health outcomes. When applied for screening for atrial fibrillation, more cases are found with routine care, but this would be undone when physicians would perform systematic pulse palpation. In most studies, the harms of routine ECG use (such as unnecessary diagnostic testing, emotional distress, increased health expenses) were poorly documented. As such, the routine performing of ECGs in asymptomatic primary care patients, whether it is for cardiovascular disease risk assessment or atrial fibrillation, cannot be recommended.

Prognostic performance of ECG abnormalities compared to vital signs in acutely ill patients in a resource-poor hospital in Uganda

Background

There are few reports of electrocardiogram (ECG) findings and their prognostic value in acutely ill patients admitted to low resource hospitals in sub-Saharan Africa.

Methods

We undertook an observational study of acutely ill medical patients admitted to a low-resource hospital in Uganda. Vital signs were used to calculate the National Early Warning Score (NEWS), and all ECGs were assessed using Tan et al.’s scoring system as described in Clin Cardiol 2009;32:82–86.

Results

There were 1361 ECGs performed, covering 68% of all acutely ill medical patients admitted to the hospital during the study. The most common ECG abnormality was a prolonged QTc interval (42% of all patients) and left ventricular hypertrophy (13.5%). Compared to the 519 patients (38%) with no Tan score abnormality, the 842 (62%) patients with one or more abnormalities were more likely to die in hospital (OR = 2.82; CI_95% = 1.50–5.36) and within 30 days of discharge (OR = 2.46; CI_95% = 1.50–4.08). There was no relationship between age and mortality; however, after adjustment by logistic regression, any NEWS ≥1 on admission, a Tan score of ≥1, and male sex all remained clinically significant predictors of both in-hospital and 30-day mortality.

Discussion

The majority of acutely ill medical patients admitted in a low-resource hospital in sub-Saharan Africa had ECG abnormalities, of which prolonged QTc and left ventricular hypertrophy were most common. Those with any Tan score abnormality were twice as likely to die as those without an abnormality.

Associations between common ECG abnormalities and out-of-hospital cardiac arrest

Background

Out-of-hospital cardiac arrest (OHCA) is often the first manifestation of unrecognised cardiac disease. ECG abnormalities encountered in primary care settings may be warning signs of OHCA.

Objective

We examined the association between common ECG abnormalities and OHCA in a primary care setting.

Methods

We cross-linked individuals who had an ECG recording between 2001 and 2011 in a primary care setting with the Danish Cardiac Arrest Registry and identified OHCAs of presumed cardiac cause.

Results

A total of 326 227 individuals were included and 2667 (0,8%) suffered an OHCA. In Cox regression analyses, adjusted for age and sex, the following ECG findings were strongly associated with OHCA: ST-depression without concomitant atrial fibrillation (HR 2.79; 95% CI 2.45 to 3.18), left bundle branch block (LBBB; HR 3.44; 95% CI 2.85 to 4.14) and non-specific intraventricular block (NSIB; HR 3.15; 95% CI 2.58 to 3.83). Also associated with OHCA were atrial fibrillation (HR 1.89; 95% CI 1.63 to 2.18), Q-wave (HR 1.75; 95% CI 1.57 to 1.95), Cornell and Sokolow-Lyon criteria for left ventricular hypertrophy (HR 1.56; 95% CI 1.33 to 1.82 and HR 1.27; 95% CI 1.12 to 1.45, respectively), ST-elevation (HR 1.40; 95% CI 1.09 to 1.54) and right bundle branch block (HR 1.29; 95% CI 1.09 to 1.54). The association between ST-depression and OHCA diminished with concomitant atrial fibrillation (HR 1.79; 95% CI 1.42 to 2.24, p < 0.01 for interaction). Among patients suffering from OHCA, without a known cardiac disease at the time of the cardiac arrest, 14.2 % had LBBB, NSIB or ST-depression.

Conclusions

Several common ECG findings obtained from a primary care setting are associated with OHCA.

Relation of Minor Electrocardiographic Abnormalities to Cardiovascular Mortality

Although minor electrocardiographic (ECG) abnormalities are common findings in clinical practice, their prognostic significance remains unclear due to inconsistent reports. We hypothesized that this inconsistency is due to the traditional focus on examining their prognostic significance as a binary variable (i.e., presence vs absence of any abnormality) ignoring the number of abnormalities. We tested this hypothesis in 6,467 participants (mean age 59 years, 53% women) from the Third National Health and Nutrition Examination Survey who were free of baseline cardiovascular disease (CVD) and major ECG abnormalities. ECG abnormalities were defined from digitally recorded and centrally processed standard electrocardiograms using the Minnesota ECG Classification. CVD mortality was ascertained using National Death Index. About 38% of participants (n = 2,438) had at least 1 minor ECG abnormality at baseline. During a median follow-up of 13.9 years, 755 CVD deaths occurred. In a multivariable Cox model, presence of at least 1 minor ECG abnormality was marginally associated with increased risk of CVD mortality (hazard ratio (95% confidence interval):1.15(1.00,1.34), p-value = 0.04)). However, as the number of ECG abnormalities increases, the association with CVD mortality showed a dose-response relation (event rate per 1,000 person-year of 7.3, 10.1, and 16.7 in participants with 0, 1, and ≥2 ECG abnormalities, respectively; p-value for trend <0.01). Also, each additional minor ECG abnormality was associated with a 13% increased risk of CVD mortality (hazard ratio (95% confidence interval): 1.13(1.04, 1.24)). In conclusion, the number, not only the mere presence of minor ECG abnormalities should be taken into account to understand the prognostic significance of these common findings.

Trends in electrocardiographic abnormalities and risk of cardiovascular mortality in Lithuania, 1986-2015

Background

This study aimed to assess the trends in the prevalence of electrocardiographic (ECG) abnormalities from 1986 to 2015 and impact of ECG abnormalities on risk of death from cardiovascular diseases (CVD) in the Lithuanian population aged 40–64 years.

Methods

Data from four surveys carried out in Kaunas city and five randomly selected municipalities of Lithuania were analysed. A resting ECG was recorded and CVD risk factors were measured in each survey. ECG abnormalities were evaluated using Minnesota Code (MC). Trends in age-standardized prevalence of ECG abnormalities were estimated for both sexes. Multivariate Cox proportional hazards models were used to estimate hazard ratios (HR) for coronary heart disease (CHD) and CVD mortality. Net reclassification index (NRI), integrated discrimination improvement and other indices were used for evaluation of improvement in the prediction of CVD and CHD mortality risk after addition of ECG abnormalities variable to Cox models.

Results

From1986 to 2008, the decrease in the prevalence of Q-QS MC was observed in both genders. The prevalence of high R waves increased in men, while the prevalence of ST segment and T wave abnormalities as well as arrhythmias decreased in women. Ischemic changes and possible MI were associated with a 2.5-fold and 4.4-fold higher risk of death from CVD in men and 1.51-fold and 2.56-fold higher mortality risk from CVD in women as compared to individuals with marginal or no ECG abnormalities. The addition of ECG abnormalities to traditional CVD risk factors improved Cox regression models performance. According to NRI, 18.6% of men were correctly reclassified in CVD mortality prediction model and 25.2% of men - in CHD mortality prediction model.

Conclusions

the decreasing trends in the prevalence of ischemia on ECG in women and increasing trends in the prevalence of left VH in men were observed. ECG abnormalities were associated with higher risk of CVD mortality. The addition of ECG abnormalities to the prediction models modestly improved the prediction of CVD mortality beyond traditional CVD risk factors. The use of ECG as routine screening to identify high risk individuals for more intensive preventive interventions warrants further research.

QRS voltage is a predictor of in-hospital mortality of acutely ill medical patients

BACKGROUND

Low QRS voltage has been shown to be associated with increased mortality in the general population and in a small pilot study the combined QRS voltage of ECG leads I and II was found to be associated with in-hospital mortality.

HYPOTHESIS

Confirm that low QRS voltage predicts the in-hospital mortality of acutely ill patients, and compare QRS voltage with other predictors of mortality that can be easily, quickly and cheaply obtained at the bedside.

METHODS

Prospective observational study of vital signs, QRS voltage and simple tools used to assess mental, functional and nutritional status at the bedside in unselected acutely ill patients admitted to a resource-poor hospital in sub-Saharan Africa.

RESULTS

Out of 1486 patients, 77 died (5.2%) in hospital. A combined lead I + II voltage <1.8 mV was present in 789 (53.1%) of patients, and significantly associated with in-hospital mortality (odds ratio 3.6, 95% CI 2.0-6.5, χ² 21.2, P < 0.00001). On logistic regression impaired mobility, the National Early Warning Score, male gender and lead I + II voltage were the only independent predictors of mortality. None of the 445 patients who were mobile on admission with a lead I + II voltage ≥ 1.8 mV died in hospital.

CONCLUSIONS

Low QRS voltage, male gender, NEWS, and impaired mobility were independent predictors of in-hospital mortality in the study population. These four variables, which are easily obtained at the bedside, could potentially provide a rapid, easy, and cheap risk stratification system.

Electrical risk score beyond the left ventricular ejection fraction: prediction of sudden cardiac death in the Oregon Sudden Unexpected Death Study and the Atherosclerosis Risk in Communities Study

Aims

There is an urgent need to extend sudden cardiac death (SCD) risk stratification beyond the left ventricular ejection fraction (LVEF). We evaluated whether a cumulative electrocardiogram (ECG) risk score would improve identification of individuals at high risk of SCD.

Methods and results

In the community-based Oregon Sudden Unexpected Death Study (catchment population ∼1 million), 522 SCD cases with archived 12-lead ECG available (65.3 ± 14.5 years, 66% male) were compared with 736 geographical controls to assess the incremental value of multiple ECG parameters in SCD prediction. Heart rate, LV hypertrophy, QRS transition zone, QRS-T angle, QTc, and Tpeak-to-Tend interval remained significant in the final model, which was externally validated in the Atherosclerosis Risk in Communities (ARIC) Study. Sixteen percent of cases and 3% of controls had ≥4 abnormal ECG markers. After adjusting for clinical factors and LVEF, increasing ECG risk score was associated with progressively greater odds of SCD. Overall, subjects with ≥4 ECG abnormalities had an odds ratio (OR) of 21.2 for SCD [95% confidence interval (CI) 9.4-47.7; P < 0.001]. In the LVEF >35% subgroup, the OR was 26.1 (95% CI 9.9-68.5; P < 0.001). The ECG risk score increased the C-statistic from 0.625 to 0.753 (P < 0.001), with net reclassification improvement of 0.319 (P < 0.001). In the ARIC cohort validation, risk of SCD associated with ≥4 ECG abnormalities remained significant after multivariable adjustment (hazard ratio 4.84; 95% CI 2.34-9.99; P < 0.001; C-statistic improvement 0.759-0.774; P = 0.019).

Conclusion

This novel cumulative ECG risk score was independently associated with SCD and was particularly effective for LVEF >35% where risk stratification is currently unavailable. These findings warrant further evaluation in prospective clinical investigations.

Minor Electrocardiographic ST-T Change and Risk of Stroke in the General Japanese Population

BACKGROUND

Minor ST-T changes are frequently observed on the electrocardiogram (ECG), but the risk of stroke associated with such changes is unclear.Methods and Results:In 10,642 subjects from the Japanese general population, we evaluated minor and major ST-T changes (major ST depression ≥0.1 mV) on ECGs obtained at annual health examinations. At baseline, minor ST-T changes were found in 10.7% of the subjects and 0.5% had major ST-T changes. Minor ST-T changes were associated with older age, female gender, higher systolic blood pressure, presence of hyperlipidemia, and use of antihypertensive medication. There were 375 stroke events during the follow-up period (128.7±28.1 months). In all subjects, minor ST-T changes (HR, 2.10; 95% CI: 1.57-2.81) and major ST-T changes (HR, 8.64; 95% CI: 4.44-16.82) were associated with an increased risk of stroke, but the stroke risk associated with minor ST-T changes had borderline significance after adjustment for conventional risk factors (P=0.055). In subgroup analysis, the risk of stroke was significantly associated with minor ST-T changes in subjects who had hyperlipidemia (HR, 1.75; 95% CI: 1.15-2.67) compared to those without hyperlipidemia (HR, 1.01; 95% CI: 0.64-1.59; P for interaction=0.016), even after adjustment for ECG-diagnosed left ventricular hypertrophy.

CONCLUSIONS

Minor ST-T changes were particularly associated with a higher risk of stroke in subjects with hyperlipidemia and this association was independent of electrocardiographic left ventricular hypertrophy.

Screening for Cardiovascular Disease Risk With Electrocardiography: US Preventive Services Task Force Recommendation Statement

IMPORTANCE

Cardiovascular disease (CVD), which encompasses atherosclerotic conditions such as coronary heart disease, cerebrovascular disease, and peripheral arterial disease, is the most common cause of death among adults in the United States. Treatment to prevent CVD events by modifying risk factors is currently informed by CVD risk assessment with tools such as the Framingham Risk Score or the Pooled Cohort Equations, which stratify individual risk to inform treatment decisions.

OBJECTIVE

To update the 2012 US Preventive Services Task Force (USPSTF) recommendation on screening for coronary heart disease with electrocardiography (ECG).

EVIDENCE REVIEW

The USPSTF reviewed the evidence on whether screening with resting or exercise ECG improves health outcomes compared with the use of traditional CVD risk assessment alone in asymptomatic adults.

FINDINGS

For asymptomatic adults at low risk of CVD events (individuals with a 10-year CVD event risk less than 10%), it is very unlikely that the information from resting or exercise ECG (beyond that obtained with conventional CVD risk factors) will result in a change in the patient's risk category as assessed by the Framingham Risk Score or Pooled Cohort Equations that would lead to a change in treatment and ultimately improve health outcomes. Possible harms are associated with screening with resting or exercise ECG, specifically the potential adverse effects of subsequent invasive testing. For asymptomatic adults at intermediate or high risk of CVD events, there is insufficient evidence to determine the extent to which information from resting or exercise ECG adds to current CVD risk assessment models and whether information from the ECG results in a change in risk management and ultimately reduces CVD events. As with low-risk adults, possible harms are associated with screening with resting or exercise ECG in asymptomatic adults at intermediate or high risk of CVD events.

CONCLUSIONS AND RECOMMENDATION

The USPSTF recommends against screening with resting or exercise ECG to prevent CVD events in asymptomatic adults at low risk of CVD events. (D recommendation) The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening with resting or exercise ECG to prevent CVD events in asymptomatic adults at intermediate or high risk of CVD events. (I statement).

Screening for Cardiovascular Disease Risk With Resting or Exercise Electrocardiography: Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Cardiovascular disease (CVD) is the leading cause of death in the United States.

OBJECTIVE

To review the evidence on screening asymptomatic adults for CVD risk using electrocardiography (ECG) to inform the US Preventive Services Task Force.

DATA SOURCES

MEDLINE, Cochrane Library, and trial registries through May 2017; references; experts; literature surveillance through April 4, 2018.

STUDY SELECTION

English-language randomized clinical trials (RCTs); prospective cohort studies reporting reclassification, calibration, or discrimination that compared risk assessment using ECG plus traditional risk factors vs traditional risk factors alone. For harms, additional study designs were eligible. Studies of persons with symptoms or a CVD diagnosis were excluded.

DATA EXTRACTION AND SYNTHESIS

Dual review of abstracts, full-text articles, and study quality; qualitative synthesis of findings.

MAIN OUTCOMES AND MEASURES

Mortality, cardiovascular events, reclassification, calibration, discrimination, and harms.

RESULTS

Sixteen studies were included (N = 77 140). Two RCTs (n = 1151) found no significant improvement for screening with exercise ECG (vs no screening) in adults aged 50 to 75 years with diabetes for the primary cardiovascular composite outcomes (hazard ratios, 1.00 [95% CI, 0.59-1.71] and 0.85 [95% CI, 0.39-1.84] for each study). No RCTs evaluated screening with resting ECG. Evidence from 5 cohort studies (n = 9582) showed that adding exercise ECG to traditional risk factors such as age, sex, current smoking, diabetes, total cholesterol level, and high-density lipoprotein cholesterol level produced small improvements in discrimination (absolute improvements in area under the curve [AUC] or C statistics, 0.02-0.03, reported by 3 studies); whether calibration or appropriate risk classification improves is uncertain. Evidence from 9 cohort studies (n = 66 407) showed that adding resting ECG to traditional risk factors produced small improvements in discrimination (absolute improvement in AUC or C statistics, 0.001-0.05) and appropriate risk classification for prediction of multiple cardiovascular outcomes, although evidence was limited by imprecision, quality, considerable heterogeneity, and inconsistent use of risk thresholds used for clinical decision making. Total net reclassification improvements ranged from 3.6% (2.7% event; 0.6% nonevent) to 30% (17% event; 19% nonevent) for studies using the Framingham Risk Score or Pooled Cohort Equations base models. Evidence on potential harms (eg, from subsequent angiography or revascularization) in asymptomatic persons was limited.

CONCLUSIONS AND RELEVANCE

RCTs of screening with exercise ECG found no improvement in health outcomes, despite focusing on higher-risk populations with diabetes. The addition of resting ECG to traditional risk factors accurately reclassified persons, but evidence for this finding had many limitations. The frequency of harms from screening is uncertain.

Association of isolated minor nonspecific ST-T abnormalities with left ventricular hypertrophy and diastolic dysfunction

The aim of this study was to examine the associations of isolated minor nonspecific ST-T abnormalities (NSSTTA) on 12-lead electrocardiogram (ECG) with left ventricular (LV) diastolic function and LV geometry on echocardiography. A cross-sectional study comprised of 74,976 Koreans who underwent ECG and echocardiography as part of a comprehensive health examination between March 2011 and December 2014. ECG was coded using Minnesota Code criteria. The frequencies of NSSTTA, impaired LV relaxation, and echocardiographic LVH were 1,139 (1.5%), 21,118 (28.2%), and 1,687 (2.3%) patients, respectively. The presence of NSSTTA was positively associated with the prevalence of impaired LV relaxation and LVH on echocardiography. In a multivariable-adjusted model, the odds ratio (95% CIs) comparing patients with NSSTTA to control patients was 1.55 (1.33-1.80) for impaired LV relaxation and 3.15 (2.51-3.96) for echocardiographic LVH. The association between NSSTTA and impaired LV relaxation was stronger in the intermediate to high cardiovascular disease-risk group than in the low-risk group according to Framingham Risk Score stratification (P for interaction = 0.02). NSSTTA were associated with increased prevalence of impaired LV relaxation and LVH, suggesting NSSTTA as an early indicator of subclinical cardiac dysfunction and geometric abnormalities.

Prevalence and prognostic impact of electrocardiographic abnormalities in outpatients with extracardiac artery disease

Identifying cardiac disease in patients with extracardiac artery disease (ECAD) is essential for clinical decision-making. Electrocardiography (ECG) is an easily accessible tool to unmask subclinical cardiac disease and to risk stratify patient with or without manifest cardiovascular disease (CV). We aimed to examine the prevalence and prognostic impact of ECG changes in outpatients with ECAD. Outpatients with carotid or lower extremity artery disease (n = 435) and community-based controls (n = 397) underwent resting ECG. The patients were followed during a median of 4·8 years for CV events (hospitalization or death caused by ischaemic heart disease, cardiac arrest, heart failure, or stroke). ECG abnormalities were classified according to the Minnesota Code. Major (33% versus 15%, P<0·001) but not minor ECG abnormalities (23% versus 26%, P = 0·42) were significantly more common in patients versus controls. During the follow-up, 141 patients experienced CV events. Both major ECG abnormalities [hazard ratio (HR) 1·58, 95% confidence interval (CI) 1·11-2·25, P = 0·012] and any ECG abnormalities (HR 1·57, 95% CI 1·06-2·33, P = 0·024) were significantly associated with CV events after adjustment for potential risk factors. In conclusion, ECG abnormalities were common in these outpatients with ECAD. Major and any ECG abnormalities were independent predictors of CV events. Addition of easily accessible ECG information might be useful in risk stratification for such patients.

Ischemic ECG abnormalities are associated with an increased risk for death among subjects with COPD, also among those without known heart disease

Abstract presentation

An abstract, including parts of the results, has been presented at an oral session at the European Respiratory Society International Conference, London, UK, September 2016.

Background

Cardiovascular comorbidity contributes to increased mortality among subjects with COPD. However, the prognostic value of ECG abnormalities in COPD has rarely been studied in population-based surveys.

Aim

To assess the impact of ischemic ECG abnormalities (I-ECG) on mortality among individuals with COPD, compared to subjects with normal lung function (NLF), in a population-based study.

Methods

During 2002–2004, all subjects with FEV₁/VC <0.70 (COPD, n=993) were identified from population-based cohorts, together with age- and sex-matched referents without COPD. Re-examination in 2005 included interview, spirometry, and 12-lead ECG in COPD (n=635) and referents [n=991, whereof 786 had NLF]. All ECGs were Minnesota-coded. Mortality data were collected until December 31, 2010.

Results

I-ECG was equally common in COPD and NLF. The 5-year cumulative mortality was higher among subjects with I-ECG in both groups (29.6% vs 10.6%, P<0.001 and 17.1% vs 6.6%, P<0.001). COPD, but not NLF, with I-ECG had increased risk for death assessed as the mortality risk ratio [95% confidence interval (CI)] when compared with NLF without I-ECG, 2.36 (1.45–3.85) and 1.65 (0.94–2.90) when adjusted for common confounders. When analyzed separately among the COPD cohort, the increased risk for death associated with I-ECG persisted after adjustment for FEV₁ % predicted, 1.89 (1.20–2.99). A majority of those with I-ECG had no previously reported heart disease (74.2% in NLF and 67.3% in COPD) and the pattern was similar among them.

Conclusion

I-ECG was associated with an increased risk for death in COPD, independent of common confounders and disease severity. I-ECG was of prognostic value also among those without previously known heart disease.

Elevated neutrophil to lymphocyte ratio and ischemic stroke risk in generally healthy adults

Elevated neutrophil to lymphocyte ratio (NLR) has been reported as a marker for chronic inflammation, associated with poor prognosis in ischemic stroke patients, but there has been no study that investigated its association with ischemic stroke risk. This study was conducted to investigate elevated NLR as an independent risk factor for ischemic stroke incidence. Our retrospective cohort study included 24,708 generally healthy subjects aged 30–75 who received self-referred health screening at Seoul National University Hospital. Data on ischemic stroke incidence was retrieved from national medical claims registry. Median follow-up time was 5.9 years (interquartile range 4.2 years). Adjusted for major cardiovascular risk factors, compared to subjects with NLR<1.5, subjects with 2.5≤NLR<3.0, 3.0≤NLR<3.5, and NLR≥3.5 had elevated risk for ischemic stroke incidence with aHR (95% CI) of 1.76 (1.09–2.84), 2.21 (1.21–4.04), and 2.96 (1.57–5.58), respectively. NLR showed significant improvement in discrimination for ischemic stroke incidence compared to traditional cardiovascular risk factors (C-index 0.748 vs. 0.739, P = 0.025). There was significant net improvement in reclassification in Framingham risk for ischemic stroke incidence after addition of NLR, with IDI 0.0035 (P<0.0001), and NRI 6.02% (P = 0.0015). This reclassification for ischemic stroke incidence by NLR was markedly pronounced among subjects with atrial fibrillation with CHA₂DS₂-VASc<2 (NRI 42.41%, P = 0.056). Our study suggests elevated NLR to be an independent risk factor for ischemic stroke incidence in generally healthy adults. Future studies are needed to validate our results and further assess how subjects with elevated NLR should be managed within current guidelines.

Electrocardiographic Abnormalities and Cardiovascular Disease Risk in Type 1 Diabetes: The Epidemiology of Diabetes Interventions and Complications (EDIC) Study

OBJECTIVE

We examined the association between the prevalence and incidence of electrocardiographic (ECG) abnormalities and the development of cardiovascular disease (CVD) in patients with type 1 diabetes, among whom these ECG abnormalities are common.

RESEARCH DESIGN AND METHODS

We conducted a longitudinal cohort study involving 1,306 patients with type 1 diabetes (mean age 35.5 ± 6.9 years; 47.7% female) from the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) Study. ECG abnormalities were defined by the Minnesota Code ECG classification as major, minor, or no abnormality. CVD events were defined as the first occurrence of myocardial infarction, stroke, confirmed angina, coronary artery revascularization, congestive heart failure, or death from any CVD.

RESULTS

During a median follow-up of 19 years, 155 participants (11.9%) developed CVD events. In multivariable Cox proportional hazard models adjusted for demographics and potential confounders, the presence of any major ECG abnormalities as a time-varying covariate was associated with a more than twofold increased risk of CVD events (hazard ratio [HR] 2.10 [95% CI 1.26, 3.48] vs. no abnormality/normal ECG, and 2.19 [1.46, 3.29] vs. no major abnormality). Also, each visit (year) at which the diagnosis of major ECG abnormality was retained was associated with a 30% increased risk of CVD (HR 1.30 [95% CI 1.14, 1.48]). The presence of minor ECG abnormalities was not associated with a significant increase in CVD risk.

CONCLUSIONS

The presence of major ECG abnormalities is associated with an increased risk of CVD in patients with type 1 diabetes. This suggests a potential role for ECG screening in patients with type 1 diabetes to identify individuals at risk for CVD.

Utility of Normal Findings on Electrocardiogram and Echocardiogram in Subjects ≥65 Years

The lack of abnormalities found on noninvasive cardiac testing possibly improves cardiovascular disease (CVD) risk stratification efforts and conveys reduced risk despite the presence of traditional risk factors. This analysis included 3,805 (95% white and 61% women) participants from the Cardiovascular Health Study (CHS) without baseline CVD. The combination of a normal electrocardiogram (ECG) and echocardiogram was assessed for the development of CVD. A normal ECG was defined as the absence of major or minor Minnesota code abnormalities. A normal echocardiogram was defined as the absence of contractile dysfunction, wall motion abnormalities, or abnormal left ventricular mass. Cox regression was used to compute the 10-year risk of developing coronary heart disease, stroke, and heart failure events. There were 1,555 participants (41%) with normal findings on both measures. After accounting for traditional CVD risk factors, a protective benefit was observed for all outcomes among participants who had normal ECG and echocardiographic findings (coronary heart disease: hazard ratio [HR] 0.56, 95% confidence interval [CI] 0.46, 0.69; stroke: HR 0.57, 95% CI 0.43, 0.76; heart failure: HR 0.36, 95% CI 0.29, 0.41). The addition of this normal profile resulted in significant net reclassification improvement of the Framingham risk score for heart failure (net reclassification improvement 4.3%, 95% CI 1.0, 8.0). In conclusion, normal findings on routine noninvasive cardiac assessment identify subjects in whom CVD risk is low.

Predictors of electrocardiographic abnormalities in type 1 Diabetes: the Wisconsin Epidemiologic Study of Diabetic Retinopathy

PURPOSE

To determine the incidence and determinants of developing abnormalities on the 12-lead electrocardiogram (ECG) in persons with type 1 diabetes.

METHODS

We evaluated the distribution of ECG abnormalities and risk factors for developing new abnormalities in 266 (mean age = 44 years ± 9.0; 50 % female) people with type 1 diabetes from the Wisconsin Epidemiologic Study of Diabetic Retinopathy. This analysis included participants with complete ECG data from study visit 5 (2000-2001) and follow-up ECGs from study visit 7 (2012-2014). ECG abnormalities were classified as major and minor according to Minnesota Code Classification.

RESULTS

At baseline, 94 (35 %) participants had at least one ECG abnormality, including 13 major ECG abnormalities. At follow-up, 117 (44 %) participants developed at least one new ECG abnormality, including 35 new major ECG abnormalities. In a multivariable logistic regression model, older age (per 5-year increase: OR = 1.31, 95 % CI = 1.08, 1.60) was associated with the development of at least one new ECG abnormality, while serum HDL cholesterol (per 10-unit increase: OR = 0.98, 95 % CI = 0.96, 1.00) was protective against developing new ECG abnormalities.

CONCLUSIONS

The development of new ECG abnormalities is common in type 1 diabetes. Older age and HDL cholesterol are independent risk factors for developing new ECG abnormalities. Further research is needed to determine whether routine ECG screening is indicated in people with type 1 diabetes to identify those with underlying subclinical coronary heart disease.

The clinical utility of normal findings on noninvasive cardiac assessment in the prediction of atrial fibrillation

BACKGROUND

The absence of abnormalities on noninvasive cardiac assessment possibly confers a reduced risk of atrial fibrillation (AF) despite the presence of traditional risk factors.

HYPOTHESIS

Normal findings on noninvasive cardiac assessment are associated with a lower risk of AF development.

METHODS

We examined the clinical utility of normal findings on routine noninvasive cardiac assessment in 5331 participants (85% white; 57% women) from the Cardiovascular Health Study who were free of baseline AF. The combination of a normal electrocardiogram (ECG) + normal echocardiogram was assessed for the development of AF events. A normal ECG was defined as the absence of major or minor Minnesota code abnormalities. A normal echocardiogram was defined as the absence of contractile dysfunction, wall motion abnormalities, or abnormal left ventricular mass. Cox regression was used to compute the 10-year risk of developing AF.

RESULTS

During the 10-year study period, a total of 951 (18%) AF events were detected. A normal ECG (multivariable hazard ratio [HR]: 0.80, 95% confidence interval [CI]: 0.69-0.92) and normal echocardiogram (multivariable HR: 0.75, 95% CI: 0.65-0.87) were associated with a reduced risk of AF in isolation. This association improved in those with normal ECG + normal echocardiogram (multivariable HR: 0.66, 95% CI: 0.55-0.79) compared with participants who had abnormal ECG + abnormal echocardiogram (referent).

CONCLUSIONS

Normal findings on routine noninvasive cardiac assessment identify persons in whom the risk of AF is low. Further studies are needed to explore the utility of this profile regarding the decision to implement certain risk factor modification strategies in older adults to reduce AF burden.

Changes in ischaemic ECG abnormalities and subsequent risk of cardiovascular disease

Objective

The prognostic importance of changes in ischaemic ECG abnormalities over time (especially ST-T abnormalities) among Asians has not been fully investigated. We examined the associations between changes in ischaemic abnormalities upon serial ECG (improvement, persistence, deterioration) and cardiovascular disease (CVD) risk.

Methods

A prospective study cohort was conducted with 9374 men and women aged 40–69 years in four communities. Participants had multiple ECGs at study entry and during the next 10 years, and were followed up for a median period of 23.0 years. Total CVD (stroke and coronary heart disease) was ascertained under systematic surveillance. ECG abnormalities were defined by the Minnesota Code, ST depression (Code4), abnormal T wave (Code5) and categorised into nine groups (no–no, no–minor, no–major, minor–no, minor–minor, minor–major, major–no, major–minor, major–major) by comparison with the point of entrance and maximum change.

Results

We documented 1196 CVD events. Compared with no–no abnormality, no–minor, minor–major and major–major in Code4, HRs (95% CI) adjusted for cardiovascular risk factors were 1.19 (1.00–1.42), 1.57 (1.15–2.12) and 1.87 (1.42–2.47). Similar results were observed in Code5.

Conclusions

Changes in ischaemic ECG abnormalities from none to minor, and minor to major, as well as persistent major abnormalities, were associated with an increased risk of CVD.

Usefulness of Maintaining a Normal Electrocardiogram Over Time for Predicting Cardiovascular Health

We hypothesized that maintaining a normal electrocardiogram (ECG) status over time is associated with low cardiovascular (CV) disease in a dose-response fashion and subsequently could be used to monitor programs aimed at promoting CV health. This analysis included 4,856 CV disease-free participants from the Atherosclerosis Risk in Communities study who had a normal ECG at baseline (1987 to 1989) and complete electrocardiographic data in subsequent 3 visits (1990 to 1992, 1993 to 1995, and 1996 to 1998). Participants were classified based on maintaining their normal ECG status during these 4 visits into "maintained," "not maintained," or "inconsistent" normal ECG status as defined by the Minnesota ECG classification. CV disease events (coronary heart disease, heart failure, and stroke) were adjudicated from Atherosclerosis Risk in Communities visit-4 through 2010. Over a median follow-up of 13.2 years, 885 CV disease events occurred. The incidence rate of CV disease events was lowest among study participants who maintained a normal ECG status, followed by those with an inconsistent pattern, and then those who did not maintain their normal ECG status (trend p value <0.001). Similarly, the greater the number of visits with a normal ECG status, the lower was the incidence rate of CV disease events (trend p value <0.001). Maintaining (vs not maintaining) a normal ECG status was associated with a lower risk of CV disease, which was lower than that observed in those with inconsistent normal ECG pattern (trend p value <0.01). In conclusion, maintaining a normal ECG status over time is associated with low risk of CV disease in a dose-response fashion, suggesting its potential use as a monitoring tool for programs promoting CV health.

Arterial Stiffness and Risk of Overall Heart Failure, Heart Failure With Preserved Ejection Fraction, and Heart Failure With Reduced Ejection Fraction: The Health ABC Study (Health, Aging, and Body Composition)

Higher arterial stiffness is associated with increased risk of atherosclerotic events. However, its contribution toward risk of heart failure (HF) and its subtypes, HF with preserved ejection fraction (HFpEF) and HF with reduced ejection fraction (HFrEF), independent of other risk factors is not well established. In this study, we included Health ABC study (Health, Aging, and Body Composition) participants without prevalent HF who had arterial stiffness measured as carotid-femoral pulse wave velocity (cf-PWV) at baseline (n=2290). Adjusted Cox-proportional hazards models were constructed to determine the association between continuous and data-derived categorical measures (tertiles) of cf-PWV and incidence of HF and its subtypes (HFpEF [ejection fraction >45%] and HFrEF [ejection fraction ≤45%]). We observed 390 HF events (162 HFpEF and 145 HFrEF events) over 11.4 years of follow-up. In adjusted analysis, higher cf-PWV was associated with greater risk of HF after adjustment for age, sex, ethnicity, mean arterial pressure, and heart rate (hazard ratio [95% confidence interval] for cf-PWV tertile 3 versus tertile 1 [ref] =1.35 [1.05-1.73]). However, this association was not significant after additional adjustment for other cardiovascular risk factors (hazard ratio [95% confidence interval], 1.14 [0.88-1.47]). cf-PWV velocity was also not associated with risk of HFpEF and HFrEF after adjustment for potential confounders (most adjusted hazard ratio [95% confidence interval] for cf-PWV tertile 3 versus tertile 1 [ref]: HFpEF, 1.06 [0.72-1.56]; HFrEF, 1.28 [0.83-1.97]). In conclusion, arterial stiffness, as measured by cf-PWV, is not independently associated with risk of HF or its subtypes after adjustment for traditional cardiovascular risk factors.

The ability of an electrocardiogram to predict fatal and non-fatal cardiac events in asymptomatic middle-aged subjects

INTRODUCTION

The long-term prognostic value of a standard 12-lead electrocardiogram (ECG) for predicting cardiac events in apparently healthy middle-aged subjects is not well defined.

MATERIALS AND METHODS

A total of 9511 middle-aged subjects (mean age 43 ± 8.2 years, 52% males) without a known cardiac disease and with a follow-up 40 years were included in the study. Fatal and non-fatal cardiac events were collected from the national registries. The predictive value of ECG was separately analyzed for 10 and 30 years. Major ECG abnormalities were classified according to the Minnesota code.

RESULTS

Subjects with major ECG abnormalities (N = 1131) had an increased risk of cardiac death after 10-years (adjusted hazard ratio [HR] 1.7; 95% confidence interval [95% CI], 1.1-2.5, p = 0.009) and 30-years of follow-up (HR 1.3, 95% CI, 1.1-1.5, p < 0.001). Model discrimination measured with the C-index showed only a minor improvement with the inclusion of ECG abnormalities: 0.851 versus 0.853 and 0.742 versus 0.743 for 10- and 30-year follow-up, respectively. ECG did not predict non-fatal cardiac events after 10-years or 30-years of follow-up.

DISCUSSION

Major ECG abnormalities are associated with an increased risk of short and long-term cardiac mortality in middle-aged subjects. However, the improvement in discrimination between subjects with and without fatal cardiac events was marginal with abnormal ECG.

KEY MESSAGES

Abnormalities observed on 12-lead electrocardiogram are shown to have prognostic significance for cardiac events in elderly subjects without known cardiac disease. Our results suggest that ECG abnormalities increase the risk of fatal cardiac events also in middle-aged healthy subjects.

An Electrocardiogram-Based Risk Equation for Incident Cardiovascular Disease From the National Health and Nutrition Examination Survey

Importance

Electrocardiography (ECG) may detect subclinical cardiovascular disease (CVD) in asymptomatic individuals, but its role in assessing adverse events beyond traditional risk factors is not clear. Interval and vector data that are commonly available on modern ECGs may offer independent prognostic information that improves risk classification.

Objectives

To derive and validate a CVD risk equation based on ECG metrics and to determine its incremental benefit in addition to the Framingham risk score (FRS).

Design, Setting, and Participants

This study included 3640 randomly selected community-based adults aged 40 to 74 years without known CVD from the First National Health and Nutrition Examination Survey (NHANES I) cohort (1971-1975) and 6329 from the NHANES III cohort (1988-1994). Participants were sampled from across the United States. A risk score to assess incident nonfatal and fatal CVD events was derived based on computer-generated ECG data, including frontal P, R, and T axes; heart rate; and PR, QRS, and QT intervals from NHANES I. The most prognostic variables, along with age and sex, were incorporated into the NHANES ECG risk equation. The equation was evaluated in the NHANES III cohort for an independent validation. Follow-up in the NHANES III cohort was completed on December 31, 2006. Data for this study were analyzed from August 11, 2015, to May 20, 2016.

Main Outcomes and Measures

The primary end point was CVD death. Secondary outcomes included 10-year ischemic heart disease and all-cause death.

Results

The final study sample included 9969 participants (4714 men [47.3%]; 5255 women [52.7%]; mean [SD] age, 55.3 [10.1] years) from both cohorts. Frontal T axis, heart rate, and heart rate-corrected QT interval were the most significant ECG factors in the NHANES I cohort. In the validation cohort (NHANES III), the equation provided for prognostic information for fatal CVD with a hazard ratio (HR) of 3.23 (95% CI, 2.82-3.72); the C statistic was 0.79 (95% CI, 0.76-0.81). When added to the FRS in Cox proportional hazards regression models, the categorical (1%, 5%, and 10% cutoffs) net reclassification improvement was 24%. When the FRS and ECG scores were combined in a single model, the C statistic improved by 0.04 (95% CI, 0.02-0.06) to 0.80 (95% CI, 0.77-0.82). Similar improvements were noted when the ECG score was added to the pooled cohort equation. When the equation for prognostic information about ischemic heart disease and all-cause death was evaluated, the results were similar.

Conclusions and Relevance

An ECG risk score based on age, sex, heart rate, frontal T axis, and QT interval assesses the risk for CVD and compares favorably with the FRS alone in an independent cohort of asymptomatic individuals. Although the ECG risk equation is low cost, further research is needed to ascertain whether this additional step in risk stratification may improve prevention efforts and reduce CVD events.

Genetic Investigation Into the Differential Risk of Atrial Fibrillation Among Black and White Individuals

IMPORTANCE

White persons have a higher risk of atrial fibrillation (AF) compared with black individuals despite a lower prevalence of risk factors. This difference may be due, at least in part, to genetic factors.

OBJECTIVES

To determine whether 9 single-nucleotide polymorphisms (SNPs) associated with AF account for this paradoxical differential racial risk for AF and to use admixture mapping to search genome-wide for loci that may account for this phenomenon.

DESIGN, SETTING, AND PARTICIPANTS

Genome-wide admixture analysis and candidate SNP study involving 3 population-based cohort studies that were initiated between 1987 and 1997, including the Cardiovascular Health Study (CHS) (n = 4173), the Atherosclerosis Risk in Communities (ARIC) (n = 12 341) study, and the Health, Aging, and Body Composition (Health ABC) (n = 1015) study. In all 3 studies, race was self-identified. Cox proportional hazards regression models and the proportion of treatment effect method were used to determine the impact of 9 AF-risk SNPs among participants from CHS and the ARIC study. The present study began July 1, 2012, and was completed in 2015.

MAIN OUTCOMES AND MEASURES

Incident AF systematically ascertained using clinic visit electrocardiograms, hospital discharge diagnosis codes, death certificates, and Medicare claims data.

RESULTS

A single SNP, rs10824026 (chromosome 10: position 73661450), was found to significantly mediate the higher risk for AF in white participants compared with black participants in CHS (11.4%; 95% CI, 2.9%-29.9%) and ARIC (31.7%; 95% CI, 16.0%-53.0%). Admixture mapping was performed in a meta-analysis of black participants within CHS (n = 811), ARIC (n = 3112), and Health ABC (n = 1015). No loci that reached the prespecified statistical threshold for genome-wide significance were identified.

CONCLUSIONS AND RELEVANCE

The rs10824026 SNP on chromosome 10q22 mediates a modest proportion of the increased risk of AF among white individuals compared with black individuals, potentially through an effect on gene expression levels of MYOZ1. No additional genetic variants accounting for a significant portion of the differential racial risk of AF were identified with genome-wide admixture mapping, suggesting that additional genetic or environmental influences beyond single SNPs in isolation may account for the paradoxical racial risk of AF among white individuals and black individuals.

Independent Prognostic Value of Single and Multiple Non-Specific 12-Lead Electrocardiographic Findings for Long-Term Cardiovascular Outcomes: A Prospective Cohort Study

Aims

The long-term prognostic effect of non-specific 12-lead electrocardiogram findings is unknown. We aimed to evaluate the cumulative prognostic impact of axial, structural, and repolarization categorical abnormalities on cardiovascular death, independent from traditional risk scoring systems such as the Framingham risk score and the NIPPON DATA80 risk chart.

Methods and Results

A total of 16,816 healthy men and women from two prospective, longitudinal cohort studies were evaluated. 3,794 (22.6%) individuals died during a median follow-up of 15 years (range, 2.0–24 years). Hazard ratios for cardiovascular death, all-cause death, coronary death and stroke death were calculated for the cumulative and independent axial, structural, and repolarization categorical abnormalities adjusted for the Framingham risk score and the NIPPON DATA80 risk chart. Individuals with two or more abnormal categories had a higher risk of cardiovascular death after adjustment for Framingham risk score (men: HR 4.27, 95%CI 3.35–5.45; women: HR 4.83, 95%CI 3.76–6.22) and NIPPON DATA80 risk chart (men: HR 2.39, 95%CI 1.87–3.07; women: HR 2.04, 95%CI 1.58–2.64).

Conclusion

Cumulative findings of axial, structural, and repolarization abnormalities are significant predictors of long-term cardiovascular death in asymptomatic, healthy individuals independent of traditional risk stratification systems.

Prevalence of electrocardiographic abnormalities based on hypertension severity and blood pressure levels: the Reasons for Geographic and Racial Differences in Stroke study

We evaluated the prevalence of major and minor electrocardiographic (ECG) abnormalities based on blood pressure (BP) control and hypertension (HTN) treatment resistance. We analyzed data from the Reasons for Geographic and Racial Differences in Stroke study of 20,932 participants who were divided into presence of major (n = 3782), only minor (n = 8944), or no (n = 8206) ECG abnormalities. The cohort was stratified into normotension (n = 3373), pre-HTN (n = 4142), controlled HTN (n = 8619), uncontrolled HTN (n = 3544), controlled apparent treatment-resistant HTN (aTRH, n = 400), and uncontrolled aTRH (n = 854) groups, and the prevalence ratios (PRs) of major and minor ECG abnormalities were assessed separately for each BP group. The full multivariable adjustment included demographics, risk factors, and HTN duration. Compared with normotension, the PRs of major ECG abnormalities for pre-HTN, controlled HTN, uncontrolled HTN, controlled aTRH, and uncontrolled aTRH groups were 1.01 (0.90-1.14), 1.30 (1.16-1.45), 1.37 (1.23-1.54), 1.42 (1.22-1.64), and 1.44 (1.26-1.65), respectively (P < .001), whereas the PRs of minor ECG abnormalities among each of the above BP groups were similar. Detection of major ECG abnormalities among hypertensive persons with poor control and treatment resistance may help improve their cardiovascular risk stratification and early intervention.

Cardiovascular risk prediction: Can Systematic Coronary Risk Evaluation (SCORE) be improved by adding simple risk markers? Results from the Copenhagen City Heart Study

AIM

European society of cardiology (ESC) guidelines recommend that cardiovascular disease (CVD) risk stratification in asymptomatic individuals is based on the Systematic Coronary Risk Evaluation (SCORE) algorithm, which estimates individual 10-year risk of death from CVD. We assessed the potential improvement in CVD risk stratification of 19 easily available risk markers by adding them to the SCORE algorithm.

METHODS AND RESULTS

We followed 8476 individuals without prior CVD or diabetes from the Copenhagen City Heart study. The 19 risk markers were: major and minor electrocardiographic (ECG) abnormalities, heart rate, family history (of ischaemic heart disease), body mass index (BMI), waist-hip ratio, walking duration and pace, leisure time physical activity, forced expiratory volume (FEV)1%pred, household income, education, vital exhaustion, high-density lipoprotein (HDL) cholesterol, triglycerides, apolipoprotein A1 (ApoA1), apolipoprotein B (ApoB), high-sensitive C-reactive protein (hsCRP) and fibrinogen. With the exception of family history, BMI, triglycerides and minor ECG changes, all risk markers remained significantly associated with CVD mortality after adjustment for SCORE variables. However, the addition of the remaining 15 risk markers resulted in only small changes in discrimination calculated by area under the curve (AUC) and integrated discrimination improvement (IDI) and no improvement in net reclassification improvement (NRI). HsCRP improved AUC by 0.006 (p = 0.015) and IDI by 0.012 (p = 0.002); FEV1%pred improved AUC by 0.006 (p = 0.032) and IDI by 0.006 (p = 0.029). In the intermediate risk group FEV1%pred, education, vital exhaustion and ApoA1 all improved NRI but FEV1%pred was the only risk marker to significantly improve both IDI, AUC and NRI.

CONCLUSION

The SCORE algorithm predicted CVD mortality in a Danish cohort well. Despite strong association with CVD mortality, the individual addition of 19 easily available risk makers to the SCORE model resulted in small risk stratification improvements.

Progression of Electrocardiographic Abnormalities in Type 1 Diabetes During 16 Years of Follow-up: The Epidemiology of Diabetes Interventions and Complications (EDIC) Study

BACKGROUND

The electrocardiogram (ECG) is an objective tool for cardiovascular disease (CVD) risk assessment.

METHODS AND RESULTS

We evaluated distribution of ECG abnormalities and risk factors for developing new abnormalities in 1314 patients with type 1 diabetes (T1D) from the Epidemiology of Diabetes Interventions and Complications (EDIC) study. Annual ECGs were centrally read. ECG abnormalities were classified as major and minor according to the Minnesota ECG Classification. At EDIC year 1 (baseline), 356 (27.1%) of the participants had at least 1 ECG abnormality (major or minor) whereas 26 (2%) had at least one major abnormality. During 16 years of follow-up, 1016 (77.3%) participants developed at least 1 new ECG abnormality (major or minor), whereas 172 (13.1%) developed at least 1 new major abnormality. Independent risk factors for developing new major ECG abnormalities were: age, current smoking, increased systolic blood pressure, and higher glycosylated hemoglobin (hazard ratio [HR] [95% CI]: 1.04 [1.02-1.06] per 1-year increase, 1.75 [1.22-2.53], 1.03 [1.01-1.05] per 1 mm Hg increase, and 1.16 [1.04-1.29] per 10% increase, respectively). Independent risk factors for developing any new ECG abnormalities (major or minor) were age and systolic blood pressure (HR [95% CI]: 1.02 [1.01-1.03] per 1-year increase and 1.01 [1.00-1.02] per 1 mm Hg increase, respectively).

CONCLUSIONS

New ECG abnormalities commonly occur in the course of T1D, consistent with the recognized increasing risk for CVD as patients age. Advanced age, increased systolic blood pressure, smoking, and higher HbA1c are independent risk factor for developing major ECG abnormalities, which underscores the importance of tight glucose control in T1D in addition to management of common CVD risk factors.

Body Mass Index as a Predictor of Sudden Cardiac Death and Usefulness of the Electrocardiogram for Risk Stratification

Evidence of the role of body mass index (BMI) as a risk factor for sudden cardiac death (SCD) is conflicting, and how electrocardiographic (ECG) SCD risk markers perform in subjects with different BMIs is not known. In this study, a general population cohort consisting of 10,543 middle-aged subjects (mean age 44 years, 52.7% men) was divided into groups of lean (BMI <20, n = 374), normal weight (BMI 20.0 to 24.9, n = 4,334), overweight (BMI 25.0 to 29.9, n = 4,390), and obese (BMI >30, n = 1,445) subjects. Cox proportional hazards models adjusted for confounders were used to assess the risk for SCD associated with BMI and the risk for SCD associated with ECG abnormalities in subjects with different BMIs. The overweight and obese subjects were at increased risk for SCD (hazard ratios [95% CIs] were 1.33 [1.13 to 1.56], p = 0.001 and 1.79 [1.44 to 2.23], p <0.001 for overweight and obese subjects, respectively). The risk of non-SCD had a similar relation with BMI as SCD. Hazard ratios associated with ECG abnormalities were 3.03, 1.75, 1.74, and 1.34 in groups of lean, normal weight, overweight, and obese subjects, respectively, but no statistical significance was reached in the obese. ECG abnormalities improved integrated discrimination indexes and continuous net reclassification indexes statistically significantly only in the normal weight group. In conclusion, the overweight and obese are at increased risk for SCD but also for non-SCD, and ECG abnormalities are associated with increased risk of SCD also in normal weight subjects presenting with less traditional cardiovascular risk factors.

Association between resistin levels and cardiovascular disease events in older adults: The health, aging and body composition study

OBJECTIVE

Prospective data on the association between resistin levels and cardiovascular disease (CVD) events are sparse with conflicting results.

METHODS

We studied 3044 aged 70-79 years from the Health, Aging, and Body Composition Study. CVD events were defined as coronary heart disease (CHD) or stroke events. «Hard » CHD events were defined as CHD death or myocardial infarction. We estimated hazard ratio (HR) and 95% confidence intervals (CI) according to the quartiles of serum resistin concentrations and adjusted for clinical variables, and then further adjusted for metabolic disease (body mass index, fasting plasma glucose, abdominal visceral and subcutaneous adipose tissue, leptin, adiponectin, insulin) and inflammation (C-reactive protein, interleukin-6, tumor necrosis factors-α).

RESULTS

During a median follow-up of 10.1 years, 559 patients had « hard » CHD events, 884 CHD events and 1106 CVD Events. Unadjusted incidence rate for CVD events was 36.6 (95% CI 32.1-41.1) per 1000 persons-year in the lowest quartile and 54.0 per 1000 persons-year in the highest quartile (95% CI 48.2-59.8, P for trend < 0.001). In the multivariate models adjusted for clinical variables, HRs for the highest vs. lowest quartile of resistin was 1.52 (95% CI 1.20-1.93, P < 0.001) for « Hard » CHD events, 1.41 (95% CI 1.16-1.70, P = 0.001) for CHD events and 1.35 (95% CI 1.14-1.59, P = 0.002) for CVD events. Further adjustment for metabolic disease slightly reduced the associations while adjustment for inflammation markedly reduced the associations.

CONCLUSIONS

In older adults, higher resistin levels are associated with CVD events independently of clinical risk factors and metabolic disease markers, but markedly attenuated by inflammation.

Electrocardiographic Screening for Prolonged QT Interval to Reduce Sudden Cardiac Death in Psychiatric Patients: A Cost-Effectiveness Analysis

IMPORTANCE

Sudden cardiac death is a leading cause of mortality in psychiatric patients. Long QT (LQT) is common in this population and predisposes to Torsades-de-Pointes (TdP) and subsequent mortality.

OBJECTIVE

To estimate the cost-effectiveness of electrocardiographic screening to detect LQT in psychiatric inpatients.

DESIGN, SETTING, AND PARTICIPANTS

We built a decision analytic model based on a decision tree to evaluate the cost-effectiveness and utility of LQT screening from a health care perspective. LQT proportion parameters were derived from an in-hospital cross-sectional study. We performed experts' elicitation to estimate the risk of TdP, given extent of QT prolongation. A TdP reduction of 65% after LQT detection was based on positive drug dechallenge rate and through adequate treatment and electrolyte adjustments. The base-case model uncertainty was assessed with one-way and probabilistic sensitivity analyses. Finally, the TdP related mortality and TdP avoidance parameters were varied in a two-way sensitivity analysis to assess their effect on the Incremental Cost-Effectiveness Ratio (ICER).

MAIN OUTCOMES AND MEASURES

Costs, Quality Ajusted Life Year (QALY), ICER, and probability of cost effectiveness thresholds ($ 10,000, $25,000, and $50,000 per QALY).

RESULTS

In the base-case scenario, the numbers of patients needed to screen were 1128 and 2817 to avoid one TdP and one death, respectively. The ICER of systematic ECG screening was $8644 (95%CI, 3144-82 498) per QALY. The probability of cost-effectiveness was 96% at a willingness-to-pay of $50,000 for one QALY. In sensitivity analyses, results were sensitive to the case-fatality of TdP episodes and to the TdP reduction following the diagnosis of LQT.

CONCLUSION AND RELEVANCE

In psychiatric hospitals, performing systematic ECG screening at admission help reduce the number of sudden cardiac deaths in a cost-effective fashion.

Prognostic value of non-specific ST-T changes and left ventricular hypertrophy electrocardiographic criteria in hypertensive patients: 16-year follow-up results from the MINACOR cohort

BACKGROUND

Non-specific electrocardiographic ST-T wave changes and voltage criteria for left ventricular hypertrophy (LVH) have been associated with cardiovascular morbidity and mortality. The aim of the cohort study was to evaluate the prognostic value of non-specific ST-T changes and LVH electrocardiographic criteria on cardiovascular events and mortality in hypertensive patients.

METHODS

A cohort study of 352 non-diabetic hypertensive patients, without associated cardiovascular disease, randomly selected from 1,780 hypertensive patients attended in a primary care center. An electrocardiogram was performed at the baseline visit (classified according to the Minnesota Code). Cardiovascular events and death from any cause during the follow-up period were evaluated. A multivariate analysis adjusted for gender, age and cardiovascular risk factors was performed.

RESULTS

Data of 273 patients were analyzed: 58.2% women, age 44.1 (7.9) years, 27.8% smokers, blood pressure at baseline 142.7 (15.3)/89.3 (9.6) mmHg. During the 197.5 (59.24) month follow-up, 62 patients (22.7%) had a cardiovascular event. On multivariate analysis, age, systolic blood pressure, incidence of diabetes, smoking and electrocardiographic LVH criteria (HR 2.66 [CI 95% 1.39 - 5.10]), were significantly associated with cardiovascular events, but the presence of non-specific ST-T abnormalities (HR 0.97 [CI 95% 0.49 -1.90]) was not significantly associated with cardiovascular morbidity and mortality.

CONCLUSIONS

Hypertensive patients with LVH electrocardiographic criteria have significantly higher cardiovascular mortality and morbidity, but non-specific electrocardiographic ST-T changes are not associated with cardiovascular morbidity and mortality.