Subclinical coronary atherosclerosis and resting ECG abnormalities in an unselected general population

Sex differences in the association between minor nonspecific ST-segment and T-wave abnormalities and coronary artery calcification

BACKGROUND AND AIMS

Although minor nonspecific ST-segment and T-wave abnormalities (NSSTTA) have been associated with adverse cardiovascular outcomes, their relationship with subclinical atherosclerosis remains controversial. Therefore, the associations between electrocardiographic (ECG) abnormalities, including NSSTTA, and coronary artery calcification (CAC) were investigated in this study.

METHODS

This cross-sectional study included 136,461 Korean participants with no known cardiovascular disease or cancer, who underwent a health checkup including ECG and computed tomography to measure the coronary artery calcium score (CACS) by Agatston method between 2010 and 2018. ECG abnormalities were defined in accordance with the Minnesota Code using an automated ECG analysis program. A multinomial logistic regression model was used to calculate prevalence ratios (PRs) with 95% confidence intervals (CI) for each CACS category.

RESULTS

In men, both NSSTTA and major ECG abnormalities were associated with all levels of CACS. The multivariable-adjusted PRs (95% CI) for CACS >400 comparing NSSTTA and major ECG abnormalities to the reference (neither NSSTTA nor major ECG abnormalities) were 1.88 (1.29-2.74) and 1.50 (1.18-1.91), respectively. Women with major ECG abnormalities were more likely to have a CACS of 101-400, the PRs (95% CI) comparing major ECG abnormalities to the reference group was 1.75 (1.18-2.57). NSSTTA were not associated with any CACS level in women.

CONCLUSIONS

NSSTTA and major ECG abnormalities are associated with CAC in men, though NSSTTA were not associated with CAC in women, suggesting that NSSTTA should be considered sex-specific risk factors for coronary artery disease in men, but not in women.

Machine learning derived ECG risk score improves cardiovascular risk assessment in conjunction with coronary artery calcium scoring

Background

Precision estimation of cardiovascular risk remains the cornerstone of atherosclerotic cardiovascular disease (ASCVD) prevention. While coronary artery calcium (CAC) scoring is the best available non-invasive quantitative modality to evaluate risk of ASCVD, it excludes risk related to prior myocardial infarction, cardiomyopathy, and arrhythmia which are implicated in ASCVD. The high-dimensional and inter-correlated nature of ECG data makes it a good candidate for analysis using machine learning techniques and may provide additional prognostic information not captured by CAC. In this study, we aimed to develop a quantitative ECG risk score (eRiS) to predict major adverse cardiovascular events (MACE) alone, or when added to CAC. Further, we aimed to construct and validate a novel nomogram incorporating ECG, CAC and clinical factors for ASCVD.

Methods

We analyzed 5,864 patients with at least 1 cardiovascular risk factor who underwent CAC scoring and a standard ECG as part of the CLARIFY study (ClinicalTrials.gov Identifier: NCT04075162). Events were defined as myocardial infarction, coronary revascularization, stroke or death. A total of 649 ECG features, consisting of measurements such as amplitude and interval measurements from all deflections in the ECG waveform (53 per lead and 13 overall) were automatically extracted using a clinical software (GE Muse™ Cardiology Information System, GE Healthcare). The data was split into 4 training (S_tr) and internal validation (S_v) sets [S_tr (1): S_v (1): 50:50; S_tr (2): S_v (2): 60:40; S_tr (3): S_v (3): 70:30; S_tr (4): S_v (4): 80:20], and the results were compared across all the subsets. We used the ECG features derived from S_tr to develop eRiS. A least absolute shrinkage and selection operator-Cox (LASSO-Cox) regularization model was used for data dimension reduction, feature selection, and eRiS construction. A Cox-proportional hazards model was used to assess the benefit of using an eRiS alone (M_ecg), CAC alone (M_cac) and a combination of eRiS and CAC (M_ecg+cac) for MACE prediction. A nomogram (M_nom) was further constructed by integrating eRiS with CAC and demographics (age and sex). The primary endpoint of the study was the assessment of the performance of M_ecg, M_cac, M_ecg+cac and M_nom in predicting CV disease-free survival in ASCVD.

Findings

Over a median follow-up of 14 months, 494 patients had MACE. The feature selection strategy preserved only about 18% of the features that were consistent across the various strata (S_tr). The M_ecg model, comprising of eRiS alone was found to be significantly associated with MACE and had good discrimination of MACE (C-Index: 0.7, p = <2e-16). eRiS could predict time-to MACE (C-Index: 0.6, p = <2e-16 across all S_v). The M_ecg+cac model was associated with MACE (C-index: 0.71). Model comparison showed that M_ecg+cac was superior to M_ecg (p = 1.8e-10) or M_cac (p < 2.2e-16) alone. The M_nom, comprising of eRiS, CAC, age and sex was associated with MACE (C-index 0.71). eRiS had the most significant contribution, followed by CAC score and other clinical variables. Further, M_nom was able to identify unique patient risk-groups based on eRiS, CAC and clinical variables.

Conclusion

The use of ECG features in conjunction with CAC may allow for improved prognostication and identification of populations at risk. Future directions will involve prospective validation of the risk score and the nomogram across diverse populations with a heterogeneity of treatment effects.

Electrocardiogram Risk Score and Prevalence of Subclinical Atherosclerosis: A Cross-Sectional Study

Integrated abnormal electrocardiogram (ECG) parameters predict the risk of cardiovascular disease (CVD); however, its relationship with subclinical CVD is unknown. We aimed to evaluate the association between the integrated ECG risk score and the prevalence of coronary artery calcium (CAC). A cross-sectional study comprised 134,802 participants with no known CVD who underwent ECG and CAC computed tomography. The ECG risk score was the sum of five ECG abnormalities: heart rate of >80 beats, QRS of >110 ms, left ventricular hypertrophy, T-wave inversion, and prolonged QTc. A multinomial regression model was used to estimate the prevalence ratios (PRs) and their 95% confidence intervals (CIs) for prevalent CAC. The prevalence of CAC progressively increased as the ECG risk score increased. After adjustment for conventional CVD risk factors and other confounders, the multivariable-adjusted PRs (95% CI) for a CAC of 1−100 in the 1, 2, and ≥3 ECG risk score groups were 1.06 (1.02−1.10), 1.12 (1.03−1.22), and 1.19 (1.00−1.42), respectively, while the corresponding PRs for a CAC of >100 were 1.03 (0.95−1.12), 1.44 (1.25−1.66), and 1.75 (1.33−2.29), respectively. Integrative ECG scoring may help identify individuals requiring lipid-lowering medications, even in young and asymptomatic populations.

Aortic Unfolding Measurement Using Non-Contrast Cardiac CT: Normal Range of Low-Risk Subjects

Purpose

Materials and Methods

Results

Conclusion

Ca2+ Flux: Searching for a Role in Efferocytosis of Apoptotic Cells in Atherosclerosis

In atherosclerosis, macrophages in the arterial wall ingest plasma lipoprotein-derived lipids and become lipid-filled foam cells with a limited lifespan. Thus, efficient removal of apoptotic foam cells by efferocytic macrophages is vital to preventing the dying foam cells from forming a large necrotic lipid core, which, otherwise, would render the atherosclerotic plaque vulnerable to rupture and would cause clinical complications. Ca²⁺ plays a role in macrophage migration, survival, and foam cell generation. Importantly, in efferocytic macrophages, Ca²⁺ induces actin polymerization, thereby promoting the formation of a phagocytic cup necessary for efferocytosis. Moreover, in the efferocytic macrophages, Ca²⁺ enhances the secretion of anti-inflammatory cytokines. Various Ca²⁺ antagonists have been seminal for the demonstration of the role of Ca²⁺ in the multiple steps of efferocytosis by macrophages. Moreover, in vitro and in vivo experiments and clinical investigations have revealed the capability of Ca²⁺ antagonists in attenuating the development of atherosclerotic plaques by interfering with the deposition of lipids in macrophages and by reducing plaque calcification. However, the regulation of cellular Ca²⁺ fluxes in the processes of efferocytic clearance of apoptotic foam cells and in the extracellular calcification in atherosclerosis remains unknown. Here, we attempted to unravel the molecular links between Ca²⁺ and efferocytosis in atherosclerosis and to evaluate cellular Ca²⁺ fluxes as potential treatment targets in atherosclerotic cardiovascular diseases.

The annual rate of coronary artery calcification with combination therapy with a PCSK9 inhibitor and a statin is lower than that with statin monotherapy

Statins and/or PCSK9 inhibitors cause the regression of coronary atheroma and reduce clinical events. However, it currently remains unclear whether these drugs modulate coronary atheroma calcification in vivo. Coronary artery calcium (CAC) scores (Agatston Units, AUs) were estimated in 120 patients receiving coronary computed tomographic angiography (CCTA) (63% males; median age 56 years). The CAC scores were compared among the three groups: (1) neither statin nor PCSK9 inhibitor therapy, (2) statin monotherapy, and (3) statin and PCSK9 inhibitor combination therapy in an unpaired cross-sectional study. Additionally, CCTA was performed twice at an interval in 15 patients undergoing statin monotherapy to compare the previous (baseline) and subsequent (follow-up) CAC scores in a paired longitudinal study. In addition, a PCSK9 inhibitor was administered to 16 patients undergoing statin therapy. Before and after that, CCTA was performed twice to compare the previous and subsequent CAC scores in a paired longitudinal study. The unpaired cross-sectional study and paired longitudinal study consist of completely different patients. Among 120 patients, 40 (33%) had a CAC score >100 AUs. The median CAC score increased in the following order: statin group, statin and PCSK9 group, and no-statin-no-PCSK9 group. Annual CAC score progression was 29.7% by statin monotherapy and 14.3% following the addition of the PCSK9 inhibitor to statin therapy. The annual rate of CAC with the combination therapy with a PCSK9 inhibitor and a statin is lower than that with statin monotherapy. CAC may be prevented with PCSK9 Inhibitor.

Cardiac computed tomography in patients with symptomatic new-onset atrial fibrillation, rule-out acute coronary syndrome, but with intermediate pretest probability for coronary artery disease admitted to a chest pain unit

Background

Atrial fibrillation (AF) and coronary artery disease (CAD) may be encountered coincidently in a large portion of patients. However, data on coronary artery calcium burden in such patients are lacking. Thus, we sought to determine the value of cardiac computed tomography (CCT) in patients presenting with new-onset AF associated with an intermediate pretest probability for CAD admitted to a chest pain unit (CPU).

Methods

Calcium scores (CS) of 73 new-onset, symptomatic AF subjects without typical clinical, electrocardiographic, or laboratory signs of acute coronary syndrome (ACS) admitted to our CPU were analyzed. In addition, results from computed tomography angiography (CTA) were related to coronary angiography findings whenever available.

Results

Calcium scores of zero were found in 25%. Median Agatston score was 77 (interquartile range: 1–270) with gender- and territory-specific dispersal. CS scores above average were present in about 50%, high (> 400)-to-very high (> 1000) CS scores were found in 22%. Overall percentile ranking showed a relative accordance to the reference percentile distribution. Additional CTA was performed in 47%, revealing stenoses in 12%. Coronary angiography was performed in 22% and resulted in coronary intervention or surgical revascularization in 7%. On univariate analysis, CS > 50th percentile failed to serve as an independent determinant of significant stenosis during catheterization.

Conclusions

Within a CPU setting, relevant CAD was excluded or confirmed in almost 50%, the latter with a high proportion of coronary angiographies and subsequent coronary interventions, underlining the diagnostic value of CCT in symptomatic, non-ACS, new-onset AF patients when admitted to a CPU.

Prolongation of the QTc interval in HIV-infected individuals compared to the general population

OBJECTIVES

Prolonged QT interval is associated with arrhythmias and sudden death. An increased prevalence of QT interval prolongation in human immunodeficiency virus-infected (HIV) subjects was previously described. The impact of different medications and HIV infection itself on the QT interval is rarely investigated in large HIV+ cohorts.

METHODS

We compared QT interval measurement in 496 HIV(+) patients of the HIV-HEART study (HIVH) and 992 sex- and age-matched controls of the population-based German Heinz Nixdorf Recall study (HNR). QT corrected for heart rate (QTc) >440 ms in male and >460 ms in female was considered pathological. We analysed the impact of HIV status and HIV medication on QTc prolongation in the HIVH subjects.

RESULTS

We observed longer QTc in HIVH subjects compared with HNR controls: 424.1 ms ± 23.3 vs. 411.3 ± 15.3 ms for male and 435.5 ms ± 19.6 vs. 416.4 ms ± 17.3 for female subjects (p < 0.0001 for both sexes). Adjusting for QT prolonging medication the mean differences in QTc between the two studies remained significant with 12.6 ms (95% CI 10.5-14.8; p value <0.0001) for male and 19.3 ms (95% CI 14.5-24.2; p value <0.0001) for female subjects. Prolongation of QTc was pathologic in 22.8 vs. 3.9% of HIV(+) and non-infected males and in 12.1 vs. 1.8% of the females [OR of 7.9 (5.0-12.6) and OR of 6.7 (1.8-24.2), respectively]. Smoking behaviour was an independent factor to lengthen QTc in HIV(+) patients. Diabetes mellitus was not a risk factor itself, but might be associated with medication which was associated with LQT. We could not observe any influence of the HIV status, ART, or any co-medication on the QTc.

CONCLUSIONS

Our study showed that HIV(+) patients had significantly longer QTc intervals compared to the general population. The number of patients with pathologic QTc prolongation was significantly increased in HIV(+) population.

Coronary Artery Calcium as an Independent Surrogate Marker in the Risk Assessment of Patients With Atrial Fibrillation and an Intermediate Pretest Likelihood for Coronary Artery Disease Admitted to a German Chest Pain Unit

BACKGROUND

About 10% of patients admitted to a chest pain unit (CPU) exhibit atrial fibrillation (AF).

HYPOTHESIS

To determine whether calcium scores (CS) are superior over common risk scores for coronary artery disease (CAD) in patients presenting with atypical chest pain, newly diagnosed AF, and intermediate pretest probability for CAD within the CPU.

METHODS

In 73 subjects, CS was related to the following risk scores: Global Registry of Acute Coronary Events (GRACE) score, including a new model of a frequency-normalized approach; Thrombolysis In Myocardial Infarction score; European Society of Cardiology Systematic Coronary Risk Evaluation (SCORE); Framingham risk score; and Prospective Cardiovascular Münster Study score. Revascularization rates during index stay were assessed.

RESULTS

Median CS was 77 (interquartile range, 1-270), with higher values in men and the left anterior descending artery. Only the modified GRACE (ρ = 0.27; P = 0.02) and the SCORE (ρ = 0.39; P < 0.005) were significantly correlated with CS, whereas the GRACE (τ = 0.21; P = 0.04) and modified GRACE (τ = 0.23; P = 0.02) scores were significantly correlated with percentile groups. Only the CS significantly discriminated between those with and without stenosis (P < 0.01).

CONCLUSIONS

Apart from modified GRACE score, overall correlations between risk scores and calcium burden, as well as revascularization rates during index stay, were low. By contrast, the determination of CS may be used as an additional surrogate marker in risk stratification in AF patients with intermediate pretest likelihood for CAD admitted to a CPU.

Resting heart rate is an independent predictor of all-cause mortality in the middle aged general population

BACKGROUND

High resting heart rate (RHR) predicts cardiovascular outcomes in patients with vascular disease and heart failure. We evaluated the prognostic value of RHR in a large contemporary population-based, prospective cohort of individuals without known coronary artery disease.

METHODS AND RESULTS

Resting heart rate (RHR) was determined in 4091 individuals (mean age 59.2 ± 7.7; 53 % women) from the Heinz Nixdorf RECALL study, of whom, 3348 were free of heart rate lowering medication. During 10.5 years of follow-up (median), 159 (3.9 %) individuals developed a coronary event and 398 (9.7 %) died of any cause. Persons without any event (n = 3603) had similar heart rates as persons with coronary events (69.5 ± 11 versus 69.9 ± 11 bpm, p = 0.51) but lower heart rates than persons who died (72.3 ± 13 bpm, p < 0.0001). In individuals without heart rate lowering medication, an increase in heart rate by 5 bpm was associated with an increased hazard ratio (HR) for all-cause mortality of 13 % in unadjusted analysis and also upon adjustment for traditional cardiovascular risk factors, including coronary artery calcification [full model: HR (95 % CI) 1.13 (1.07-1.20), p < 0.0001], but not for coronary events [HR 1.02 (0.94-1.11), p = 0.60]. In individuals without heart rate lowering medication, the HR (full model) for heart rate ≥70 versus <70 bpm with regard to all-cause mortality and coronary events was 1.68 (1.30-2.18), p < 0.0001, and 1.20 (0.82-1.77), p = 0.35. Analysis of the entire cohort revealed a continuous relationship of heart rate with all-cause mortality [HR for lowest to highest heart rate quartile 1.64 (1.22-2.22), p = 0.001, full model] but not with coronary events [HR 1.04 (0.65-1.66), p = 0.86].

CONCLUSIONS

In the general population without known coronary artery disease and heart rate lowering medication, elevated RHR is an independent risk marker for all-cause mortality but not for coronary events.

High dose and long-term statin therapy accelerate coronary artery calcification

BACKGROUND

In randomized clinical trials statins and placebo treated patients showed the same degree of coronary artery calcium (CAC) progression. We reanalyzed data from two clinical trials to further investigate the time and dose dependent effects of statins on CAC. Additionally, we investigated whether CAC progression was associated with incident cardiovascular events.

METHODS AND RESULTS

Data were pooled from two clinical trials: St. Francis Heart Study (SFHS) (419 and 432 patients treated with placebo and 20 mg atorvastatin daily, respectively) and EBEAT Study (164 and 179 patients respectively treated with 10 mg and 80 mg atorvastatin daily). CAC scores were assessed at baseline, 2 years and 4-6 years in SFHS; in EBEAT they were measured at baseline and 12 months. After a short-term follow-up (12 to 24 months) placebo and low dose atorvastatin showed a similar CAC increase, although 80 mg/daily atorvastatin increased CAC an additional 12-14% over placebo (p<0.001). In the long-term, atorvastatin caused a greater progression of CAC compared to placebo (additional 1.1%, p=0.04). In SFHS 42 cardiovascular events occurred after the second CT scan. The baseline and progression of CAC were greater in patients with events. However, only baseline CAC and family history of premature cardiovascular disease but not CAC progression were independent predictors of events.

CONCLUSIONS

Despite a greater CAC increase with high dose and long-term statin therapy, events did not occur more frequently in statin treated patients. This suggests that CAC growth under treatment with statins represents plaque repair rather than continuing plaque expansion.

Association of epicardial adipose tissue and left atrial size on non-contrast CT with atrial fibrillation: the Heinz Nixdorf Recall Study

AIMS

Epicardial adipose tissue (EAT) is increased in subjects with atrial fibrillation (AF). Likewise, EAT is associated with left atrial (LA) size, as itself is a strong predictor of AF. We aimed to determine the association of EAT and LA size as computed tomography (CT)-derived measures with prevalent and incident AF and investigated whether both measures independently predict AF.

METHODS AND RESULTS

Participants from the Heinz Nixdorf Recall study without known cardiovascular disease were included. At baseline, EAT, defined as fat volume inside the pericardial sac, and LA size, defined as an axial area at the level of the mitral valve, were quantified from non-contrast enhanced cardiac CT. AF was determined from electrocardiogram at baseline and also at 5-year follow-up examination. Overall, 3467 participants (age: 58.9 ± 7.6 years, 47% male) were included. Ninety-six subjects had AF (46 prevalent and 50 incident). A 1-standard deviation (SD) change of EAT was associated with nearly two-fold increased prevalence of AF in univariate analysis, which persisted after adjustment for AF risk factors [odds ratio (OR) (95% confidence interval, 95% CI): 1.38 (1.11-1.72), P = 0.003]. Ancillary adjusting for LA reduced the effect [1.26 (0.996-1.60), P = 0.054]. For incident AF, no relevant effect was observed for EAT when adjusting for risk factors [1.19 (0.88-1.61), P = 0.26]. In contrast, a 1-SD chance of LA was strongly associated with AF independently of EAT and risk factors [2.70 (2.22-2.20), P < 0.0001]. LA but not EAT as non-contrast CT-derived measures improved the prediction of AF over risk factors (receiver operating characteristics: 0.810-0.845, P = 0.025).

CONCLUSION

LA size from non-contrast CT is strongly associated with prevalent and incident AF and ultimately diminishes the link of EAT with AF.

Risk loci for coronary artery calcification replicated at 9p21 and 6q24 in the Heinz Nixdorf Recall Study

Background

Atherosclerosis is the primary cause of coronary heart disease (CHD), preceding the onset of cardiovascular disease by decades in most cases. Here we examine the association between single nucleotide polymorphisms (SNPs) integrated on Metabochip and coronary artery calcification (CAC), a valid risk factor for CHD, in an unselected, population-based German cohort.

Methods

The Metabochip is a custom iSELECT array containing >195,000 SNPs that was designed to support large-scale follow-up of putative associations for metabolic and cardiovascular-associated traits. We used generalized linear regression models to explore the impact of Metabochip SNPs on quantitative CAC in 4,329 participants.

Results

The 9p21 variant, rs1537373, was most strongly associated (Beta = 0.30; 95% confidence interval (CI) = 0.21-0.39; p = 4.05x10^-11) with quantitative CAC. The second strongest association with CAC was with rs9349379 in the phosphatase and actin regulator 1 gene, PHACTR1, (Beta = 0.30; 95% CI = 0.22-0.40; p = 4.67x10^-11). Both SNPs remained nominally significant in dichotomized analyses for the presence of any CAC (odds ratio_rs1537373 (OR) = 1.19; 95% CI = 1.07-1.31; p = 0.001 and OR_rs9349379 = 1.26; 95% CI = 1.14-1.40); p = 1.5x10^-5). Fine mapping of the 9p21 and PHACTR1 gene region revealed several other SNPs that were strongly associated with CAC.

Conclusion

We demonstrate that SNPs near 9p21 and in PHACTR1 that have previously been shown to be associated with CHD are strongly associated with CAC in the Heinz Nixdorf Recall Study cohort. Our findings suggest that the 9p21 and 6q24 loci might be involved in cardiac outcome via promoting development of atherosclerosis in the coronary arteries.

[The Heinz Nixdorf Recall study]

The Heinz Nixdorf Recall Study is a population-based study that aims to improve the prediction of cardiovascular events by integrating new imaging and non-imaging modalities in risk assessment. One focus of the study is the evaluation of the quantification of subclinical coronary artery calcifications (coronary artery calcification, CAC) as a prognostic factor in predicting cardiac events. Primary endpoints are myocardial infarction and sudden cardiac death. The study was initiated in the late 1990s and enrolled a total of 4,814 participants aged 45-75 years between December 2000 and August 2003. A 5-year follow-up examination took place between 2006 and 2008. Currently, the 10-year follow-up is under way and is estimated to be finished in July 2013. Extending the original aims of the study, serial CAC measurements will allow the characterization of the natural history of CAC dynamics, the identification of its determinants and an understanding of the impact of CAC progression on the primary endpoints. The Heinz Nixdorf Recall Study will significantly extend our knowledge about new modalities in the prediction of cardiac events.

[ECG changes in patients with chronic non-cancer pain: a prospective observational study]

BACKGROUND

Patients with chronic non-cancer pain not only show reduced quality of life, but also chronic morbidity and increased mortality. However, little is known about prevalence and type of abnormal electrocardiogram (ECG) recordings in these individuals.

MATERIAL AND METHODS

A total of 100 consecutive patients (≥ 18 years) with chronic (≥ 3 months) non-cancer pain were examined prospectively using ECG recordings and a questionnaire [German Pain Society (DGSS); further questions]. Data were collected at the first and next two follow-up outpatients' clinic appointments.

RESULTS

Participation rate was 98%. Of all patients, 26% had an abnormal ECG, while 5% of these patients had an abnormal ECG first at the follow-up when consuming a different analgesic regimen. Findings were QTc prolongation (16%), ventricular block (7%), artrioventricular block (6%), and atrial fibrillation (4%).

CONCLUSION

The prevalence of abnormal ECG recordings should be considered in the pain management of these patients. General ECG screening in this population should be discussed. Future studies should examine a larger population to identify potential risk factors (e.g., medication).

Prevalence and prognostic significance of ECG abnormalities in HIV-infected patients: results from the Strategies for Management of Antiretroviral Therapy study

BACKGROUND

It remains debated whether to include resting electrocardiogram (ECG) in the routine care of human immunodeficiency virus (HIV)-infected patients.

METHODS

This analysis included 4518 HIV-infected patients (28% women and 29% blacks) from the Strategies for Management of Antiretroviral Therapy study, a clinical trial aimed to compare 2 HIV treatment strategies. ECG abnormalities were classified using the Minnesota Code. Cox proportional hazards analysis was used to examine the association between baseline ECG abnormalities and incident cardiovascular disease (CVD).

RESULTS

More than half of the participants (n = 2325, or 51.5%) had either minor or major ECG abnormalities. Minor ECG abnormalities (48.6%) were more common than major ECG abnormalities (7.7%). During a median follow-up of 28.7 months, 155 participants (3.4%) developed incident CVD. After adjusting for the study-treatment arms, the presence of major, minor, and either minor or major ECG abnormalities was significantly predictive of incident CVD (hazard ratio [95% confidence interval]: 2.76 [1.74-4.39], P < .001; 1.58 [1.14-2.20], P = .006; 1.57 [1.14-2.18], P = .006, respectively). However, after adjusting for demographics, CVD risk factors, and HIV characteristics (full model), presence of major ECG abnormalities were still significantly predictive of CVD (1.83 [1.12-2.97], P = .015) but not minor or major abnormalities taken together (1.26 [0.89-1.79], P = .18; 1.25 [0.89-1.76], P = .20, respectively). Individual ECG abnormalities that significantly predicted CVD in the fully adjusted model included major isolated ST-T abnormalities, major prolongation of QT interval, minor isolated ST-T, and minor isolated Q-QS abnormalities.

CONCLUSION

Nearly 1 in 2 of the HIV-infected patients in our study had ECG abnormalities; 1 in 13 had major ECG abnormalities. Presence of ECG abnormalities, especially major ECG abnormalities, was independently predictive of incident CVD. These results suggest that the ECG could provide a convenient risk-screening tool in HIV-infected patients.

Lessons from human coronary aspirate

The interventional implantation of a stent into an atherosclerotic coronary artery is a unique and paradigmatic scenario of plaque rupture in humans. The use of protection devices not only prevents the released plaque particles and the superimposed thrombotic material from being washed and embolized into the coronary microcirculation of the individual patient, but permits also the retrieval and ex vivo analysis of particulate plaque debris and soluble substances. The particulate debris comprises typical cholesterol crystals, foam cells, hyalin material and calcium deposits from the atheroma as well as platelets and coagulation material; soluble substances include vasoconstrictors, such as serotonin and thromboxane, as well as inflammatory mediators, such as TNFα which amplifies vasoconstriction by inducing endothelial dysfunction. The vasoconstriction observed in a bioassay ex vivo correlates to clinical symptoms, angiographic stenosis and plaque burden, as assessed by intravascular ultrasound. The release of TNFα into the aspirate correlates to restenosis. Detailed analysis of the human coronary aspirate may promote a better understanding of the pathophysiology of the vulnerable atherosclerotic plaque and help to better antagonize the microvascular consequences of coronary microembolization, including the no reflow phenomenon. This article is part of a Special Issue entitled "Coronary Blood Flow."

Utility of nonspecific resting electrocardiographic features for detection of coronary artery stenosis by computed tomography in acute chest pain patients: from the ROMICAT trial

Twelve-lead surface electrocardiography (ECG) and computed tomography (CT) are used to evaluate for myocardial ischemia and coronary artery disease (CAD), respectively. We aimed to determine features on resting ECG that predict coronary artery stenosis by cardiac CT. In 309 acute chest pain patients, we compared the initial triage resting ECG to contrast-enhanced 64-slice cardiac CT angiography. We assessed for 6 quantitative (QT interval, QTc interval, QTc > 440 ms, gender-specific QTc, QT dispersion and QRS duration) and 4 qualitative ECG parameters (ST depression >0.05 to ≤0.1 mV, T wave inversion ≥0.1 mV, T wave flattening, and any T wave abnormalities) and for the presence of coronary stenosis by CT (>50% luminal narrowing). Specificities of these ECG parameters were excellent (83.6-97.0%) while sensitivities were poor (12.2-29.3%). For coronary stenosis detection, the ECG features with the greatest performance were the presence of ST depression (positive likelihood ratio [LR+] 4.09) and T wave inversion (LR+ 4.58). In multivariable analyses, the risk for coronary stenosis increased by 33-41% for every 20 ms prolongation of the QTc interval after adjusting for age, gender, and cardiac risk factors or adjustment for Framingham risk score. Similarly, there was an increase of fourfold with the presence of ST depression >0.05 to ≤0.1 mV or T wave inversion ≥0.1 mV. In acute chest pain patients, resting ECG features of QTc interval prolongation, mild ST depression, and T wave inversion are independently associated with the presence of CT coronary stenosis and their presence suggests an increase risk of CAD.

Accuracy of advanced versus strictly conventional 12-lead ECG for detection and screening of coronary artery disease, left ventricular hypertrophy and left ventricular systolic dysfunction

Background

Resting conventional 12-lead ECG has low sensitivity for detection of coronary artery disease (CAD) and left ventricular hypertrophy (LVH) and low positive predictive value (PPV) for prediction of left ventricular systolic dysfunction (LVSD). We hypothesized that a ~5-min resting 12-lead advanced ECG test ("A-ECG") that combined results from both the advanced and conventional ECG could more accurately screen for these conditions than strictly conventional ECG.

Methods

Results from nearly every conventional and advanced resting ECG parameter known from the literature to have diagnostic or predictive value were first retrospectively evaluated in 418 healthy controls and 290 patients with imaging-proven CAD, LVH and/or LVSD. Each ECG parameter was examined for potential inclusion within multi-parameter A-ECG scores derived from multivariate regression models that were designed to optimally screen for disease in general or LVSD in particular. The performance of the best retrospectively-validated A-ECG scores was then compared against that of optimized pooled criteria from the strictly conventional ECG in a test set of 315 additional individuals.

Results

Compared to optimized pooled criteria from the strictly conventional ECG, a 7-parameter A-ECG score validated in the training set increased the sensitivity of resting ECG for identifying disease in the test set from 78% (72-84%) to 92% (88-96%) (P < 0.0001) while also increasing specificity from 85% (77-91%) to 94% (88-98%) (P < 0.05). In diseased patients, another 5-parameter A-ECG score increased the PPV of ECG for LVSD from 53% (41-65%) to 92% (78-98%) (P < 0.0001) without compromising related negative predictive value.

Conclusion

Resting 12-lead A-ECG scoring is more accurate than strictly conventional ECG in screening for CAD, LVH and LVSD.

Association of electrocardiographic abnormalities with coronary artery calcium and carotid artery intima-media thickness in individuals without clinical coronary heart disease (from the Multi-Ethnic Study of Atherosclerosis [MESA])

Isolated minor nonspecific ST-segment and T-wave abnormalities (NSSTAs), minor and major electrocardiographic (ECG) abnormalities are established, independent risk markers for incident cardiovascular events. Their association with subclinical atherosclerosis has been postulated but is not clearly defined. The aim of this study was to define the association between ECG abnormalities and measurements of subclinical atherosclerosis. We studied participants from MESA, a multiethnic sample of men and women 45 to 84 years of age and free of clinical cardiovascular disease at enrollment. Baseline examination included measurement of traditional risk factors, 12-lead electrocardiograms at rest, coronary artery calcium (CAC) measurement, and common carotid intima-media thickness (CC-IMT). Electrocardiograms were coded using Novacode criteria and were defined as having minor abnormalities (e.g., minor NSSTTAs, first-degree atrioventricular block, and QRS-axis deviations) or major abnormalities (e.g., pathologic Q waves, major STTAs, significant dysrhythmias, and conduction system delays). Multivariable logistic and linear regressions were used to determine cross-sectional associations of ECG abnormalities with CAC and CC-IMT. Of 6,710 participants, 52.7% were women, with a mean age of 62 years. After multivariable adjustment, isolated minor STTAs and minor and major ECG abnormalities were not associated with presence of CAC (>0) in men (odds ratio 1.04, 95% confidence interval 0.81 to 1.33; 1.10, 0.91 to 1.32; and 1.03, 0.81 to 1.31, respectively) or women (1.01, 0.82 to 1.24; 1.04, 0.87 to 1.23; and 0.94, 0.73 to 1.22, respectively). Lack of association remained consistent when using log CAC and CC-IMT as continuous variables. In conclusion, ECG abnormalities are not associated with markers of subclinical atherosclerosis in a large multiethnic cohort.

Abnormal T-wave axis is associated with coronary artery calcification in older adults

OBJECTIVE

To determine whether T-wave axis on the resting electrocardiogram (ECG) is associated with coronary artery calcification (CAC) score, a measurement of coronary atherosclerosis, in older adults.

METHODS

The sample consisted of 2004 adults aged 66 and over participating in the prospective, population-based Age-Gene/Environment Susceptibility-Reykjavik Study. The cohort was divided into gender-stratified quartiles based upon Agatston CAC score derived from computerized tomography. Frontal T-axis deviation from 45 degrees was assessed using surface ECG. Statistical analysis was performed with Tobit regression models adjusted for demographic and cardiovascular risk factors.

RESULTS

In the entire study population, T-axis deviation from 45 degrees was significantly associated with increasing CAC score in men (p<0.001) and women (p=0.03). In men without clinically recognized coronary heart disease (CHD), the association with CAC score remained statistically significant (p=0.02). This association was significant among women without CHD once male CAC cut points were used (p=0.05).

CONCLUSION

An abnormal T-wave axis is associated with an increasing CAC score in this population of Icelandic older adults. This association remains in the subgroup of subjects without clinical CHD.

Prevalence, prognosis, and implications of isolated minor nonspecific ST-segment and T-wave abnormalities in older adults: Cardiovascular Health Study

BACKGROUND

The prevalence and prognostic significance of isolated minor nonspecific ST-segment and T-wave abnormalities (NSSTTAs) in older adults are poorly understood.

METHODS AND RESULTS

Cardiovascular Health Study participants free of both clinical cardiovascular disease and major ECG abnormalities were included. We examined the prospective association of isolated minor NSSTTAs (defined by Minnesota Codes 4-3, 4-4, 5-3, and 5-4) with total, cardiovascular, and coronary mortality and incident nonfatal myocardial infarction. Among 3224 participants (61.9% women; mean age, 72 years), 233 (7.2%) had isolated NSSTTAs at baseline. Covariates associated with isolated NSSTTAs included older age, nonwhite race (20.5% of blacks versus 4.8% of whites; P<0.001), diabetes, and higher blood pressure and body mass index but not the presence of subclinical cardiovascular disease. After 39 518 person-years of follow-up, the presence of isolated NSSTTAs was associated with significantly increased risk for coronary heart disease mortality (multivariable-adjusted hazards ratio, 1.76; 95% CI, 1.18 to 2.61) but not with incident nonfatal myocardial infarction (multivariable-adjusted hazards ratio, 0.71; 95% CI, 0.43 to 1.17). The association of isolated NSSTTAs with coronary death was independent of subclinical atherosclerosis and left ventricular mass measures. In secondary analyses, among those with cardiac death, there was a significantly higher rate of primary arrhythmic death (32.3% versus 15.4%; P=0.02) in participants with isolated NSSTTAs versus those without NSSTTAs.

CONCLUSIONS

Isolated NSSTTAs are common in older Americans and are associated with significantly increased risk for coronary death. However, isolated NSSTTAs are not associated with incident nonfatal myocardial infarction, suggesting that they are associated particularly with increased risk for primary arrhythmic death.

Cardiovascular risk factors and signs of subclinical atherosclerosis in the Heinz Nixdorf Recall Study

INTRODUCTION

Modern investigation modalities allow markers of atherosclerosis to be detected at a subclinical stage. The aim of the study was to analyze the prevalence of these markers in relation to traditional risk factors.

METHODS

The population based study included 4814 participants, aged 45 to 75 years, with a response rate of 55.8% of those contacted. The patients' history, psychosocial and environmental risk factors were assessed.

RESULTS

The prevalence of obesity was 26.2% in men and 28.1% in women, 26% of men and 21% of women were smokers. Hypertension was found in 46% of men and 31% of women, diabetes in 9.3% of men and 6.3% of women. Markers of subclinical peripheral arterial disease were found in 6.4% of men and 5.1% of women, of subclinical carotid artery disease in 43.2% and 30.7%, and of subclinical coronary artery calcification in 82.3% and 55.2%, respectively. The prevalence of coronary calcification measured using an Agatston Score >100 was in 40% in men and 15% in women, using a score >400, 16.8% and 4.5%, respectively.

DISCUSSION

A high prevalence of subclinical atherosclerosis was found in the older population. The follow-up period will demonstrate whether the detection of markers of subclinical atherosclerosis will improve risk stratification beyond that offered by traditional risk factors.