Thresholds in the relationship between mortality and left ventricular hypertrophy defined by electrocardiography

Relationship between presystolic wave and subclinical left ventricular dysfunction as assessed by myocardial performance index in patients with metabolic syndrome

The myocardial performance index (MPI) is an index that shows both systolic and diastolic functions of the ventricle. Presystolic wave (PSW) is a late diastolic wave encountered in the left ventricular outflow tract (LVOT) and is associated with increased left ventricular stiffness and decreased left ventricular compliance. In our study, MPI was compared between patients with metabolic syndrome and normal patients, and we also investigated whether PSW could predict subclinical left ventricular dysfunction (SCLVD) in patients with metabolic syndrome. A total of 119 patients, 59 with metabolic syndrome and 60 healthy volunteers, were included in our study. Our study is a two-center prospective study. The patient groups were compared in terms of demographic, laboratory and echocardiographic parameters. Univariate and multivariate regression analyzes were performed to detect predictors of SCLVD. Higher MPI and PSW were found in patients with metabolic syndrome compared to the normal population (0.56 ± 0.11 vs. 0.46 ± 0.07, p < 0.001, 34 (57.6%) vs. 19 (31.7%), p = 0.004, respectively). MPI was found to be higher in patients with metabolic syndrome with PSW ( +) (0.59 ± 0.13 vs. 0.52 ± 0.05, p = 0.005). Smoking and PSW were found as Independent Predictors of Subclinical Left Ventricular Dysfunction in the Multivariate Logistic Regression Analysis Model (OR 0.146, 95%CI 0.028-0.767, p = 0.023 and OR 10.689, 95%CI 2.176-52.515, p = 0.004, respectively). Higher MPI and SCLVD were detected in patients with metabolic syndrome compared to the normal population. In addition, PSW positivity was associated with SCLVD in this patient group.

The association between frontal QRS-T angle and reverse dipper status in newly diagnosed hypertensive patients

The frontal QRS-T angle (fQRS-T angle) in ECG is a new measure of myocardial repolarization, in which a higher fQRS-T angle is linked with worse cardiac outcomes. Reverse dipper hypertension is also linked to poor cardiac outcomes. The purpose of this study was to investigate the association between the fQRS-T angle and reverse dipper status in individuals newly diagnosed with hypertension who did not have left ventricular hypertrophy (LVH). The investigation recruited 171 hypertensive individuals without LVH who underwent 24-h ambulatory blood pressure monitoring (ABPM). On the basis of the findings of 24-h ABPM, the study population was categorized into the following three groups: patients with dipper hypertension, non-dipper hypertension, and reverse dipper hypertension. LVH was defined by echocardiography. The fQRS-T angle was measured using the 12-lead ECG. The fQRS-T angle in individuals with reverse dipper hypertension was substantially greater than in patients with and without dipper hypertension (51° ± 28° vs. 28° ± 22° vs. 39° ± 25°, respectively, P < 0.001). The fQRS-T angle (odds ratio: 1.040, 95% confidence interval: 1.016-1.066; P = 0.001) was independently associated with reverse dipper hypertension according to multivariate analysis. In receiver operating characteristic curve analysis, the fQRS-T angle to predict reverse dipper hypertension was 33.5° with 76% sensitivity and 71% specificity. This study showed that an increased fQRS-T angle was associated with reverse dipper hypertension in newly diagnosed hypertensive patients without LVH.

The relationship of frontal QRS-T angle between patients with newly diagnosed true and white coat hypertension

OBJECTIVES

The frontal QRS-T (f-QRST) angle is a measure of depolarization and repolarization heterogeneity and may be a predictor of poor ventricular health. We aimed to investigate whether the f-QRST angle indicates myocardial damage and predicts newly diagnosed true hypertension (HT) in patients with white coat hypertension.

METHODS

We measured the f-QRST angle of 63 subjects with WHC and 105 patients with newly diagnosed HT. Laboratory tests and ABPM were followed up in all patients. The f-QRST angle was calculated on the surface ECGs.

RESULTS

Of the patients in the study, 38.9% were female and 61.1% were male. The mean age was calculated as 59 ± 11 years. A comparison between both groups with the f-QRST angles was seen to be statistically significantly higher in the true HT group. The results of the receiving operating characteristic curve showed that the AUC value of the f-QRST angle was 0.94 (95% confidence interval, 0.91-0.97), the cutoff value was 60.5°, the sensitivity was 89.5%, and the specificity was 81%.

CONCLUSION

In our study, the f-QRST angle was found to be lower in patients with WHC than in true hypertensive patients. We think that ECG, which is a simple test, can be used to distinguish between true HT and WHC.

Diagnostic performance of electrocardiographic criteria in echocardiographic diagnosis of different patterns of left ventricular hypertrophy

Background

Electrocardiogram (ECG) is considered the initial screening method for the detection of left ventricular hypertrophy (LVH) despite its low sensitivity. However, there are no data on how ECG criteria for LVH perform in patients with concentric (cLVH) and eccentric LVH (eLVH).

Methods

In the setting of the Corinthia cross‐sectional study, ECGs were analyzed in 1,570 participants of the study. Seven ECG LVH criteria were calculated (Sokolow–Lyon voltage, index, and product, sex‐specific Cornell voltage and product, Lewis voltage, and the Framingham), whereas LVH was defined, based on echocardiographic data, as left ventricular mass indexed for body surface area (BSA) of at least 125 g/m² in men and at least 110 g/m² in women.

Results

Regarding the frequency encountered for each ECG LVH criterion, there was no difference between eLVH and cLVH. However, when ECG criteria were compared as continuous variables between LVH groups, Cornell voltage and product were higher in cLVH individuals, with a value of Cornell voltage >13.95 mV having 61% sensitivity and 62% specificity to differentiate cLVH from eLVH (p = .05). Even after adjustment for age, sex, body mass index, and hypertension, the occurrence of Cornell voltage or product increased the odds of cLVH by 1.6 times (p = .001).

Conclusion

Cornell voltage and product criteria disclosed a superior discriminative ability for the detection of LVH via ECG. When further categorizing LVH as concentric and eccentric, Cornell product depicted the higher discriminative ability for cLVH.

Conventional and new electrocardiographic criteria for hypertension-mediated cardiac organ damage: A narrative review

Hypertension-mediated organ damage (HMOD) is frequently observed in hypertensive patients at different cardiovascular (CV) risk profile. This may have both diagnostic and therapeutic implications for the choice of the most appropriate therapies. Among different markers of HMOD, the most frequent functional and structural adaptations can be observed at cardiac level, including left ventricular hypertrophy (LVH), diastolic dysfunction, aortic root dilatation, and left atrial enlargement. In particular, LVH was shown to be a strong and independent risk factor for major CV events, namely myocardial infarction, stroke, congestive heart failure, CV death. Thus, early identification of LVH is a key element for preventing CV events in hypertension. Although echocardiographic assessment of LVH represents the gold standard technique, this is not cost-effective and cannot be adopted in routine clinical practice of hypertension. On the other hand, electrocardiographic (ECG) assessment of HMOD relative to the heart is a simple, reproducible, widely available and cost-effective method to assess the presence of LVH, and could be preferred in large scale screening tests. Several new indicators have been proposed and tested in observational studies and clinical trials of hypertension, in order to improve the relatively low sensitivity of the conventional ECG criteria for LVH, despite high specificity. This article reviews the differences in the use of the main conventional and the new 12 lead ECG criteria of LVH for early assessment of asymptomatic, subclinical cardiac HMOD in a setting of clinical practice of hypertension.

Electrocardiographic measures of left ventricular hypertrophy in the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial

Left ventricular hypertrophy (LVH) predicts cardiovascular risk in hypertensive patients. We analyzed baseline/follow-up electrocardiographies in 26,376 Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial participants randomized to amlodipine (A), lisinopril (L), or chlorthalidone (C). Prevalent/incident LVH was examined using continuous and categorical classifications of Cornell voltage. At 2 and 4 years, prevalence of LVH in the C group (5.57%; 6.14%) was not statistically different from A group (2 years: 5.47%; P = .806, 4 years: 6.54%; P = .857) or L group (2 years: 5.64%; P = .857, 4 years: 6.50%; P = .430). Incident LVH followed similarly, with no difference at 2 years for C (2.99%) compared to A (2.57%; P = .173) or L (3.16%; P = .605) and at 4 years (C = 3.52%, A = 3.29%, L = 3.71%; P = .521 C vs. A, P = .618 C vs. L). Mean Cornell voltage decreased comparably across treatment groups (Δ baseline, 2 years = +3 to -27 μV, analysis of variance P = .8612; 4 years = +10 to -17 μV, analysis of variance P = .9692). We conclude that risk reductions associated with C treatment in secondary end points of the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial cannot be attributed to differential improvements in electrocardiography LVH.

Development and Validation of a Sudden Cardiac Death Prediction Model for the General Population

BACKGROUND

Most sudden cardiac death (SCD) events occur in the general population among persons who do not have any prior history of clinical heart disease. We sought to develop a predictive model of SCD among US adults.

METHODS

We evaluated a series of demographic, clinical, laboratory, electrocardiographic, and echocardiographic measures in participants in the ARIC study (Atherosclerosis Risk in Communities) (n=13 677) and the CHS (Cardiovascular Health Study) (n=4207) who were free of baseline cardiovascular disease. Our initial objective was to derive a SCD prediction model using the ARIC cohort and validate it in CHS. Independent risk factors for SCD were first identified in the ARIC cohort to derive a 10-year risk model of SCD. We compared the prediction of SCD with non-SCD and all-cause mortality in both the derivation and validation cohorts. Furthermore, we evaluated whether the SCD prediction equation was better at predicting SCD than the 2013 American College of Cardiology/American Heart Association Cardiovascular Disease Pooled Cohort risk equation.

RESULTS

There were a total of 345 adjudicated SCD events in our analyses, and the 12 independent risk factors in the ARIC study included age, male sex, black race, current smoking, systolic blood pressure, use of antihypertensive medication, diabetes mellitus, serum potassium, serum albumin, high-density lipoprotein, estimated glomerular filtration rate, and QTc interval. During a 10-year follow-up period, a model combining these risk factors showed good to excellent discrimination for SCD risk (c-statistic 0.820 in ARIC and 0.745 in CHS). The SCD prediction model was slightly better in predicting SCD than the 2013 American College of Cardiology/American Heart Association Pooled Cohort risk equations (c-statistic 0.808 in ARIC and 0.743 in CHS). Only the SCD prediction model, however, demonstrated similar and accurate prediction for SCD using both the original, uncalibrated score and the recalibrated equation. Finally, in the echocardiographic subcohort, a left ventricular ejection fraction <50% was present in only 1.1% of participants and did not enhance SCD prediction.

CONCLUSIONS

Our study is the first to derive and validate a generalizable risk score that provides well-calibrated, absolute risk estimates across different risk strata in an adult population of white and black participants without a clinical diagnosis of cardiovascular disease.

Prevention of electrocardiographic left ventricular remodeling by the angiotensin receptor blocker olmesartan in patients with type 2 diabetes

OBJECTIVE

To assess the ability of olmesartan (OLM) to prevent or delay left ventricular remodeling and hypertrophy in patients with type 2 diabetes.

METHODS

This prespecified ECG substudy of Randomised OlmesArtan and Diabetes MicroAlbuminuria Prevention (ROADMAP), which compared OLM with placebo, assessed the signs of left ventricular remodeling in patients with a 12-lead ECG at baseline and after at least 2 years. Cornell voltage QRS duration product (primary objective), Cornell voltage index and Sokolow-Lyon index were assessed.

RESULTS

In total, 9418 ECG recordings and 1513 patients from ROADMAP were analyzed (placebo, n = 736; OLM, n = 777). Quartiles defined by baseline Cornell voltage QRS duration product were assessed and the proportion of patients in the highest quartile (≥200 mVms) increased from 24.0 to 26.5% in the placebo group and decreased from 25.5 to 22.3% in the OLM group [odds ratio (OR) 0.598 (95% confidence interval [CI] 0.440-0.813); P = 0.0011]. The OR did not change after adjustment for baseline parameters. By the end of study, 38.7% of patients in the placebo group and 34.7% in the OLM group shifted from a lower to a higher quartile or remained in the highest quartile of Cornell voltage QRS duration product [OR 0.797 (95% CI 0.637-0.996); P = 0.0465]. This translated into a 20.3% risk reduction with OLM and suggested OLM attenuated the progression of left ventricular remodeling versus placebo.

CONCLUSION

OLM substantially delayed the development of left ventricular remodeling in type 2 diabetes. This effect was not explained by the differences in blood pressure control. Thus, OLM delayed the onset of microalbuminuria, as well as the ECG signs of cardiac structural adaptation in type 2 diabetes.

Effect of Intensive Blood Pressure Lowering on Left Ventricular Hypertrophy in Patients With Diabetes Mellitus: Action to Control Cardiovascular Risk in Diabetes Blood Pressure Trial

Left ventricular hypertrophy (LVH), a marker of cardiac end-organ damage, is a common complication of hypertension. Regression of LVH is achievable by sustained lowering of systolic blood pressure (BP). However, it is unknown whether a strategy aimed at lowering BP beyond that recommended would lower the risk of LVH. We examined the effect of intensive (systolic BP<120 mm Hg), compared with standard (systolic BP<140 mm Hg), BP lowering on the risk of LVH in 4331 patients with diabetes mellitus from the Action to Control Cardiovascular Risk in Diabetes (ACCORD) BP trial, a randomized controlled trial. The outcome measures were electrocardiographic LVH defined by Cornell voltage (binary variable) and mean Cornell index (continuous variable). The baseline prevalence of LVH (5.3% versus 5.4%; P=0.91) and the mean Cornell index (1456 versus 1470 µV; P=0.45) were similar in the intensive (n=2154) and standard (n=2177) BP-lowering arms, respectively. However, after median follow-up of 4.4 years, intensive, compared with standard, BP lowering was associated with a 39% lower risk of LVH (odds ratio [95% confidence interval], 0.61[0.43, 0.88]; P=0.008) and a significantly lower adjusted mean Cornell index (1352 versus 1447 µV; P<0.001). The lower risk of LVH associated with intensive BP lowering during follow-up was because of more regression of baseline LVH and lower rate of developing new LVH, compared with standard BP lowering. No interactions by age, sex, or race were observed. These results provide evidence that targeting a systolic BP of <120 mm Hg when compared with <140 mm Hg in patients with hypertension and diabetes mellitus produces a greater reduction in LVH.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00000620.

Electrocardiographic Measures and Prediction of Cardiovascular and Noncardiovascular Death in CKD

Limited studies have assessed the resting 12-lead electrocardiogram (ECG) as a screening test in intermediate risk populations. We evaluated whether a panel of common ECG parameters are independent predictors of mortality risk in a prospective cohort of participants with CKD. The Chronic Renal Insufficiency Cohort (CRIC) study enrolled 3939 participants with eGFR<70 ml/min per 1.73 m(2) from June 2003 to September 2008. Over a median follow-up of 7.5 years, 750 participants died. After adjudicating the initial 497 deaths, we identified 256 cardiovascular and 241 noncardiovascular deaths. ECG metrics were independent risk markers for cardiovascular death (hazard ratio, 95% confidence interval): PR interval ≥200 ms (1.62, 1.19-2.19); QRS interval 100-119 ms (1.64, 1.20-2.25) and ≥120 ms (1.75, 1.17-2.62); corrected QT (QTc) interval ≥450 ms in men or ≥460 ms in women (1.72, 1.19-2.49); and heart rate 60-90 beats per minute (1.21, 0.89-1.63) and ≥90 beats per minute (2.35, 1.03-5.33). Most ECG measures were stronger markers of risk for cardiovascular death than for all-cause mortality or noncardiovascular death. Adding these intervals to a comprehensive model of cardiorenal risk factors increased the C-statistic for cardiovascular death from 0.77 to 0.81 (P<0.001). Furthermore, adding ECG metrics to the model adjusted for standard risk factors resulted in a net reclassification of 12.1% (95% confidence interval 8.1%-16.0%). These data suggest common ECG metrics are independent risk factors for cardiovascular death and enhance the ability to predict death events in a population with CKD.

Fractal Analysis of Myocardial Trabeculations in 2547 Study Participants: Multi-Ethnic Study of Atherosclerosis

PURPOSE

To quantitatively determine the population variation and relationship of left ventricular (LV) trabeculation to LV function, structure, and clinical variables.

MATERIALS AND METHODS

This HIPAA-compliant multicenter study was approved by institutional review boards of participating centers. All participants provided written informed consent. Participants from the Multi-Ethnic Study of Atherosclerosis with cardiac magnetic resonance (MR) data were evaluated to quantify LV trabeculation as a fractal dimension (FD). Entire cohort participants free of cardiac disease, hypertrophy, hypertension, and diabetes were stratified by body mass index (BMI) into three reference groups (BMI <25 kg/m(2); BMI ≥25 kg/m(2) to <30 kg/m(2); and BMI ≥30 kg/m(2)) to explore maximal apical FD (FDMaxApical). Multivariable linear regression models determined the relationship between FD and other parameters.

RESULTS

Included were 2547 participants (mean age, 68.7 years ± 9.1 [standard deviation]; 1211 men). FDMaxApical are in arbitrary units. FDMaxApical reference ranges for BMI 30 kg/m(2) or greater (n = 163), 25 kg/m(2) or greater to less than 30 kg/m(2) (n = 206), and less than 25 kg/m(2) (n = 235) were 1.203 ± 0.06 (95% confidence interval: 1.194, 1.212), 1.194 ± 0.06 (95% confidence interval: 1.186, 1.202), and 1.169 ± 0.05 (95% confidence interval: 1.162, 1.176), respectively. In the entire cohort, adjusted for anthropometrics, trabeculation was higher in African American participants (standardized β [sβ] = 0.09; P ≤ .001) and Hispanic participants (sβ = 0.05; P = .013) compared with white participants and was also higher in African American participants compared with Chinese American participants (sβ = 0.08; P = .01), and this persisted after adjustment for hypertension and LV size. Hypertension (sβ = 0.07; P < .001), LV mass (sβ = 0.22; P < .001), and wall thickness (sβ = 0.27; P < .001) were positively associated with FDMaxApical even after adjustment. In the group with BMIs less than 25 kg/m(2), Chinese American participants had less trabeculation than white participants (sβ = -0.15; P = .032).

CONCLUSION

Fractal analysis of cardiac MR imaging data measures endocardial complexity, which helps to differentiate normal from abnormal trabecular patterns in healthy versus diseased hearts. Trabeculation is influenced by race and/or ethnicity and, more importantly, by cardiac loading conditions and comorbidities. Clinicians who interpret cine MR imaging data should expect slightly less endocardial complexity in Chinese American patients and more in African American patients, Hispanic patients, hypertensive patients, and those with hypertrophy.

Determinants of discrepancies in detection and comparison of the prognostic significance of left ventricular hypertrophy by electrocardiogram and cardiac magnetic resonance imaging

Despite the low sensitivity of the electrocardiogram (ECG) in detecting left ventricular hypertrophy (LVH), ECG-LVH is known to be a strong predictor of cardiovascular risk. Understanding reasons for the discrepancies in detection of LVH by ECG versus imaging could help improve the diagnostic ability of ECG. We examined factors associated with false-positive and false-negative ECG-LVH, using cardiac magnetic resonance imaging (MRI) as the gold standard. We also compared the prognostic significance of ECG-LVH and MRI-LVH as predictors of cardiovascular events. This analysis included 4,748 participants (mean age 61.9 years, 53.5% females, 61.7% nonwhites). Logistic regression with stepwise selection was used to identify factors associated with false-positive (n = 208) and false-negative (n = 387), compared with true-positive (n = 208) and true-negative (n = 4,041) ECG-LVH, respectively. A false-negative ECG-LVH status was associated with increased odds of Hispanic race/ethnicity, current smoking, hypertension, increased systolic blood pressure, prolongation of QRS duration, and higher body mass index and with lower odds of increased ejection fraction (model-generalized R(2) = 0.20). A false-positive ECG-LVH status was associated with lower odds of black race, Hispanic race/ethnicity, minor ST-T abnormalities, increased systolic blood pressure, and presence of any major electrocardiographic abnormalities (model-generalized R(2) = 0.29). Both ECG-LVH and MRI-LVH were associated with an increased risk of cardiovascular disease events (hazard ratio 1.51, 95% confidence interval 1.03 to 2.20 and hazard ratio 1.81, 95% confidence interval 1.33 to 2.46, respectively). In conclusion, discrepancy in LVH detection by ECG and MRI can be relatively improved by considering certain participant characteristics. Discrepancy in diagnostic performance, yet agreement on predictive ability, suggests that LVH by ECG and LVH by imaging are likely to be two distinct but somehow related phenotypes.

Major electrocardiographic abnormalities and 25-hydroxy vitamin D deficiency: insights from National Health and Nutrition Examination Survey-III

BACKGROUND

We explored the relationship between major electrocardiogram (ECG) abnormalities (mECG) and 25-hydroxy (25-OH) vitamin D deficiency (VDD) and the effect of mECG abnormalities on all-cause and cardiovascular mortality in a healthy cohort with 25-OH vitamin D insufficiency and deficiency.

HYPOTHESIS

Lower levels of serum 25-OH vitamin D are associated with increased prevalence of mECG on resting ECG.

METHODS

We identified 5108 individuals from the National Health and Nutrition Examination Survey-III. mECG abnormalities included: major Q-QS wave abnormalities, ST depression/elevation, negative T waves, Wolff-Parkinson-White pattern, and ventricular conduction defect. Our cohort was divided into 3 groups based on 25-OH vitamin D levels: Group 1 (referent): > 40 ng/mL; group 2 (insufficient): ≥ 20.01 to ≤ 40 ng/mL; and group 3 (deficient): ≤ 20 ng/mL. Logistic regression and Cox proportional hazards regression models were built.

RESULTS

The prevalence of major ECG abnormalities across 25-OH vitamin D sufficiency, insufficiency, and deficiency was .9%, 11%, and 13 %, respectively (P = 0.01). VDD was an independent predictor of mECG abnormalities after adjusting for traditional risk factors (continuous variable odds ratio [OR]: 0.98, 95% confidence interval [CI]: 0.97-0.99, P = 0.007; categorical variable group 3 vs group 1 OR: 2.36, 95% CI: 1.1-5.12, P = 0.03). Baseline major ECG abnormalities were predictive of long-term all-cause (hazard ratio [HR]:1.52, 95% CI: 1.23-1.89), composite cardiovascular (HR: 1.7, 95% CI: 1.34-2.15), cardiovascular (HR: 1.64, 95% CI: 1.27-2.12), and ischemic heart disease mortality (HR: 1.98, 95% CI: 1.46-2.69) in individuals with 25-OH vitamin D levels ≤ 40 ng/mL.

CONCLUSIONS

VDD is associated with increased prevalence of major ECG abnormalities. Well-structured trials are needed to assess progression/resolution of mECG abnormalities with vitamin D supplementation in deficient individuals.

Electrocardiographic deep terminal negativity of the P wave in V1 and risk of mortality: the National Health and Nutrition Examination Survey III

INTRODUCTION

Deep terminal negativity of P wave in V1 (DTNPV1), defined as negative P prime larger than one small box (1 mm, or 0.1 mV), could be easily detected by simple visual inspection of the resting 12-lead ECG. The objective of this study was to determine the relationship between DTNPV1 and all-cause-, cardiovascular disease (CVD), and ischemic heart disease (IHD) mortality in the National Health and Nutrition Examination Survey III (NHANES III).

METHODS AND RESULTS

After exclusion of participants with atrial fibrillation and missing data, DTNPV1 was automatically measured from standard 12-lead ECG in 8,146 participants. Minnesota and Novacode algorithms were used for the determination of major and minor ECG abnormalities. National Death Index was used to identify the date and cause of death. During a median follow-up of 13.8 years, a total of 2,975 deaths (1,303 CVD and 742 IHD deaths) occurred. After adjustment for age, gender, race/ethnicity, IHD, heart failure, chronic obstructive pulmonary disease, cancer, diabetes, body mass index, smoking, dyslipidemia, hypertension, use of antihypertensive and lipid-lowering medications, and ECG abnormalities, DTNPV1 was associated with significantly increased risk of all-cause death (HR [95% CI]: 1.30 [1.10, 1.53]; P = 0.002), CVD death (HR [95% CI]: 1.36 [1.08, 1.72]; P = 0.010), and IHD death (HR [95% CI]: 1.36 [1.00, 1.85]; P = 0.047).

CONCLUSION

In a large sample of the adult United States population, DTNPV1 is independently associated with increased risk of death due to all-cause, CVD, and IHD, findings suggesting its potential usefulness as a simple marker to identify individuals at risk of poor outcomes.

Isolated nonspecific ST-segment and T-wave abnormalities in a cross-sectional United States population and Mortality (from NHANES III)

Most clinicians regard isolated, minor, or nonspecific ST-segment and T-wave (NS-STT) abnormalities to be incidental, often transient, and benign findings in asymptomatic patients. We sought to evaluate whether isolated NS-STT abnormalities on routine electrocardiograms (ECGs) are associated with increased risk of cardiovascular mortality (CM) and all-cause mortality (AM) in a cross-sectional United States population without known coronary artery disease. We included all adults 40 to 90 years of age without known coronary artery disease or risk equivalent based on history and laboratory values, enrolled in the NHANES III from 1988 to 1994, with electrocardiographic data available, and a total follow-up period of 59,781.75 patient-years. NS-STT abnormalities were defined by Minnesota Coding. Subjects were excluded if their mortality data were missing or if they had major electrocardiographic abnormalities, heart rate >120 beats/min, nonsinus rhythm, cardiac infarction/injury score ≥ 20 on ECG, left ventricular hypertrophy by Minnesota Codes 3.1 and 3.3, or patient-reported history coronary artery disease, congestive heart failure, stroke, diabetes, or peripheral arterial disease. The remaining 4,426 subjects were stratified by presence or absence of NS-STT abnormalities. Mortality was judged based on International Classification of Diseases, Tenth Revision coding linked to the National Death Index. Cox proportional hazard ratio was used for multivariate analysis, showing that CM (hazards ratio 1.71, 95% confidence interval 1.04 to 2.83, p = 0.04) and AM (hazards ratio 1.37, 95% confidence interval 1.03 to 1.81, p = 0.02) were significantly higher in the isolated NS-STT abnormalities group. In conclusion, isolated NS-STT abnormalities on ECG were associated with a higher incidence of CM and AM in this large nationally representative cross-sectional cohort without known coronary artery disease or coronary artery disease risk equivalents.

[Cardiovascular morbidity and mortality and electrocardiographic criteria of left ventricular hypertrophy in hypertensive patients treated in primary care]

FUNDAMENTALS AND OBJECTIVE: Electrocardiographic voltage criteria are the preferred method for diagnosis of left ventricular hypertrophy (LVH) in Primary Health Care (PHC). Several of these have been described as major adverse cardiovascular events (MACE) predictors. The aim of this study was to analyse the relationship between MACE occurrence in a cohort of hypertensive subjects in PHC and different electrocardiographic criteria recorded.

PATIENTS AND METHODS

265 hypertensive subjects attending PHC were randomly selected and followed up for 12 years. Standard 12-lead electrocardiograms were recorded at the beginning of the study. The occurrence of ischemic heart disease, heart failure, stroke, peripheral vascular disease, arrhythmia or cardiovascular death was considered as MACE. Electrocardiographic voltage criteria recorded were: Sokolow-Lyon, Minnesota code 3.1, Gubner and Ungerleider, Cornell voltage and Schillaci and Dalfó modifications. Data were analyzed using the life-table method and Cox regression models.

RESULTS

14,3% of patients lost to follow-up showed no differences in baseline characteristics from the rest of the cohort. The median follow-up was 10.1 years (IQR: 5.8-12.0). The cumulative survival rate was 53.5% (95% CI, 45.7-61.3%). The incidence of MACE was 5.85 (95% CI, 4.73-6.97) per 100 hypertensive patients-year. In the multivariate analysis none of the ECG criteria showed statistical association with the occurrence of MACE.

CONCLUSIONS

No association has been found between different electrocardiographic LVH criteria and the incidence of MACE in a cohort of hypertensive patients followed-up in a PHC setting for 12 years.

Left ventricular hypertrophy and cardiovascular mortality by race and ethnicity

BACKGROUND

Left ventricular hypertrophy is a major independent risk factor for cardiovascular mortality. The contribution of left ventricular hypertrophy to racial and ethnic differences in cardiovascular mortality is poorly understood.

METHODS

We used data from the Third National Health and Nutrition Examination Survey and from the National Death Index to compare mortality for those with an electrocardiographic (ECG) diagnosis of left ventricular hypertrophy to those without left ventricular hypertrophy separately for whites, African Americans, and Latinos. We used Cox proportional hazards regression to control for other known prognostic factors.

RESULTS

ECG left ventricular hypertrophy was significantly associated with 10-year cardiovascular mortality in all 3 racial/ethnic groups, both unadjusted and adjusted for other known prognostic factors. The hazard ratio for this association was significantly greater for African Americans (2.31; 95% confidence interval [CI], 1.55-3.42) than for whites and Latinos (1.32; 95% CI, 1.14-1.76 and 2.11; 95% CI, 1.35-3.30, respectively), independent of systolic blood pressure.

CONCLUSIONS

ECG left ventricular hypertrophy contributes more to the risk of cardiovascular mortality in African Americans than it does in whites. Using regression of ECG left ventricular hypertrophy as a goal of therapy might be a means to reduce racial differences in cardiovascular mortality; prospective validation is required.