Combined Echocardiographic Left Ventricular Hypertrophy and Electrocardiographic ST Depression Improve Prediction of Mortality in American Indians

Prognostic Significance of Echocardiographic Measures of Cardiac Remodeling in the Community

PURPOSE OF REVIEW

Echocardiography is a noninvasive tool of choice for evaluating cardiac structure and function in numerous cardiac conditions ranging from congenital heart disease, myocardial diseases, coronary artery disease (CAD), valvulopathies, arrhythmias, and pericardial disorders. We review the prognostic significance of echocardiographic indices of cardiac remodeling in the general population.

RECENT FINDINGS

Recent meta-analyses have confirmed the prognostic significance of echocardiographic measurements (left ventricular mass/hypertrophy, systolic and diastolic dysfunction, left atrial dimensions and function, and strain rate measures) in asymptomatic people in the community for adverse clinical outcomes including CAD, stroke, heart failure, atrial fibrillation, sudden death, and all-cause mortality. The clinical utility of screening echocardiography has been examined comprehensively in hypertensive patients, where it is challenged by measurement variability. Echocardiographic measures predict cardiovascular disease outcomes consistently in multiple community-based epidemiological studies. However, the clinical utility of screening asymptomatic individuals with echocardiography in population-based settings is limited.

Indexation of left ventricular mass to predict adverse clinical outcomes in pre-dialysis patients with chronic kidney disease: KoreaN cohort study of the outcome in patients with chronic kidney disease

Background

No study has compared the clinical impact of indexation of left ventricular mass (LVM) on adverse clinical outcomes in pre-dialysis patients with chronic kidney disease (CKD).

Methods

We reviewed 2,101 patients from a large-scale multi-center prospective study that gathered anthropometric and echocardiographic measurements and clinical outcomes. The LVM was indexed as body surface area (LVMI-BSA) and height raised to the power of 2.7 (LVMI-H2.7). The main outcomes were composite renal and cardiovascular events and all-cause mortality. Left ventricular hypertrophy (LVH) was defined as the highest sex-specific quartile of LVMI-BSA or LVMI-H2.7.

Results

During a mean period of 3.5 years, 692 patients developed composite outcomes (32.9%). The area under the curve at 5 year of LVM (60.6%) for composite outcome was smaller than that for LVMI-BSA (63.2%, P <0.001) and LVMI-H2.7 (63.4%, P <0.001). The hazard ratio (HR) and 95% confidence interval (CI) per one unit increase in LVM (g), LVMI-BSA (g/m²), and LVMI-H2.7 (g/m^2.7) for composite outcomes were 1.004 (1.002–1.005, P <0.001), 1.011 (1.006–1.016, P <0.001), and 1.023 (1.012–1.035, P <0.001), respectively. Patients with LVH determined by LVMI-BSA and LVMI-H2.7 (HR 1.352, 95% CI 1.123–1.626, P = 0.001) and LVH determined by only LVMI-BSA (HR 1.908, 95% CI 1.233–2.953, P = 0.004) showed an independent increase in the risk of composite-outcome development, when compared with patients without LVH, according to LVMI-BSA and LVMI-H2.7.

Conclusion

Indexation of LVM improved the prediction of adverse outcomes. BSA may be as useful as height^2.7 in indexing of LVM for predicting adverse outcomes in pre-dialysis patients with CKD.

Electrocardiographic criteria for the diagnosis of abnormal hypertensive cardiac phenotypes

This article compared the performance of 18 electrocardiographic (ECG) left ventricular hypertrophic (LVH) criteria and four P-wave indices for the diagnosis of echocardiographic (ECHO) LVH and left atrial enlargement (LAE), including the deepest S-wave amplitude added to the S-wave amplitude of lead V4 (SD +SV4 ) and P-wave terminal force in lead V1 (PTFV1 ). A total of 152 middle-aged hypertensive patients without evident cardiovascular diseases (CVDs) were enrolled. The gold standard for the diagnosis of LVH and LAE was ECHO left ventricular mass index (LVMI) and largest left atrial volume index (LAVI). For the detection of LVH, Sokolow-Lyon voltage, Cornell voltage, Cornell product, SD +SV4 , Manning, and R+S in any precordial lead had relatively higher sensitivity, especially SD +SV4 criteria. Their combination could further increase sensitivity (43% vs 29% [SD +SV4 ], P = 0.016). PTFV1 was the only criterion that had significant diagnostic value for ECHO LAE (AUC, 0.68; 95% CI: 0.54-0.73, P = 0.008). For middle-aged hypertensive patients without evident cardiovascular diseases, SD +SV4 had the highest sensitivity for the diagnosis of LVH and the combination of several ECG LVH criteria might further increase sensitivity. PTFV1 had significant diagnostic value for ECHO LAE.

Electrocardiographic ST-T Area Assessed by a Computerized Quantitative Method and Its Relation to Cardiovascular Events: The J-HOP Study

BACKGROUND

Although many studies have reported that the presence of minor or major ST-T change of electrocardiography (ECG) was associated with a risk of cardiovascular events, it is not clear whether there is a difference in the prognostic power depending on the summation of ST-T area (ST-Tarea) assessed by a quantitative method.

METHODS

Electrocardiograms were performed in 834 clinical patients with one or more cardiovascular risks. ST-Tarea was assessed as the area enclosed by the baseline from the end of the QRS complex to the end of the ST-T segment using a computerized quantitative method. We used the lower magnitude of ST-Tarea in the V5 or V6 lead for the analysis.

RESULTS

After a mean follow-up 8.4 ± 2.9 years (7,001 person-years), there were 92 cardiovascular events. With adjustment for covariates, the results from Cox proportional hazards models (Model 1) suggested that the lowest quartile of ST-Tarea was associated with a higher risk for cardiovascular outcome compared with the remaining quartile groups (hazard ratio, 2.08; 95% confidence interval, 1.36-3.16, P < 0.01). Even when adding the ECG left ventricular hypertrophy by Cornell voltage (Model 2) and Cornell product (Model 3) to Model 1, the significance remained (both P < 0.01). When we used ST-Tarea as a continuous variable substitute for the lowest quartile of ST-Tarea, these associations were similar in all models (all P < 0.01).

CONCLUSION

The lower summations of ST-T area assessed by a computerized quantitative method were associated with increased risk of cardiovascular disease incidence in a clinical population.

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.

The Romhilt-Estes electrocardiographic score predicts sudden cardiac arrest independent of left ventricular mass and ejection fraction

BACKGROUND

The Romhilt-Estes point score system (RE) is an established ECG criterion for diagnosing left ventricular hypertrophy (LVH). In this study, we assessed for the first time, whether RE and its components are predictive of sudden cardiac arrest (SCA) independent of left ventricular (LV) mass.

METHODS

Sudden cardiac arrest (SCA) cases occurring between 2002 and 2014 in a Northwestern US metro region (catchment area approx. 1 million) were compared to geographic controls. ECGs and echocardiograms performed prior to the SCA and those of controls were acquired from the medical records and evaluated for the ECG criteria established in the RE score and for LV mass.

RESULTS

Two hundred forty-seven SCA cases (age 68.3 ± 14.6, male 64.4%) and 330 controls (age 67.4 ± 11.5, male 63.6) were included in the analysis. RE scores were greater in cases than controls (2.5 ± 2.1 vs. 1.9 ± 1.7, p < .001), and SCA cases were more likely to meet definite LVH criteria (18.6% vs. 7.9%, p < .001). In a multivariable model including echocardiographic LVH and LV function, definite LVH remained independently predictive of SCA (OR 2.04, 95% CI 1.16-3.59, p = .013). The model was replicated with the individual ECG criteria, and only SV_1.2  ≥ 30 mm and delayed intrinsicoid deflection remained significant predictors of SCA.

CONCLUSION

Left ventricular hypertrophy (LVH) as defined by the RE point score system is associated with SCA independent of echocardiographic LVH and reduced LV ejection fraction. These findings support an independent role for purely electrical LVH, in the genesis of lethal ventricular arrhythmias.

Cranial Magnetic Resonance Imaging in Elderly American Indians: Design, Methods, and Implementation of the Cerebrovascular Disease and Its Consequences in American Indians Study

The Cerebrovascular Disease and its Consequences in American Indians (CDCAI) Study recruited surviving members of a 20-year, longitudinal, population-based cohort of American Indians focused on cardiovascular disease, its risk factors, and its consequences. The goal of the CDCAI Study is to characterize the burden, risk factors, and manifestations of vascular brain injury identified on cranial MRI. The CDCAI Study investigators enrolled 1,033 participants aged 60 and older from 11 American Indian communities and tribes in the Northern Plains, Southern Plains, and Southwestern United States. In addition to cranial MRI performed according to standardized protocols, participants underwent extensive medical interview, clinical examination, neurocognitive testing, physical function evaluation, electrocardiogram, and provided blood and urine specimens. Participants also self-administered questionnaires covering demographics, quality of life, and medical history. This report describes the design, implementation, and some of the unique challenges of this study and data collection.

Do Combined Electrocardiographic and Echocardiographic Markers of Left Ventricular Hypertrophy Improve Cardiovascular Risk Estimation?

The authors estimated the risk of cardiovascular mortality associated with echocardiographic (ECHO) left ventricular hypertrophy (LVH) and subtypes of this phenotype in patients with and without electrocardiographic (ECG) LVH. A total of 1691 representatives of the general population were included in the analysis. During a follow-up of 211 months, 89 cardiovascular deaths were recorded. Compared with individuals with neither ECHO LVH nor ECG LVH, fully adjusted risk of cardiovascular mortality increased (hazard ratio [HR], 3.36; 95% confidence interval [CI], 1.51-7.47; P=.003) in patients with both ECHO-LVH and ECG-LVH, whereas the risk entailed by ECHO-LVH alone was of borderline statistical significance (P=.04). Combined concentric nondilated LVH and ECG-LVH, but not concentric nondilated LVH alone, predicted cardiovascular death (HR, 3.79; 95% CI, 1.25-11.38; P=.01). Similar findings were observed for eccentric nondilated LVH (HR, 3.37; 95% CI, 1.05-10.78; P=.04.). The present analysis underlines the value of combining ECG and ECHO in the assessment of cardiovascular prognosis related to abnormal left ventricular geometric patterns.

Review: New approaches to the assessment of left ventricular hypertrophy

In hypertension, Left ventricular hypertrophy is initially a useful compensatory process that represents an adaptation to increased ventricular wall stress; however, it is also the first step toward the development of overt clinical disease. For this reason most international guidelines recommend the assessment of cardiac target organ damage in hypertensive patients for cardiovascular risk stratification. It is therefore of great importance to keep in mind the strengths and weakness of the different available methods for LVH assessment.

Several methods are currently available for the assessment of LVH; however the various techniques differ in cost, availability, sensitivity and specificity. Due to its wide availability and its low cost, eLectrocardiography should be part of all routine assessment of subjects with high blood pressure; however, despite its good specificity, the sensitivity for LVH detection is low. Several other methods have been proposed for LVH detection. Cardiac magnetic resonance imaging allows 3D reconstruction of the heart with high spatial resolution; however its main limitation is represented by the relatively low availability and by its costs. Echocardiography certainly represents a valuable method for the detection of LVH in hypertensive patients, due to its wide availability and its relatively low cost. The main limitations of the technique are represented by the lower spatial resolution and reproducibility in comparison with magnetic resonance. The development of new matrix-array transducers and new software for 3D reconstruction with echocardiography make this approach particularly promising for the future; in the meantime, standard echocardiography, widely available and with low cost, will probably remain the most used tool for the evaluation of left ventricular structure and function in hypertension.

Recommendations on the Use of Echocardiography in Adult Hypertension: A Report from the European Association of Cardiovascular Imaging (EACVI) and the American Society of Echocardiography (ASE)

Hypertension remains a major contributor to the global burden of disease. The measurement of blood pressure continues to have pitfalls related to both physiological aspects and acute variation. As the left ventricle (LV) remains one of the main target organs of hypertension, and echocardiographic measures of structure and function carry prognostic information in this setting, the development of a consensus position on the use of echocardiography in this setting is important. Recent developments in the assessment of LV hypertrophy and LV systolic and diastolic function have prompted the preparation of this document. The focus of this work is on the cardiovascular responses to hypertension rather than the diagnosis of secondary hypertension. Sections address the pathophysiology of the cardiac and vascular responses to hypertension, measurement of LV mass, geometry, and function, as well as effects of treatment.

Hemodynamic and echocardiographic profiles in African American compared with White offspring of hypertensive parents: the HyperGEN study

BACKGROUND

Alterations in cardiovascular structure and function have been shown to precede the finding of elevated blood pressure.

METHODS

This study is part of the Hypertension Genetic Epidemiologic Network (HyperGEN) in which genetic and environmental determinants of hypertension were investigated in 5 geographical field centers. All nonhypertensive offspring (n = 1,035) were included from the entire HyperGEN study population that consists of 2,225 hypertensive patients and 1,380 nonhypertensive patients who had adequate echocardiographic left ventricular (LV) mass measurements. Participants were compared by self-declared race (African American and white).

RESULTS

Nonhypertensive African American offspring were younger (aged 31 years vs. 38 years), more likely to be female, and had a higher body mass index (BMI) and higher systolic blood pressure (SBP) than their white counterparts. After adjusting for age, sex, SBP, pulse pressure (PP), BMI, diabetes status, and family effects, we observed statistically significant and potentially pathophysiological differences (all with P ≤ 0.001) with greater LV mass/height, relative wall thickness, and posterior wall thickness and with lesser midwall shortening, PP/stroke volume, and (PP/stroke volume)/fat-free body mass.

CONCLUSION

This study shows that ethnic differences in hemodynamic and echocardiographic profiles exist in a large, population-based cohort of nonhypertensive offspring of hypertensive parents.

T-wave alternans and ST depression assessment identifies low risk individuals with ischemic cardiomyopathy in the absence of left ventricular hypertrophy

BACKGROUND

Although ECG left ventricular hypertrophy (LVH) by Cornell product (CP) predicts increased mortality in patients with ischemic cardiomyopathy (ICM), those without CP LVH remain at relatively high risk. We examined whether T-wave alternans (TWA) testing and ST depression can improve risk stratification in these patients.

METHODS AND RESULTS

This study examined 317 patients with ICM, nonsustained ventricular tachycardia, and a resting ECG in sinus rhythm, who presented for electrophysiology and TWA testing, and potential implantable cardioverter defibrillator (ICD) implantation. LVH was defined by CP :[(RaVL + SV3 ) +6 mm in women] × QRS duration > 2440 mm * msec. ST depression was examined as a categorical variable using an established threshold of depression of ≥50 μV in V5 or V6 . In Cox multivariate models, abnormal TWA testing and ST depression were independent predictors of mortality in patients without CP LVH (HR 2.52, CI 1.09-5.80, P = 0.030 and HR 2.87, CI 1.41-5.81, P = 0.004, respectively). Individuals with no LVH by CP, normal TWA, and no significant ST depression, comprised 23% of the study population and had a 5.6% 3-year mortality, compared to an overall 20% mortality.

CONCLUSIONS

TWA and ST depression testing are strong predictors of mortality among ICM patients without CP LVH, with normal testing conversely predicting low 3-year mortality. Thus, risk assessment with TWA testing and a resting ECG can identify ICM patients at low risk who may be less likely to benefit from ICD implantation.

Impact of electrocardiographic findings for diagnosis of left ventricular hypertrophy in patients with primary aldosteronism

BACKGROUND

Compared to patients with similar levels of hypertension, patients with primary aldosteronism have a greater left ventricular hypertrophy (LVH). The presence of LVH should be detected as early as possible to prevent cardiovascular complications associated with the condition. We evaluated comparative diagnostic value of electrocardiographic (ECG) indexes for LVH in patients with primary aldosteronism.

METHODS

ECG and echocardiographic data were obtained in 88 patients with primary aldosteronism. We analyzed the four most commonly used ECG indexes, including Sokolow-Lyon index, Cornell voltage index, Cornell product index, and Gubner index.

RESULTS

Echocardiographic LVH was found in 35 patients (40%). Sensitivity ranged from 0% for Gubner index to 49% for Cornell product index. Specificity ranged from 81% for Sokolow-Lyon index to 100% for Gubner index. Sokolow-Lyon index (r=0.43, p<0.001), Cornell voltage index (r=0.55, p<0.001) and Cornell product index (r=0.52, p<0.001) correlated significantly with left ventricular mass (LVM) index. No significant correlation was found between Gubner index and LVM index.

CONCLUSIONS

ECG indexes had a reasonably high specificity, but a low sensitivity for LVH in patients with primary aldosteronism. Cornell voltage index and Cornell product index had a better diagnostic value of LVH, and had a better correlation with LVM index in these patients.

Association of heart failure hospitalizations with combined electrocardiography and echocardiography criteria for left ventricular hypertrophy

BACKGROUND

The value of performing echocardiography in hypertensive patients with electrocardiographic left ventricular hypertrophy (LVH) is uncertain.

METHODS

Baseline echo- and electrocardiographic data and cardiovascular events over 4.8 years study treatment were assessed in 922 hypertensive patients in the Losartan Intervention For Endpoint reduction in hypertension echocardiography substudy. Patients were grouped according to presence of LVH on both electrocardiogram (ECG) and echocardiogram (n = 515), only on ECG (n = 172), only on echocardiogram (n = 135), or on none tests (n = 100). LVH was diagnosed by Sokolow Lyon and Cornell product criteria by electrocardiography and as LV mass index >116 g/m(2) in men and >104 g/m(2) in women by echocardiography.

RESULTS

Patients with LVH on both tests were older, had higher systolic blood pressure and LV mass, lower LV systolic function, and included more patients with aortic regurgitation, albuminuria, and history of ischemic heart disease (all P < 0.05). Incidence of combined myocardial infarction, stroke, or cardiovascular death did not differ between groups. Incidence of hospitalization for heart failure was 5.3 and 2.6 times higher in patients with LVH on both tests compared to patients with LVH on ECG or echocardiogram only (P < 0.01). In Cox regression, LVH on both tests predicted hospitalization for heart failure (hazard ratio 4.29 (95% confidence interval 1.26-14.65), P = 0.020) independent of other covariates including study treatment allocation and history of ischemic heart disease.

CONCLUSIONS

Our results suggest that combining LVH assessment on a single ECG and echocardiogram provides a simple tool for additional heart failure risk stratification in asymptomatic high-risk hypertensive patients.

Prognostic value of ST-T abnormalities and left high R waves with cardiovascular mortality in Japanese (24-year follow-up of NIPPON DATA80)

Little is known about the prognostic value of ST-segment depression and/or T wave (ST-T abnormalities) with or without left high R waves on electrocardiogram recorded at rest for death from cardiovascular disease (CVD) in Asian populations. Japanese participants without a history of CVD and free of major electrocardiographic (ECG) abnormalities were followed for 24 years. Subjects were divided into 4 groups based on baseline ECG findings: isolated left high R waves, isolated ST-T abnormalities, ST-T abnormalities with left high R waves, and normal electrocardiogram. Cox proportional hazard model was used to estimate risk of CVD mortality in groups with ECG abnormalities compared to the normal group. Of 8,572 participants (44.4% men, mean age 49.5 years; 55.6% women, mean age 49.4 years), 1,142 had isolated left high R waves, 292 had isolated ST-T abnormalities, and 128 had ST-T abnormalities with left high R waves at baseline. Multivariable-adjusted hazard ratios of ST-T abnormalities with left high R waves for CVD mortality were 1.95 (95% confidence interval 1.25 to 3.04) in men and 2.68 (95% confidence interval 1.81 to 3.97) in women. Isolated ST-T abnormalities increased the risk for CVD death by 1.66 times (95% confidence interval 1.01 to 2.71) in men and 1.62 times (95% confidence interval 1.18 to 2.24) in women. Association of ECG abnormalities with CVD mortality was independent of age, body mass index, systolic blood pressure, serum cholesterol, blood glucose, smoking and drinking, and antihypertensive medication. In conclusion, ST-T abnormalities with or without left high R waves on electrocardiogram recorded at rest constitute an independent predictor of CVD mortality in Japanese men and women.

Prognostic significance of baseline and serial changes in electrocardiographic strain pattern in resistant hypertension

OBJECTIVES

The prognostic importance of serial changes in electrocardiographic strain pattern of lateral ST-depression and T-wave inversion is unclear. The objective was to evaluate the significance of baseline and serial changes in strain pattern as predictors of cardiovascular morbidity and mortality in patients with resistant hypertension.

METHODS

At baseline and during follow-up, 532 resistant hypertensive patients had the presence of strain pattern examined on 12-lead ECGs. Other clinical laboratory, echocardiographic and ambulatory blood pressure data were obtained. Primary endpoints were a composite of total cardiovascular events and mortality. Strokes and coronary heart disease events were secondary endpoints. Multiple Cox regression assessed the associations between strain pattern and subsequent endpoints.

RESULTS

At baseline, 115 patients (21.6%) presented the strain pattern and during follow-up, 17 patients regressed and 22 developed new strain pattern. After a median follow-up of 4.8 years, 69 patients died, 46 from cardiovascular causes; and 107 cardiovascular events occurred, 44 strokes and 42 coronary heart disease events. After adjustment for several cardiovascular risk factors, including time-varying ambulatory blood pressures and electrocardiographic voltage criteria of left ventricular hypertrophy, the persistence or development of strain during follow-up was a predictor of the composite endpoint (hazard ratio 1.97, 95% confidence interval 1.19-3.25), all-cause mortality (hazard ratio 1.99, 95% confidence interval 1.10-3.61) and of stroke (hazard ratio 3.09, 95% confidence interval 1.40-6.81). The combination of strain pattern and left ventricular hypertrophy voltage criteria improved stratification of cardiovascular risk.

CONCLUSION

Serial changes in electrocardiographic strain pattern during follow-up predict cardiovascular morbidity and mortality in resistant hypertensive patients. Regression or prevention of the strain pattern during antihypertensive treatment may be a therapeutic goal to improve prognosis.

The prognostic value of the ECG in hypertension: where are we now?

In hypertension, the presence of left ventricular hypertrophy (LVH) is associated with increased risk of both cardiovascular morbidity and mortality. To date, the electrocardiogram (ECG) remains the cornerstone of LVH diagnosis in clinical practice because it is universally available, technically easy to perform and highly specific. In the most recent European Society of Hypertension/European Society of Cardiology guidelines for the treatment of arterial hypertension, the Sokolow-Lyon voltage criterion was recommended as part of all routine assessment of subjects with hypertension. However, the use of the ECG in the diagnosis of LVH is somewhat limited by its poor sensitivity. In this review article, we discuss the individual strength and weaknesses of the commonly used ECG criteria in diagnosing LVH. In addition, we present the latest data on the prognostic significance of ECG LVH and the survival differences conferred in different genders. In view of the recent Losartan Intervention for Endpoint Reduction in Hypertension trial, the prognostic benefit of LVH regression will also be addressed. Finally, with the wider availability of echocardiography, the role of combining both modalities to improve risk stratification in hypertension is reviewed.

Utility of the myocardial performance index in a population with high prevalences of obesity, diabetes, and hypertension: the strong heart study

INTRODUCTION

The myocardial performance index (MPI) introduced by Tei, a Doppler-derived echocardiographic measure that reflects both left ventricular (LV) systolic and diastolic function, has been shown to have prognostic value in several clinical settings, including myocardial infarction and congestive heart failure. There are scant data on the correlates and prognostic value of MPI in a population without overt cardiovascular (CV) disease.

METHODS

We investigated clinical and physiologic correlates of MPI, as assessed from echocardiographic Doppler recordings in 1,862 American Indian participants free of coronary or valvular disease or LV systolic dysfunction in the population-based strong heart study (SHS). We then assessed the prognostic value of MPI for incident CV events, including nonfatal stroke, coronary heart disease, congestive heart failure, and CV death.

RESULTS

The study population was 59 +/- 8 years old (66% women); 48% had diabetes, 44% hypertension, and 54% were obese. In univariable analyses, MPI (mean = 0.24 +/- 0.17) showed significant negative associations with creatinine clearance, C-reactive protein (CRP), LV ejection fraction (EF), mitral valve E- and A-wave velocities, cardiac index (CI), stroke index (SI) and stroke index/pulse pressure (SI/PP), and significant positive associations with serum creatinine and total peripheral resistance index (TPRI) (all P < 0.05). There were no significant associations of MPI with hypertension or diabetes status, systolic or diastolic blood pressure, body mass index, hemoglobin A1C or LV mass. After adjusting for age, sex, diabetes, and hypertension, MPI remained weakly but significantly correlated with CRP, EF, CI, SI, SI/PP, mitral E- and A-wave velocities, and TPRI. MPI did not predict fatal and nonfatal CV events (risk ratio 1.06 per unit MPI, 95% C.I. 0.56-2.04; P = 0.85) at a mean follow-up of 7.1 +/- 2.2 years.

CONCLUSIONS

In a population-based sample of adults with high prevalence of diabetes, hypertension, and obesity but without overt CV disease, MPI has weak associations with clinical and physiologic determinants of cardiac function. Moreover, MPI does not provide prognostic information for CV events in this population. Though conceptually attractive as a global measure of cardiac function, MPI has limited utility in a high-risk population without clinical CV disease.

Quantitative Measures of Electrocardiographic Left Ventricular Mass, Conduction, and Repolarization, and Long-Term Survival After Coronary Artery Bypass Grafting

Background— Quantitative ECG measures of left ventricular mass and repolarization predict outcome in population-based cohorts and patients with hypertension. We assessed the prognostic value of preoperative quantitative electrocardiography in patients who underwent isolated coronary artery bypass grafting.

Methods and Results— For 6 years we followed 8166 patients who underwent primary isolated coronary artery bypass grafting between 1990 and 2003, all of whom had routine preoperative ECGs. With use of specialized digital software, quantitative measures were recorded on ventricular rate, P duration, PR interval, QRS duration, QT interval, QRS axis, Sokolow-Lyon and Cornell voltages, and ST-segment depression and slope. There were 1516 deaths. After adjustment for age, gender, clinical characteristics, left ventricular ejection fraction, and other confounders, death was independently predicted by ventricular rate (adjusted hazard ratio [AHR] for 90 versus 60 beats per minute, 1.34; 95% confidence interval [CI], 1.21 to 1.50; P <.0001), PR interval (AHR for 200 versus 150 ms, 1.05; 95% CI, 1.00 to 1.10; P <.0001), QRS duration (AHR for 120 versus 80 ms, 1.24; 95% CI, 1.07 to 1.44; P <.0001), Sokolow-Lyon voltage (AHR for 3.5 versus 1.5 mV, 1.18; 95% CI, 1.05 to 1.31; P <.0001), and ST-segment slope (AHR for −0.1 versus 0 mV, 1.16; 95% CI, 1.02 to 1.31; P <.0001). We derived a quantitative ECG score and demonstrated that, with the exception of age, it was the most powerful predictor of long-term death.

Conclusions— Quantitative ECG measures of left ventricular rate, mass, and repolarization are predictive of mortality among patients who underwent isolated coronary artery bypass grafting. These findings suggest that quantitative electrocardiography may be valuable for risk stratification in patients with severe coronary artery disease.

Usefulness of quantitative assessment of electrocardiographic ST depression for predicting new-onset heart failure in American Indians (from the Strong Heart Study)

The qualitative electrocardiographic strain pattern of ST depression (STD) and T-wave inversion is strongly associated with coronary heart disease and left ventricular hypertrophy and is an independent predictor of new-onset heart failure in hypertensive participants. However, whether quantitative measures of STD in the lateral precordial leads predict new heart failure is unclear. Digital electrocardiograms were examined in 2,059 American-Indian participants in the second Strong Heart Study examination with no history of heart failure. The absolute magnitude of ST segment deviation was measured using computer to the nearest 5 microV in leads V(5) and V(6). During 5.7 +/-1.4 years of follow-up, heart failure developed in 77 participants (3.7%). Participants who developed heart failure had greater STD in leads V(5) or V(6) (-11 +/- 35 vs 12 +/- 27 microV; p <0.001) than those who did not. In univariate Cox analyses, STD was a significant predictor of new heart failure, with each 10-microV greater STD associated with a 31% greater risk of heart failure (hazard ratio [HR] 1.31, 95% confidence interval [CI] 1.24 to 1.39). Increasing STD grouped according to quartiles was strongly associated with the development of heart failure, with stepwise increasing risk of heart failure compared with the lowest quartile of STD for the second (HR 2.39, 95% CI 0.77 to 7.40), third (HR 3.01, 95% CI 1.00 to 9.08), and fourth quartiles of STD (HR 9.06, 95% CI 3.26 to 25.16). In Cox multivariate analyses controlling for age, gender, diabetes, coronary heart disease, albuminuria, and other baseline risk factors, STD remained a significant predictor of incident heart failure (HR 1.22, 95% CI 1.13 to 1.32 per 10-muV increment in STD; p <0.001). In conclusion, increasing STD in lateral precordial leads is strongly associated with increased risk of developing heart failure independent of other risk factors for new heart failure.

Electrocardiographic characteristics and metabolic risk factors associated with inappropriately high left ventricular mass in patients with electrocardiographic left ventricular hypertrophy: the LIFE Study

BACKGROUND

To investigate electrocardiographic (ECG) and metabolic abnormalities associated with left ventricular (LV) mass inappropriately high for workload and body size (termed 'inappropriate left ventricular mass'; ILVM) in hypertensive patients with ECG left ventricular hypertrophy (LVH).

METHODS

In patients enrolled in the Losartan Intervention for Endpoint Reduction (LIFE) Echocardiographic Substudy, LV structure and functions were assessed by echocardiography; Sokolow-Lyon and Cornell voltage, QRS duration, Cornell voltage-duration product and ST strain pattern in leads V5-V6 were evaluated on standard ECG tracings. ILVM was defined as observed LV mass greater than 128% of that predicted by sex, body size and stroke work.

RESULTS

In univariate analysis, compared with subjects with appropriate LV mass (n = 593), ILVM (n = 348) was associated with older age, diabetes, higher body mass index, lower systolic blood pressure, higher serum creatinine and urinary albumin/creatinine levels, higher LV mass index and greater prevalence of wall motion abnormalities (all P < 0.05). ILVM was associated with higher Cornell voltage and voltage-duration product but not higher Sokolow-Lyon voltage, with longer QRS and higher prevalences of ECG ST strain and echocardiographic wall motion abnormalities, independent of covariates including echocardiographically defined LVH or LV geometry. In separate logistic models, the likelihood of ILVM was significantly related to prolonged QRS duration, higher Cornell voltage, and greater Cornell voltage-duration independently (all P < 0.01).

CONCLUSION

In hypertensive patients with ECG LVH, ILVM was associated with prolonged QRS duration and higher Cornell voltage, with ECG ST strain pattern, and with echocardiographic wall motion abnormalities independent of traditionally defined LVH.

Evaluation of subclinical target organ damage for risk assessment and treatment in the hypertensive patients: left ventricular hypertrophy

At some point in the natural history of hypertension, the compensatory increase in left ventricular mass ceases to be beneficial. Left ventricular hypertrophy (LVH) becomes a preclinical disease and an independent risk factor for congestive heart failure, ischemic heart disease, arrhythmia, sudden death, and stroke. In addition to elevated BP, several mechanisms are involved, including body size, age, gender, race, fibrogenic cytokines, and neurohumoral factors, notably angiotensin II, which favor interstitial collagen deposition and perivascular fibrosis. These tissue changes are responsible for the insidious contractile dysfunction that is associated with LVH, consequent to decreased coronary reserve and altered diastolic ventricular filling and relaxation. The cardinal investigations are echocardiography and electrocardiography. All antihypertensive drugs regress LVH, notably those that act on the renin-angiotensin-aldosterone system, which also could target the detrimental tissue changes. Regression enhances systolic midwall performance, normalizes autonomic function, and restores coronary reserve. The resulting improvement in prognosis has enshrined the detection, prevention, and reversal of LVH in the current guidelines of hypertension management.

Importance of the Electrocardiographic Strain Pattern in Patients With Resistant Hypertension

The electrocardiographic strain pattern is a marker of left ventricular hypertrophy and adverse cardiovascular prognosis. The objective of this study was to assess the factors associated with the presence of ECG strain in patients with resistant hypertension and, specifically, to evaluate the relationships between strain and left ventricular mass (LVM) and structure. In a cross-sectional design, 440 resistant hypertensive subjects were evaluated. Clinical, laboratory, electrocardiographic, 24-hour ambulatory blood pressures, and echocardiographic variables were obtained. Statistical analysis involved bivariate tests, analysis of covariance, and multivariate logistic regression. An ECG strain pattern was present in 101 patients (23%). Patients with strain were more frequently men with lower body mass index, had more target-organ damage, higher 24-hour blood pressure, higher serum creatinine and 24-hour microalbuminuria, and more prolonged QT interval duration than those without strain. After controlling for all covariates, the presence of strain remained associated with increased LVM and wall thicknesses, both in all patients and also in those with echocardiographic left ventricular hypertrophy. Furthermore, the presence of ECG strain was associated with increased LVM (P<0.001), higher 24-hour systolic blood pressure (P<0.001), prolonged maximum QTc-interval duration (P<0.001), lower waist circumference (P=0.009), male gender (P=0.011), physical inactivity (P=0.020), higher serum creatinine (P=0.031) and fasting glycemia (P=0.027), and the presence of coronary heart disease (P=0.001) and peripheral arterial disease (P=0.045). Thus, in resistant hypertension patients, the presence of ECG strain is independently associated with increased left ventricular wall thicknesses and mass and also with other potentially adverse factors. These relationships offer insight into the known association between strain and unfavorable cardiovascular prognosis.

Electrocardiographic abnormalities predict deaths from cardiovascular disease and ischemic heart disease in Pima Indians with type 2 diabetes

BACKGROUND

The association between electrocardiographic (ECG) abnormalities and deaths from cardiovascular diseases (CVD) and ischemic heart disease (IHD) has been reported in the general population, but there is little information regarding persons with type 2 diabetes.

METHODS

Minor and major ECG abnormalities were identified and classified according to the Minnesota Code in a longitudinal study of 1605 Pima Indians aged > or =35 years with type 2 diabetes. Underlying causes of death were determined by review of all available clinical records, autopsy reports, medical examiners' findings, and death certificates.

RESULTS

During a median follow-up of 14.1 years (range 0.1 to 33.8 years), there were 190 CVD deaths, 135 (71.1%) of which were attributable to IHD. The age-adjusted CVD death rates in men with none, minor, and major ischemic ECG abnormalities were 7.3, 12.2 and 27.8, and in women, 4.3, 4.8 and 12.5 per 1000 person-years, respectively. After adjustment for other co-variables in a multiple proportional hazards model, subjects with minor and major ischemic abnormalities on ECG had 1.22 (95% CI, 0.76-1.97) and 1.83 (95% CI, 1.21-2.76) times the CVD death rate, and 1.32 (95% CI, 0.70-2.50) and 2.12 (95% CI, 1.26-3.57) times the IHD death rate of those with no ischemic ECG abnormalities, respectively.

CONCLUSIONS

The CVD and IHD death rates were higher in men and in subjects with major ischemic ECG abnormalities. Major ischemic abnormalities on ECG predicted death after accounting for other cardiovascular risk factors, including proteinuria.

Randomized Clinical Trials on Surrogate End Points: Are They Useful for Evaluating Cardiovascular and Renal Disease Protection in Hypertension? The Case for Yes

Hard end point studies represent the best available evidence for demonstrating the cardiovascular and renal protection that is achievable with a given treatment in hypertensive patients, yet properly designed end point studies require large cohorts of patients and long follow-up, are expensive, and do not provide any insight on the mechanisms that lead to the clinical manifestations. Studies that are based on the incidence of preclinical alterations, i.e., the surrogate end points, may circumvent these limitations provided that their relationship with the major cardiovascular events is scientifically proved. In this respect, among the many surrogate end points that are under investigation, left ventricular hypertrophy, microalbuminuria, and treatment-induced diabetes seem most promising for replacing the hard end points in view of their undisputed mechanistic relationship with the clinical events and of the mounting evidence indicating that from their changes it is possible to predict the clinical outcome of patients. In addition, the limited resources that are required to carry out this kind of investigations make them preferable to hard end point studies for anticipating the cardiovascular and renal benefit associated with the use of antihypertensive agents.

Electrocardiographic Strain Pattern and Prediction of New-Onset Congestive Heart Failure in Hypertensive Patients

Background— The ECG strain pattern of ST depression and T-wave inversion is strongly associated with left ventricular hypertrophy (LVH) independently of coronary heart disease and with an increased risk of cardiovascular morbidity and mortality in hypertensive patients. However, whether ECG strain is an independent predictor of new-onset congestive heart failure (CHF) in the setting of aggressive antihypertensive therapy in unclear.

Methods and Results— The relationship of ECG strain at study baseline to the development of CHF was examined in 8696 patients with no history of CHF who were enrolled in the Losartan Intervention for Endpoint Reduction in Hypertension (LIFE) study. All patients had ECG LVH by Cornell product and/or Sokolow-Lyon voltage criteria on a screening ECG, were treated in a blinded manner with atenolol- or losartan-based regimens, and were followed up for a mean of 4.7±1.1 years. Strain was defined as a downsloping convex ST segment with inverted asymmetrical T-wave opposite the QRS axis in lead V 5 or V 6 . ECG strain was present in 923 patients (10.6%), and new-onset CHF occurred in 265 patients (3.0%), 26 of whom had a CHF-related death. Compared with patients who did not develop CHF, hypertensive patients who developed CHF were older; were more likely to be black, current smokers, and diabetic; were more like to have a history of myocardial infarction, ischemic heart disease, stroke, or peripheral vascular disease; and had greater baseline severity of LVH by Cornell product and Sokolow-Lyon voltage, higher baseline body mass indexes, higher serum glucose levels and albuminuria, similar baseline systolic and diastolic pressures, and reductions in diastolic pressure with treatment but greater reductions in systolic pressure. In univariate Cox analyses, ECG strain was a significant predictor of new-onset CHF (hazard ratio [HR], 3.27; 95% CI, 2.49 to 4.29) and CHF mortality (HR, 4.74; 95% CI, 2.11 to 10.64). In Cox multivariable analyses adjusting for baseline differences between patients with and without new-onset CHF, in-treatment differences in systolic and diastolic pressures, Sokolow-Lyon voltage, and Cornell product, and the impact of treatment with losartan versus atenolol on outcomes, ECG strain remained a significant predictor of incident CHF (HR, 1.80; 95% CI, 1.30 to 2.48) and CHF-related death (HR, 2.78; 95% CI, 1.02 to 7.63).

Conclusions— ECG strain identifies hypertensive patients at increased risk of developing CHF and dying as a result of CHF, even in the setting of aggressive blood pressure lowering.

C-Reactive Protein and Electrocardiographic ST-Segment Depression Additively Predict Mortality

OBJECTIVES

This study was designed to examine whether high-sensitivity C-reactive protein (CRP) and electrocardiographic (ECG) ST-segment depression (STD) have additive utility for predicting cardiovascular disease (CVD) death and all-cause death (ACD).

BACKGROUND

C-reactive protein, a marker of systemic inflammation, and ECG STD, an index of myocardial ischemia and hypertrophy, independently predict mortality.

METHODS

Electrocardiograms and CRP levels were examined in 2,155 American Indian participants in the second Strong Heart Study examination. ST-segment depression >/=50 microV (n = 127) and CRP >7.0 mg/l (defining the upper quartile of CRP levels, n = 540) were considered abnormal.

RESULTS

After 5.2 +/- 1.2 years follow-up there were 95 CVD deaths and 310 ACD. In univariate Cox analyses, the combination of CRP and ECG STD improved risk stratification compared to either alone, with the presence of both CRP >7.0 and ECG STD associated with a 7.7-fold increased risk of CVD death (95% confidence interval [CI] 3.3 to 18.2) and a 6.5-fold increased risk of ACD (95% CI 4.1 to 10.3). After adjustment for age, gender, and relevant risk factors, the combination of high CRP and STD remained predictive of CVD death and ACD, with the presence of both abnormal CRP and STD associated with the highest risks of CVD death (hazard ratio [HR] 3.2, 95% CI 1.1 to 10.5) and ACD (HR 3.9, 95% CI 2.1 to 7.2) and the presence of either high CRP or abnormal STD associated with intermediate risks of CVD death (HR 2.2, 95% CI 1.4 to 3.4) and ACD (HR 1.5, 95% CI 1.2 to 2.0).

CONCLUSIONS

The combination of ECG STD and CRP increases the risk of mortality, demonstrating the additive impacts of active inflammation and preclinical CVD on prognosis.

Usefulness of QT-interval parameters for cardiovascular risk stratification in type 2 diabetic patients with arterial hypertension

QT-interval parameters are potential indicators of increased cardiovascular risk. We evaluated prospectively their prognostic value, in relation to other risk markers, for cardiovascular fatal and nonfatal events in a cohort of 271 hypertensive type 2 diabetic outpatients. QT intervals were measured from 12-lead standard ECGs obtained on admission and maximum rate-corrected QT-interval duration and QT-interval dispersion (QTd) calculated. Clinical and laboratory data and 2-D echocardiograms (available in 126 patients) were recorded. Survival analyses included Kaplan-Meier survival curves, uni and multivariate Cox proportional-hazards models. After a median follow-up of 55 months (range 2-84), 68 total fatal or nonfatal cardiovascular events and 34 cardiovascular deaths (24 of them from cardiac causes) were observed. In multivariate Cox analysis, QTd was an independent predictor for total cardiovascular events (HR: 1.16, 95% CI: 1.01-1.34, for each 10 ms increments) and for cardiac deaths (HR: 1.28, 95% CI: 1.01-1.60). Other independent risk indicators for cardiovascular morbidity and mortality were echocardiographic left ventricular hypertrophy (Echo-LVH), serum triglycerides, presence of pre-existing cardiac and peripheral arterial disease, age, diabetes duration, heart rate and the presence of frequent ventricular premature contractions on ECG. The combination of QTd and Echo-LVH improved cardiovascular risk stratification compared with either alone, the presence of both prolonged QTd (>65 ms) and Echo-LVH was associated with a 3.2-fold (95% CI: 1.7-6.1) increased risk of a first cardiovascular event and a 5.9-fold (95% CI: 2.1-16.4) increased risk of cardiovascular death. Thus, QT provided additive prognostic information for cardiovascular morbidity and mortality beyond that obtained from conventional risk markers, including Echo-LVH, in type 2 diabetic patients with arterial hypertension.

Electrocardiographic Strain Pattern and Prediction of Cardiovascular Morbidity and Mortality in Hypertensive Patients

The ECG strain pattern of lateral ST depression and T-wave inversion is a marker for left ventricular hypertrophy (LVH) and adverse prognosis in population studies. However, whether ECG strain is an independent predictor of cardiovascular (CV) morbidity and mortality in the setting of aggressive antihypertensive therapy is unclear. ECGs were examined at study baseline in 8854 hypertensive patients with ECG LVH who were treated in a blinded manner with atenolol- or losartan-based regimens. Strain was defined by the presence of a downsloping convex ST segment with an inverted asymmetrical T wave opposite to the QRS axis in leads V 5 and/or V 6 and was present in 971 patients (11.0%). The Losartan Intervention For Endpoint reduction in hypertension (LIFE) study composite end point of CV death or nonfatal myocardial infarction or stroke occurred in 1035 patients (11.7%). In Cox analyses adjusting only for treatment effect, ECG strain was a significant predictor of CV death (hazard ratio [HR] 2.26, 95% confidence interval [CI] 1.78 to 2.86), fatal/nonfatal myocardial infarction (HR 2.16, 95% CI 1.67 to 2.80), fatal/nonfatal stroke (HR 1.76, 95% CI 1.39 to 2.21), and the composite CV end point (HR 1.99, 95% CI 1.70 to 2.33). After further adjusting for standard CV risk factors, baseline blood pressure, and severity of ECG LVH, ECG strain remained a significant predictor of CV mortality (HR 1.53, 95% CI 1.18 to 2.00), myocardial infarction (HR 1.55, 95% CI 1.16 to 2.06), and the composite CV end point (HR 1.33, 95% CI 1.11 to 1.59). Thus, ECG strain is a marker of increased CV risk in hypertensive patients in the setting of aggressive blood pressure lowering, independent of baseline severity of ECG LVH.