Validity of electrocardiographic classification of left ventricular hypertrophy across adult ethnic groups with echocardiography as a standard

Diagnostic Accuracy of the Electrocardiography Criteria for Left Ventricular Hypertrophy (Cornell Voltage Criteria, Sokolow-Lyon Index, Romhilt-Estes, and Peguero-Lo Presti Criteria) Compared to Transthoracic Echocardiography

Objective/Aim: We aimed to evaluate the diagnostic utility of the widely used left ventricular hypertrophy (LVH) electrocardiography (ECG) criteria (Cornell Voltage Criteria [CVC], Sokolow-Lyon Index [SLI], Romhilt-Estes [REC], and Peguero-Lo Presti [PLP] Criteria) compared with the left ventricular mass measured by echocardiography.

Methods: In this prospective diagnostic accuracy study, we screened all consecutive adults (18 to 65 years) who presented to our academic emergency department (ED) with increased blood pressure (≥130/85 mmHg) between January 2016 and January 2017, and we enrolled a convenience sample of 165 patients in our study. The attending emergency physician managed all patients as per their primary complaint. The consulting cardiologist performed a transthoracic echocardiogram (TTE) of the patient and calculated the left ventricular mass (LVM) according to the American Society of Echocardiography (ASE) formula. After completing the patient recruitment phase, researchers evaluated all ECGs and calculated scores for SLI, CVC, REC, and PLP. We used contingency tables to calculate the diagnostic utility metrics of all ECG criteria.

Results: The prevalence of LVH by TTE was 31.5%. CVC, SLI, REC, and PLP criteria correctly identified (true positive rate) abnormal LVM in only 3.9%, 1.9%, 9.6%, and 19.2% of the patients, respectively. CVC, SLI, REC score and PLP criteria performed poorly with extremely low sensitivities (3.9%, 1.9%, 10%, 19.2%) and poor accuracies (67.3%, 64.9%, 57.7%, 69.7%).

Conclusion: ECG voltage criteria's clinical utility in estimating LVM and LVH is low, and it should not be used for this purpose.

Arterial hypertension in adults. Clinical guidelines 2020

Arterial hypertension in adults. Clinical guidelines 2020

Cohort Study of ECG Left Ventricular Hypertrophy Trajectories: Ethnic Disparities, Associations With Cardiovascular Outcomes, and Clinical Utility

Background

ECG left ventricular hypertrophy (LVH) is a well‐known predictor of cardiovascular disease. However, no prior study has characterized patterns of presence/absence of ECG LVH (“ECG LVH trajectories”) across the adult lifespan in both sexes and across ethnicities. We examined: (1) correlates of ECG LVH trajectories; (2) the association of ECG LVH trajectories with incident coronary heart disease, transient ischemic attack, ischemic stroke, hemorrhagic stroke, and heart failure; and (3) reclassification of cardiovascular disease risk using ECG LVH trajectories.

Methods and Results

We performed a cohort study among 75 412 men and 107 954 women in the Northern California Kaiser Permanente Medical Care Program who had available longitudinal exposures of ECG LVH and covariates, followed for a median of 4.8 (range <1–9.3) years. ECG LVH was measured by Cornell voltage‐duration product. Adverse trajectories of ECG LVH (persistent, new development, or variable pattern) were more common among blacks and Native American men and were independently related to incident cardiovascular disease with hazard ratios ranging from 1.2 for ECG LVH variable pattern and transient ischemic attack in women to 2.8 for persistent ECG LVH and heart failure in men. ECG LVH trajectories reclassified 4% and 7% of men and women with intermediate coronary heart disease risk, respectively.

Conclusions

ECG LVH trajectories were significant indicators of coronary heart disease, stroke, and heart failure risk, independently of level and change in cardiovascular disease risk factors, and may have clinical utility.

Novel Approach to the Detection of Left Ventricular Hypertrophy Using Body Mass Index-Corrected Electrocardiographic Voltage Criteria in a Group of African Ancestry

BACKGROUND

Electrocardiographic (ECG) QRS voltages used to generate criteria for left ventricular hypertrophy (LVH) detection are considerably attenuated by obesity. This effect renders the utility of ECG criteria to detect LVH in obese individuals of African ancestry to be of limited value.

HYPOTHESIS

A novel approach to correcting QRS voltages for the attenuating effect of body mass index (BMI) will improve the ability of ECG criteria to detect LVH in a group of African descent.

METHODS

Left ventricular mass was determined from echocardiography in 661 randomly selected participants (43.0% obese) of black African ancestry in South Africa.

RESULTS

As compared with Cornell and Sokolow-Lyon voltage criteria, BMI best correlated with RaVL , Gubner-Ungerleider, and Lewis QRS complex voltages, but these relations were noted only in those with BMI <29 kg/m(2) . Correcting RaVL and Lewis voltages by the difference in the slope of BMI-voltage relations in those with BMI <29 kg/m(2) vs those with BMI ≥29 kg/m(2) showed the greatest performance for LVH detection (uncorrected RaVL : 0.695 ± 0.025, corrected RaVL : 0.733 ± 0.022; P < 0.0001), and also increased the sensitivity (uncorrected RaVL : 30.6%, corrected RaVL : 42.4%; P < 0.0005) with no significant change in specificity (uncorrected RaVL : 86.3%, corrected RaVL : 83.0%; P = 0.28).

CONCLUSIONS

We offer a novel approach to correcting ECG voltages for the attenuating effects of obesity in individuals of African ancestry, and this improves the performance and sensitivity for LVH detection.

Are classic predictors of voltage valid in cardiac amyloidosis? A contemporary analysis of electrocardiographic findings

BACKGROUND

Low voltage electrocardiography (ECG) coupled with increased ventricular wall thickness is the hallmark of cardiac amyloidosis. However, patient characteristics influencing voltage in the general population, including bundle branch block, have not been evaluated in amyloid heart disease.

METHODS

A retrospective analysis was performed of patients with newly diagnosed cardiac amyloidosis from 2002 to 2014. ECG voltage was calculated using limb (sum of QRS complex in leads I, II and III) and precordial (Sokolow: S in V1 plus R in V5-V6) criteria. The associations between voltage and clinical variables were tested using multivariable linear regression. A Cox model assessed the association of voltage with mortality.

RESULTS

In 389 subjects (transthyretin ATTR 186, light chain AL 203), 30% had conduction delay (QRS >120ms). In those with narrow QRS, 68% met low limb, 72% low Sokolow and 57% both criteria, with lower voltages found in AL vs ATTR. LV mass index as well as other typical factors that impact voltage (age, sex, race, hypertension, BSA, and smoking) in the general population were not associated with voltage in this cardiac amyloidosis cohort. Patients with LBBB and IVCD had similar voltages when compared to those with narrow QRS. Voltage was significantly associated with mortality (p<0.001 for both criteria) after multivariable adjustment.

CONCLUSION

Classic predictors of ECG voltage in the general population are not valid in cardiac amyloidosis. In this cohort, the prevalence estimates of ventricular conduction delay and low voltage are higher than previously reported. Voltage predicts mortality after multivariable adjustment.

Hyperuricemia is associated with an increased prevalence of atrial fibrillation in hospitalized patients with type 2 diabetes

PURPOSE

Hyperuricemia/gout and atrial fibrillation (AF) are two pathological conditions that are highly prevalent in type 2 diabetes and share multiple cardiovascular risk factors. However, the relationship between elevated levels of serum uric acid and risk of AF in type 2 diabetes is currently poorly known.

METHODS

We studied a hospital-based sample of 842 (male/female = 463/379) patients with type 2 diabetes discharged from our Division of Endocrinology during 2007-2011. Hyperuricemia was defined as a serum uric acid level >7 mg/dl for men and >6 mg/dl for women or allopurinol use. The diagnosis of AF was confirmed in affected participants on the basis of ECGs and medical history by experienced cardiologists.

RESULTS

Overall, 243 (28.9 %) patients had hyperuricemia and 91 (10.8 %) patients had persistent or permanent AF. Compared with those with normal serum uric acid levels, patients with hyperuricemia had a remarkably greater prevalence of AF (20.6 vs. 7.1 %; p < 0.001). Hyperuricemia was significantly associated with an increased risk of prevalent AF (odds ratio 3.41, 95 % CI 2.19-5.32; p < 0.001). Adjustments for age, sex, smoking, hemoglobin A1c, hypertension status, chronic kidney disease, chronic obstructive pulmonary disease and previous histories of hyperthyroidism, ischemic heart disease and valvular heart diseases did not weaken this association (adjusted-odds ratio 6.27, 95 % CI 1.82-21.5; p < 0.01).

CONCLUSIONS

These results indicate that hyperuricemia is associated with an increased prevalence of AF in hospitalized patients with type 2 diabetes, independently of multiple risk factors and potential confounders.

Association of nonalcoholic fatty liver disease with QTc interval in patients with type 2 diabetes

BACKGROUND AND AIMS

The relationship between nonalcoholic fatty liver disease (NAFLD) and prolonged heart rate-corrected QT (QTc) interval, a risk factor for ventricular arrhythmias and sudden cardiac death, is currently unknown. We therefore examined the relationship between NAFLD and QTc interval in patients with type 2 diabetes.

METHODS AND RESULTS

We studied a random sample of 400 outpatients with type 2 diabetes. Computerized electrocardiograms were performed for analysis and quantification of QTc interval. NAFLD was diagnosed by ultrasonographic detection of hepatic steatosis in the absence of other liver diseases. Mean QTc interval and the proportion of those with increased QTc interval (defined as either QTc interval above the median, i.e. ≥416 ms, or QTc interval >440 ms) increased steadily with the presence and ultrasonographic severity of NAFLD. NAFLD was associated with increased QTc interval (odds ratio [OR] 2.16, 95% CI 1.4-3.4, p < 0.001). Adjustments for age, sex, smoking, alcohol consumption, BMI, hypertension, electrocardiographic left ventricular hypertrophy, diabetes-related variables and comorbid conditions did not attenuate the association between NAFLD and increased QTc interval (adjusted-OR 2.26, 95% CI 1.4-3.7, p < 0.001). Of note, the exclusion of those with established coronary heart disease or peripheral artery disease from analysis did not appreciably weaken this association.

CONCLUSION

This is the first study to demonstrate that the presence and severity of NAFLD on ultrasound is strongly associated with increased QTc interval in patients with type 2 diabetes even after adjusting for multiple established risk factors and potential confounders.

Relation of elevated serum uric acid levels to incidence of atrial fibrillation in patients with type 2 diabetes mellitus

The association between serum uric acid (SUA) levels and atrial fibrillation (AF) is currently poorly known. We examined the association between SUA levels and risk of incident AF in patients with type 2 diabetes mellitus. We followed for 10 years a random sample of 400 type 2 diabetic outpatients, who were free from AF at baseline. A standard 12-lead electrocardiography was undertaken annually and a diagnosis of incident AF was confirmed in affected participants by a single cardiologist. Over 10 years, there were 42 incident AF cases (cumulative incidence of 10.5%). Elevated SUA level was associated with an increased risk of incident AF (odds ratio 2.43, 95% confidence interval 1.8 to 3.4, p <0.0001 for each 1-SD increase in SUA level). Adjustments for age, gender, body mass index, hypertension, chronic kidney disease, electrocardiographic features (left ventricular hypertrophy and PR interval), and use of diuretics and allopurinol did not attenuate the association between SUA and incident AF (adjusted odds ratio 2.44, 95% confidence interval 1.6 to 3.9, p <0.0001). Further adjustment for variables that were included in the 10-year Framingham Heart Study-derived AF risk score did not appreciably weaken this association. Results remained unchanged even when SUA was modeled as a categorical variable (stratifying by either SUA median or hyperuricemia), and when patients with previous coronary heart disease or heart failure were excluded from analysis. In conclusion, our findings suggest that elevated SUA levels are strongly associated with an increased incidence of AF in patients with type 2 diabetes mellitus even after adjustment for multiple clinical risk factors for AF.

Non-alcoholic fatty liver disease is associated with an increased prevalence of atrial fibrillation in hospitalized patients with type 2 diabetes

NAFLD (non-alcoholic fatty liver disease) and AF (atrial fibrillation) are two pathological conditions that are highly prevalent in developed countries and share multiple risk factors. The relationship between NAFLD and AF in Type 2 diabetes is currently unknown. We studied a hospital-based sample of 702 patients with Type 2 diabetes discharged from our Division of Endocrinology during 2007-2011. The diagnosis of AF was confirmed in affected participants on the basis of ECGs and medical history by experienced cardiologists. NAFLD was defined by ultrasonographic detection of hepatic steatosis in the absence of other liver diseases. Of the 702 hospitalized patients included in the study, 514 (73.2%) of them had NAFLD and 85 (12.1%) had persistent or permanent AF. NAFLD was associated with an increased risk of prevalent AF {OR (odds ratio), 3.04 [95% CI (confidence interval), 1.54-6.02]; P<0.001}. Adjustments for age, sex, systolic BP (blood pressure), HbA1c, (glycated haemoglobin), estimated GFR (glomerular filtration rate), total cholesterol, electrocardiographic LVH (left ventricular hypertrophy), COPD (chronic obstructive pulmonary disease), and prior history of HF (heart failure), VHD (valvular heart disease) or hyperthyroidism did not attenuate the association between NAFLD and AF [adjusted OR, 5.88 (95% CI, 2.72-12.7); P<0.001]. In conclusion, our results show that ultrasound-diagnosed NAFLD is strongly associated with an increased prevalence of persistent or permanent AF in patients with Type 2 diabetes, independently of several clinical risk factors for AF. The potential impact of NAFLD on AF deserves particular attention, especially with respect to the implications for screening and surveillance strategies in the growing number of patients with NAFLD.

Non-alcoholic fatty liver disease is associated with an increased incidence of atrial fibrillation in patients with type 2 diabetes

Background

The relationship between non-alcoholic fatty liver disease (NAFLD) and atrial fibrillation (AF) in type 2 diabetes is currently unknown. We examined the relationship between NAFLD and risk of incident AF in people with type 2 diabetes.

Methods and Results

We prospectively followed for 10 years a random sample of 400 patients with type 2 diabetes, who were free from AF at baseline. A standard 12-lead electrocardiogram was undertaken annually and a diagnosis of incident AF was confirmed in affected participants by a single cardiologist. At baseline, NAFLD was defined by ultrasonographic detection of hepatic steatosis in the absence of other liver diseases. During the 10 years of follow-up, there were 42 (10.5%) incident AF cases. NAFLD was associated with an increased risk of incident AF (odds ratio [OR] 4.49, 95% CI 1.6–12.9, p<0.005). Adjustments for age, sex, hypertension and electrocardiographic features (left ventricular hypertrophy and PR interval) did not attenuate the association between NAFLD and incident AF (adjusted-OR 6.38, 95% CI 1.7–24.2, p = 0.005). Further adjustment for variables that were included in the 10-year Framingham Heart Study-derived AF risk score did not appreciably weaken this association. Other independent predictors of AF were older age, longer PR interval and left ventricular hypertrophy.

Conclusions

Our results indicate that ultrasound-diagnosed NAFLD is strongly associated with an increased incidence of AF in patients with type 2 diabetes even after adjustment for important clinical risk factors for AF.

Increased pulse pressure independently predicts incident atrial fibrillation in patients with type 2 diabetes

OBJECTIVE

To examine whether baseline pulse pressure (PP), a marker of arterial stiffness, is associated with subsequent development of atrial fibrillation (AF) in type 2 diabetes.

RESEARCH DESIGN AND METHODS

A total of 350 type 2 diabetic patients, who were free from AF at baseline, were followed for 10 years. A standard electrocardiogram was performed annually and a diagnosis of incident AF was confirmed in affected participants by a single cardiologist.

RESULTS

During the follow-up, 32 patients (9.1% of total) developed incident AF. After adjustments for age, sex, BMI, diabetes duration, presence of left ventricular hypertrophy, hypertension treatment, kidney dysfunction, and pre-existing history of coronary heart disease, heart failure, and mild valvular disease, baseline PP was associated with an increased incidence of AF (adjusted odds ratio 1.76 for each SD increment [95% CI 1.1-2.8]; P < 0.01).

CONCLUSIONS

Our findings suggest that increased PP independently predicts incident AF in patients with type 2 diabetes.

Seven mistakes and potential solutions in epidemiology, including a call for a World Council of Epidemiology and Causality

All sciences make mistakes, and epidemiology is no exception. I have chosen 7 illustrative mistakes and derived 7 solutions to avoid them. The mistakes (Roman numerals denoting solutions) are:

1. Failing to provide the context and definitions of study populations. (I Describe the study population in detail)

2. Insufficient attention to evaluation of error. (II Don't pretend error does not exist.)

3. Not demonstrating comparisons are like-for-like. (III Start with detailed comparisons of groups.)

4. Either overstatement or understatement of the case for causality. (IV Never say this design cannot contribute to causality or imply causality is ensured by your design.)

5. Not providing both absolute and relative summary measures. (V Give numbers, rates and comparative measures, and adjust summary measures such as odds ratios appropriately.)

6. In intervention studies not demonstrating general health benefits. (VI Ensure general benefits (mortality/morbidity) before recommending application of cause-specific findings.)

7. Failure to utilise study data to benefit populations. (VII Establish a World Council on Epidemiology to help infer causality from associations and apply the work internationally.)

Analysis of these and other common mistakes is needed to benefit from the increasing discovery of associations that will be multiplying as data mining, linkage, and large-scale scale epidemiology become commonplace.