Electrocardiogram machine learning for detection of cardiovascular disease in African Americans: the Jackson Heart Study.

AIMS: Almost half of African American (AA) men and women have cardiovascular disease (CVD). Detection of prevalent CVD in community settings would facilitate secondary prevention of CVD. We sought to develop a tool for automated CVD detection. METHODS AND RESULTS: Participants from the Jackson Heart Study (JHS) with analysable electrocardiograms (ECGs) (n=3679; age, 6212 years; 36% men) were included. Vectorcardiographic (VCG) metrics QRS, T, and spatial ventricular gradient vectors magnitude and direction, and traditional ECG metrics were measured on 12-lead ECG. Random forests, convolutional neural network (CNN), lasso, adaptive lasso, plugin lasso, elastic net, ridge, and logistic regression models were developed in 80% and validated in 20% samples. We compared models with demographic, clinical, and VCG input (43 predictors) and those after the addition of ECG metrics (695 predictors). Prevalent CVD was diagnosed in 411 out of 3679 participants (11.2%). Machine learning models detected CVD with the area under the receiver operator curve (ROC AUC) 0.690.74. There was no difference in CVD detection accuracy between models with VCG and VCG + ECG input. Models with VCG input were better calibrated than models with ECG input. Plugin-based lasso model consisting of only two predictors (age and peak QRS-T angle) detected CVD with AUC 0.687 [95% confidence interval (CI) 0.6250.749], which was similar (P=0.394) to the CNN (0.660; 95% CI 0.5970.722) and better (P<0.0001) than random forests (0.512; 95% CI 0.4930.530). CONCLUSIONS: Simple model (age and QRS-T angle) can be used for prevalent CVD detection in limited-resources community settings, which opens an avenue for secondary prevention of CVD in underserved communities.

Sex differences in vectorcardiogram of African-Americans with and without cardiovascular disease: a cross-sectional study in the Jackson Heart Study cohort.

OBJECTIVES: We hypothesised that (1) the prevalent cardiovascular disease (CVD) is associated with global electrical heterogeneity (GEH) after adjustment for demographic, anthropometric, socioeconomic and traditional cardiovascular risk factors, (2) there are sex differences in GEH and (3) sex modifies an association of prevalent CVD with GEH. DESIGN: Cross-sectional, cohort study. SETTING: Prospective African-American The Jackson Heart Study (JHS) with a nested family cohort in 2000-2004 enrolled residents of the Jackson, Mississippi metropolitan area. PARTICIPANTS: Participants from the JHS with analysable ECGs recorded in 2009-2013 (n=3679; 62±12 y; 36% men; 863 family units). QRS, T and spatial ventricular gradient (SVG) vectors' magnitude and direction, spatial QRS-T angle and sum absolute QRST integral (SAI QRST) were measured. OUTCOME: Prevalent CVD was defined as the history of (1) coronary heart disease defined as diagnosed/silent myocardial infarction, or (2) revascularisation procedure defined as prior coronary/peripheral arterial revascularisation, or (3) carotid angioplasty/carotid endarterectomy, or (4) stroke. RESULTS: In adjusted mixed linear models, women had a smaller spatial QRS-T angle (-12.2 (95% CI -19.4 to -5.1)°; p=0.001) and SAI QRST (-29.8 (-39.3 to -20.3) mV*ms; p<0.0001) than men, but larger SVG azimuth (+16.2(10.5-21.9)°; p<0.0001), with a significant random effect between families (+20.8 (8.2-33.5)°; p=0.001). SAI QRST was larger in women with CVD as compared with CVD-free women or men (+15.1 (3.8-26.4) mV*ms; p=0.009). Men with CVD had a smaller T area (by 5.1 (95% CI 1.2 to 9.0) mV*ms) and T peak magnitude (by 44 (95%CI 16 to 71) µV) than CVD-free men. T vectors pointed more posteriorly in women as compared with men (peak T azimuth + 17.2(8.9-25.6)°; p<0.0001), with larger sex differences in T azimuth in some families by +26.3(7.4-45.3)°; p=0.006. CONCLUSIONS: There are sex differences in the electrical signature of CVD in African-American men and women. There is a significant effect of unmeasured genetic and environmental factors on cardiac repolarisation.

Kidney Function and Aortic Stiffness, Pulsatility, and Endothelial Function in African Americans: The Jackson Heart Study.

RATIONALE & OBJECTIVE: The relation of vascular stiffness, endothelial function, and kidney function is incompletely elucidated in African Americans. Our hypothesis was that increased vascular stiffness and endothelial dysfunction are associated with low estimated glomerular filtration rate (eGFR) and albuminuria in African Americans. STUDY DESIGN: Cross-sectional cohort analysis of data from the Jackson Heart Study. SETTINGS & PATIENTS: 2,244 Jackson Heart Study participants (2012-2017 after Exam 3) who had undergone noninvasive hemodynamic assessment using arterial tonometry. PREDICTORS: Baseline carotid-femoral pulse wave velocity, pulsatile hemodynamics forward wave amplitude, and hyperemic brachial artery flow were measured. Reduced eGFR was defined as eGFR between 15 and 60 mL/min/1.73 m2. OUTCOMES: Prevalent albuminuria, urinary albumin-creatinine ratio. ANALYTICAL APPROACH: 2-sample t test for continuous variables and χ2 test for categorical variables in addition to logistic and linear regression models to assess the risk for chronic kidney disease with each proposed hemodynamic variable. RESULTS: Among 2,244 participants, mean age was 66 ± 11 years and 64% were women. Reduced eGFR was present in 233 (10.4%), and elevated urinary albumin-creatinine ratio, in 232 (10.4%). In multivariable-adjusted analyses, higher carotid-femoral pulse wave velocity was associated with the presence of reduced eGFR (OR, 1.37 [95% CI, 1.08-1.75] per SD; P = 0.01) and with prevalent albuminuria (OR, 1.66 [95% CI, 1.32-2.11]; P < 0.001). Higher forward wave amplitude was significantly associated with prevalent albuminuria (OR, 1.37 [95% CI, 1.14-1.65]; P = 0.001). LIMITATIONS: Cross-sectional analyses cannot inform causality. CONCLUSIONS: Higher arterial stiffness and pulsatility are associated with higher odds of reduced eGFR in African Americans. Future studies should focus on whether improving arterial stiffness contributes to kidney protection in African Americans.

Left Ventricular False Tendons are Associated With Left Ventricular Dilation and Impaired Systolic and Diastolic Function.

BACKGROUND: Left ventricular false tendons (LVFTs) are chord-like structures that traverse the LV cavity and are generally considered to be benign. However, they have been associated with arrhythmias, LV hypertrophy and LV dilation in some small studies. We hypothesize that LVFTs are associated with LV structural and functional changes assessed by echocardiography. METHODS: We retrospectively evaluated echocardiographic and clinical parameters of 126 patients identified as having LVFTs within the past 2 years and compared them to 85 age-matched controls without LVFTs. RESULTS: There were no significant differences in age (52 ± 18 versus 54 ± 18 years, P = 0.37), sex (55% versus 59% men, P = 0.49), race (36% versus 23% white, P = 0.07), systolic blood pressure (131 ± 22 versus 132 ± 23mmHg, P = 0.76) or body mass index (BMI, 31 ± 8 versus 29 ± 10kg/m2, P = 0.07) between controls and patients with LVFTs, respectively. Patients with LVFTs had more prevalent heart failure (43% versus 21%, P = 0.001). Patients with LVFTs had more LV dilation, were 2.5 times more likely to have moderate-to-severe mitral regurgitation, had more severe diastolic dysfunction and reduced LV systolic function (18% lower) compared with controls (all P < 0.05). After adjustment for covariates, basal and middle LVFT locations were associated with reduced LV systolic function (P < 0.01), and middle LVFTs were associated with LV dilation (P < 0.01). CONCLUSIONS: Our findings suggest that LVFTs may not be benign variants, and basal and middle LVFTs may have more deleterious effects. Further prospective studies should be performed to determine their pathophysiological significance and whether they play a causal role in LV dysfunction.