Six-lead electrocardiography compared to single-lead electrocardiography and photoplethysmography of a wrist-worn device for atrial fibrillation detection controlled by premature atrial or ventricular contractions: six is smarter than one.

Background: Smartwatches are commonly capable to record a lead-I-like electrocardiogram (ECG) and perform a photoplethysmography (PPG)-based atrial fibrillation (AF) detection. Wearable technologies repeatedly face the challenge of frequent premature beats, particularly in target populations for screening of AF. Objective: To investigate the potential diagnostic benefit of six-lead ECG compared to single-lead ECG and PPG-based algorithm for AF detection of the wrist-worn device. Methods and results: From the database of DoubleCheck-AF 249 adults were enrolled in AF group (n = 121) or control group of SR with frequent premature ventricular (PVCs) or atrial (PACs) contractions (n = 128). Cardiac rhythm was monitored using a wrist-worn device capable of recording continuous PPG and simultaneous intermittent six-lead standard-limb-like ECG. To display a single-lead ECG, the six-lead ECGs were trimmed to lead-I-like ECGs. Two diagnosis-blinded cardiologists evaluated reference, six-lead and single-lead ECGs as "AF", "SR", or "Cannot be concluded". AF detection based on six-lead ECG, single-lead ECG, and PPG yielded a sensitivity of 99.2%, 95.7%, and 94.2%, respectively. The higher number of premature beats per minute was associated with false positive outcomes of single-lead ECG (18.80 vs. 5.40 beats/min, P < 0.01), six-lead ECG (64.3 vs. 5.8 beats/min, P = 0.018), and PPG-based detector (13.20 vs. 5.60 beats/min, P = 0.05). Single-lead ECG required 3.4 times fewer extrasystoles than six-lead ECG to result in a false positive outcome. In a control subgroup of PACs, the specificity of six-lead ECG, single-lead ECG, and PPG dropped to 95%, 83.8%, and 90%, respectively. The diagnostic value of single-lead ECG (AUC 0.898) was inferior to six-lead ECG (AUC 0.971) and PPG-based detector (AUC 0.921). In a control subgroup of PVCs, the specificity of six-lead ECG, single-lead ECG, and PPG was 100%, 96.4%, and 96.6%, respectively. The diagnostic value of single-lead ECG (AUC 0.961) was inferior to six-lead ECG (AUC 0.996) and non-inferior to PPG-based detector (AUC 0.954). Conclusions: A six-lead wearable-recorded ECG demonstrated the superior diagnostic value of AF detection compared to a single-lead ECG and PPG-based AF detection. The risk of type I error due to the widespread use of smartwatch-enabled single-lead ECGs in populations with frequent premature beats is significant.

High Specificity Wearable Device With Photoplethysmography and Six-Lead Electrocardiography for Atrial Fibrillation Detection Challenged by Frequent Premature Contractions: DoubleCheck-AF.

Background: Consumer smartwatches have gained attention as mobile health (mHealth) tools able to detect atrial fibrillation (AF) using photoplethysmography (PPG) or a short strip of electrocardiogram (ECG). PPG has limited accuracy due to the movement artifacts, whereas ECG cannot be used continuously, is usually displayed as a single-lead signal and is limited in asymptomatic cases. Objective: DoubleCheck-AF is a validation study of a wrist-worn device dedicated to providing both continuous PPG-based rhythm monitoring and instant 6-lead ECG with no wires. We evaluated its ability to differentiate between AF and sinus rhythm (SR) with particular emphasis on the challenge of frequent premature beats. Methods and Results: We performed a prospective, non-randomized study of 344 participants including 121 patients in AF. To challenge the specificity of the device two control groups were selected: 95 patients in stable SR and 128 patients in SR with frequent premature ventricular or atrial contractions (PVCs/PACs). All ECG tracings were labeled by two independent diagnosis-blinded cardiologists as "AF," "SR" or "Cannot be concluded." In case of disagreement, a third cardiologist was consulted. A simultaneously recorded ECG of Holter monitor served as a reference. It revealed a high burden of ectopy in the corresponding control group: 6.2 PVCs/PACs per minute, bigeminy/trigeminy episodes in 24.2% (31/128) and runs of ≥3 beats in 9.4% (12/128) of patients. AF detection with PPG-based algorithm, ECG of the wearable and combination of both yielded sensitivity and specificity of 94.2 and 96.9%; 99.2 and 99.1%; 94.2 and 99.6%, respectively. All seven false-positive PPG-based cases were from the frequent PVCs/PACs group compared to none from the stable SR group (P < 0.001). In the majority of these cases (6/7) cardiologists were able to correct the diagnosis to SR with the help of the ECG of the device (P = 0.012). Conclusions: This is the first wearable combining PPG-based AF detection algorithm for screening of AF together with an instant 6-lead ECG with no wires for manual rhythm confirmation. The system maintained high specificity despite a remarkable amount of frequent single or multiple premature contractions.

Lower than average HDL cholesterol efflux capacity in Lithuanian population.

BACKGROUND: The aim of our study was to evaluate high-density lipoprotein cholesterol (HDL-C) efflux capacity in healthy controls and patients with severe dyslipidemia. Evaluation of HDL function may be beneficial for better understanding of cardiovascular diseases, as well as for taking actions to minimize residual cardiovascular risk. METHODS: During 2016-2017 a total of 93 participants - 48 (51.6%) women and 45 (48.4%) men - were included in this cross-sectional study. Data of 45 (48.4%) participants with severe dyslipidemia (SD) and 48 (51.6%) controls without dyslipidemia was used for statistical analysis. Total lipid panel, concentration of lipoprotein (a) and apolipoproteins were measured, data about cardiovascular risk factors were collected and detailed evaluation of HDL-C quality was performed for all patients. RESULTS: Increased HDL-C concentration was associated with higher ApoA1 (r = 0.866 in controls, r = 0.63 in SD group), ApoA2 (r = 0.41 in controls, r = 0.418 in SD group) and LDL-C concentrations (r = - 0.412 in SD group), lower ApoE (r = - 0.314 in SD group) and TG concentrations (r = - 0.38 in controls, r = - 0.608 in SD group), lower ApoB/ApoA1 ratio (r = - 0.567 in control group), below average HDL-C efflux capacity (r = - 0.335 in SD group), lower BMI (r = - 0.327 in controls, r = - 0.531 in SD group) and abdominal circumference (r = - 0.309 in women with SD). Below-average HDL-C efflux capacity was found in 67.7% (N = 63) of participants. It was more often found among patients with normal weight or BMI 30-31 kg/m2. HDL-C efflux capacity was inversely associated with HDL-C concentration (r = - 0.228). CONCLUSION: Abnormal HDL function may be associated with residual cardiovascular risk in Lithuanian population.

Is the coronary artery calcium score the first-line tool for investigating patients with severe hypercholesterolemia?

BACKGROUND: Coronary artery calcium (CAC) is known as a reliable tool for estimating risk of myocardial infarction, coronary death, all-cause mortality and is even used to evaluate suitable asymptomatic patients. We therefore aimed to evaluate whether CAC scoring can be applied in the algorithm for clinical examination of patients with severe hypercholesterolemia (SH). METHODS: During the period of 2016-2017 a total of 213 asymptomatic adults, underwent computed tomography angiography to evaluate their CAC scoring. The sample consisted of 110 patients with SH and 103 age and sex matched controls without dyslipidemia and established cardiovascular disease. RESULTS: In total there were 79 (37.2%) subjects with elevated (≥25th) CAC percentiles. Out of them 47 (59.5%) had SH and 32 (40.5%) did not. CAC score did not differ between groups (SH (+) 140.30 ± 185.72 vs SH (-) 87.84 ± 140.65, p = 0.146), however there was a comparable difference in how the participants of these groups distributed among different percentile groups (p = 0.044). Gender, blood pressure, tabaco use, physical activity, family history of coronary artery disease and diabetes mellitus were not associated with CAC score (p > 0.05). There were no significant correlations between biochemical parameters and CAC percentiles except for increase in lipoprotein(a) (p = 0.038). Achilles tendon pathology, visceral obesity, body mass index and increased waist-hip ratio were not associated with CAC percentiles either (p > 0.05). CONCLUSIONS: CAC score is not associated with presence of SH. CAC score is not an appropriate diagnostic tool in the algorithm for clinical examination of patients with SH. Further larger studies are needed to support our findings.

Achilles tendon ultrasonography - A useful screening tool for cardiovascular risk estimation in patients with severe hypercholesterolemia.

BACKGROUND AND AIMS: Achilles tendon lesions have long been associated with genetic defects in lipid metabolism and increased risk of cardiovascular diseases (CVD). With this study we aimed to evaluate the usefulness of Achilles tendon ultrasonography in identifying people at greater risk among subjects with severe hypercholesterolemia (SH) in a high-risk population. METHODS: During the period of 2016-2017 a total of 213 participants were enrolled in this case-control study. Data of 110 patients with SH and 103 age and sex matched controls without dyslipidaeplemia and established CVD was collected. RESULTS: Achilles tendinopathy (AT) was present in 42.7% of subjects with SH and in 29.1% of controls (p = 0.039). Stronger association between SH and AT was seen in women - 24.1% vs 2.0% (p = 0.001). SH increased odds of AT by 1.815 (95% CI, 1.028-3.206). Prevalence of AT was higher in males despite presence (SH+) or absence (SH-) of severe hypercholesterolemia (SH+ 60.7% vs 24.1%, SH- 55.8% vs 2.0%, p < 0.001). AT was associated with higher proportion of subjects exceeding normal mean values of TC (80.5% vs 52.9%, p = 0.001), LDL-C (76.6% vs 52.2%), TG (54.5% vs. 22.1%), ApoB (57.1% vs 22.2%), ApoE (44.0% vs 22.4%) levels and ApoB/ApoA ratio (46.1% vs 21.5%) (p = 0.001) and family history of premature coronary heart disease (CHD). CONCLUSIONS: AT is more prevalent among subjects with SH and is associated with higher levels of TC, TG, LDL-C, ApoB, ApoE, ApoB/ApoA ratio, family history of premature CHD. SH increases the odds of developing AT.

Lipid profile evaluation and severe hypercholesterolaemia screening in the middle-aged population according to nationwide primary prevention programme in Lithuania.

BACKGROUND AND AIMS: Cardiovascular disease (CVD) is a major cause of premature death in Lithuania where abnormal lipid levels are very common among middle-aged adults. The aim of this study was to evaluate lipid profile in middle-aged Lithuanians and perform population-based severe hypercholesterolaemia (SH) screening. METHODS: This study included men aged 40-54 and women aged 50-64 years without overt CVD, participating in the Lithuanian High Cardiovascular Risk (LitHiR) primary prevention programme during the period 2009-2016. Lipidograms of 92,373 adults (58.4% women and 41.6% men) included in the database were analysed and screening for SH was performed. RESULTS: The mean levels of total cholesterol, LDL cholesterol (LDL-C) and triglycerides (TG) among participants were 6.08 mmol/l, 3.87 mmol/l, and 1.59 mmol/l, respectively. Any type of dyslipidaemia was present in 89.7%, and severe dyslipidaemia in 13.4% of the study population. 80.2% of adults without overt CVD had LDL-C ≥3 mmol/l. SH (LDL-C ≥6 mmol/l) was detected in 3.2% of study participants. Prevalence of SH decreased from 2.91% to 2.82% during the period 2009-2016 (p for trend = 0.003). LDL-C ≥6.5 mmol/l was observed in 1.5% of subjects while both LDL-C ≥6.5 mmol/l, and TG ≤ 1.7 mmol/l was found in 0.6% of subjects. CONCLUSIONS: SH was present in 3.2% of the middle-aged population without overt CVD. Slightly decreasing prevalence of SH was observed during the period 2009-2016 in Lithuania. Likely phenotypic familial hypercholesterolaemia was observed in 1.5% of middle-aged Lithuanians. Further clinical and genetic evaluation of people with SH is needed to detect familial forms of SH.

Establishing a national screening programme for familial hypercholesterolaemia in Lithuania.

BACKGROUND AND AIMS: Familial hypercholesterolaemia (FH) is a widely underdiagnosed genetic disorder characterized by severely elevated levels of serum cholesterol and associated with premature mortality. Screening programmes and registries have been established worldwide to find and monitor patients with FH. The aim of this paper was to describe the approaches currently applied to identify patients with possible FH in Lithuania. METHODS: An electronic extraction tool was applied to the medical records of 92,373 subjects evaluated in primary care settings from 2009 to 2016, 1714 secondary prevention patients with early onset (<50 years) coronary heart disease (CHD) treated in tertiary care hospital from 2005 to 2016 and high-risk subjects in specialized cardiovascular prevention units. The electronic databases were screened for likely FH phenotype, which was described simply as LDL-C ≥6.5 mmol/l. RESULTS: Likely FH phenotype was observed in 1385 (1.5%) middle-aged Lithuanians, 290 (16.9%) people with premature CHD and 330 adults from high-risk subjects referred to specialized cardiovascular prevention units. A total of 2005 patients with likely phenotypic FH were included in the Lithuanian FH screening programme, covering about 15% of estimated FH cases in Lithuania. CONCLUSIONS: Screening for extremely elevated LDL-C levels in primary prevention database and additional enrolment of patients with premature CVD as well as high-risk subjects may be a valid way to set up a national FH screening programme. It is crucially important to identify and initiate the treatment of FH patients as early as possible to reduce high cardiovascular mortality in these patients.

Cardiovascular risk assessment of dyslipidemic middle-aged adults without overt cardiovascular disease over the period of 2009-2016 in Lithuania.

BACKGROUND: Cardiovascular mortality in Lithuania is extremely high and abnormal lipid levels are very common among Lithuanian adults. Dyslipidemia is one of the main independent risk factors for cardiovascular diseases (CVD) leading to high absolute CVD risk. The aim of this study was to assess CVD risk in dyslipidemic middle-aged subjects. METHODS: During the period of 2009-2016 a total of 92,373 people (58.4% women and 41.6% men) were evaluated. This study included men aged 40-54 and women aged 50-64 without overt CVD. RESULTS: Any type of dyslipidemia was present in 89.7% of all study population. 7.5% of dyslipidemic patients did not have any other conventional risk factors. Three and more risk factors were detected in 60.1% of dyslipidemic subjects. All analyzed risk factors, except smoking, were more common in dyslipidemic adults compared to subjects without dyslipidemia: arterial hypertension (55.8% vs. 43.3%, p < 0.001), diabetes (11.1% vs. 7.3%, p < 0.001), abdominal obesity (45.3% vs. 30.2%, p < 0.001), BMI ≥30 kg/m2 (35.8% vs. 23.7%, p < 0.001), metabolic syndrome (34.0% vs. 9.2%, p < 0.001), family history of coronary heart disease (26.3% vs. 23.1%, p < 0.001), unbalanced diet (62.5% vs. 52.9%, p < 0.001) and insufficient physical activity (52.0% vs. 44.2%, p < 0.001). The prevalence of all evaluated risk factors, except smoking, increased with age. Average SCORE index was 1.87 in all study population, while dyslipidemic subjects had higher SCORE compared to control group (1.95 vs 1.20, p < 0.001). CONCLUSIONS: Almost two thirds of dyslipidemic middle-aged Lithuanian adults without overt cardiovascular disease had three or more other CVD risk factors, which synergistically increase absolute risk of CVD. The average 10-year risk of CVD death in patients with dyslipidemia was 1.95%. The importance of managing dyslipidemia as well as other risk factors in order to reduce burden of cardiovascular disease in Lithuania is evident.

Cardiovascular risk profile of patients with atherogenic dyslipidemia in middle age Lithuanian population.

BACKGROUND: Atherogenic dyslipidemia (AD) is a blood serum lipid profile abnormality characterized by elevation of triglycerides and reduced levels of high density lipoprotein cholesterol (HDL-C). It is associated with residual cardiovascular risk. This study evaluated and compared the risk profiles of patients with hypertriglyceridemia, low-HDL-C levels or AD, in order to understand, which lipid profile is associated with greater risk. METHODS: During the period of 2009-2016 a population of 92,373 Lithuanian adults (men 40-54 years old and women 50-64 years old) without overt cardiovascular disease were analyzed. Data of 25,746 patients (68.6% women and 31.4% men) with hypertriglyceridemia and/or low HDL-C low levels were collected and used for further statistical analysis. RESULTS: Participants with AD tend to have more unfavorable risk profile than participants with hypertriglyceridemia or low-HDL-C. AD tends to cluster with other atherogenic risk factors, such as arterial hypertension [odds ratio (OR) 1.96, 95% confidence intervals (CI) 1.87-2.01], smoking [OR 1.20, 95% CI 1.14-1.27], diabetes mellitus [OR 2.74, 95% CI 2.58-2.90], obesity [OR 2.92, 95% CI 2.78-3.10], metabolic syndrome [OR 22.27, 95% CI 20.69-23.97], unbalanced diet [OR 1,59, 95% CI 1.51-1.68], low physical activity [OR 1.80, 95% CI 1.71-1,89], CHD history in first degree relatives [OR 1.18, 95% CI 1.12-1.25] and total number of risk factors [OR 1.47, 95% CI 1.38-1.57]. CONCLUSION: AD is associated with more unfavorable cardiovascular risk profile than hypertriglyceridemia or low-HDL cholesterol levels. Once identified AD should require additional medical attention since it is an important factor of residual cardiovascular risk.