Using a non-invasive multi-sensor device to evaluate left atrial pressure: an estimated filling pressure derived from ballistocardiography.

BACKGROUND: Heart failure is a global health problem, and elevated left atrial pressure (LAP) is a precursor to identifying decompensated heart failure. At present, out-of-hospital monitoring of patients with heart failure is mostly based on the patient's symptoms and signs, and the use of non-invasive technology is scarce. In this study, a non-invasive ballistocardiography (BCG) device was used to collect thoracic vibration signals generated by heartbeat. We collected these signals from more than 1,000 adults, including those with different heart diseases, and used a sensor system and a composite index related to LAP recognition named the LAP-index, to analyze them. This study aimed to verify the reliability and accuracy of the LAP-index in identifying elevated LAP within heart failure patients. METHODS: We prospectively included 158 patients with various extent of diastolic function, some of whom had various underlying diseases, and collected BCG and echocardiographic data using a cross-section methodology. The BCG signal was recorded from multiple optical fiber vibration sensors placed on the back of each patient. We adopted the 2016 ASE/EACVI echocardiography guideline as the standard for determining LAP level from echocardiography parameters. To evaluate the diagnostic efficacy of the LAP-index, we drew a receiver operating characteristic (ROC) curve and calculated the area under the ROC curve (AUC). RESULTS: The LAP-index of the 158 patients ranged from 6 to 32. Of them, 39 were diagnosed as high LAP by echocardiography, and 119 cases had normal or slightly elevated LAP. Comparison of the LAP-index results and echocardiographic results revealed the ROC c-statistic of the LAP-index for identifying high LAP was 0.86 (95% CI: 0.79-0.93; P<0.0001). When the LAP-index was at the best cut-off value of 15.5, the positive agreement rate between it and echocardiography LAP was 0.85, the negative agreement rate was 0.80, and the overall agreement rate was 0.81. CONCLUSIONS: The sensor system and the LAP-index, a composite index derived from BCG, have high reliability and accuracy in identifying elevated LAP, which provides a novel possibility for the non-invasive detection of hemodynamic congestion in heart failure patients.

Ballistocardiography to identify high left atrial pressure in patients with heart failure.

BACKGROUND: Due to a high prevalence and morbidity rate, heart failure (HF) constitutes an immense economic burden on the global health care system. An increase in left atrial pressure (LAP) precedes the occurrence of any HF symptoms. In this study, we applied a novel non-invasive method of ballistocardiography (BCG) to extract early diastolic ventricular vibration waves [the BCG-B3 index, which corresponds to the third heart sound (S3) at the end of the rapid filling phase of diastole]. This study evaluated the predictive value of the BCG-B3 index for LAP in HF patients. METHODS: A total of 83 HF patients and 20 patients with underlying diseases were prospectively enrolled, and their cross-sectional BCG and echocardiography (ECHO) data were collected. BCG obtains a signal through a high-precision fiber-optic sensor placed on the patient's back. LAP or pulmonary capillary wedge pressure (PCWP) was estimated by the ratio of mitral inflow peak early diastolic velocity to the early diastolic velocity of the mitral annulus (E/e') or the Nagueh equation (LAP = 1.24 × E/e' + 1.9). To evaluate the diagnostic efficacy of the BCG-B3 index, a receiver operating characteristic (ROC) curve was plotted, and the area under the ROC curve (AUC) was calculated. The best cutoff value for the BCG-B3 index was determined by the maximum Youden index. RESULTS: The correlation coefficient between the BCG-B3 index and E/e' ratio was 0.51 (P<0.01). Under an optimal cutoff value of 55.13, the BCG-B3 index showed a positive consistency value of 0.93, a negative consistency value of 0.53, and an overall consistency value of 0.82 for identification of significantly elevated LAP. CONCLUSIONS: The BCG-B3 index derived by noninvasive BCG using a built-in fiber-optic sensor has important diagnostic value for identifying significantly elevated LAP in HF patients with high accuracy. BCG examination is not limited by place or the doctor's experience. Therefore, BCG can provide timely assessments for HF patients, enabling early diagnosis and treatment.

Ambient air pollution and markers of fetal growth: A retrospective population-based cohort study of 2.57 million term singleton births in China.

BACKGROUNDS: Evidence is scarce on the relation between maternal exposure to ambient air pollution during pregnancy and fetal growth in developing countries. Moreover, the current evidence is inconsistent. We aimed to investigate the association of trimester-specific exposure to air pollution with risk of being born small for gestational age (SGA) and birth weight-markers of fetal growth-among Chinese term births. METHODS: This retrospective population-based cohort study consisted of 2,567,457 singleton term live-births from January 1, 2014 to December 31, 2017 across 123 Chinese districts and counties. Personal exposure to ambient air pollutants including carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), particulate matter with aerodynamic diameter < 2.5 µm (PM2.5), and PM10 was assigned using the inverse distance weighting spatial interpolation algorithm. Generalized estimating equations (GEE) logistic regression models were performed to estimate the associations between trimester-specific exposure to air pollution and risk of SGA or low birth weight (LBW), and GEE linear regression to examine the associations between the exposure and term birth weight, adjusting for maternal demographics, maternal cigarette smoking status during pregnancy, mode of delivery, gravidity, gestational age, year and month of conception, neonate's sex, and meteorological factors. Stratified and sensitivity analyses were also performed. RESULTS: When mother exposed to ambient air pollutants over the entire pregnancy, per IQR increment (0.122 mg/m3) in ambient CO concentrations was associated with higher risk of SGA (odds ratio (OR) = 1.04, 95% confidence interval (CI): 1.02, 1.05) and reduced birth weight among term births (-5.95 g, 95% CI: -8.01, -3.89). This association was also pronounced in the second and third trimesters. Term birth weight was negatively associated with per IQR increase of O3 (-3.52 g, 95% CI: -6.23, -0.81), PM2.5 (-5.93 g, 95% CI: -8.36, -3.49) and PM10 (-7.78 g, 95% CI: -10.41, -5.16) during the entire pregnancy, respectively. No significant association was detected between maternal exposure to air pollutants and term LBW. Effect estimates of heterogeneity suggested that maternal age and infant sex modified the impact of air pollution on birth weight. CONCLUSIONS: The findings suggest that maternal exposure to air pollution during pregnancy is adversely affecting fetal growth. Further studies are warranted to integrate these findings and take clinical or public health interventions in pregnancy.

Adverse birth outcomes in Guangdong province, China, 2014-2017: a spatiotemporal analysis of 2.9 million births.

OBJECTIVES: Adverse birth outcomes pose a great threat to the public health and bring a heavy burden of disease in China. A comprehensive examination of the temporal and spatial trends of preterm birth (PTB), low birth weight (LBW) and small for gestational age (SGA) epidemics can provide some elementary information for subsequent aetiological and epidemiological studies. This study aimed to characterise the spatiotemporal features of PTB, LBW and SGA based on a large cohort of live births in China. DESIGN: Spatiotemporal descriptive analysis was performed in Guangdong province, China, from 2014 to 2017. SETTING: Data involving 2 917 098 live births in Guangdong province, China from 2014 to 2017 was collected from Guangdong Birth Certificate System. Information was collected, including the date of birth, gestational age in week, birth weight, sex of the infant, age of the mother and registered residence of the mother. RESULTS: The estimated rate of PTB, LBW and SGA was 4.16%, 4.14% and 12.86%, respectively. For temporal trends, the rates of PTB, LBW and SGA showed seasonal fluctuations, especially for LBW and SGA. In addition, there were regional differences in the rates of PTB, LBW and SGA between the Pearl River Delta and Non-Pearl River Delta regions. From 2014 to 2017, the high rates of PTB and LBW expanded from the Pearl River Delta region to the Non-Pearl River Delta regions. However, compared with the Pearl River Delta region, the rate of SGA was higher in the Non-Pearl River Delta regions on the whole. CONCLUSION: The findings of this study contribute to the understanding of the aetiology and epidemiology of PTB, LBW and SGA in south China.