Low ambient temperature might trigger the symptom onset of pulmonary embolism: A nationwide case-crossover study at hourly level in China

Prognostic value of SAPS II score for 28-day mortality in ICU patients with acute pulmonary embolism

BACKGROUND

Acute pulmonary embolism (APE) is a common and life-threatening emergency in intensive care units (ICUs). Effective risk assessment tools are essential to improve patient outcomes. This study aims to evaluate the association between Simplified Acute Physiology Score II (SAPS II) and 28-day mortality in ICU patients with APE.

METHODS

We conducted a retrospective cohort study involving 1031 APE patients from the Multiparameter Intelligent Monitoring in Intensive Care Database IV (MIMIC-IV) databases (Derivation cohort, n = 745) and the Intensive Care Unit (ICU) of the First Affiliated Hospital of Dalian Medical University databases (External Validation cohort, n = 286) between 2008 and 2023. Our study collected 65 variables, including ICU-related clinical data and common scoring systems for response prognosis. First, we used the derived cohort to perform COX regression and random survival forest (RSF) to screen out important variables. Secondly, we evaluated the predictive value of the most important clinical variables. Finally, we further validated the results in an external validation cohort.

RESULTS

A total of 259 people (25.1 %) died from all causes. We performed COX regression in the derived cohort and found that SAPII was associated with prognosis (p < 0.001). We used the RSF machine learning method to sort the importance of variables and found that SAPII score was the most important clinical variable. The restricted cubic splines (RCS) found that SAPII score was nonlinearly correlated with prognosis, and SAPII = 33 was the threshold associated with prognosis. SAPII score was the best compared with the other five scoring systems, and the AUC curve was 0.835 (95 %CI 0.801-0.870). We also found that SAPII score was the best in the validation cohort.

CONCLUSION

SAPS II effectively predict 28-day mortality in ICU patients with APE, outperforming other commonly used scoring systems. It also provides practical thresholds for clinical risk stratification, which can enhance clinical decision-making and resource allocation in the ICU.

Hourly-level association between ambient temperature and onset of acute chest pain: a case-crossover study in Foshan, China

Exposure to low and high ambient daily temperature has been associated with cardiovascular diseases. However, the hourly association, which may enable a more precise healthcare response, has rarely been explored. This study conducted a time-stratified case-crossover analysis of emergency patients with acute chest pain at the Chest Pain Center (CPC) in Foshan, China from 2018 to 2023. We employed a conditional logistic regression model coupled with a distributed lag non-linear model (DLNM) to evaluate the hourly exposure-lag-response associations with adjustment for potential confounding factors. A total of 17,634 emergency patients with acute chest pain were recorded in this study. We found that cold exposure was significantly associated with the risk of cardiac chest pain (CCP) onset within 0-144 h prior to onset. The odds ratios (ORs) of CCP onset were 1.793 (95% CI: 1.345, 2.390) for cold air temperature (14.7 ℃) and 1.772 (95% CI: 1.353, 2.320) for cold apparent temperature (13.9 ℃), respectively. Non-optimal temperatures exposure, particularly heat, was associated with an elevated risk of non-cardiac chest pain (NCCP) onset, with the highest cumulative risk occurring at a lag of 72 h, and the corresponding ORs were 2.368 (95% CI: 1.374, 4.082) for air temperature and 2.107 (95% CI: 1.334, 3.327) for apparent temperature. This study reveals the positive association between hourly temperature and the onset of the acute chest pain. These findings highlight the importance of positive measures, such as enhancing timely temperature alert systems and optimizing medical resource allocation.

The association between short-term apparent temperature exposure and human coagulation: A time-series study from Beijing, 2014-2023

A growing body of evidence suggests that non-optimal ambient temperatures are associated with increased incidence rate and mortality of thromboembolic diseases. We aim to investigate the association between apparent temperature (AT) and coagulation, which is a central pathological link in the formation of thrombi. In this study, we conducted a time series analysis using data from 18,894 participants collected from a health check-up center in Beijing between 2014 and 2023, and validated our findings using 20,549 participants from an andrology outpatient clinic. The daily mean AT was calculated using data on ambient temperature, relative humidity, and wind speed from Beijing. Participants were matched to the lagged moving average of AT (0-7 days) based on their specific health examination dates. The study employed generalized additive models to analyzed the linear and nonlinear associations between AT and coagulation indices. The results indicated that heat resulted in shortened prothrombin time and activated partial thromboplastin time, whereas cold resulted in shortened thrombin time. Fibrinogen showed an increase at both high and low temperatures. Logistic regression analysis revealed that the risk of hypercoagulable state increased in both high and low temperature environments compared to moderate temperatures, with a significant increase observed under extreme heat conditions. Subgroup analyses by sex and age, sensitivity analyses, and the external validation indicated that the association between AT and coagulation was robust. The findings support that both cold and heat can augment blood coagulability through distinct stages of the coagulation cascade, thereby leading to an elevated risk of thromboembolic diseases.

Epidemiology of pulmonary embolism in China, 2021: a nationwide hospital-based study

Background

Pulmonary embolism (PE) as a preventable and potentially fatal noncommunicable disease was believed to have a lower incidence in Asian populations compared to Western populations. However, the incidence and mortality rates of PE in China and the impact of venous thromboembolism (VTE) prevention system constructions on PE still lack nationwide evidence.

Methods

For this nationwide hospital-based observational study, we used data from the National Hospital Quality Monitoring System (HQMS) and public database in China. We estimated the incidence and in-hospital mortality rates of PE by age group, sex, and regions of geographical and socioeconomic level. VTE prevention and management system constructions were quantified by geographical density. We then calculated the incidence and mortality rates in different conditions of VTE prevention and management system construction.

Findings

During the 12 months period between January and December 2021, a total number of 200,112 PE patients and 14,123 deaths were recorded from 5101 hospitals in the HQMS database. The incidence of PE was 14.19 (200,112, 95% CI 14.13-14.26) per 100,000 population and the mortality rate was 1.00 (95% CI 0.99-1.02) per 100,000 population. The incidence of PE was higher in male patients (14.43 per 100,000 population) than in female patients (13.95 per 100,000 population). Disparities of incidence and mortality rates were shown within age groups and geographical regions. The incidence and mortality rates of PE showed decreasing trend with increasing geographical density of VTE-related facilities and VTE prevention system developments.

Interpretation

China had a substantially large number of PE patients. The incidence and mortality rates of PE showed disparities in terms of sex, age, and geography. The incidence and mortality rates of PE decrease across regions with increasing levels of socioeconomic development, potentially influenced by the existing VTE prevention and management systems. Optimizing the health policies and healthcare investment in VTE prevention may help reduce the disease burden of PE.

Funding

CAMS Innovation Fund for Medical Sciences (CIFMS) (2023-I2M-A-014); National High Level Hospital Clinical Research Funding (2022-NHLHCRF-LX-01-0108); National Key Research and Development Program of China (2023YFC2507200); Discipline-Innovation and Talent-Introduction Program for Colleges and Universities (111 Plan, B23038).

Periovulatory PM2.5 constituent exposures and human clinically recognized early pregnancy loss: Susceptible exposure time windows and high-risk constituents

Evidence for effects of PM2.5 chemical constituent exposures during the periovulatory period on pregnancy complications was limited. We explored the associations of maternal PM2.5 and constituent exposures from the 12th week before to 4th week after ovulation with human clinically recognized early pregnancy loss (CREPL). From July 2017 to January 2024, 828 CREPL and 828 normal early pregnancy (NEP) participants were recruited in Tianjin, China. Daily residential exposures to PM2.5 and five main constituents of all participants were estimated using data of the Tracking Air Pollution in China platform. Nonlinear and linear associations between weekly pollutant exposures and CREPL were estimated using conditional logistic regression models combined with distributed lag nonlinear and distributed lag models, respectively. The risk of CREPL increased with per 10 μg/m³ increment in PM2.5 and per 1 μg/m³ increment in sulfate, nitrate, and ammonium exposures during specific weeks from the 5th week before to 2nd week after ovulation, with the largest OR (95% CI) of CREPL associated with PM2.5, sulfate, nitrate, and ammonium being 1.73 (1.07, 2.78), 1.71 (1.18, 2.46), 1.80 (1.12, 2.90), and 1.61 (1.01, 2.56), respectively. CREPL was positively associated with the 10th to 90th percentiles exposure to organic matter during the 2nd and 3rd week after ovulation. In analyses for constituent residuals, the five constituents were all independently related to CREPL, with organic matter being the highest risk constituent, and nitrate and ammonium affecting at the initial stage of preantral follicle development. In conclusion, periovulatory PM2.5 and constituent exposures were associated with increased risk of CREPL. Women planning a pregnancy are advised to take exposure precautions starting from the follicular development period.

Association of short-term exposure to ambient air pollution and temperature with bronchiectasis mortality: a nationwide time-stratified case-crossover study

BACKGROUND

Ambient pollution and non-optimal temperature are major risk factors for respiratory health. However, the relationships between short-term exposure to these factors and bronchiectasis mortality remain unknown.

METHODS

A nationwide, time-stratified case-crossover study across Mainland China was conducted from 2013 to 2019. Records of bronchiectasis deaths were extracted from the National Death Registration Reporting Information System. Daily concentrations of fine particulate matter (PM2.5), coarse particulate matter (PM2.5-10), nitrogen dioxide (NO2), ozone (O3), and daily temperature were obtained from high-resolution prediction models. We utilized conditional logistic regression model and distributed lag nonlinear model to explore the associations of these exposures with bronchiectasis mortality.

FINDINGS

We included a total of 19,320 bronchiectasis deaths. Air pollutant was associated with bronchiectasis mortality within the first 3 days after exposure and the exposure-response relationships were almost linear. An interquartile range increase in PM2.5, PM2.5-10, and O3 was associated with increments of 3.18%, 4.14%, and 4.36% in bronchiectasis mortality at lag 02 d, respectively. Additionally, lower temperature was associated with higher odds of bronchiectasis mortality. Compared to referent temperature (23.6 °C), the odds ratio for bronchiectasis mortality associated with extremely low temperature (P1: -13.4 °C) was 1.54 (95% CI: 1.05, 2.25).

INTERPRETATION

This national study provides compelling evidence, and highlights the necessity and importance of reducing air pollution exposures and keeping warm for susceptible populations.

FUNDING

National Natural Science Foundation of China (81925001; 82330070); Innovation Program of Shanghai Municipal Education Commission (202101070007-E00097); Program of Shanghai Municipal Science and Technology Commission (21DZ2201800); Program of Shanghai Shenkang Development Center (SHDC12023110); and Major Project of National Health Commission of China.

Chronobiological perspectives and meteorological associations in symptomatic popliteal artery aneurysms

The potential influence of circadian rhythm, seasonal variations, and alterations in meteorological parameters has been studied across various vascular events. However, there is a lack of evidence on the potential chronobiological impacts on thromboembolic events related to the most common peripheral aneurysm, the popliteal artery aneurysm (PAA). Data was obtained from a German PAA registry and the German Meteorological Service (Deutscher Wetterdienst). In this observational cohort study seasonality and chronobiology as well as associations with meteorological parameters of symptomatic PAA were investigated. In a multivariate logistic regression analysis, it was further analyzed whether meteorological parameters could distinguish asymptomatic from symptomatic patients in the registry. Of 1200 registered PAA, n = 142 PAA presented with acute limb ischemia between February 2011 and September 2022. More symptomatic patients (57.0%) presented to the hospital between January and June than in the second half of the year with a nadir in the fall season. Symptom onset was predominantly in the morning hours (39.5%). Atmospheric pressure and humidity values from the index dates diverged from a normal distribution showing a bimodal ("double-peak") configuration. Most patients developed symptoms after a reduction in temperatures compared to 1 or 2 d prior to the index date. However, we found evidence for an interaction between age and temperature difference, where the effects of a decreasing temperature fade with increasing age. Facing the complexity of individual-environment interactions, further investigations are needed to determine whether meteorological parameters are true risk modifiers or surrogates for seasonal differences and altered behaviors.

Association between periodic variation of air temperature, humidity, atmospheric pressure and hospital admissions for acute occlusive mesenteric ischaemia

Referring to the intestinal ischemic injury caused by sudden interruption of the blood supply, acute mesenteric ischemia (AMI) is a highly fatal emergency with mortality rates varying from 58 to 80%. The aim of this study was to explore the effect of temperature on AMI admission. This was a retrospective, multicentric study. The medical records of 1477 patients with verified AMI who were consecutively admitted to 3 hospitals anytime between January 2010 and December 2020 were included in the study. Distributed lag non-linear model was applied, the model was adjusted for temperature, atmospheric pressure, relative humidity, year, holiday, day of the week, time and seasonality. AMI exhibited obvious sex preference, AMI patients tended to be male (M/F ratio = 2.3:1) and in their late 50 s. Hospital admissions of acute mesenteric arterial thromboembolism (AMAT) increased significantly with high temperatures on day of exposure and lag 0-14 day. The effect curve of daily average temperature on acute mesenteric venous thromboembolism (AMVT) admission was J-shaped, and the duration of cold effect was longer, while the duration of heat effect was shorter. An increase in hospital admissions of AMVT was found above 20 °C at lag 0-30. For the first time, our study indicated that temperature is significantly associated with the risk of AMI. Although it is not possible to always avoid exposure to extreme temperatures, one should be aware of dramatic temperature fluctuations and take appropriate precautions.

Dust particulate matter increases pulmonary embolism onset: A nationwide time-stratified case-crossover study in China

BACKGROUND

Particulate matter (PM) has been found to elevate the risk of pulmonary embolism (PE) onset. Among the contributors to PM, dust PM stands as the second natural source, and its emissions are escalating due to climate change. Despite this, information on the effect of dust PM on PE onset is scarce. Hence, this study aims to investigate the impacts of dust PM10, dust PM2.5-10, and dust PM2.5 on PE onset.

METHODS

A nationwide time-stratified case-crossover study was conducted between 2015 and 2020, using data from 18,616 PE onset cases across 1,921 hospitals in China. The analysis employed a conditional logistic regression model to quantify the associations between dust PM10, dust PM2.5-10, and dust PM2.5 and PE onset. Furthermore, the study explored the time-distributed lag pattern of the effect of dust PM on PE development. Stratified analyses were performed based on sex, age, region, and season.

RESULTS

Dust PM10, dust PM2.5-10, and dust PM2.5 exhibited significant health effects on PE onset, particularly concerning exposure on the same day. The peak estimates were observed at lag 01 day, with the odds ratio being 1.011 [95 % confidence interval (CI): 1.003, 1.019], 1.014 (95 % CI: 1.003, 1.026), and 1.039 (95 % CI: 1.011, 1.068), for a 10 μg/m3 increase in the concentration of dust PM10, dust PM2.5-10, and dust PM2.5, respectively. In addition, the study identified a higher risk of PE onset associated with dust PM exposure during the warm season than that in cool season, particularly for dust PM2.5.

CONCLUSIONS

The findings from this study suggest that short-term exposure to dust PM, particularly dust PM2.5, may trigger PE onset, posing a significant health threat. Implementing measures to mitigate dust PM emissions and protect patients with PE from dust PM exposure is imperative.

Hourly Air Pollution Exposure and Emergency Hospital Admissions for Stroke: A Multicenter Case-Crossover Study

BACKGROUND

Daily exposure to ambient air pollution is associated with stroke morbidity and mortality; however, the association between hourly exposure to air pollutants and risk of emergency hospital admissions for stroke and its subtypes remains relatively unexplored.

METHODS

We obtained hourly concentrations of fine particulate matter (PM2.5), respirable particulate matter (PM10), nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone (O3), and carbon monoxide (CO) from the China National Environmental Monitoring Center. We conducted a time-stratified case-crossover study among 86 635 emergency hospital admissions for stroke across 10 hospitals in 3 cities (Jinhua, Hangzhou, and Zhoushan) in Zhejiang province, China, between January 1, 2016 and December 31, 2021. Using a conditional logistic regression combined with a distributed lag linear model, we estimated the association between hourly exposure to multiple air pollutants and risk of emergency hospital admissions for total stroke, ischemic stroke, hemorrhagic stroke, and undetermined type.

RESULTS

Hourly exposure to PM2.5, PM10, NO2, and SO2 was associated with an increased risk of hospital admissions for total stroke and ischemic stroke. The associations were most pronounced during the concurrent hour of exposure and lasted for ≈2 hours. We found that the risk was more pronounced among male patients or those aged <65 years old.

CONCLUSIONS

Our findings suggest that exposure to PM2.5, PM10, NO2, and SO2, but not CO and O3, is associated with emergency hospital admissions for total stroke or ischemic stroke shortly after exposure. Implementing targeted pollution emission reduction measures may have significant public health implications in controlling and reducing the burden of stroke.