Low temperature and temperature decline increase acute aortic dissection risk and burden: A nationwide case crossover analysis at hourly level among 40,270 patients

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.

Small-area association of hourly ambient temperature and acute morbidity

Previous studies have reported the association between daily temperature and morbidity at city level, but small-area association of hourly temperature and acute morbidity is limited. We aimed to assess the association between hourly temperature and acute morbidity at the smallest administrative units (communities), and to explore the sources of regional heterogeneity. This case time series design was conducted using 145,678 non-accidental ambulance dispatch records in 328 communities in Fuzhou, China (2019-2024). Small-area associations between hourly temperatures and ambulance dispatches were assessed by quasi-Poisson regression with distributed lag nonlinear model. Multivariate meta-regressions used to explore modification of natural and social features. Unstandardized and standardized attributable number calculated for disease burden. We observed a U-shaped exposure-response curves of hourly temperature and risk of ambulance dispatches, with significantly adverse cold and heat effects referent at minimum risk temperature of 21 °C. The male and the elderly were more susceptible to non-optimal temperature. The unstandardized attributable numbers of non-accident ambulance dispatches due to cold and heat were 1,389 (95%eCI: 875, 1,748) and 590 (95%eCI: 319, 811), with corresponding standardized attribution number of 36 (95%eCI: 23, 46) and 15 (95%eCI: 8, 21). The standardized attributable number due to cold and heat were greater in the downtown and areas of higher proportions of the elderly and the higher population density, and lower NDVI level. High greenness mitigated heat-related adverse effects and temperature-related disease burden. The finding support the optimization of urbanized environment and public health strategies to reduce temperature-related disease burden under global warming.

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.

Mortality risk and burden of aortic aneurysm and dissection attributable to low temperatures: A nationwide case-crossover analysis in Brazil, a predominantly tropical country

BACKGROUND

Low temperatures are adverse contributors to cardiovascular diseases, but the associations between short-term exposure to cold and the risk of death from aortic dissection and aneurysm remain unclear, particularly in tropical regions.

OBJECTIVE

This study was conducted based on 123,951 records of deaths caused by aortic dissection and aneurysms extracted from the national Mortality Information System in Brazil between 2000 and 2019.

METHODS

Relative risks and 95 % confidence intervals (CI) for the aortic-related deaths associated with low ambient temperatures were estimated using the conditional logistic model combined with the distributed lag nonlinear model. Subgroup analyses were performed by age group, sex, race, education level, and residential region. Furthermore, this study calculated the number and fraction of aortic-related deaths attributed to temperatures below the temperature threshold to quantify the cold-related mortality burden of aortic diseases.

RESULTS

During the study period, aortic-related deaths and mortality rates in Brazil exhibited a steady increase, rising from 4419 (2.66/100,000) in 2000 to 8152 (3.88/100,000) in 2019. Under the identified temperature threshold (26 °C), per 1 °C decrease in daily mean temperature was associated with a 4.77 % (95 % CI: 4.35, 5.19) increase in mortality risk of aortic-related diseases over lag 0-3 days. Females, individuals aged 50 years or older, Asian and Black race, and northern residents were more susceptible to low temperatures. Low temperatures were responsible for 19.10 % (95 % CI: 17.71, 20.45) of aortic-related deaths in Brazil.

CONCLUSION

This study highlights that low temperatures were associated with an increased risk of aortic-related deaths, with a remarkable burden even in this predominantly tropical country.

Short-term effects of air pollution and weather changes on the occurrence of acute aortic dissection in a cold region

Background

Air pollution and severe weather conditions can adversely affect cardiovascular disease emergencies. Nevertheless, it remains unclear whether air pollutants and low ambient temperature can trigger the occurrence of acute aortic dissection (AAD) in cold regions.

Methods

We applied a retrospective analysis to assess the short-term effects of air pollution and ambient temperature on the occurrence of AAD in Harbin, China. A total of 564 AAD patients were enrolled from a major hospital in Harbin between January 1, 2017, and February 5, 2021. Weather condition data and air pollutant concentrations, including fine particulate matter smaller than 10 μm (PM10) and 2.5 μm in diameter (PM2.5), nitrogen dioxide (NO2), sulfur dioxide (SO2), carbon monoxide (CO), and ozone (O3), were collected every day. Conditional logistic regressions and correlation analysis were applied to analyze the relationship of environmental and atmospheric parameters with AAD occurrence at lags of 0 to 7 days. Specifically, we appraised the air quality index, CO, NO2, SO2, O3, PM10, PM2.5, temperature, dew point temperature, atmospheric pressure, and cloud amount.

Results

A total of 1,496 days at risk were assessed, of which 564 patients developed AAD. Specifically, AAD did not occur on 1,043 (69.72%) days, while 1 or more cases occurred on 453 (30.28%) days. Several pollution and weather predictors for AAD were confirmed by multilevel modeling. The air quality index (p = 0.0012), cloud amount (p = 0.0001), and concentrations of PM2.5 (p = 0.0004), PM10 (p = 0.0013), NO2 (p = 0.0007) and O3 (p = 0.0001) predicted AAD as early as 7 days before the incident (lag of 7 days) in the study period. However, only concentrations of the air pollutants NO2 (p = 0.0468) and O3 (p = 0.011) predicted the occurrence of AAD after the COVID-19 outbreak. Similar predictive effects were observed for temperature, dew point temperature, and atmospheric pressure (all p < 0.05) on all days.

Conclusion

The risk of AAD is closely related to air pollution and weather characteristics in Harbin. While causation was not determined, the impact of air pollutants on the risk of AAD was reduced after the COVID-19 outbreak.

Risk assessment and disease burden of extreme precipitation on hospitalizations for acute aortic dissection in a subtropical coastal Chinese city

Background

Extreme precipitation events are becoming more frequent due to climate change. The present study aimed to explore the impacts of extreme precipitation on hospitalizations for acute aortic dissection (AAD) and to identify susceptible populations and quantify the corresponding disease burden.

Methods

The present study used a distributed lag nonlinear model (DLNM) with a quasi-Poisson function to investigate the association between extreme precipitation (≥95th percentile) and the risk of hospitalizations for AAD from 2015 to 2020 in Shantou, Guangdong Province, China.

Results

The significant adverse effects of extreme precipitation (relative to no precipitation) on daily AAD hospitalizations lasted from lag 5 [relative risk (RR): 1.0318, 95% confidence interval (CI): 1.0067-1.0575] to lag 9 (RR: 1.0297, 95% CI: 1.0045-1.0555) and reached its maximum at lag 7 (RR: 1.0382, 95% CI: 1.0105-1.0665). Males and older adult individuals (≥60 years) were more susceptible to extreme precipitation. A total of 3.68% (118 cases) of AAD hospitalizations were due to extreme precipitation.

Conclusion

Extreme precipitation was significantly correlated with AAD hospitalizations. Government departments should actively implement extreme precipitation intervention measures to strengthen the protection of males and the older adult (≥60 years) and effectively reduce AAD hospitalizations.

Hourly air pollution exposure and the onset of symptomatic arrhythmia: an individual-level case-crossover study in 322 Chinese cities

BACKGROUND

Few studies have explored the relationship between air pollution and arrhythmia onset at the hourly level. We aimed to examine the association of exposure to air pollution with the onset of acute symptomatic arrhythmia at an hourly level.

METHODS

We conducted a nationwide, time-stratified, case-crossover study in China between 2015 and 2021. We obtained hourly information on the onset of symptomatic arrhythmia (including atrial fibrillation, atrial flutter, atrial and ventricular premature beats and supraventricular tachycardia) from the Chinese Cardiovascular Association Database - Chest Pain Center (including 2025 certified hospitals in 322 cities). We obtained data on hourly concentrations of 6 air pollutants from the nearest monitors, including fine particles (PM2.5), coarse particles (PM2.5-10), nitrogen dioxide (NO2), sulfur dioxide (SO2), carbon monoxide (CO) and ozone. For each patient, we matched the case period to 3 or 4 control periods during the same hour, day of week, month and year. We used conditional logistic regression models to analyze the data.

RESULTS

We included a total of 190 115 patients with acute onset of symptomatic arrhythmia. Air pollution was associated with increased risk of onset of symptomatic arrhythmia within the first few hours of exposure; this risk attenuated substantially after 24 hours. An interquartile range increase in PM2.5, NO2, SO2 and CO in the first 24 hours after exposure (i.e., lag period 0-24 h) was associated with significantly higher odds of atrial fibrillation (1.7%-3.4%), atrial flutter (8.1%-11.4%) and supraventricular tachycardia (3.4%-8.9%). Exposure to PM2.5-10 was associated with significantly higher odds of atrial flutter (8.7%) and supraventricular tachycardia (5.4%), and exposure to ozone was associated with higher odds of supraventricular tachycardia (3.4%). The exposure-response relationships were approximately linear, without discernible concentration thresholds.

INTERPRETATION

Exposure to air pollution was associated with the onset of symptomatic arrhythmia shortly after exposure. This finding highlights the importance of further reducing air pollution and taking prompt protective measures for susceptible populations during periods of elevated levels of air pollutants.

Hourly Ultrafine Particle Exposure and Acute Myocardial Infarction Onset: An Individual-Level Case-Crossover Study in Shanghai, China, 2015-2020

Associations between ultrafine particles (UFPs) and hourly onset of acute myocardial infarction (AMI) have rarely been investigated. We aimed to evaluate the impacts of UFPs on AMI onset and the lag patterns. A time-stratified case-crossover study was performed among 20,867 AMI patients from 46 hospitals in Shanghai, China, between January 2015 and December 2020. Hourly data of AMI onset and number concentrations of nanoparticles of multiple size ranges below 0.10 μm (0.01-0.10, UFP/PNC_0.01-0.10; 0.01-0.03, PNC_0.01-0.03; 0.03-0.05, PNC_0.03-0.05; and 0.05-0.10 μm, PNC_0.05-0.10) were collected. Conditional logistic regressions were applied. Transient exposures to these nanoparticles were significantly associated with AMI onset, with almost linear exposure-response curves. These associations occurred immediately after exposure, lasted for approximately 6 h, and attenuated to be null thereafter. Each interquartile range increase in concentrations of total UFPs, PNC_0.01-0.03, PNC_0.03-0.05, and PNC_0.05-0.10 during the preceding 0-6 h was associated with increments of 3.29, 2.08, 2.47, and 2.93% in AMI onset risk, respectively. The associations were stronger during warm season and at high temperatures and were robust after adjusting for criteria air pollutants. Our findings provide novel evidence that hourly UFP exposure is associated with immediate increase in AMI onset risk.