Association between Weather-Related Factors and Cardiac Arrest of Presumed Cardiac Etiology: A Prospective Observational Study Based on Out-of-Hospital Care Data

Air temperature and humidity impact out-of-hospital-cardiac-arrests in Germany: A 10-year cohort study from the German Resuscitation Registry

Objectives

This study examines the impact of temperature variations on out-of-hospital-cardiac-arrests in Germany over a decade (2010-2019). Out-of-hospital-cardiac-arrests affects 164 per 100,000 inhabitants annually in Germany, 11% survive to hospital discharge. The following study investigates days with the following characteristics: summer days, frost days, and high humidity days. Furthermore, the study explores incidence, causes, demographics, and outcomes of out-of-hospital-cardiac-arrests.

Methods

Data from the German Resuscitation Registry and Meteorological Service were combined for analysis. The theory posits that temperature and humidity play a significant role in the occurrence and outcomes of out-of-hospital-cardiac-arrests, potentially triggering pre-existing health issues.

Results

Findings reveal increased out-of-hospital-cardiac-arrests during frost days (6.39 up to 7.00, p < 0.001) monthly per 100,000 inhabitants), notably due to cardiac-related causes. Conversely, out-of-hospital-cardiac-arrests incidence decreases on summer days (6.61-5.79, p < 0.001 monthly per 100,000 inhabitants). High-humidity days exhibit a statistically significant increase in out-of-hospital-cardiac-arrests incidence (6.43-6.89, p < 0.001 monthly per 100,000 inhabitants).

Conclusion

In conclusion, there's a notable rise in out-of-hospital-cardiac-arrests incidence and worse outcomes during cold days, and a significant increase in out-of-hospital-cardiac-arrests during high-humidity days. Moreover, extreme temperature events in unaccustomed regions also elevate out-of-hospital-cardiac-arrests rates. However, the dataset lacks sufficient hot days for conclusive findings, hinting that very hot days might also affect out-of-hospital-cardiac-arrests incidence. Further research, particularly on hotter days, is essential.No third-party funding was received for this study.

Short-term exposures to temperature and risk of sudden cardiac death in women: A case-crossover analysis in the Nurses' Health Study

Background

Sudden cardiac death (SCD) is a major source of mortality and is the first manifestation of heart disease for most cases. Thus, there is a definite need to identify risk factors for SCD that can be modified on the population level. Short-term exposures to temperature have been implicated as a potential risk factor. Our objective was to determine if short-term temperature exposures were associated with increased risk of SCD in a US-based time-stratified case-crossover study.

Methods

A total of 465 cases of SCD were identified among participants of the prospective Nurses' Health Study (NHS). Control days were selected from all other matching days of the week within the same month as the case day. Average ambient temperature on the current day (Lag0) and preceding 27 days (Lags1-27) was determined at the residence level using 800-m resolution estimates. Conditional logistic distributed lag nonlinear models (DLNMs) were used to assess the relative risk (RR) of the full range of temperature exposures over the lag period.

Results

Warmer exposures in the days before event and colder temperatures 21-28 days prior were associated with increased risks of SCD. These results were driven by associations in regions other than the Northeast and among married women.

Conclusions

Both warm and cold ambient temperatures are suggestively associated with risks of SCD among middle-aged and older women living across the United States.

Effect of Temperature on Emergency Ambulance Call-Outs for Cardiovascular Causes: A Scoping Review

Climate change has increased interest in the effects of the thermal environment on cardiovascular health. Most studies have focused on mortality data. However, pre-hospital care data are better able to evaluate these effects, as they can register the full spectrum of the disease in real time. This scoping review aims to synthesize the epidemiological evidence regarding the effects of the thermal environment on cardiovascular morbidity in the pre-hospital setting, evaluated through ambulance calls. A staged literature search was performed using the PubMed database for the period between 1st January 2000 and 30th March 2023, using the MeSH terms "Weather" AND "Emergency Medical Services". A total of 987 publications were identified that examined the correlation between the thermal environment and ambulance call-outs for cardiovascular causes. The studies were mostly ecological time series, with significant variability in the methodological aspects employed. An increase in the number of ambulance call-outs has been observed in association with low temperatures, both for overall cardiovascular pathologies and for certain pathological subtypes. For high temperatures, no effect has been observed in overall call-outs, although an increase has been observed during heat waves. The demand for ambulances for cardiac arrests is increased by both low and high temperatures and during heat waves. Ambulance call-outs for cardiovascular causes increase with low temperatures and heat waves, with no significant increase in the overall demand associated with high temperatures. Ambulance call-outs for cardiac arrests are the only subtype that is increased by high temperatures.

Extreme temperature and out-of-hospital-cardiac-arrest. Nationwide study in a hot climate country

BACKGROUND

Out-of-hospital-cardiac arrest (OHCA) is frequently linked to environmental exposures. Climate change and global warming phenomenon have been found related to cardiovascular morbidity, however there is no agreement on their impact on OHCA occurrence. In this nationwide analysis, we aimed to assess the incidence of the OHCA events attended by emergency medical services (EMS), in relation to meteorological conditions: temperature, humidity, heat index and solar radiation.

METHODS

We analyzed all adult cases of OHCA in Israel attended by EMS during 2016-2017. In the case-crossover design, we compared ambient exposure within 72 h prior to the OHCA event with exposure prior to the four control times using conditional logistic regression in a lag-distributed non-linear model.

RESULTS

There were 12,401 OHCA cases (68.3% were pronounced dead-on-scene). The patients were on average 75.5 ± 16.2 years old and 55.8% of them were males. Exposure to 90th and 10th percentile of temperature adjusted to humidity were positively associated with the OHCA with borderline significance (Odds Ratio (OR) =1.20, 95%CI 0.97; 1.49 and OR 1.16, 95%CI 0.95; 1.41, respectively). Relative humidity below the 10th percentile was a risk factor for OHCA, independent of temperature, with borderline significance (OR = 1.16, 95%CI 0.96; 1.38). Analysis stratified by seasons revealed an adverse effect of exposure to 90th percentile of temperature when estimated in summer (OR = 3.34, 95%CI 1.90; 3.5.86) and exposure to temperatures below 10th percentile in winter (OR = 1.75, 95%CI 1.23; 2.49). Low temperatures during a warm season and high temperatures during a cold season had a protective effect on OHCA. The heat index followed a similar pattern, where an adverse effect was demonstrated for extreme levels of exposure.

CONCLUSIONS

Evolving climate conditions characterized by excessive heat and low humidity represent risk factors for OHCA. As these conditions are easily avoided, by air conditioning and behavioral restrictions, necessary prevention measures are warranted.

Ambient temperatures, heatwaves and out-of-hospital cardiac arrest in Brisbane, Australia

BACKGROUND

The health impacts of temperatures are gaining attention in Australia and worldwide. While a number of studies have investigated the association of temperatures with the risk of cardiovascular diseases, few examined out-of-hospital cardiac arrest (OHCA) and none have done so in Australia. This study examined the exposure-response relationship between temperatures, including heatwaves and OHCA in Brisbane, Australia.

METHODS

A quasi-Poisson regression model coupled with a distributed lag non-linear model was employed, using OHCA and meteorological data between 1 January 2007 and 31 December 2019. Reference temperature was chosen to be the temperature of minimum risk (21.4°C). Heatwaves were defined as daily average temperatures at or above a heat threshold (90th, 95th, 98th, 99th percentile of the yearly temperature distribution) for at least two consecutive days.

RESULTS

The effect of any temperature above the reference temperature was not statistically significant; whereas low temperatures (below reference temperature) increased OHCA risk. The effect of low temperatures was delayed for 1 day, sustained up to 3 days, peaking at 2 days following exposures. Heatwaves significantly increased OHCA risk across the operational definitions. When a threshold of 95th percentile of yearly temperature distribution was used to define heatwaves, OHCA risk increased 1.25 (95% CI 1.04 to 1.50) times. When the heat threshold for defining heatwaves increased to 99th percentile, the relative risk increased to 1.48 (1.11 to 1.96).

CONCLUSIONS

Low temperatures and defined heatwaves increase OHCA risk. The findings of this study have important public health implications for mitigating strategies aimed at minimising temperature-related OHCA.

Association between climate variables (cold and hot weathers, humidity, atmospheric pressures) with out-of-hospital cardiac arrests in Rasht, Iran

Climate change is one of the most important concerns for public health that affects communities and is a threat to human health. Few cross-sectional studies investigated the effects of extreme temperature as a risk factor on the cardiovascular system and the Out-of-Hospital Cardiac Arrests (OHCA).The current study aims to investigate the association between climate variables (cold and hot weathers, humidity, atmospheric pressures) with Out-of-Hospital Cardiac Arrests in Rasht, Iran.This is an ecological time-series study, which investigated 392 patients with OHCA that were hospitalized in Dr. Heshmat Medical center of Rasht city in a 3-years period. Data on meteorological variables were obtained from the General Meteorological Department of Guilan Province. Information regarding the number of cardiac arrest admissions was obtained from the sole specialized cardiac hospital of Rasht. Data were analyzed using R software.Hot weather decreases the number of cardiac attacks on the same day (lag 0), while the cold weather (relative risk (RR) = 1.408; confidence interval (CI): 1.014-1.955) increases the number of OHCA cases and unsuccessful cardiopulmonary resuscitation (CPRs). Low humidity (RR = 1.76; CI: 1.006-3.79) is associated with increased unsuccessful CPRs. High atmospheric pressures (RR = 1.166; CI: 1.001 to 1.787) are also associated with an increased number of cardiac arrest admissions. For women, men, and those aged >65 years of old, exposure with severe cold (RR = 1.335; CI: 1.014-1.758) and hot weathers, respectively, increases and decreases the number of cardiac arrest admissions.Cold weather has immediate impacts on the incidence of OHCA cases and unsuccessful CPRs. Decreasing humidity also increases the number of and decreases the success rate of CPRs. Increasing the awareness of patients with cardiovascular diseases (CVDs as well as improving the preparedness of emergency care teams can decrease the impacts of climate variables.

Relationship of meteorological factors and air pollutants with medical care utilization for gastroesophageal reflux disease in urban area

BACKGROUND

Gastroesophageal reflux disease (GERD) is a highly prevalent disease of the upper gastrointestinal tract, and it is associated with environmental and lifestyle habits. Due to an increasing interest in the environment, several groups are studying the effects of meteorological factors and air pollutants (MFAPs) on disease development.

AIM

To identify MFAPs effect on GERD-related medical utilization.

METHODS

Data on GERD-related medical utilization from 2002 to 2017 were obtained from the National Health Insurance Service of Korea, while those on MFAPs were obtained from eight metropolitan areas and merged. In total, 20071900 instances of GERD-related medical utilizations were identified, and 200000 MFAPs were randomly selected from the eight metropolitan areas. Data were analyzed using a multivariable generalized additive Poisson regression model to control for time trends, seasonality, and day of the week.

RESULTS

Five MFAPs were selected for the prediction model. GERD-related medical utilization increased with the levels of particulate matter with a diameter ≤ 2.5 μm (PM_2.5) and carbon monoxide (CO). S-shaped and inverted U-shaped changes were observed in average temperature and air pollutants, respectively. The time lag of each variable was significant around nine days after exposure.

CONCLUSION

Using five MFAPs, the final model significantly predicted GERD-related medical utilization. In particular, PM_2.5 and CO were identified as risk or aggravating factors for GERD.

Effect of meteorological factors and air pollutants on out-of-hospital cardiac arrests: a time series analysis

OBJECTIVES

We aimed to investigate the effects of meteorological factors and air pollutants on out-of-hospital cardiac arrest (OHCA) according to seasonal variations because the roles of these factors remain controversial to date.

METHODS

A total of 38 928 OHCAs of cardiac origin that occurred within eight metropolitan areas between 2012 and 2016 were identified from the Korean nationwide emergency medical service database. A time series multilevel approach based on Poisson analysis following a Granger causality test was used to analyse the influence of air pollution and 13 meteorological variables on OHCA occurrence.

RESULTS

Particulate matter (PM) ≤2.5 µm (PM_2.5), average temperature, daily temperature range and humidity were significantly associated with a higher daily OHCA risk (PM_2.5: 1.59%; 95% CI: 1.51% to 1.66% per 10µg/m³, average temperature 0.73%, 95% CI: 0.63% to 0.84% per 1°C, daily temperature range: 1.05%, 95% CI: 0.63% to 1.48% per 1°C, humidity -0.48, 95% CI: -0.40 to -0.56 per 1%) on lag day 1. In terms of the impact of these four risk factors in different seasons, average temperature and daily temperature range were highly associated with OHCA in the summer and winter, respectively. However, only PM_2.5 elevation (to varying extents) was an independent and consistent OHCA risk factor irrespective of the season.

CONCLUSIONS

PM_2.5, average temperature, daily temperature range and humidity were independently associated with OHCA occurrence in a season-dependent manner. Importantly, PM_2.5 was the only independent risk factor for OHCA occurrence irrespective of seasonal changes.

Impact of Foehn Wind and Related Environmental Variables on the Incidence of Cardiac Events

In Poland there is no data related to the impact of halny wind and the related environmental variables on the incidence of cardiac events. We decided to investigate the relationship between this weather phenomenon, as well as the related environmental variables, and the incidence of cardiac events in the population of southern Poland, a region affected by this type of wind. We also decided to determine whether the environmental changes coincide with or predate the event examined. We analysed data related to 465 patients admitted to the cardiology ward in a large regional hospital during twelve months of 2011 due to acute myocardial infarction. All the patients in the study group lived in areas affected by halny wind and at the time of the event were staying in those areas. The frequency of admissions on halny days did not differ significantly from the admissions on the remaining days of the year (p = 0.496). No statistically significant differences were found between the number of admissions on halny days and on the remaining days during halny months (p = 0.084). We have identified a difference in the number of admissions between days with no halny and days immediately preceding onset of halny (p = 0.001). However, no effects of the related environmental variables have been observed in the incidence of cardiac events (p = 0.866, F = 0.37). On the days with halny wind, incidence of cardiac events is similar to that on the remaining days of the year.

[Influence of extreme weather conditions on the deployment volume of emergency medical services]

BACKGROUND

Due to global warming a worldwide increase in the frequency and intensity of heat waves have been forecast. In the context of the overall increasing number of emergency service calls, weather-induced effects on the number of calls are highly relevant. We evaluated the influence of extreme temperatures on emergency medical services.

MATERIALS AND METHODS

The study was conducted in Bochum, Germany. The authors examined the data from 16,767 emergency calls. In addition, the daily updated temperature data were collected for each emergency doctor call. Data were collected from 01 January 2014 until 31 December 2015. The primary question was the influence of extremes of the perceived temperature (PT; on the day of the call and the three previous days) on the diagnosis group of cardiovascular diseases. A secondary question was the influence of extremes of the temperature parameters (air temperature, PT, physiological equivalent temperature [PET]) on the day of call and the three previous days.

RESULTS

A total of 16,767 calls were assessed. The threshold values (upper and lower 5%) were -8.7 and 32.5 °C for PT and -0.7 and 26.7 °C for air temperature. Examination of the PT indicated a significantly increased rate of calls for cold spells on the day of the call (RR = 1.14; p = 0.033) as well as a lag effect of 3 days (RR = 1.1; p = 0.049).

CONCLUSION

The present study shows that during cold spells there is an increased rate of calls for cardiovascular diseases. This effect is not only observable on the extreme day itself but also 3 days later.