Impact of temperature and atmospheric pressure on the incidence of major acute cardiovascular events

Patterns in acute aortic dissection and a connection to meteorological conditions in Germany

Acute type A aortic dissection (ATAAD) is a dramatic emergency exhibiting a mortality of 50% within the first 48 hours if not operated. This study found an absolute value of cosine-like seasonal variation pattern for Germany with significantly fewer ATAAD events (Wilcoxon test) for the warm months of June, July, and August from 2005 to 2015. Many studies suspect a connection between ATAAD events and weather conditions. Using ERA5 reanalysis data and an objective weather type classification in a contingency table approach showed that for Germany, significantly more ATAAD events occurred during lower temperatures (by about 4.8 K), lower water vapor pressure (by about 2.6 hPa), and prevailing wind patterns from the northeast. In addition, we used data from a classification scheme for human-biometeorological weather conditions which was not used before in ATAAD studies. For the German region of Berlin and Brandenburg, for 2006 to 2019, the proportion of days with ATAAD events during weather conditions favoring hypertension (cold air advection, in the center of a cyclone, conditions with cold stress or thermal comfort) was significantly increased by 13% (Chi-squared test for difference of proportions). In contrast, the proportion was decreased by 19% for conditions associated with a higher risk for patients with hypotension and therefore a lower risk for patients with hypertension (warm air advection ahead of warm fronts, conditions with no thermal stress or heat stress, in the center of a cyclone with thermal stress). As many studies have shown that hypertension is a risk factor for ATAAD, our findings support the hypothesized relation between ATAAD and hypertension-favoring weather conditions.

Rapid weather changes are associated with daily hospital visitors for atrial fibrillation accompanied by abnormal ECG repolarization: a case-crossover study

BACKGROUND

Atrial fibrillation (AF) is highly prevalent in the population, yet the factors contributing to AF events in susceptible individuals remain partially understood. The potential relationship between meteorological factors and AF, particularly with abnormal electrocardiograph (ECG) repolarization, has not been adequately studied. This case-crossover study aims to investigate the association between meteorological factors and daily hospital visits for AF with abnormal ECG repolarization in Shanghai, China.

METHODS

The study cohort comprised 10,325 patients with ECG-confirmed AF who sought treatment at Shanghai Sixth People's Hospital between 2015 and 2018. Meteorological and air pollutant concentration data were matched with the patient records. Using a case-crossover design, we analyzed the association between meteorological factors and the daily count of hospital visitors for AF with abnormal ECG repolarization at our AF center. Lag analysis models were applied to examine the temporal relationship between meteorological factors and AF events.

RESULTS

The analysis revealed statistically significant associations between AF occurrence and specific meteorological factors. AF events were significantly associated with average atmospheric pressure (lag 0 day, OR 0.9901, 95% CI 0.9825-0.9977, P < 0.05), average temperature (lag 1 day, OR 0.9890, 95% CI 0.9789-0.9992, P < 0.05), daily pressure range (lag 7 days, OR 1.0195, 95% CI 1.0079-1.0312, P < 0.01), and daily temperature range (lag 5 days, OR 1.0208, 95% CI 1.0087-1.0331, P < 0.01). Moreover, a significant correlation was observed between daily pressure range and daily temperature range with AF patients, particularly those with abnormal ECG repolarization, as evident in the case-crossover analysis.

CONCLUSION

This study highlights a significant correlation between meteorological factors and daily hospital visits for AF accompanied by abnormal ECG repolarization in Shanghai, China. In addition, AF patients with abnormal ECG repolarization were found to be more vulnerable to rapid daily changes in pressure and temperature compared to AF patients without such repolarization abnormalities.

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.

Association between air pollution exposure and coronary heart disease hospitalization in a humid sub-tropical region of China: A time-series study

Objective

Emerging evidence has highlighted the possible links of environmental pollution with several cardiovascular diseases (CVDs). The current study aimed to explore the impact of short-term air pollution exposure on CHD hospitalization in Hefei.

Methods

Data about the daily number of CHD admissions (from 2014 to 2021) were retrieved from the First Affiliated Hospital of Anhui Medical University. Air pollutants and meteorological data were obtained from the China Environmental Monitoring Station and the China Meteorological Data Service Center, respectively. The correlation between air pollution and CHD hospitalization was assessed using distributed lag non-linear model (DLNM) and Poisson generalized linear regression.

Results

In the single-pollutant model, NO₂, O₃, and CO strongly correlated with CHD hospitalization rate. Specifically, exposure to NO₂ (lag0, relative risk [RR]: 1.013, 95%CI: 1.002-1.024, per 10 μg/m³ increase) and CO (lag13, RR: 1.035, 95%CI: 1.001-1.071, per 1 μg/m³ increase) revealed a positive correlation with an increased rate of CHD hospitalization. Interestingly, O₃ had a protective association with hospitalization of CHD (lag0, RR: 0.993, 95%CI: 0.988-0.999, per 10 μg/m³ increase). Similar results, to those of the single-pollutant model, were revealed following verification using two-pollutant models. Subgroup analyses indicated that young people, women, and people in hot seasons were more susceptible to NO₂ exposure, while the elderly, women, and people in cold seasons were more susceptible to O₃. Furthermore, the elderly were more susceptible to CO exposure.

Conclusion

Overall, exposure to NO₂ and CO increases the rate of CHD hospitalization, but exposure to O₃ shows a protective association with the rate of CHD hospitalization. Therefore, early preventive measures against air pollutants should be applied to protect vulnerable patients with CHD.

Temperature effects on incidence of surgery for acute type A aortic dissection in the Nordics

We aimed to investigate a hypothesised association between daily mean temperature and the risk of surgery for acute type A aortic dissection (ATAAD). For the period of 1 January 2005 until 31 December 2019, we collected daily data on mean temperatures and date of 2995 operations for ATAAD at 10 Nordic cities included in the Nordic Consortium for Acute Type A Aortic Dissection (NORCAAD) collaboration. Using a two-stage time-series approach, we investigated the association between hot and cold temperatures relative to the optimal temperature and the rate of ATAAD repair in the selected cities. The relative risks (RRs) of cold temperatures (≤-5°C) and hot temperatures (≥21°C) compared to optimal temperature were 1.47 (95% CI: 0.72-2.99) and 1.43 (95% CI: 0.67-3.08), respectively. In line with previous studies, we observed increased risk at cold and hot temperatures. However, the observed associations were not statistically significant, thus only providing weak evidence of an association.

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

Background

Acute aortic dissection (AAD) is a life-threatening cardiovascular emergency with high mortality, so identifying modifiable risk factors of AAD is of great public health significance. The associations of non-optimal temperature and temperature variability with AAD onset and the disease burden have not been fully understood.

Methods

We conducted a time-stratified case-crossover study using a nationwide registry dataset from 1,868 hospitals in 313 Chinese cities. Conditional logistic regression and distributed lag models were used to investigate associations of temperature and temperature changes between neighboring days (TCN) with the hourly AAD onset and calculate the attributable fractions. We also evaluated the heterogeneity of the associations.

Findings

A total of 40,270 eligible AAD cases were included. The exposure-response curves for temperature and TCN with AAD onset risk were both inverse and approximately linear. The risks were present on the concurrent hour (for temperature) or day (for TCN) and lasted for almost 1 day. The cumulative relative risks of AAD were 1.027 and 1.026 per 1°C lower temperature and temperature decline between neighboring days, respectively. The associations were significant during the non-heating period, but were not present during the heating period in cities with central heating. 23.13% of AAD cases nationwide were attributable to low temperature and 1.58% were attributable to temperature decline from the previous day.

Interpretation

This is the largest nationwide study demonstrating robust associations of low temperature and temperature decline with AAD onset. We, for the first time, calculated the corresponding disease burden and further showed that central heating may be a modifier for temperature-related AAD risk and burden.

Funding

This work was supported by the National Natural Science Foundation of China (92043301 and 92143301), Shanghai International Science and Technology Partnership Project (No. 21230780200), the Medical Research Council-UK (MR/R013349/1), and the Natural Environment Research Council UK (NE/R009384/1).

The relationship between air pollutant levels and aneurysmal subarachnoid hemorrhage

BACKGROUND

The relationship between air pollutants, including fine particles (particulate matter [PM] < 10 μm and < 2.5 μm), and aneurysmal subarachnoid hemorrhage (SAH) has been inadequately studied, and the results remain inconclusive. In this study, we attempted to investigate the relationship between air pollutant levels and aneurysmal SAH.

METHODS

Ninety-two patients diagnosed with aneurysmal SAH were retrospectively included in the study. Medical records were reviewed, and levels of pollutants, including those of sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), carbon monoxide (CO), and PM with an aerodynamic diameter < 10 and 2.5 μm (PM10 and PM2.5), were collected from the open-source Air Korea website for a period of 4 days. Independent t-tests were conducted to identify the difference in the pollutant levels between the data obtained on the day of aneurysm rupture (D-0) and the other 3 days (D-7, D-2, and D-1).

RESULTS

A majority (40.2%) of the patients experienced aneurysm rupture during the fall season when the mean daily pollutant levels were 0.004 ± 0.001 (ppm, SO2), 0.517 ± 0.218 (ppm, CO), 0.02056 ± 0.012 (ppm, O3), 0.02628 ± 0.015 (ppm, NO2), 36.36957 ± 24.538 (μg/m3, PM10), and 19.75581 ± 13.494 (μg/m3, PM2.5), respectively. The level of NO2 was significantly higher on the day of aneurysm rupture (P = .035) than on the other days, while the levels of CO and O3 were nonsignificantly higher (P = .081, P = .055, respectively) on the day of aneurysm rupture than on the other days. There was no significant differences in the PM levels between the 4 days.

CONCLUSION

A relationship between PM levels and aneurysm rupture was not identified. Only the levels of classic air pollutant (CO, O3, and NO2) were higher on the aneurysm rupture day than on the other days.

Determination of the influence of weather and air constituents on aortic aneurysm ruptures

In this article, we present a method to determine the influence of meteorology and air pollutants on ruptured aortic aneurysm (rAA). In contrast to previous studies, our work takes into account highly resolved seasonal relationships, a time-lagged effect relationship of up to two weeks, and furthermore, potential confounding influences between the meteorological and air-hygienic variables are considered and eliminated using a cross-over procedure. We demonstrate the application of the method using the cities of Augsburg and Munich in southern Germany as examples, where a total of 152 rAA can be analyzed for the years 2010–2019. With the help of a Wilcoxon rank-sum test and the analysis of the atmospheric circulation, typical weather situations could be identified that have an influence on the occurrence of rAA in the southern German region. These are a rainy northwest wind-type in spring, humid weather in summer and warm southwest wind-type weather in autumn and winter.

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Influence of meteorology and air pollutants on ruptured aortic aneurysm (rAA).

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Consideration of time lags within flexible high temporal resolution analyses.

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Case-crossover procedure ensures that only relevant variables influence the results.

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Developed methodology can be applied to all regions of the world.

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In southern Germany, specific weather conditions significantly influence rAA.

A Meteorological Paradox: Low Atmospheric Pressure-Associated Decrease in Blood Pressure Is Accompanied by More Cardiac and Cerebrovascular Complications: Five-Year Follow-up of Elderly Hypertensive Patients

Background: Variations in atmospheric pressure (AP) are known to affect blood pressure (BP). We assessed the effect of AP on BP, and the major fatal and nonfatal complications thereof (i.e., stroke, myocardial infarction, and pulmonary emboli). Methods: In this observational cohort study, 250 hypertensive patients (aged 65–92 years old) were followed for 3.5–5.4 years in a primary care clinic. Cox proportional hazard regression was performed to define the associations between AP, clinical, demographic and environmental factors, and major complications such as stroke, myocardial infarction, etc. Results: AP fluctuated between 1007 and 1024 millibars (MB). A total of 132 patients (53%) developed various complications, of which 13 (9.8%) were fatal. Among all fatalities, 93 of 119 nonfatal cases and 7 of 13 fatal cases occurred at AP < 1013 MB. A Cox regression analysis showed that low AP (AP < 1013 MB) had a higher hazard ratio (HR) on hypertension (HTN) complications among all demographic, clinical and environmental parameters. Conclusions: Most major complications were associated with very low APs. Low AP was the best predictive risk-factor for major complications of HTN.

Increasing atmospheric temperature implicates increasing risk for acute type A dissection in hypertensive patients

Background

Acute type A aortic dissection (AAAD) is a life-threatening condition with high mortality within 24 hours. We hypothesized if there is a correlation between seasonal weather changes and the occurrence of AAAD. The aim of the present study was to identify seasonal specific weather and patient characteristics predicting the occurrence of AAAD.

Methods

This is a retrospective analysis of all consecutive patients of our department with AAAD between January 1st 2006 and December 31st 2016. The national meteorological department provided the data of temperature, humidity and air pressure during the study period. The occurrence of AAAD, preoperative neurological impairment and mortality were analyzed in correlation with the obtained daily weather data within the entire cohort and in patients with and without hypertension separately.

Results

A total of 517 patients were included. Mean age was 63.4±13 years, 69.4% were male and 68.8% had documented hypertension. In-hospital mortality was 17.7%. In the whole cohort, the occurrence of AAAD was significantly increased in March, October, December (P=0.016). In hypertensive patients, the occurrence was increased 34% with rising temperature (0.1-9.6 °C, OR1.34, 95% CI: 1.06-1.69, P=0.015). There was no correlation between weather variables and preoperative neurological impairment or mortality.

Conclusions

Our data suggests a relation between an increasing number of events of AAAD and certain months within our catchment area and a significantly increased occurrence with rising temperatures (independent from absolute temperature at time of the event) in hypertensive patients.

Effects of seasonal and climate variations on in-hospital mortality and length of stay in patients with type A aortic dissection

Objective

To investigate the effects of seasonal and climatic changes on postoperative in-hospital mortality and length of stay (LOS) in patients with type A acute aortic dissection (AAD).

Methods

Patients undergoing implantation of the modified triple-branched stent graft to replace the descending aorta in addition to aortic root reconstruction for type A AAD in our hospital from January 2016 to December 2019 were included. Relevant data were retrospectively collected and analyzed.

Results

A total of 404 patients were included in our analyses. The multivariate unconditional logistic regression analysis showed that patients admitted in autumn (OR 4.027, 95% CI 1.023–17.301, P = 0.039) or with coronary heart disease (OR 8.938, 95% CI 1.991–29.560, P = 0.049) were independently associated with an increased risk of postoperative in-hospital mortality. Furthermore, patients admitted in autumn (OR 5.956, 95% CI 2.719–7.921, P = 0.041) or with hypertension (OR 3.486, 95% CI 1.192–5.106, P = 0.035) were independently associated with an increased risk of longer LOS.

Conclusion

Patients admitted in autumn or with coronary heart disease are at higher risk of in-hospital mortality following surgery for type A AAD. Also, patients admitted in autumn or with hypertension have a longer hospital LOS. In the autumn of the temperature transition, we may need to strengthen the management of medical quality after surgery for type A AAD.

Association of Daily Mean Temperature and Temperature Variability With Onset Risks of Acute Aortic Dissection

Background The association between ambient temperature and cardiovascular diseases has been well established, but evidence of temporal changes in the risk of acute aortic dissection (AAD) onset is lacking. Methods and Results We conducted an 8-year time-series study based on data from 2120 patients diagnosed with AAD at Tongji Hospital (Wuhan, China). Daily meteorological parameters were measured in the study area. Spearman's rank correlation analysis was applied to measure the associations between daily meteorological data and air pollution indicators. A distributed lag nonlinear model following quasi-Poisson regression was used to express the nonlinear exposure-response relationships and lag effects of daily mean temperature and temperature variability on the occurrence of AAD. Considering a 25-day lag effect, lower or higher temperatures with reference to 25°C did not alter the onset risk of AAD. The lag effect of daily mean temperature on the incidence of AAD is statistically significant within 2 days, and the impact of daily mean temperature on the risk is most influential on the day. The exposure-response curve between daily mean temperature and onset risks of AAD at lag 0 showed that the extremely cold temperature (2.5th percentile, 0.5°C) significantly increased the AAD risk for the total (relative risk, 1.733; 95% CI, 1.130-2.658) and type A dissection (relative risk, 3.951; 95% CI, 1.657-9.418). Temperature variability within 1 week did not affect the onset risks of AAD for the total. Conclusions We confirmed that extremely cold temperatures significantly increased the AAD risk, which could contribute to early prevention and timely diagnosis of the disease.

Do meteorological factors influence the occurrence of acute aortic dissection? A 10-year retrospective institutional study

OBJECTIVE

This study aimed to clarify the relationship between meteorological factors and the occurrence of aortic dissection.

METHODS

The study included 282 consecutive patients who were admitted to our institute with acute aortic dissection over a 10-year period. The local meteorological data over the same period were analyzed.

RESULTS

On the days with occurrences of acute aortic dissection, there were significant differences in the following factors: the minimum and maximum temperature (p < 0.0001), difference in the minimum and maximum temperature from the 10-year average, atmospheric pressure (p < 0.0001), and difference in atmospheric pressure between the day of occurrence and the previous day. Cut-off values were determined by ROC curve analysis. Univariate analyses identified the following factors as significant predictors of the occurrence of acute aortic dissection: minimum temperature < 4.0 °C (OR 2.42, p < 0.0001), maximum temperature < 15.1 °C (OR 2.23, p < 0.0001), atmospheric pressure > 1008.9 hPa (OR 1.75, p < 0.0001), difference between the minimum temperature and 10-year average < 0.3 °C, difference between the maximum temperature and 10-year average < 0.44 °C; and the difference in atmospheric pressure between the day of occurrence and the previous day > 0.4 hPa. However, the differences of the minimum and maximum temperatures from the 10-year average were the only factors that remained significant in the multivariate analysis. The minimum (R² = 0.3055) and maximum temperatures (R² = 0.4151) were weakly and moderately correlated, respectively, with the occurrence of acute aortic dissection.

CONCLUSION

Meteorological factors influenced the occurrence of acute aortic dissection. In particular, a minimum temperature of < 4 °C and maximum temperature difference from the 10-year average < 0.44 °C was identified as strong risk factors for the occurrence of acute aortic dissection.

Thermal Environment Perceptions from a Longitudinal Study of Indoor Temperature Profiles in Inpatient Wards

Inpatient wards in general have cooling systems with a “one-size-fits-all” approach, driven by a fixed set-point temperature (21–24 °C) that is flexible to lower limits down to 18 °C or less. This approach does not consider patients’ temperature demands, which vary due to thermo-physiology caused by medical conditions, and mixed demographics. It also causes additional cooling demands in hot climates that are infrequently utilized by patients, who tend to adopt warmer internal set temperatures. Thus, this research examined the indoor temperature profiles (distribution of shape) in patient rooms in fully air-conditioned inpatient wards over an extended period of time. During four months of summer, longitudinal monitoring of internal temperature and relative humidity was carried out in 18 patient rooms in the surgical, medical, cardiology, and oncology wards of two hospitals in Saudi Arabia. In parallel, 522 patients were surveyed to capture common subjective thermal indices. The findings revealed that the most frequently preferred temperature (peaks) varied significantly between wards; peaks (modes) were 20.1–21.8 °C in cardiology; 22.2–23.9 °C in the surgical ward; warmer 24.8–25.3 °C in medical ward; and 25.3–26.8 °C in oncology. Surveys also showed that patients were not satisfied with the indoor environment in both hospitals. Given the significant variance in temperature profiles between wards and patient dissatisfaction with the indoor environment, these results suggest that more appropriately designed zoned cooling strategies are needed in hospitals as per the nature of each ward. Besides its implications for benchmarking the HVAC system, this approach will substantially reduce energy loads and operational costs in hot-climate hospitals if patients desire warmer conditions than the set conditions provided by system.

Impact of meteorological factors on the occurrence of acute aortic dissection in Fujian Province, China: a single-center seven-year retrospective study

Background

The aim of this study was to investigate the correlation between meteorological factors and the occurrence of acute aortic dissection (AAD) in Fujian Province, China.

Methods

The clinical data of 2004 patients diagnosed with AAD in our hospital and the relevant local meteorological data from January 2013 to November 2019 were retrospectively analyzed.

Results

The incidence of AAD had a clear tendency toward concentration, and the corresponding peak in terms of the occurrence date was from January 13 to 14. The average minimum temperature, the average maximum temperature, and the average daily temperature differences on the “day with AAD” were significantly lower than those on the “day without AAD”. From 5 days to 3 days before AAD onset, the average daily temperature difference showed a downward trend, but statistical analysis showed that the average minimum, average maximum and average daily temperature differences were not significantly different from the values 5 days to 0 days before AAD onset.

Conclusions

The incidence of AAD is related to the season and month. The lowest average temperature may increase the incidence of AAD in patients with complicated cardiovascular diseases.

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.

Impact of Relative Change in Temperature and Atmospheric Pressure on Acute Aortic Syndrome Occurrence in France

Acute aortic syndromes (AAS) have been related to significant circadian and seasonal conditions. We used time series analyses to study the impact of meteorological variations on AAS occurrence. We retrospectively assessed 140 patients presenting with AAS over a 6-year period in a French university hospital. Average daily temperature (T) and atmospheric pressure (AP) at the location of the event were collected within the previous 10 days, and their association with AAS investigated with generalized additive models. A decrease in temperature of more than 5 °C within the previous seven days was significantly associated with an increased risk of AAS occurrence (OR equal to 1.86 [1.06; 3.44]). Subgroup analysis revealed that the risk was only significant among normotensive individuals (n = 41) free from blood pressure lowering medication (OR equal to 2.3 [1.05; 5.37]), but not among hypertensive individuals under blood pressure lowering medication despite a larger patient number (n = 99). Similarly, only among the subgroup of normotensive individuals a decrease of AP between 2 and 4 kPa within the previous 3 days was associated with an increased risk of AAS (OR equal to 2.93 [1.1; 8.15]) and an increased between 2 and 4 kPa was associated with a decreased risk (OR equal to 0.59 [0.36; 1.00]). Variations of meteorological conditions (temperature and AP) within the previous week seem to have effects on triggering AAS especially among the population free from blood pressure lowering medication.

Analysis of weather exposure 7 days before occurrence of ST-segment elevation myocardial infarction

BACKGROUND

Several studies have highlighted the relationship between weather patterns and the occurrence of ST-elevation myocardial infarction (STEMI).

AIM

To evaluate the statistical association between the occurrence of STEMI and meteorological variables over the preceding 7 days.

METHODS

This was a retrospective study, using prespecified data from the ORBI (Breton Regional Observatory on Myocardial Infarction) registry, which includes all consecutive patients hospitalized for STEMI in the geographical area of Brest, France. Over a 7-year period, we compared the number of STEMIs per week with the mean values of meteorological variables over the preceding 7 days.

RESULTS

Overall, 7517 patients with STEMI were recorded in the ORBI registry between January 2009 and January 2016. After exclusion of patients not living in the geographical area of interest, 742 patients were included. The weekly incidence of STEMI ranged from 0 to 7 (median 2, interquartile range 1-3). In the univariate analysis, air temperature (odds ratio [OR] 1.05, 95% confidence interval [CI] 1.005-1.01 per 1°C decrease; P=0.03) and atmospheric pressure (OR 1.03, 95% CI 1.01-1.06 per 1 hPa increase; P=0.008) were associated with the weekly incidence of STEMI. In the multivariable analysis, air temperature (OR 1.06, 95% CI 1.01-1.10 per 1°C decrease; P=0.01), atmospheric pressure (OR 1.05, 95% CI 1.02-1.08 per 1 hPa increase; P<0.001) and duration of humidity>80% (OR 1.09, 95% CI 1.02-1.15 per 1hour increase; P=0.007) in the previous 7 days were associated with the occurrence of STEMI.

CONCLUSIONS

In this specific geographical area, occurrence of STEMI was statistically associated with a decrease in air temperature, an increase in atmospheric pressure and an increase in humidity over the preceding 7-day period.

Risk of Out-of-Hospital Cardiac Arrest in Aged Individuals in Relation to Cold Ambient Temperature - A Report From North Tochigi Experience

BACKGROUND

The impact of cold ambient temperature on out-of-hospital cardiac arrest (OHCA) in aged individuals caused by cardiovascular events in indoor environments has not been investigated sufficiently.Methods and Results:We conducted a case-crossover study. The relationship between OHCA caused by cardiovascular events and exposure to minimum temperature <0℃ was analyzed. Conditional logistic regression analysis was performed to estimate the odds ratios for the relationship between exposure to minimum temperature <0℃ and the risk of OHCA. Between January 1, 2011, and December 31, 2015, a total of 1,452 cases of OHCA were documented, and patients were screened for enrollment. A total of 458 individuals were enrolled in this analysis, and were divided into 2 groups of 110 (elderly group: 65-74 years old) and 348 (aged group: ≥75 years old). The aged individuals had a significant increased risk of OHCA after exposure to minimum temperature <0℃ (odds ratio [OR]: 1.528, 95% confidence interval [CI] 1.009-2.315, P=0.045). Cold ambient temperature was an especially significant increased risk for OHCA occurrence for males (OR: 1.997, 95% CI 1.036-3.773, P=0.039) and during winter (OR: 2.391, 95% CI 1.312-4.360, P=0.004) in the aged group.

CONCLUSIONS

Cold ambient temperature significantly affected aged individuals (≥75 years old) experiencing an OHCA caused by cardiovascular events in indoor environments.

Complex effects of atmospheric parameters on acute cardiovascular diseases and major cardiovascular risk factors: data from the CardiometeorologySM study

Several studies have examined the cardiovascular effects of atmospheric parameters as separate factors; however, few have investigated atmospheric parameters’ joint effects. We aim to explore the joint effects of atmospheric parameters on acute cardiovascular diseases (ACVDs) and on major cardiovascular risk factors (CRFs). We correlated all ACVD admissions with major CRFs and local atmospheric conditions during a 5-year study period. A seasonal variation was detected in a higher incidence rate during cold atmospheric conditions. There were significant incidence relative ratios, including: 1.140 (95% CI [1.020, 1.283]) for daily temperature change (≥5 °C); 0.991 (95% CI [0.988, 0.994]) for average daily temperature; and 1.290 (95% CI [1.090, 1.599]) for the interaction of daily temperature change (≥5 °C) with humidity change (≥40%). We observed a significant association between the atmospheric parameters’ joint effects and hyperlipidaemia, diabetes, and previous ACVDs. Patients with diabetes had the highest significant incidence relative ratio at 2.429 (95% CI [1.088, 5.424]) for humidity-temperature interactions. Thus, the atmospheric parameters’ joint effects play an important role as minor CRFs. These unfavourable atmospheric situations are predicted to increase the number of ACVDs mainly. Our study may help to organize prevention strategies more effectively and to reduce cardiovascular risks.

Forecasting aortic aneurysm rupture: A systematic review of seasonal and atmospheric associations

BACKGROUND

Abdominal aortic aneurysms (AAAs) represent a significant burden of disease worldwide, and their rupture, without treatment, has an invariably high mortality rate. Whereas some risk factors for ruptured AAAs (rAAAs) are well established, such as hypertension, smoking, and female sex, the impact of seasonal and meteorologic variables is less clear. We systematically reviewed the literature to determine whether these variables are associated with rAAA.

METHODS

Review methods were according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We calculated pooled proportions and incidence rate ratios (IRRs) for the different months and seasons. Funnel plots were constructed to assess for publication bias. Given the poor methodologic quality of included studies, a sensitivity analysis was performed on better-quality studies, which scored 6 and above of 9 in the author-modified Newcastle-Ottawa Scale.

RESULTS

The pooled proportion of rAAA was highest in the autumn season (incidence rate, 26.6%; 95% confidence interval [CI], 25.6%-27.7%; I² = 15.4%), followed by winter (incidence rate, 26.2%; 95% CI, 24.1%-28.2%; I² = 72.4%), and lowest in summer (incidence rate, 21.1%; 95% CI, 19.3%-23.0%; I² = 70.4%). The IRRs of rAAA were -6.9% (95% CI, -9.8% to -3.9%), -19.5% (95% CI, -22% to -16.8%), +10.5% (95% CI, 7.2%-13.9%), and +18.1% (95% CI, 15%-22%) in spring, summer, autumn, and winter compared with the remaining seasons, respectively (all P < .0001), thus affirming existence of seasonal variation. The pooled proportion of rAAA was highest in December (incidence rate, 8.9%; 95% CI, 7.1%-10.9%; I² = 54.5%) but lowest in July (incidence rate, 5.7%; 95% CI, 4.2%-7.3%; I² = 54.5%). The IRR was significantly the highest in January (IRR, 1.14; 95% CI, 1.01-1.29; P = .031) but lowest in July (IRR, 0.75; 95% CI, 0.65-0.87; P < .0001). There is also some evidence for a possible association with atmospheric pressure. Associations with temperature and daylight hours, however, are at best speculative.

CONCLUSIONS

Autumn and winter are significantly associated with a higher incidence of rAAAs, and autumn is associated with the highest rupture incidence of all the seasons. However, the inability to appropriately control for other confounding factors known to increase the risk of AAA rupture precludes any additional recommendations to alter current provision of vascular services on the basis of these data.

Impact of meteorological conditions on the incidence of acute aortic dissection

BACKGROUND:

There is still much controversy about whether meteorological conditions influence the occurrence of acute aortic dissection (AAD). The aim of the present study was to investigate the possible correlation between atmospheric pressure, temperature, lunar cycle and the event of aortic dissection in our patient population.

METHODS:

The clinical data for 348 patients with AAD (73% type Stanford A) were confronted with the meteorological data provided by the Cologne weather station over the same period.

RESULTS:

There were no statistically significant differences between meteorological parameters on days of AAD events compared with control days. A logistic regression model showed that air pressure (odds ratio [OR] 1.004, 95% confidence interval [CI] 0.991-1.017, p = 0.542), air temperature (OR 0.978, 95% CI 0.949-1.008, p = 0.145), season ( p = 0.918) and month of the event ( p = 0.175) as well as presence of full moon (OR 1.579, 95% CI 0.763-3.270, p = 0.219) were not able to predict AAD events. Also, no predictive power of meteorological data and season was found on analysing their impact on different types of AAD events.

CONCLUSIONS:

Our study did not reveal any dependence of atmospheric pressure, air temperature or the presence of full moon on the incidence of different types of AAD.

The effect of meteorological conditions and air pollution on the occurrence of type A and B acute aortic dissections

To explore the association of weather conditions and air pollutants with incidence risk of acute aortic dissection (AAD), we included patients who consecutively admitted to the emergency units of our hospital for AAD between Dec. 1, 2013, and Apr. 30, 2017. Their medical records were reviewed. The meteorological data (daily precipitation, minimal and maximal temperatures, mean atmospheric pressure, relative humidity) and air pollutants values [air daily index (AQI), aerodynamic diameter of 2.5 mm or less (PM2.5), aerodynamic diameter of 10 mm or less (PM10), ozone, nitrogen dioxide (NO2), carbon monoxide (CO), sulfur dioxide (SO2), and ozone (O3_8h)] over the same period were provided by the Chengdu Meteorological Bureau. Finally, a total of 345 patients were admitted with AAD. The results showed that the incidence of AAD was higher in winter than in summer (p < 0.001). Statistical analysis highlighted lower the atmospheric temperature, higher the incidence of AAD (p < 0.001). A significant correlation was found between air pollutants and AAD onset. AQI, PM2.5, SO2, and NO2 were independent predictors of incidence of AAD (OR = 1.006, p = 0.007; OR = 1.020, p < 0.001; OR = 1.037, p < 0.001; and OR = 0.925, p < 0.001; respectively). While, PM10, CO, and O3_8H had a neutral effect on risk of AAD onset. In conclusions, cold atmospheric temperature and larger daily temperature change were correlated with a higher incidence of AAD. AQI, PM2.5, and SO2 played important roles in triggering acute aortic events.

Environmental Determinants of Cardiovascular Disease

Many features of the environment have been found to exert an important influence on cardiovascular disease (CVD) risk, progression, and severity. Changes in the environment because of migration to different geographic locations, modifications in lifestyle choices, and shifts in social policies and cultural practices alter CVD risk, even in the absence of genetic changes. Nevertheless, the cumulative impact of the environment on CVD risk has been difficult to assess and the mechanisms by which some environment factors influence CVD remain obscure. Human environments are complex, and their natural, social, and personal domains are highly variable because of diversity in human ecosystems, evolutionary histories, social structures, and individual choices. Accumulating evidence supports the notion that ecological features such as the diurnal cycles of light and day, sunlight exposure, seasons, and geographic characteristics of the natural environment such as altitude, latitude, and greenspaces are important determinants of cardiovascular health and CVD risk. In highly developed societies, the influence of the natural environment is moderated by the physical characteristics of the social environments such as the built environment and pollution, as well as by socioeconomic status and social networks. These attributes of the social environment shape lifestyle choices that significantly modify CVD risk. An understanding of how different domains of the environment, individually and collectively, affect CVD risk could lead to a better appraisal of CVD and aid in the development of new preventive and therapeutic strategies to limit the increasingly high global burden of heart disease and stroke.

Seasonal Periodicity of Ischemic Heart Disease and Heart Failure

Seasonal variation for ischemic heart disease and heart failure is known. The interplay of environmental, biological, and physiologic changes is fascinating. This article highlights the seasonal periodicity of ischemic heart disease and heart failure and examines some of the potential reasons for these unique observations.

Chronobiology of Takotsubo Syndrome and Myocardial Infarction: Analogies and Differences

Several pathophysiologic factors, not harmful if taken alone, are capable of triggering unfavorable events when presenting together within the same temporal window (chronorisk), and the occurrence of many cardiovascular events is not evenly distributed in time. Both acute myocardial infarction and takotsubo syndrome seem to exhibit a temporal preference in their onset, characterized by variations according to time of day, day of the week, and month of the year, although with both analogies and differences.

The Interaction Effects of Meteorological Factors and Air Pollution on the Development of Acute Coronary Syndrome

This study investigated the interaction effects of meteorological factors and air pollutants on the onset of acute coronary syndrome (ACS). Data of ACS patients were obtained from the Taiwan ACS Full Spectrum Registry and comprised 3164 patients with a definite onset date during the period October 2008 and January 2010 at 39 hospitals. Meteorological conditions and air pollutant concentrations at the 39 locations during the 488-day period were obtained. Time-lag Poisson and logistic regression were used to explore their association with ACS incidence. One-day lag atmospheric pressure (AP), humidity, particulate matter (PM_2.5, and PM₁₀), and carbon monoxide (CO) all had significant interaction effects with temperature on ACS occurrence. Days on which high temperatures (>26 °C) and low AP (<1009 hPa) occurred the previous day were associated with a greater likelihood of increased incidence of developing ACS. Typhoon Morakot was an example of high temperature with extremely low AP associated with higher ACS incidence than the daily average. Combinations of high concentrations of PM or CO with low temperatures (<21 °C) and high humidity levels with low temperatures were also associated with increased incidence of ACS. Atmospheric pollution and weather factors have synergistic effects on the incidence of ACS.

Revisiting the role of environmental and climate factors on the epidemiology of Kawasaki disease

Can environmental factors, such as air-transported preformed toxins, be of key relevance to the health outcomes of poorly understood human ailments (e.g., rheumatic diseases such as vasculitides, some inflammatory diseases, or even severe childhood acquired heart diseases)? Can the physical, chemical, or biological features of air masses be linked to the emergence of diseases such as Kawasaki disease (KD), Henoch-Schönlein purpura, Takayasu's aortitis, and ANCA-associated vasculitis? These diseases surprisingly share some common epidemiological features. For example, they tend to appear as clusters of cases grouped geographically and temporarily progress in nonrandom sequences that repeat every year in a similar way. They also show concurrent trend changes within regions in countries and among different world regions. In this paper, we revisit transdisciplinary research on the role of environmental and climate factors in the epidemiology of KD as a paradigmatic example of this group of diseases. Early-warning systems based on environmental alerts, if successful, could be implemented as a way to better inform patients who are predisposed to, or at risk for, developing KD. Further research on the etiology of KD could facilitate the development of vaccines and specific medical therapies.

The Chronobiology of Stanford Type A Aortic Dissections: A Comparison of Northern versus Southern Hemispheres

BACKGROUND

Seasonal variations of Stanford Type A dissections (STADs) have been previously described in the Northern Hemisphere (NH). This study sought to determine if these variation are mirrored in the Southern Hemisphere (SH).

METHODS

Data from patients treated surgically for STADs were retrospectively obtained from existing administrative and clinical databases from NH and SH sites. Data points of interest included age, sex, date of dissection, and 30-day mortality. The dates of dissections (independent of year) were then organized by season.

RESULTS

A total of 1418 patients were identified (729 NH and 689 SH) with complete data available for 1415; 896 patients were male with a mean age was 61 ± 14 years, and the overall 30-day mortality was 17.3%. Comparison of NH and SH on a month-to-month basis demonstrated a 6-month phase shift and a significant difference by season, with STADs occurring predominantly in the winter and least in the summer. Decomposition of the monthly incidence using Fourier analysis revealed the phase shift of the primary harmonic to be -21.9 and 169.8 degrees (days), respectively, for NH and SH. The resultant 191.7 day difference did not exactly correspond to the anticipated 6-month difference but was compatible with the original hypothesis.

CONCLUSION

Chronobiology plays a role in the occurrence of STADs with the highest occurrence in the winter months independent of the hemisphere. Season is not the predominant reason why aortas dissect, but for patients at risk, the increase in systemic vascular resistance during the winter months may account for the seasonal variations seen.

Contrasting patterns of hot spell effects on morbidity and mortality for cardiovascular diseases in the Czech Republic, 1994-2009

The study examines effects of hot spells on cardiovascular disease (CVD) morbidity and mortality in the population of the Czech Republic, with emphasis on differences between ischaemic heart disease (IHD) and cerebrovascular disease (CD) and between morbidity and mortality. Daily data on CVD morbidity (hospital admissions) and mortality over 1994-2009 were obtained from national hospitalization and mortality registers and standardized to account for long-term changes as well as seasonal and weekly cycles. Hot spells were defined as periods of at least two consecutive days with average daily air temperature anomalies above the 95% quantile during June to August. Relative deviations of mortality and morbidity from the baseline were evaluated. Hot spells were associated with excess mortality for all examined cardiovascular causes (CVD, IHD and CD). The increases were more pronounced for CD than IHD mortality in most population groups, mainly in males. In the younger population (0-64 years), however, significant excess mortality was observed for IHD while there was no excess mortality for CD. A short-term displacement effect was found to be much larger for mortality due to CD than IHD. Excess CVD mortality was not accompanied by increases in hospital admissions and below-expected-levels of morbidity prevailed during hot spells, particularly for IHD in the elderly. This suggests that out-of-hospital deaths represent a major part of excess CVD mortality during heat and that for in-hospital excess deaths CVD is a masked comorbid condition rather than the primary diagnosis responsible for hospitalization.

Cardiovascular response to thermoregulatory challenges

A growing number of extreme climate events are occurring in the setting of ongoing climate change, with an increase in both the intensity and frequency. It has been shown that ambient temperature challenges have a direct and highly varied impact on cardiovascular health. With a rapidly growing amount of literature on this issue, we aim to review the recent publications regarding the impact of cold and heat on human populations with regard to cardiovascular disease (CVD) mortality/morbidity while also examining lag effects, vulnerable subgroups, and relevant mechanisms. Although the relative risk of morbidity/mortality associated with extreme temperature varied greatly across different studies, both cold and hot temperatures were associated with a positive mean excess of cardiovascular deaths or hospital admissions. Cause-specific study of CVD morbidity/mortality indicated that the sensitivity to temperature was disease-specific, with different patterns for acute and chronic ischemic heart disease. Vulnerability to temperature-related mortality was associated with some characteristics of the populations, including sex, age, location, socioeconomic condition, and comorbidities such as cardiac diseases, kidney diseases, diabetes, and hypertension. Temperature-induced damage is thought to be related to enhanced sympathetic reactivity followed by activation of the sympathetic nervous system, renin-angiotensin system, as well as dehydration and a systemic inflammatory response. Future research should focus on multidisciplinary adaptation strategies that incorporate epidemiology, climatology, indoor/building environments, energy usage, labor legislative perfection, and human thermal comfort models. Studies on the underlying mechanism by which temperature challenge induces pathophysiological response and CVD await profound and lasting investigation.

Air travel of patients with abdominal aortic aneurysm: urgent air medical evacuation and nonurgent commercial air repatriation

Abdominal aortic aneurysm (AAA) presents across a spectrum of severity. Although some resources suggest a theoretic risk for rupture related to air travel, this claim remains unproven. In fact, there are little data from which to make evidence-based recommendations. Air medical evacuation of a patient with either an AAA at risk of imminent rupture or status post recent rupture can be performed, assuming that local surgical care is not available and that transfer is taking the patient to a higher level of medical intervention. Furthermore, medical opinion suggests that patients with asymptomatic and/or surgically corrected AAA can safely travel by commercial aircraft for nonurgent reasons, assuming that other issues including postoperative needs are appropriately addressed. In this discussion, answers to the following issues are sought: flight safety for urgent evacuation and nonurgent repatriation scenarios, waiting time to fly nonurgently after AAA diagnosis, and the need for medical accompaniment.

Influence of meteorological conditions on hospital admission in patients with acute coronary syndrome with and without ST-segment elevation: Results of the AIRACOS study

OBJECTIVE

Evaluate whether the meterological parameters affecting revenues in patients with ST-segment and non-ST-segment elevation ACS.

DESIGN

A prospective cohort study was carried out.

SETTING

Coronary Care Unit of Hospital Universitario de Canarias

PATIENTS

We studies a total of 307 consecutive patients with a diagnosis of ST-segment and non-ST-segment elevation ACS. We analyze the average concentrations of particulate smaller than 10 and 2.5μm diameter, particulate black carbon, the concentrations of gaseous pollutants and meteorological parameters (wind speed, temperature, relative humidity and atmospheric pressure) that were exposed patients from one day up to 7 days prior to admission.

INTERVENTIONS

None.

VARIABLES OF INTEREST

Demographic, clinical, atmospheric particles, concentrations of gaseous pollutants and meterological parameters.

RESULTS

A total of 138 (45%) patients were classified as ST-segment and 169 (55%) as non-ST-segment elevation ACS. No statistically significant differences in exposure to atmospheric particles in both groups. Regarding meteorological data, we did not find statistically significant differences, except for higher atmospheric pressure in ST-segment elevation ACS (999.6±2.6 vs. 998.8±2.5 mbar, P=.008). Multivariate analysis showed that atmospheric pressure was significant predictor of ST-segment elevation ACS presentation (OR: 1.14, 95% CI: 1.04-1.24, P=.004).

CONCLUSIONS

In the patients who suffer ACS, the presence of higher number of atmospheric pressure during the week before the event increase the risk that the ST-segment elevation ACS.

Higher outdoor temperatures are progressively associated with lower blood pressure: a longitudinal study in 100,000 healthy individuals

This study investigated the shape of associations between climate parameters (mean daily temperature and humidity) and systolic and diastolic blood pressure in a large longitudinal cohort of healthy individuals. The study population comprised 101,377 Dutch whole blood and plasma donors (50% men), who made 691,107 visits to the blood bank between 2007 and 2009. Climate parameters were acquired from the Royal Netherlands Meteorological Institute. Associations with blood pressure, measured prior to each blood donation, were studied using (piecewise) linear regression analyses within Generalized Estimating Equation models. On average, systolic blood pressure was 0.18 mm Hg, and diastolic blood pressure was 0.11 mm Hg lower per one degree Celsius higher mean daily temperature. Higher daily temperatures were associated with lower blood pressure, independent of humidity and potentially confounding factors. These associations were stronger at older age and higher temperatures. Seasonality should therefore be taken into account when monitoring blood pressure, particularly in older individuals.

Influence of weather conditions on the frequent onset of acute myocardial infarction

BACKGROUND

This study was conducted to clarify the influence of weather conditions on the onset of acute myocardial infarction (AMI) in Kumamoto.

METHODS

We studied 642 consecutive patients (males 433, females 209; 71±13 years) who were admitted with AMI. Days of frequent onset (F-days) were defined as days on which ≥2 patients had been admitted for AMI, whereas days of non-frequent onset (N-days) indicated those with fewer than 2 admissions for AMI. Meteorological factors, including the mean atmospheric pressure and rainfall, the mean, maximum, and minimum temperature, intra-day temperature difference, humidity, wind speed, and the number of sunlight hours, were analyzed. All variables were measured on the day of onset of AMI and on each of the 2 days immediately prior to the day of onset.

RESULTS

There were 86 F-days and 1740 N-days. F-days were significantly associated with lower air temperature (mean, maximum, and minimum), higher intra-day temperature difference, lower humidity, and longer daily duration of sunlight compared with N-days. In addition, meteorological factors for frequent onset of AMI affected older subjects to a greater extent than either young or female subjects. Multiple logistic regression analysis showed that minimum temperature two days before onset was associated with the frequent onset of AMI (odds ratio, 0.805; p<0.05).

CONCLUSION

Lower minimum temperature on the 2nd day preceding the onset is an independent risk factor for the frequent onset of AMI. The association between low ambient temperature and frequent onset of AMI was stronger in elderly and female subjects.

Atmospheric pressure changes are associated with type a acute aortic dissections and spontaneous abdominal aortic aneurysm rupture in tuzla canton

Aim:

The aim of this study was to investigate a relationship between seasonal variation and incidence of type A acute aortic dissection (AAD) and spontaneous abdominal aneurysm rupture (rAAA) in Canton Tuzla, Bosnia and Herzegovina.

Patients and methods:

A total of 81 cases, 41 AAD and 40 of ruptured AAA were identified from one center over a 6-year, from 2008 till 2013. In 2012 were admitted (45.6% or 36 patients).

Results:

Seasonal analysis showed that 19(23.4%) patients were admitted in spring, 15(18.5) in summer, 26(32%) in autumn and 21(25.9) in winter. The most frequent period was autumn/winter with 47 or 58% patients. A causal link between atmospheric pressure (AP) and incidence of rAAA and AAD on seasonal and monthly basis was found.

Influence of daily individual meteorological parameters on the incidence of acute coronary syndrome

BACKGROUND

A nationwide study was conducted to explore the short term association between daily individual meteorological parameters and the incidence of acute coronary syndrome (ACS) treated with coronary emergency catheter interventions in the Republic of Slovenia, a south-central European country.

METHOD

We linked meteorological data with daily ACS incidence for the entire population of Slovenia, for the population over 65 years of age and for the population under 65 years of age. Data were collected daily for a period of 4 years from 1 January 2008 to 31 December 2011. In line with existing studies, we used a main effect generalized linear model with a log-link-function and a Poisson distribution of ACS.

RESULTS AND CONCLUSIONS

Three of the studied meteorological factors (daily average temperature, atmospheric pressure and relative humidity) all have relevant and significant influences on ACS incidences for the entire population. However, the ACS incidence for the population over 65 is only affected by daily average temperature, while the ACS incidence for the population under 65 is affected by daily average pressure and humidity. In terms of ambient temperature, the overall findings of our study are in line with the findings of the majority of contemporary European studies, which also note a negative correlation. The results regarding atmospheric pressure and humidity are less in line, due to considerable variations in results. Additionally, the number of available European studies on atmospheric pressure and humidity is relatively low. The fourth studied variable-season-does not influence ACS incidence in a statistically significant way.

Effect of initial temperature changes on myocardial enzyme levels and cardiac function in acute myocardial infarction

In the present study, the effect of initial body temperature changes on myocardial enzyme levels and cardiac function in acute myocardial infarction (AMI) patients was investigated. A total of 315 AMI patients were enrolled and the mean temperature was calculated based on their body temperature within 24 h of admission to hospital. The patients were divided into four groups according to their normal body temperature: Group A, <36.5°C; group B, ≥36.5°C and <37.0°C; group C, ≥37.0°C and <37.5°C and group D, ≥37.5°C. The levels of percutaneous coronary intervention, myocardial enzymes and troponin T (TNT), as well as cardiac ultrasound images, were analyzed. Statistically significant differences in the quantity of creatine kinase at 12 and 24 h following admission were identified between group A and groups C and D (P<0.01). A significant difference in TNT at 12 h following admission was observed between groups A and D (P<0.05), however, this difference was not observed with groups B and C. The difference in TNT between the groups at 24 h following admission was not statistically significant (P>0.05). Significant differences in lactate dehydrogenase at 12 and 24 h following admission were observed between groups A and D (P<0.05), however, differences were not observed with groups B and C (P>0.05). Significant differences in glutamic-oxaloacetic transaminase at 12 and 24 h following admission were observed between groups A and D (P<0.05), however, differences were not observed in groups B and C (P>0.05). However, no significant differences were identified in cardiac function index between all the groups. Therefore, the results of the present study indicated that AMI patients with low initial body temperatures exhibited decreased levels of myocardial enzymes and TNT. Thus, the observation of an initially low body temperature may be used as a protective factor for AMI and may improve the existing clinical program.

Do outside temperature and sunlight duration influence the outcome of laser refractive surgery? Results from the Hamburg Weather Study

PURPOSE

To examine the impact of temperature and sunlight duration on refractive and visual outcome of laser-assisted in situ keratomileusis (LASIK) in myopic eyes.

SETTING

University Medical Center Hamburg-Eppendorf, Germany, and Care Vision Refractive Centers, Germany.

DESIGN

Retrospective, cross-sectional data analysis.

METHODS

This study comprised 1,052 eyes of 1,052 consecutive myopic patients (419 males, 633 females; mean age at surgery 35.0±9.0 years) with a mean preoperative refractive spherical equivalent (SE) of -3.88±1.85 diopters (D). Two subgroups were defined, comprising patients undergoing surgery during either meteorological winter or summer. Manifest refraction, uncorrected, and corrected distant visual acuity (UDVA and CDVA) were assessed pre- and postoperatively. We applied robust regression analysis with efficiency index (EI), safety index (SI), and postoperative SE (in D) as dependent variables.

RESULTS

At the 1-month (33.0±5.0 days) follow-up, the mean postoperative SE was -0.18±0.44 D. Bivariate comparisons showed that statistically significant better EI was related to days with lower temperature. We obtained a significant difference for SI which suggested that low temperature had a positive influence on SI. No change by more than one line on LogMAR scale was obtained.

CONCLUSION

Although being statistically significant, there was no clinically relevant difference in the outcome of LASIK, which demonstrates its highly standardized quality. Prospective, longitudinal studies are warranted to address meteorotropic reactions through evaluating defined meteorological parameters.

Impacts of hot and cold spells differ for acute and chronic ischaemic heart diseases

Background

Many studies have reported associations between temperature extremes and cardiovascular mortality but little has been understood about differences in the effects on acute and chronic diseases. The present study examines hot and cold spell effects on ischaemic heart disease (IHD) mortality in the Czech Republic during 1994–2009, with emphasis upon differences in the effects on acute myocardial infarction (AMI) and chronic IHD.

Methods

We use analogous definitions for hot and cold spells based on quantiles of daily average temperature anomalies, thus allowing for comparison of results for summer hot spells and winter cold spells. Daily mortality data were standardised to account for the long-term trend and the seasonal and weekly cycles. Periods when the data were affected by epidemics of influenza and other acute respiratory infections were removed from the analysis.

Results

Both hot and cold spells were associated with excess IHD mortality. For hot spells, chronic IHD was responsible for most IHD excess deaths in both male and female populations, and the impacts were much more pronounced in the 65+ years age group. The excess mortality from AMI was much lower compared to chronic IHD mortality during hot spells. For cold spells, by contrast, the relative excess IHD mortality was most pronounced in the younger age group (0–64 years), and we found different pattern for chronic IHD and AMI, with larger effects on AMI.

Conclusions

The findings show that while excess deaths due to IHD during hot spells are mainly of persons with chronic diseases whose health had already been compromised, cardiovascular changes induced by cold stress may result in deaths from acute coronary events rather than chronic IHD, and this effect is important also in the younger population. This suggests that the most vulnerable population groups as well as the most affected cardiovascular diseases differ between hot and cold spells, which needs to be taken into account when designing and implementing preventive actions.

Do air pressure and wind speed influence the outcome of myopic laser refractive surgery? Results from the Hamburg Weather Study

Laser in situ keratomileusis (LASIK) is one of the dominant procedures for the surgical correction of refractive errors. Meteorotropic reaction has been described regarding the field of ophthalmology. This study was thus initiated to assess the impact of air pressure and wind speed on the refractive and visual outcome of LASIK in myopic eyes. Our study comprised 1,052 eyes of 1,052 consecutive myopic patients (419 males, 633 females; mean age at surgery 35.0 ± 9.0 years) with mean preoperative refractive spherical equivalent (SE) of -3.88 ± 1.85 diopters (D). Two subgroups were defined, which had undergone surgery either during meteorological winter or summer. Manifest refraction, uncorrected and corrected visual acuity were assessed pre- and post-operatively. We applied robust regression analysis with efficiency index (EI), safety index, and postoperative SE (D) as dependent variables. At the 1-month (33.0 ± 5.0 days) follow-up, the mean postoperative SE was -0.18 ± 0.44 D. Bivariate comparisons showed that statistically significant better EI was related to days with low to moderate air-pressure. This was confirmed by robust regression analysis. Moderate to high wind speed was related to more appropriate postoperative SE. No change by more than one line on logMar scale was obtained. Although being statistically significant, there is no clinically relevant difference in outcome of LASIK, which demonstrates its highly standardized quality. Prospective, longitudinal studies are warranted to address meteorotropic reactions through evaluating individual risk profiles.