Low atmospheric pressure is associated with rupture of abdominal aortic aneurysms

A systematic review and case presentation: Giant abdominal aortic aneurysm

OBJECTIVE

An abdominal aortic aneurysm is considered giant when its transverse diameter is greater than 10-13 cm in diameter. A giant abdominal aortic aneurysm is rare but with a significant risk of rupture if it is not diagnosed or left untreated.

METHOD

The authors have performed a systematic review of the evidence that has looked into the clinical presentations, and management methods employed and have presented a 14 cm giant abdominal aortic aneurysm patient.

RESULTS

The systematic review has been based on level-IV evidence due to the rarity of the condition. The final analysis included 61 relevant reported cases. The mean age was 72.4 years, the male to female ratio was 52: 8, and the average size of a giant abdominal aortic aneurysm was 14.7 cm. These were mostly infra renal (72.58%). Rupture of these aneurysms was found in 23 (37.1%) patients, and was treated by laparotomy in 51 (82.25%) cases. There were 11 (17.74%) mortalities.

CONCLUSION

The size of an abdominal aortic aneurysm is known to be the biggest factor in the rupture of an aneurysm. The reason abdominal aortic aneurysms can reach such size without rupturing is unclear but needs further exploring. Early diagnosis with effective screening programmes is essential to diagnose in a timely manner to avoid life-threatening consequences.

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.

Aortic aneurysm disease-Make room for chronobiology

BACKGROUND

Aortic aneurysm (AA) is a common atherosclerotic condition, accounting for nearly 6000 deaths in England and up to 175,000 deaths globally each year. The pathological outward bulging of the aorta typically results from atherosclerosis or hereditary connective tissue disorders. AAs are usually asymptomatic until spontaneous rupture or detected on incidental screening. Eight in 10 patients do not survive the rupture and die either before reaching hospital or from complications following surgery. Similar to other cardiovascular pathologies, AA is thought to be subject to chronobiological patterns of varying incidence.

METHODS

We performed a literature review of the current literature to evaluate the association between circadian rhythms, seasonal variations, and genetic factors and the pathogenesis of AA, reviewing the impact of chronobiology.

RESULTS

The incidence of AA is found to peak in the early morning (6-11 a.m.) and colder months, and conversely troughs towards the evening and warmer months, exhibiting a similar pattern of chronobiological rhythm as other cerebrovascular pathologies, such as myocardial infarcts, or cerebrovascular strokes.

CONCLUSION

Literature suggests there exists a clear relationship between chronobiology and the incidence and pathogenesis of ruptured AA; incidence increases in the morning (6-11 a.m.), and during colder months (December-January). This is more pronounced in patients with Marfan syndrome, or vitamin D deficiency. The underlying pathophysiology and implications this has for chronotherapeutics, are also discussed. Our review shows a clear need for further research into the chronotherapeutic approach to preventing ruptured AA in the journey towards precision medicine.

Climatic influence on the risk of abdominal aortic aneurysm rupture

Our aim is to examine the effects of climatic conditions on the incidence of ruptured abdominal aortic aneurysms (rAAA) in Catalonia, Spain. We combined clinical data from the Public Health official registries in Catalonia, Spain (HD-MBDS) of all rAAA with local climatic data obtained from the closest meteorological station (69 stations, National Meteorological Service: MeteoCat) from 2008 to 2017. We analyzed the median, maximum, minimum, and variability of atmospheric pressure (hPa) and air temperature (°C), solar irradiation (MJ/m²), humidity (%), accumulated precipitation (mm), median wind, and maximum flaw direction and velocity (°, m/s), recorded on the days of events, the previous day, and mean results for 3, 7, and 30 days before, as well as seasonality. Seventy-five control days were randomly selected in a 1-year period around every rAAA day at the same meteorological station, and compared. A total of 717 days and locations with rAAA were identified, and 53,775 controls were randomly selected. For the rAAA days, there were significantly lower temperatures, lower solar global irradiation, and higher mean humidity levels in all time periods (p < 0.001, p < 0.001, p < 0.05); higher atmospheric pressure variability during 1 week and 1 month before (p = 0.011, p = 0.007); and they often occurred during autumn/winter (57.6%, p < 0.001). Logistic regression identified low mean temperatures on the days of ruptures and high mean humidity the week before as independent rupture predictors. In conclusion, low median temperatures the same day and high humidity during 1 week before were identified as independent predictors of rAAA occurrence. The role of climate on pathophysiologic mechanisms may require further investigation.

The effects of changing meteorological parameters on fatal aortic catastrophes

Background

Over the span of the last decade, medical research has been increasingly putting greater emphasis on the study of meteorological parameters due to their connection to cardiovascular diseases. The main goal of this study was to explore the relationship between fatal aortic catastrophes and changes in atmospheric pressure and temperature.

Methods

We used a Cox process model to quantify the effects of environmental factors on sudden deaths resulting from aortic catastrophes. We used transfer entropy to draw conclusion about the causal connection between mortality and meteorological parameters. Our main tool was a computer program which we developed earlier in order to evaluate the relationship between pulmonary embolism mortality and weather on data sets comprised of aortic aneurysm (AA) and acute aortic dissection (AAD) cases, where one of these two medical conditions had led to fatal rupture of the aorta. Our source for these cases were the autopsy databases of Semmelweis University, from the time period of 1994 to 2014. We have examined 160 aneurysm and 130 dissection cases in relation to changes in meteorological parameters. The algorythm implemented in our program is based on a non-parametric a Cox process model. It is capable of splitting slowly varying unknown global trends from fluctuations potentially caused by weather. Furthermore, it allows us to explore complex non-linear interactions between meteorological parameters and mortality.

Results

Model measures the relative growth of the expected number of events on the n^th day caused by the deviation of environmental parameters from its mean value. The connection between ruptured aortic aneurysms (rAA) and changes in atmospheric pressure is more significant than their connection with mean daily temperatures. With an increase in atmospheric pressure, the rate of rAA mortality also increased. The effects of meteorological parameters were weaker for deaths resulting from acute aortic dissections (AAD), although low mean daily temperatures increased the intensity of occurrence for AAD-related deaths.

Conclusion

The occurrence rate of fatal aortic catastrophes showed a slight dependence on the two examined parameters within our groups.

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.

Chronologic and Climatic Factors of Acute Aortic Dissection: Study of 1642 Patients in Two Continents

BACKGROUND

The purpose of this study was to examine whether chronologic and climatic factors and lunar phases affect the onset of acute aortic dissection (AAD).

METHODS

The frequencies of AAD were analyzed with regard to the chronologic and climatic factors and lunar phases on the day when AAD occurred for 1642 patients with AAD from two aortic referral centers in the United States and China.

RESULTS

Mean age of patients was 51.6 ± 13.1 years, and 1260 (76.7%) were men. Dissection was type A in 1125 patients (68.5%) and type B in 517 (31.5%). Early mortality rate was 11.6% (190 of 1642), including 89 aortic ruptures before operation and 101 operative deaths. There was a winter peak in occurrence (33.6%, P < .01) with a relative risk of 1.519. In a week, the frequency was highest on Wednesday (15.5%) and Monday (15.2%), and lowest on Sunday (12.8%). Month-specific incidence was significantly inversely correlated to the mean temperature (rho = -0.650, P = .022) and directly correlated to the atmospheric pressure (rho = 0.706, P = .001). The proportion of type A dissection was significantly higher in the full moon phase compared with type B dissection (73.7% vs 66.9%, P = .012).

CONCLUSIONS

Acute aortic dissection exhibits significant chronologic variation in the frequency of occurrence, with a peak in winter and on Wednesdays, and nadir in summer and on Sundays. The incidence is significantly correlated to the mean temperature and atmospheric pressure. The proportion of type A dissection is higher in the full moon phase. These results are important for understanding the mechanisms involved in triggering AAD events and helpful for improving disease prevention and patient care.

Influence of earthquakes on the occurrence of aortic aneurysm ruptures

BACKGROUND

Catastrophic events have been correlated to increased incidence of cardio-vascular events, but no correlation between RAA and seismic activities have ever been investigated.

METHODS

Hospital admissions related to RAA between January 2014 and December 2016 were retrospectively assessed in nine vascular centers of central Italy and correlated with date-matched seismic events. Correlation between RAA presentation and seismic event was first evaluated by Linear Regression analysis. Incidence of RAA events, mortality rate, and type of intervention were analyzed during seismic days (SD) and compared to outcomes during non-seismic days (nSD).

RESULTS

A total of 376 patients were admitted with a diagnosis of RAA, and a total of 783 seismic events were reviewed. Twenty patients died before intervention (untreated). Open surgery was performed in 72.8%, endovascular treatment in 27.2%. General mortality at 30 days was 26.6% (30.5% for open surgery; 21.6% for endovascular treatment; P=0.24). Linear regression analysis between RAA and seismic periods revealed a significant correlation (slope=0.11±0.04, equation: y = 0.1143 x + 3.034, P=0.02). Incidence of RAA was 0.34 event per day during the entire period, 0.32 during nSD and 0.44 during SD (P=0.006). During seismic days, patients with RAA were older (80.5 years during SD vs. 77 years during nSD, P=0.12), were in poorer general condition at admission and remained untreated more frequently (8% SD vs. 4.7% nSD, P=0.3), and had a higher mortality rate at 30 days (46.2% SD vs. 27.2% nSD, P=0.012).

CONCLUSIONS

During seismic days, the incidence of RAA is higher in comparison to non-seismic days. Patients with rupture during seismic days have a higher risk of death.

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.

Seasonal incidence of ruptured abdominal aortic aneurysm and the influence of atmospheric pressure: a systematic review and meta-analysis

Ruptured abdominal aortic aneurysm (rAAA) is a life-threatening condition with a high mortality rate. Seasonal variations in the incidence of rAAA and the influence of atmospheric pressure have been studied throughout decades; however, the conclusions are contradictory. Therefore, we aimed to conduct a meta-analysis and systematic review of literature on seasonal variations in rAAA incidence and the influence of atmospheric pressure. Studies investigating seasonal variations in rAAA incidence and influence of atmospheric pressure were retrieved. For dichotomous data, we generated risk ratios (RRs) and 95% confidence intervals (CIs) for rAAA incidence compared among seasons. The studies were subdivided according to latitude, elevation, and climatic types, for subgroup comparisons. Studies reporting monthly incidence and seasonal mortality were further investigated. For continuous data, standardized mean differences (SMDs) and 95% CIs were generated for atmospheric pressure comparisons. Twenty-four eligible studies were included, comprising a total of 38,506 patients with rAAA. Pooled rAAA incidence was 25% in spring, 23% in summer, 26% in autumn, and 26% in winter. Pooled analysis demonstrated a statistically significant higher rAAA incidence in winter than in summer (RR 1.10, P = 0.04) and in autumn than in summer (RR 1.11, P < 0.00001). However, there was no statistically significant difference among other seasons. In the study of the influence of atmospheric pressure, no statistically significant difference was observed. In conclusion, our study revealed a higher incidence of rAAA in autumn and winter than in summer; however, atmospheric pressure was found to exert no influence.

Effects of atmospheric pressure dynamics on abdominal aortic aneurysm rupture onset

BACKGROUND

The effect of atmospheric pressure (AP) on the onset of abdominal aorta aneurysm rupture (RAAA) remains an unanswered question. We have investigated the seasonal variation and the effect of AP dynamics on RAAA by analysing the largest series of intraoperatively confirmed RAAA.

PATIENTS AND METHODS

To realize this study we have performed a retrospective analysis of 546 patients with RAAA, operated within 503 days at the Clinic for vascular and endovascular surgery CCS between 1.1.2003 and 31.12.2012. AP data for Belgrade city were obtained from meteorological yearbooks published by the Republic Hydrometeorological Service of Serbia measured at the hydrometeorological station "Belgrade Observatory". Only patients with a residence within the extended Belgrade region, exposed to the similar AP values, were included in the analysis of the AP effect on RAAA.

RESULTS

RAAA were observed more frequently during winter and autumn months but without significant difference in comparison to other seasons. Months with higher AP values were associated with a higher RAAA rate (p = 0.0008, R2 = 0.665). A similar trend was observed for the monthly AP variability (p = 0.0311, R2 = 0.374). Average AP values did not differ between days with and without RAAA. However, during the three and seven days periods preceding RAAA AP variability parameters were greater and AP was rising.

CONCLUSIONS

Although these pressure differences are very small, higher AP values over longer periods of time as well as greater variability are associated with RAAA. The exact mechanism behind this association remains unclear. The postulation that low AP may precipitate RAAA based on the Laplace law should be discarded.

Atmospheric Pressure and Abdominal Aortic Aneurysm Rupture: Results From a Time Series Analysis and Case-Crossover Study

BACKGROUND

Associations between atmospheric pressure and abdominal aortic aneurysm (AAA) rupture risk have been reported, but empirical evidence is inconclusive and largely derived from studies that did not account for possible nonlinearity, seasonality, and confounding by temperature.

METHODS

Associations between atmospheric pressure and AAA rupture risk were investigated using local meteorological data and a case series of 358 patients admitted to hospital for ruptured AAA during the study period, January 2002 to December 2012. Two analyses were performed-a time series analysis and a case-crossover study.

RESULTS

Results from the 2 analyses were similar; neither the time series analysis nor the case-crossover study showed a significant association between atmospheric pressure ( P = .627 and P = .625, respectively, for mean daily atmospheric pressure) or atmospheric pressure variation ( P = .464 and P = .816, respectively, for 24-hour change in mean daily atmospheric pressure) and AAA rupture risk.

CONCLUSION

This study failed to support claims that atmospheric pressure causally affects AAA rupture risk. In interpreting our results, one should be aware that the range of atmospheric pressure observed in this study is not representative of the atmospheric pressure to which patients with AAA may be exposed, for example, during air travel or travel to high altitudes in the mountains. Making firm claims regarding these conditions in relation to AAA rupture risk is difficult at best. Furthermore, despite the fact that we used one of the largest case series to date to investigate the effect of atmospheric pressure on AAA rupture risk, it is possible that this study is simply too small to demonstrate a causal link.

Association between lower air pressure and the onset of ischemic colitis: a case-control study

OBJECTIVE

Ischemic colitis (IC) often affects the elderly. Proarteriosclerotic factors, such as hypertension and smoking, and cardiovascular disease are considered major contributors to IC. Although a possible link between certain cerebrocardiovascular disorders and meteorological phenomena has been reported, the relationship between IC onset and weather changes remains uninvestigated. This study examined whether specific meteorological factors were associated with the occurrence of IC.

PATIENTS AND METHODS

We retrospectively enrolled 303 patients who had been diagnosed with IC between January 2003 and June 2010 at Suwa Red Cross Hospital in Nagano Prefecture, Japan. The meteorological data of the days on which IC patients visited the hospital (IC+ days) were compared with those of the days on which IC patients did not (IC- days).

RESULTS

Univariate analysis indicated that IC+ days had significantly lower air pressure (P<0.001), depressed air pressure from the previous day (P<0.001), and fewer daylight hours (P<0.001), as well as higher air temperature (P=0.017), air humidity (P=0.004), wind velocity (P<0.001), and rainfall (P=0.012) compared with IC- days. Multivariate logistic regression analysis of the meteorological data showed that air pressure (odds ratio: 0.935, P<0.001) and change in air pressure from the previous day (odds ratio: 0.934, P<0.001) were related to onset of IC.

CONCLUSION

Lower air pressure and decrease in air pressure from the previous day are possible novel factors associated with the development of IC.

Weather conditions and their effect on the increase of the risk of type A acute aortic dissection onset in Berlin

In this study, a minimum distance classification and forward feature selection technique are joined to determine the relationship between weather conditions and the increase of the risk of type A acute aortic dissection (AAD) events in Berlin. The results demonstrate that changes in the amount of cloudiness and air temperature are the most representative weather predictors among the studied parameters. A discrimination surface was developed for the prediction of AAD events 6 h ahead, and it is found that, under a specific amount of cloudiness and air temperature, the risk of AAD events in Berlin increases about 20 %.

The impact of weather factors, moon phases, and seasons on abdominal aortic aneurysm rupture

BACKGROUND

Several studies have documented that weather factors, seasons of the year, time of the day, and even changes in moon phases have an impact on the occurrence of rupture of an abdominal aortic aneurysm (RAAA); however, the available data are confounding. The objective of this study was to determine the impact of these factors on the prevalence and mortality rate of RAAA.

METHODS

This is a retrospective analysis of medical records of patients treated for RAAA over a 10-year period. Weather data (i.e., atmospheric pressure, air temperature, humidity, visibility, and wind speed) and weather events (i.e., rain, snow, and storms, etc) were obtained from the local meteorologic weather station and analyzed for a correlation with RAAA.

RESULTS

Five hundred thirty patients with RAAA were identified, and these patients presented on 478 days during the 10-year study period (3,652 days), with the overall in-hospital mortality rate of 48.7%. The RAAA mortality was higher during weekends and national holidays, when compared to weekdays (59% vs 45%; P = 0.006) and in patients admitted between 3-7 am when compared to work day hours (65.5% vs 44.1%; P = 0.035). Season changes had no influence on the frequency of RAAA; however, summer seemed to be associated with an increase in mortality as opposed to autumn (54.4% vs 42.5%; P = 0.047). Mean atmospheric pressure (and fluctuations thereof) and other weather factors, including phases and parts of the moon, did not correlate with RAAA occurrence or its mortality.

CONCLUSIONS

Patients with RAAA who were admitted on weekends, national holidays and in late night hours had lower survival rates. Weather factors (including atmospheric pressure) do not influence the prevalence and mortality of RAAA.

Impact of meteorological conditions on abdominal aortic aneurysm rupture: evaluation of an 18-year period and review of the literature

OBJECTIVE

To examine the influence of local meteorological conditions on the onset of ruptured abdominal aortic aneurysms (AAA).

METHODS

A review of 6551 consecutive days with a total of 191 ruptured AAA was performed between January, 1994 and December, 2011. Days with and without ruptured AAA were compared considering local meteorological data. A systematic review of the literature was performed.

RESULTS

Atmospheric pressure, cloudiness, relative humidity, precipitation, and water vapor pressure were comparable at event and nonevent days. The 4-day variance of atmospheric pressure prior to event days was significantly higher compared to nonevent days. Maximal and average temperature and water vapor pressure were significant lower at event days. Binary regression analysis identified a higher 4-day variance in atmospheric pressure as an independent factor for ruptures.

CONCLUSIONS

Further studies-collected at different geographic and climate areas-are necessary to prove that meteorological conditions may trigger the incidence of ruptured AAA.

Winter cardiovascular diseases phenomenon

This paper review seasonal patterns across twelve cardiovascular diseases: Deep venous thrombosis, pulmonary embolism, aortic dissection and rupture, stroke, intracerebral hemorrhage, hypertension, heart failure, angina pectoris, myocardial infarction, sudden cardiac death, venricular arrythmia and atrial fibrillation, and discuss a possible cause of the occurrence of these diseases. There is a clear seasonal trend of cardiovascular diseases, with the highest incidence occurring during the colder winter months, which have been described in many countries. This phenomenon likely contributes to the numbers of deaths occurring in winter. The implications of this finding are important for testing the relative importance of the proposed mechanisms. Understanding the influence of season and other factors is essential when seeking to implement effective public health measures.

Chronobiology in aortic diseases - "is this really a random phenomenon?"

Although acute aortic rupture or dissection is relatively uncommon, it ranks in third position among necropsy-confirmed causes of out-of-hospital sudden death in the general population. Similar to other acute cardiovascular events (e.g., acute myocardial infarction, sudden death, stroke, and pulmonary embolism) there is a growing body of evidence regarding temporal patterns in onset, characterized by circadian, seasonal and weekly variations for aortic aneurysms. On one hand, it is possible that these cardiovascular diseases share common underlying pathophysiologic mechanisms, e.g., increase in blood pressure, heart rate, sympathetic activity, basal vascular tone, vasoconstrictive hormones, and prothrombotic tendency. On the other hand, the possibility exists that the connecting link is an internal disruption (dyssynchrony) of some molecular mechanisms intrinsic to the peripheral biological clock (that of cardiomyocyte is the most widely investigated). Such disruption may contribute to cardiovascular disease and biological rhythms - an intriguing hypothesis for future research.

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

BACKGROUND

The impact of meteorological conditions on the occurrence of various cardiovascular events has been reported internationally. Data about the Dutch situation are limited.

OBJECTIVES

We sought to find out a correlation between weather conditions and the incidence of major acute cardiovascular events such as type A acute aortic dissection (AAD), acute myocardial infarction (AMI) and acutely presented abdominal aortic aneurysms (AAAA).

METHODS

Between January 1998 and February 2010, patients who were admitted to our hospital (Catharina Hospital, Eindhoven, the Netherlands) because of AAD (n = 212), AMI (n = 11389) or AAAA (n = 1594) were registered. These data were correlated with the meteorological data provided by the Royal Dutch Meteorological Institute (KNMI) over the same period.

RESULTS

During the study period, a total number of 11,412 patients were admitted with AMI, 212 patients with AAD and 1593 patients with AAAA. A significant correlation was found between the daily temperature and the number of hospital admissions for AAD. The lower the daily temperature, the higher the incidence of AAD (p = 0.002). Lower temperature was also a predictor of a higher incidence of AMI (p = 0.02). No significant correlation was found between daily temperature and onset of AAAA.

CONCLUSIONS

Cold weather is correlated with a higher incidence of AAD and AMI.

Are periods of low atmospheric pressure associated with an increased risk of abdominal aortic aneurysm rupture?

INTRODUCTION

Seasonal variation in rates of abdominal aortic aneurysm (AAA) rupture has previously been described. However, only two studies, to date, have suggested that periods of low atmospheric pressure may account for this observation and both returned apparently contradictory findings. The objective of this study was to demonstrate whether periods of low atmospheric pressure are indeed associated with an increased likelihood of AAA rupture presentation.

PATIENTS AND METHODS

A total of 182 cases of ruptured AAA were identified retrospectively from two centres over a 6-year period from January 2000 to December 2005. Local meteorological data for the corresponding period was obtained from the UK Meteorological Office which was recorded daily at a local weather station. Statistical analysis using Student's t-test, ANOVA (Kruskal-Wallis), linear regression and multiple logistic regression was conducted to identify significant relationships from the data.

RESULTS

Days of rupture presentation were associated with a significantly lower daily mean atmospheric pressure when compared with days when no rupture occurred (P = 0.025). Multiple logistic regression demonstrated a significant association between low daily atmospheric pressure and rupture incidence (P = 0.033) which appeared to be independent of temperature. A significant seasonal trough in atmospheric pressure was observed in October and November (Kruskal-Wallis, P < 0.001); however, there was no corresponding autumnal peak in rupture incidence (P = 0.232).

CONCLUSIONS

The findings of this study appear to confirm the assertion that low atmospheric pressure is associated with an increased risk of AAA rupture on a day-to-day basis; however, no evidence was identified to support a change in policy regarding prioritising elective surgery based on seasonal risk.

[Abdominal aortic aneurysm and renovascular disease]

Recent technological advances in the diagnosis and therapy of abdominal aortic aneurysm and renovascular disease are continuing to bring about changes in the way patients suffering from these conditions are treated. The prevalence of both these conditions is increasing. This is due to greater life-expectancy in patients with arteriosclerosis, a pathogenetic factor underlying both conditions. The application of diagnostic imaging techniques to non-vascular conditions has led to the early diagnosis of abdominal aortic aneurysm. Clinical suspicion of reno-vascular disease can be confirmed easily using high-resolution diagnostic imaging modalities such as CT angiography and magnetic resonance angiography. Endovascular intervention is successfully replacing conventional surgical repair techniques, with the result that it may be possible to improve outcome in both conditions using effective and minimally invasive approaches. Future technological developments will enable these endovascular techniques to be applied in the large majority of patients with abdominal aortic aneurysm or renovascular disease.

Is there a relationship between weather conditions and aortic dissection?

Background

Bleeding and rupture of blood vessels has been correlated with weather conditions in the past. This is the first study in the world literature with the aim of investigating the relationship between atmospheric pressure and temperature with the presentation of aortic dissection.

Methods

The dates of all emergency aortic dissection repairs from 1996–2002 in a regional cardiothoracic unit at Blackpool Victoria Hospital were obtained. Hourly temperature and pressure data from a regional weather station for this time period was supplied by the Meteorological Office. The mean and standard deviation of hourly temperature and pressure data for that month were compared to the mean and standard deviation of the data 24 and 48 hours prior to the aortic dissection.

Results

26 patients were found to have been operated on during the time period studied. There was no statistically significant correlation between temperature or atmospheric pressure readings, and the incidence of aortic dissection, using a Bonferonni-corrected significance p-value of 0.005

Conclusion

This study is the first to examine the relationship between atmospheric pressure, temperature and dissecting thoracic aorta. No statistically significant relationship was demonstrable.

In-hospital Operative Mortality of Ruptured Abdominal Aortic Aneurysm: A Population-based Analysis of 5593 Patients in The Netherlands Over a 10-year Period

OBJECTIVE

To determine the operative mortality of ruptured abdominal aortic aneurysm (RAAA) in The Netherlands.

DESIGN

Retrospective population-based study of nation-wide in-hospital mortality of RAAA repair.

METHODS

Data were obtained from a national registry for medical diagnosis and procedures. In-hospital mortality of RAAA repair, defined as death during hospital admission irrespective of the cause of death, was determined in the period 1991-2000. Variables of potential influence on in-hospital mortality, including age, gender, date of surgery and hospital type (0-399 beds, > or =400 beds or university hospitals) were studied in a multivariate analysis.

RESULTS

The overall in-hospital mortality of RAAA repair in 5593 patients in the 10-year period was 41% (95% confidence interval: 40-42%). In the multivariate analysis, age and hospital type were the most important independent predictors for in-hospital mortality. Gender, year and season of surgery could not be identified as significant risk factors.

CONCLUSIONS

Over a recent decade, in-hospital mortality of RAAA repair remained unchanged at 41%. Age and hospital class were the most important independent risk factors.