Monday preference in onset of ischemic stroke

Daylight saving time affects European mortality patterns

Daylight saving time (DST) consists in a one-hour advancement of legal time in spring offset by a backward transition of the same magnitude in fall. It creates a minimal circadian misalignment that could disrupt sleep and homoeostasis in susceptible individuals and lead to an increased incidence of pathologies and accidents during the weeks immediately following both transitions. How this shift affects mortality dynamics on a large population scale remains, however, unknown. This study examines the impact of DST on all-cause mortality in 16 European countries for the period 1998-2012. It shows that mortality decreases in spring and increases in fall during the first two weeks following each DST transition. Moreover, the alignment of time data around DST transition dates revealed a septadian mortality pattern (lowest on Sundays, highest on Mondays) that persists all-year round, irrespective of seasonal variations, in men and women aged above 40.

Weekly Variations of Intracerebral Hemorrhage Occurrence Among Different Populations: A Cross-Sectional Study

Background and purpose: The causes of the higher incidence of intracerebral hemorrhage (ICH) on a given day are unclear. Previous studies have shown that it may vary by region and population. The purpose of this study was to detect weekly variations in ICH occurrence in southwest China and to assess differences in ICH occurrence among different populations.

Methods: This hospital-based study included patients with first-onset ICH that occurred from January 1, 2012, to December 31, 2019. The weekly variation in ICH occurrence was analyzed and stratified by sex, age, comorbidities, living habits, and residence.

Results: A total of 5,038 patients with first-onset ICH were enrolled. ICH occurrence was higher on Monday [odds ratio (OR), 1.22; 95% CI, 1.09–1.36; P < 0.001] and Friday (OR, 1.15; 95% CI, 1.03–1.28; P < 0.001) among all patients, and this pattern was consistent with that of men, whereas women showed a higher incidence on Mondays, Saturdays, and Sundays. The increase in the number of ICH events on Monday and Friday was pronounced in the age range of 41–60 years; however, no significant weekly variation in ICH occurrence was observed among other age groups. After stratifying by comorbidities, a significant weekly variation in ICH occurrence was observed in patients with hypertension or diabetes. Smoking and alcohol consumption was associated with a higher incidence of ICH on Friday; otherwise, a Monday excess was observed. The urban population demonstrated a significant weekly variation in ICH occurrence, whereas the rural population did not.

Conclusions: Intracerebral hemorrhage occurrence showed weekly variations in southwest China and was significantly affected by sex, age, comorbidities, living habits, and residence. This suggests that weekly variations in ICH occurrence maybe dependent on the region and population.

Circadian variations in the onset of aortic dissection in northern China

This study explored the periodic changes in the onset of aortic dissection in a single center in northern China, with the goal to improve predictability and prevention. We collected the clinical data of 1121 patients from Hebei Province treated for acute aortic dissection at Fuwai Hospital between January 2010 and December 2016. The patterns of aortic dissection during different periods of each day, each month, and each quarter of a year were analyzed. Variations in the number of cases were summarized for weekdays, weekends, and different periods of a day in each season. We compared the differences in gender, age, body mass index, Marfan syndrome, hypertension, and the type of aortic dissection during different time periods and different seasons. In the study, 774 patients (69.1%) with type A aortic dissection and 347 patients (30.9%) with type B aortic dissection were included. The average age of 1121 patients was 51.4 ± 12.0 years. Overall, the peak period for the onset of aortic dissection in a day was between 13:00 and 18:00. There was no statistically significant difference in the number of cases between weekdays and weekend (P = 0.94). Most cases occurred in winter (30.9%); the rate of onset was the lowest in summer (16.6%). No statistically significant difference was observed between male and female patients in terms of variations during different periods of a day (P = 0.45) and seasons (P = 0.12). In conclusion, aortic dissection displayed circadian and seasonal patterns in northern China. Onset of the disease peaked between 13:00 and 18:00 in a day. Winter was the peak season for the onset of acute aortic dissection, regardless of sex, type of dissection and age.

Daylight saving time, circadian rhythms, and cardiovascular health

Very recently, the European Parliament, called to decide on possible abolition of the Daylight Saving Time (DST), approved a resolution calling the scientific community to conduct a more in-depth evaluation. The question is based on disruption of body's circadian rhythms. We review here the relationship between DST and cardiovascular health. The available evidence suggests the existence of an association between DST and a modest increase of occurrence of acute myocardial infarction, especially in the first week after the spring shift. Possible mechanisms include sleep deprivation, circadian misalignment and environmental conditions. The role of gender and individual preference in circadian rhythms (chronotype) will need further assessment.

Higher mortality rate in patients hospitalised for acute pulmonary embolism during weekends

The management of acute pulmonary embolism (PE) is often challenging and requires specific medical expertise, diagnostic techniques and therapeutic options that may not be available in all hospitals throughout the entire week. The aim of our study was to evaluate whether or not an association exists between weekday or weekend admission and mortality for patients hospitalised with acute PE. Using routinely collected hospital administrative data, we examined patients discharged with a diagnosis of PE from the hospitals of the Emilia- Romagna Region in Italy (January 1999-December 2009). The risk of inhospital death was calculated for admissions at the weekend and compared to weekday admissions. Of a total of 26,560 PEs, 6,788 (25.6%) had been admitted during weekends. PE admissions were most frequent on Mondays (15.8%) and less frequent on Saturdays and Sun- days/holidays (12.8%) (p<0.001). Weekend admissions were associated with significantly higher rates of in-hospital mortality than weekday admissions (28% vs. 24.8%) (p<0.001). The risk of weekend admission and in-hospital mortality was higher after adjusting for sender, hospital characteristics, and the Charlson co-morbidity index. In conclusion, hospitalisation for PE on weekends seems to be associated with a significantly higher mortality rate than on weekdays. Further research is needed to investigate the reasons for this observed difference in mortality in order to try and implement future strategies that ensure an adequate level of care throughout the entire week.

Weekend Versus Weekday Admission and In-Hospital Mortality for Pulmonary Embolism: A 14-Year Retrospective Study on the National Hospital Database of Italy

We assessed the association between weekday (WD) or weekend (WE) admission and mortality for patients hospitalized with acute pulmonary embolism (PE). Weekend included holidays. We analyzed hospital administrative data of all patients discharged with a diagnosis of PE extracted from the Italian Health Ministry database (January 2001 to December 2014). A total of 265 035 hospitalizations with a diagnosis of PE were retrieved, in which PE was the primary diagnosis in 198 565 (74.9%); 200 166 (75.5%) patients were admitted on WD and 64 869 (24.5%) on WE. Admissions for PE were more frequent on Mondays (41 917 admissions, 15.8% of all events) and less frequent on Saturdays (32 295 admissions, 12.2%) and Sundays (32 574 admissions, 12.3%). Patients admitted on WE were on average 1 year older, presented more frequently with respiratory failure, and had more common comorbidities. After adjustment for age, gender, comorbidities, and presence of respiratory failure, in-hospital mortality for patients admitted on WE was greater (odds ratio: 1.15, 95% confidence interval: 1.13-1.18; P < .001). This study supports that, in Italy, hospitalization for PE on WE is associated with a significantly higher mortality rate than on WD.

Weekday variation in triglyceride concentrations in 1.8 million blood samples

Triglyceride (TG) concentration is used as a marker of cardiometabolic risk. However, diurnal and possibly weekday variation exists in TG concentrations. The objective of this work was to investigate weekday variation in TG concentrations among 1.8 million blood samples drawn between 2008 and 2015 from patients in the Capital region of Denmark. Plasma TG was extracted from a central clinical laboratory information system. Weekday variation was investigated by means of linear mixed models. In addition to the profound diurnal variation, the TG concentration was 4.5% lower on Fridays compared with Mondays (P < 0.0001). The variation persisted after multiple adjustments for confounders and was consistent across all sensitivity analyses. Out-patients and in-patients, respectively, had 5.0% and 1.9% lower TG concentrations on Fridays compared with Mondays (both P < 0.0001). The highest weekday variations in TG concentrations were recorded for out-patients between the ages of 9 and 26 years, with up to 20% higher values on Mondays compared with Fridays (all P < 0.05). In conclusion, TG concentrations were highest after the weekend and gradually declined during the week. We suggest that unhealthy food intake and reduced physical activity during the weekend increase TG concentrations which track into the week. This weekday variation may carry implications for public health and future research practice.

Temporal Variations of Stroke Occurence

Stroke is one of leading causes of death worldwide. Different frequency of stroke occurence is observed in days of the week and months in the year, and incidence of stroke has irregular time pattern. We analyzed 516 patients who had acute stroke and were treated in Clinic of Neurology, Clinical Center Kragujevac from January 1, 2013 to January 1, 2014, mean age 72,11±11,52. Statistical analysis is conducted out using the SPSS software version 20.0. We used descriptive statistic, student T-test, chi-square or Fisher exact test.

Friday is day we found the most IS and all stroke types occurences, and Wednesday is day we found the most IS in men. We found the most strokes in women younger than 65 years on Wednesday, but in women older than 65 years on Friday. Monday is day with the most admissions to hospital for patients with IS, and we observed that there is average delay in the refering to the doctor for 1.80±1.44 days. Friday is the day with the most ICH symptom beginings and the most admissions to the hospital, and Saturday is the day with the least symptom beginings and admissions to the hospital in the case of IS and ICH. The most IS occured in winter (in Decembar), and the least in summer (in August). The most ICH occured in May, and the least in July and October.

We confirmed that there is a significant weekly variability in the IS symptom onset day.

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.

"Timing" of arrival and in-hospital mortality in a cohort of patients under anticoagulant therapy presenting to the emergency departments with cerebral hemorrhage: A multicenter chronobiological study in Italy

Therapy with oral anticoagulants (OACs) is a risk factor for cerebral hemorrhage (CH). Although different studies have been undertaken to investigate the timing of the onset of major cardiovascular events, no data exist on temporal patterns of the onset of CH in subjects treated with OACs. The aim of this study is to evaluate the timing of CH in patients treated with OACs. All patients who developed CH under OACs therapy and admitted to 28 Italian Emergency Departments (EDs) between September 2011 and July 2013 were enrolled. Age, sex, time and location of the hemorrhagic lesion, type of the bleeding events (idiopathic or post-traumatic), anticoagulant therapy (warfarin or new oral anticoagulants - NOAs) and time of ED admission (i.e., hour, day, month and season) were recorded. Five hundred and seventeen patients (63.2% male aged 80 ± 7.9 yrs) with CH were involved. Warfarin was taken by 494 patients (95.6%), and NOAs by 23 (4.4%). In-hospital mortality (IHM) was recorded in 208 cases (40.2%). Cosinor analysis showed a peak of CH arrival between 12:00 and 14:00 h both in the whole population (PR 73.9%, p = 0.002) and the male subgroup (PR 65.2%, p = 0.009), whereas females showed an anticipated morning peak between 08:00 and 10:00 h (PR 65.7%, p = 0.008). A further analysis between idiopathic and post-traumatic CH confirmed the presence of a 24 h pattern with a peak between 12:00 and 14:00 h (PR 58.5%, p = 0.019) and between 08:00 and 10:00 h (PR80.1%, p < 0.001) for idiopathic events and post-traumatic hemorrhages, respectively. Moreover, a seasonal winter peak was identified for idiopathic forms (PR 74%, p = 0.035), and a summer peak for post-traumatic forms (PR 77%, p = 0.025). The present study suggests the presence of a temporal pattern of ED arrivals in CH patients treated with OACs.

Weekly and holiday-related patterns of panic attacks in panic disorder: a population-based study

BACKGROUND

While chronobiological studies have reported seasonal variation in panic attacks (PA) episodes, information on the timing of PA by week-days may enable better understanding of the triggers of PA episodes and thereby provide pointers for suitable interventional approaches to minimize PA attacks. This study investigated weekly variation in potential PA admissions including associations with holidays using a population-based longitudinal, administrative claims-based dataset in an Asian population.

METHODS

This study used ambulatory care data from the "Longitudinal Health Insurance Database 2000. We identified 993 patients with panic disorder (PD), and they had 4228 emergency room (ER) admissions for potential PA in a 3-year period between 1 January 2009 and 31 December 2011. One-way analysis of variance (ANOVA) was used to examine associations between the potential PA admissions and holidays/weekend days/work-days of the week.

RESULTS

The daily mean number of potential PA admissions was 3.96 (standard deviation 2.05). One-way ANOVA showed significant differences in potential PA admissions by holiday and day of the week (p<0.001). Daily frequencies showed a trough on Wednesday-Thursday, followed by a sharp increase on Saturday and a peak on Sunday. Potential PA admissions were higher than the daily mean for the sample patients by 29.4% and 22.1%, respectively on Sundays and holidays. Furthermore, the weekly variations were similar for females and males, although females always had higher potential PA admissions on both weekdays and holidays than the males.

CONCLUSIONS

We found that potential PA admissions among persons with PD varied systematically by day of the week, with a significant peak on weekends and holidays.

What's the healthiest day?: Circaseptan (weekly) rhythms in healthy considerations

BACKGROUND

Biological clocks govern numerous aspects of human health, including weekly clocks-called circaseptan rhythms-that typically include early-week spikes for many illnesses.

PURPOSE

To determine whether contemplations for healthy behaviors also follow circaseptan rhythms.

METHODS

We assessed healthy contemplations by monitoring Google search queries (2005-2012) in the U.S. that included the word healthy and were Google classified as health-related (e.g., healthy diet). A wavelet analysis was used in 2013 to isolate the circaseptan rhythm, with the resulting series compared by estimating ratios of relative query volume (healthy versus all queries) each day (e.g., (Monday-Wednesday)/Wednesday).

RESULTS

Healthy searches peaked on Monday and Tuesday, thereafter declining until rebounding modestly on Sunday. Monday and Tuesday were statistically indistinguishable (t=1.22, p=0.22), but their combined mean had 30% (99% CI=29, 32) more healthy queries than the combined mean for Wednesday-Sunday. Monday and Tuesday query volume was 3% (99% CI=2, 5) greater than Wednesday, 15% (99% CI=13, 17) greater than Thursday, 49% (99% CI=46, 52) greater than Friday, 80% (99% CI=76, 84) greater than Saturday, and 29% (99% CI=27, 31) greater than Sunday. We explored media-based (priming) motivations for these patterns and they were consistently rejected.

CONCLUSIONS

Just as many illnesses have a weekly clock, so do healthy considerations. Discovery of these rhythms opens the door for a new agenda in preventive medicine, including implications for hypothesis development, research strategies to further explore these rhythms, and interventions to exploit daily cycles in healthy considerations.

PAI at breakfast (whether you like it or not)

In this issue of Blood, Scheer and Shea report that the morning surge of the prothrombotic factor plasminogen activator inhibitor-1 (PAI-1) observed in humans is driven by an endogenous mechanism (as opposed to behavioral/environmental influences).

Within-Day and Weekly Variations of Thrombolysis in Acute Ischemic Stroke

Background and Purpose—

Temporal variations of thrombolysis delivery and their influence on outcome have been reported with controversial results. In this large cohort study, we evaluated whether thrombolytic treatment has a within-day and weekly variability corresponding to circadian and weekly patterns of ischemic stroke onset, and whether these have impact on clinical outcome.

Methods—

We retrospectively analyzed patients with acute ischemic stroke receiving intravenous alteplase, prospectively included in the Safe Implementation of Treatments in Stroke-International Stroke Thrombolysis Register. Patients were grouped by treatment on day hours (08:00–19:59) or night hours (20:00–07:59) and treatment on weekdays and weekends. For each subgroup, we analyzed frequency of thrombolytic treatments, time intervals, and outcomes (3-month modified Rankin Scale score 0–2 as good functional outcome, mortality, symptomatic intracerebral hemorrhage).

Results—

We included 21 513 patients. Considering the mean expected number of patients treated per hour (0.4) and per day of the week (9.8), if no temporal variations were present, patients were significantly treated more during day hours and weekdays ( P <0.0001). Median door-to-needle and onset-to-treatment times were longer for patients treated during night hours and on weekends ( P <0.01). After adjustment for confounding variables, treatment during day hours was an independent predictor of good functional outcome (odds ratio, 1.12; 95% confidence interval, 1.04–1.21; P =0.004), and patients treated during weekdays were at risk of higher mortality (odds ratio, 1.15; 95% confidence interval, 1.04–1.28; P =0.008).

Conclusions—

Frequency of thrombolytic treatment seems to follow the same circadian pattern of stroke incidence, whereas its correspondence to a weekly pattern is less clear. Time of treatment is an independent predictor of outcome.

Breaking heart: chronobiologic insights into takotsubo cardiomyopathy

A considerable amount of evidence has shown that the major acute cardiovascular diseases, ie, myocardial infarction, sudden cardiac death, stroke, pulmonary embolism, and rupture or dissection of aortic aneurysms do not occur randomly in time, but exhibit specific temporal patterns in their onset, according to time of day, month or season, and day of the week. This contributes to the definition of "chronorisk", where several factors, not harmful if taken alone, are capable of triggering unfavorable events when presenting all together within the same temporal window. This article reviews the actual knowledge about time of onset of takotsubo cardiomyopathy.

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.

Chronobiological variation in the occurrence of Tako-tsubo cardiomyopathy: experiences of two tertiary cardiovascular centers

BACKGROUND

There have been few data to review and analyze the temporal preference of the onset of Tako-tsubo cardiomyopathy (TTC). Aim of this study was to investigate chronobiological variations in the occurrence of TTC and changes of these variations according to age and gender.

METHODS

One hundred and thirty-seven patients were enrolled from our TTC registry database from January 2004 to December 2010 in Korea.

RESULTS

The median age of the entire study population was 59 years (inter-quartile range 53-72 years). The majority of patients were women (n = 101, 74%). The onset of TTC differed as a function of season (P = .001), with the peak in July and the nadir in March. Events were most frequent in summer (n = 53%, 38.7%) and least so in winter (n = 26, 19%, chi-square = 13.92, P = .003). TTC was most frequent in the morning (n = 56, 40.9%) and least so at night (n = 22, 16.1%, chi-square = 21.98, P = .001). Also, TTC was most frequent on Monday (n = 34, 24.8%) and least so on Saturday (n = 7, 5.1%, chi-square = 30.44, P = .001). Stressor pattern, age and gender do not influence these increases of occurrence in summer, on Monday, and in the morning of TTC.

CONCLUSIONS

TTC seems to exhibit a temporal variation of occurrence with preferred peaks during morning, Monday, and summer. Stressor pattern, age and gender do not influence these temporal patterns of the occurrence of TTC. Further studies are needed to investigate the potential link between chronobiological variations of TTC onset and underlying pathophysiologic mechanisms.

Tako-tsubo cardiomyopathy: is there a preferred time of onset?

The occurrence of major cardiovascular events is not randomly distributed over time, but exhibits chronobiological patterns, i.e., circadian, weekly, or seasonal. No systematic studies on the temporal preference of onset of Tako-tsubo cardiomyopathy (TTC) are known. We performed a computer-assisted search of the literature (from 2000 to January 2010), with the following search terms: transient left ventricular apical ballooning syndrome, takotsubo-like left ventricular dysfunction, ampulla cardiomyopathy, tako-tsubo or takotsubo cardiomyopathy, tako-tsubo, apical ballooning. Criteria for publication inclusion were (a) reporting of original data, (b) inclusion of at least 30 or more cases, (c) adherence to the requested diagnostic criteria for TTC. We focused on studies including in their purposes the "time of onset" of events. Out of the 19 studies found, 7 (4 from Europe, 1 each from Asia, Australia and USA) specifically addressed this aspect. A circadian (morning) and a seasonal (summer) higher frequency of events was found. TTC seems to exhibit a temporal variation of onset, with preferred peaks during morning and summer. Stress and catecholamines, also according to their temporal organization, might play a pivotal role. The demonstration of time frames characterized by highest frequency of occurrence might help to try to ensure maximal protection during particularly vulnerable periods.

Weekly variation of hospital admissions for stroke in Nis (Serbia)

OBJECTIVES

Weekly variability in stroke occurrence could be related to the change in behaviors of patients or medical personnel that occur during certain periods of the week. The aim of the present study was to examine the weekly variation in hospital admissions for stroke in Nis (Serbia), as well as to investigate how the demographic factors influenced these changes.

PATIENTS AND METHODS

The main data source for this study was the Nis Stroke Registry. During the study period (1996-2007) a total of 9675 stroke patients were registered. According to stroke subtypes, all registered patients were divided into three groups: patients with subarachnoid hemorrhage (SAH) (438 or 4.5%), patients with intracerebral hemorrhage (ICH) (1576 or 16.3%) and patients with ischemic stroke (IS) (6946 or 71.8%). Analyses were conducted separately for SAH, ICH and IS. Each stroke type was stratified by gender, age group and education level.

RESULTS

We have showed that there is a significant weekly variability in the number of SAH (p=0.028) and IS (p<0.001) admissions, with the minimum number of admissions on Sundays (39.27 and 14.04% less than expected), and the maximum one on Tuesdays (21.46% more than expected) and Wednesdays (10.96% more than expected), respectively. We have also registered more SAH (p=0.015) and IS (p<0.001) admissions on weekdays than on weekend days.

CONCLUSION

Results of this hospital-based study confirm that there is a pattern in the variation of the number of stroke admissions on the weekly level. Reasons for the weekly variation of hospital admissions for stroke cannot be determined from the present study.

The cardiomyocyte circadian clock: emerging roles in health and disease

Circadian misalignment has been implicated in the development of obesity, diabetes mellitus, and cardiovascular disease. Time-of-day-dependent synchronization of organisms with their environment is mediated by circadian clocks. This cell autonomous mechanism has been identified within all cardiovascular-relevant cell types, including cardiomyocytes. Recent molecular- and genetic-based studies suggest that the cardiomyocyte circadian clock influences multiple myocardial processes, including transcription, signaling, growth, metabolism, and contractile function. Following an appreciation of its physiological roles, the cardiomyocyte circadian clock has recently been linked to the pathogenesis of heart disease in response to adverse stresses, such as ischemia/reperfusion, in animal models. The purpose of this review is therefore to highlight recent advances regarding the roles of the cardiomyocyte circadian clock in both myocardial physiology and pathophysiology (ie, health and disease).

Seasonal and weekly patterns of hospital admissions for nonfatal and fatal myocardial infarction

OBJECTIVE

This retrospective study, based on the database of hospital admissions of the region Emilia-Romagna [RER], Italy, was aimed to confirm the existence of a seasonal or weekly pattern of hospital admission of acute myocardial infarction (AMI) and to verify possible differences between nonfatal or fatal cases.

METHODS

The study included all cases of patients with AMI hospitalized between 1998 and 2006. Day of admission was categorized, respectively, into four 3-month intervals, into twelve 1-month intervals, and into seven 1-day intervals for statistical analysis, performed by chi(2) test goodness of fit and partial Fourier series on total cases, males, females, and nonfatal and fatal cases.

RESULTS

The database included 64 191 cases of AMI (62.9% males, 12.3% fatal). Acute myocardial infarction was most frequent in winter and least in summer (P < .0001). The highest number of cases was recorded in January and the lowest in July (P < .0001). Chronobiologic analysis showed winter peaks for total cases (January, P = .035), females (December, P = .009), and fatal cases (January, P < .001). Acute myocardial infarction was most frequent on Monday and least on Sunday (P < .0001). Comparing observed vs expected events, there was a significantly higher frequency of cases on weekdays and reduced on weekends, for total (P < .0001), nonfatal (P < .0001), and fatal cases (P = .0001).

CONCLUSIONS

This study confirms a significantly higher frequency of AMI admissions in winter and on a Monday. No difference in the frequency of nonfatal vs fatal events, depending of patients' admissions on weekdays or weekends, was found.

Circadian Variation in Stroke Onset: Identical Temporal Pattern in Ischemic and Hemorrhagic Events

Stroke is the culmination of a heterogeneous group of cerebrovascular diseases that is manifested as ischemia or hemorrhage of one or more blood vessels of the brain. The occurrence of many acute cardiovascular events--such as myocardial infarction, sudden cardiac death, pulmonary embolism, critical limb ischemia, and aortic aneurysm rupture--exhibits prominent 24 h patterning, with a major morning peak and secondary early evening peak. The incidence of stroke exhibits the same 24 h pattern. Although ischemic and hemorrhagic strokes are different entities and are characterized by different pathophysiological mechanisms, they share an identical double-peak 24 h pattern. A constellation of endogenous circadian rhythms and exogenous cyclic factors are involved. The staging of the circadian rhythms in vascular tone, coagulative balance, and blood pressure plus temporal patterns in posture, physical activity, emotional stress, and medication effects play central and/or triggering roles. Features of the circadian rhythm of blood pressure, in terms of their chronic and acute effects on cerebral vessels, and of coagulation are especially important. Clinical medicine has been most concerned with the prevention of stroke in the morning, when population-based studies show it is of greatest risk during the 24 h; however, improved protection of at-risk patients against stroke in the early evening, the second most vulnerable time of cerebrovascular accidents, has received relatively little attention thus far.

Temporal Patterns of Hospital Admissions for Transient Ischemic Attack: A Retrospective Population-based Study in the Emilia-Romagna Region of Italy

Acute cerebrovascular events are not randomly distributed over time but show specific temporal patterns of occurrence. However, most studies focused stroke and little is known about transient ischemic attack. This study aimed to explore the existence of a temporal pattern of transient ischemic attack and the possible influence by the most common risk factors. The analysis included all hospital admissions with the ICD9-CM code for TIA, recorded in the database of the Emilia Romagna region of Italy (1998-2006; n = 43642, mean age 76.8 ± 11.5 years, 45.5% males). Transient ischemic attack was most frequent in autumn and winter and less common in spring and summer (P < 0.0001), with the highest number of cases in October and the lowest in February, and also most frequent on Monday (P < 0.0001). This study shows a seasonal and weekly pattern in occurrence of transient ischemic attack, independent of sex and the presence of the most common risk factors.

Off-Hour Admission and In-Hospital Stroke Case Fatality in the Get With The Guidelines-Stroke Program

Background and Purpose— Previous reports have shown higher in-hospital mortality for patients with acute stroke who arrived on weekends compared with regular workdays. We analyzed the effect of presenting during off-hours, defined as weekends and weeknights (versus weekdays), on in-hospital mortality and on quality of care in the Get With The Guidelines (GWTG)-Stroke program.

Methods— We analyzed data from 187 669 acute ischemic stroke and 34 845 acute hemorrhagic stroke admissions who presented to the emergency departments of 857 hospitals that participated in the GWTG-Stroke program during the 4-year period 2003 to 2007. Off-hour presentation was defined as presentation anytime outside of 7:00 am to 6:00 pm on weekdays. Quality of care was measured using standard GWTG quality indicators covering acute, subacute, and discharge measures. The relationship between off-hour presentation and in-hospital case fatality was examined using generalized estimating equation logistic regression adjusting for demographics, risk factors, arrival mode, and hospital characteristics.

Results— Half of ischemic stroke admissions and 57% of hemorrhagic stroke admissions presented during off-hours. Among ischemic stroke admissions, the in-hospital case fatality rate was 5.8% for off-hour presentation compared with 5.2% for on-hour presentation ( P <0.001). For hemorrhagic stroke admissions, in-hospital case fatality was 27.2% for off-hour presentation compared with 24.1% for on-hour presentation ( P <0.001). After adjusting for patient-level and hospital-level factors, presentation during off-hours was significantly associated with higher in-hospital mortality for both ischemic stroke (adjusted OR, 1.09; 95% CI, 1.03 to 1.14) and hemorrhagic stroke admissions (adjusted OR, 1.19; 95% CI, 1.12 to 1.27). No differences were observed between off-hour presentation and any of the quality of care measures.

Conclusions— Off-hour presentation was associated with an increased risk of dying in-hospital, although the absolute effect was small for ischemic stroke admissions (0.6% difference; number needed to harm=166) and moderate for hemorrhagic stroke (3.1% difference; number needed to harm=32). Reducing the disparity in hospital-based outcomes for admissions that present during off-hours represents a potential target for quality improvement efforts, although evidence of differences in the quality of care by time of presentation was lacking.

Increase of Stroke Incidence after Weekend Regardless of Traditional Risk Factors: Takashima Stroke Registry, Japan; 1988–2003

BACKGROUND AND PURPOSE

The study purpose was to identify patterns of variation in stroke incidence among days of the week and examine if it is modified by conventional stroke risk factors: hypertension, diabetes, drinking and smoking.

METHODS

Data were obtained from the Takashima Stroke Registry, which covers a stable population of roughly 55,000 residents of Takashima County in central Japan. A total of 1,773 stroke cases (men: 943 and women: 830) occurred between 1988 and 2003. We divided the days into 3 groups: 'weekend', 'after weekend' and 'rest of the week', and calculated stroke incidence rates and incidence rate ratios. To identify the effect of conventional risk factors on the variation, proportion of differences between observed and expected stroke incidences were considered.

RESULTS

The stroke incidence for the after weekend group (250.1 per 100,000 person years, 95% CI: 222.0-278.3) was higher than for the other day groups among men. The after weekend increase was observed mainly among older men aged 65 years or more. Among the stroke subtypes, the incidence for cerebral infarction was highest in the after weekend group (857.2, 95% CI: 730.6-983.8) and was 1.37 times (95% CI: 1.12-1.68) higher than in the rest of the week group. Tendency of after weekend increase was observed regardless of the presence or absence of risk factor history.

CONCLUSIONS

Week day variation for stroke was observed predominantly among older men regardless of presence and absence of risk factor history. Information about the weekly trend regarding episode of increased stroke incidence can be used as a surrogate predictor for stroke onset and would be helpful in designing more effective insights for preventive strategies.

A Meta-analysis of excess cardiac mortality on Monday

BACKGROUND

Available evidence suggests a peak in the incidence of cardiovascular events on Mondays compared to other days of the week. The exact magnitude of the excess risk and the role of age and gender, however, remain unclear.

OBJECTIVE

To quantify the excess risk associated with the Monday peak in cardiovascular mortality and to explore the role of age and gender.

METHODS

A meta-analysis of available published studies reporting on weekly patterns in incidence of myocardial infarction and sudden cardiac death was performed.

RESULTS

Reports based on routinely collected data from population statistics (n = 5) generally reported a lower odds ratio (OR) of an event on Monday than studies with a confirmed diagnosis (n = 16). The pooled OR estimate based on population statistics was 1.04 (95%CI: 1.03; 1.05), whereas the pooled OR estimate based on confirmed diagnoses was 1.19 (95%CI: 1.17; 1.21). Subgroup analysis yielded an OR of 1.19 (95%CI: 1.07; 1.31) for men and 1.15 (95%CI: 0.99; 1.32) for women. Odds ratios for patients younger than 65 years of age and 65 or older were 1.22 (95%CI: 1.09; 1.36) and 1.16 (95%CI: 1.07; 1.27), respectively. The differences between subgroup odds ratios were not statistically significant.

CONCLUSION

The incidence of sudden cardiac death is markedly increased on Monday, similar for men and women, and for subjects below and above 65 years of age.

Day of the Week and Ischemic Stroke

BACKGROUND AND PURPOSE

The study aim was to examine the incidence of ischemic stroke (IS) by day of the week and its relationship with age, sex, and socioeconomic status (SES).

METHODS

A total of 12,801 IS events in men and women aged 25 to 99 years was recorded in a population-based stroke register (FINMONICA), which was functioning in Finland from 1982 to 1992. We analyzed the weekly variation in IS incidence by pooling the data and stratifying by sex and age. Taxable income and level of education were used as indicators of SES.

RESULTS

We observed a significant weekly variation in IS occurrence, but the analysis by age group demonstrated a difference by weekday only in the age group 60 to 74, both in men and women (P<0.001 and P=0.02, respectively). The increase in the number of IS events from Sunday to Monday was pronounced in men (29.2% increase from Sunday to Monday). When stratifying by age, Monday excess in IS incidence was associated with lower SES among persons >59 years of age. No Monday excess was observed in persons with high SES.

CONCLUSIONS

Because the incidence of IS is much higher in persons with low SES than in those with high SES, the Monday excess in persons with low SES is of substantial public health interest. This finding may suggest reasons for the higher IS incidence in persons with low socioeconomic positions and open up some possibilities for prevention.

Chronobiology of rupture and dissection of aortic aneurysms

A growing body of evidence suggests that the occurrence of cardiovascular events is not evenly distributed over time, but shows peculiar temporal patterns that vary with time of day, day of the week, and month (season) of the year. These patterns coincide with the temporal variation in the pathophysiologic mechanisms that trigger cardiovascular events and the physiologic changes in body rhythms. These two factors in combination contribute to the periodicity in susceptibility to acute cardiovascular events. The classic assumption of epidemiologic studies that there is a constancy in risk for disease during the various time domains has now been challenged by the emerging new concept of chronorisk. In the last two decades temporal patterns (circadian, weekly, seasonal) have been identified for several acute cardiovascular diseases, such as acute myocardial infarction, sudden death, pulmonary embolism, and stroke, with peak incidence for most in the morning and during winter. One of the most life-threatening cardiovascular emergencies, aortic aneurysm rupture or dissection, also demonstrates periodicity, characterized by a similar temporal distribution, which suggests a common pathophysiologic mechanism or triggers similar to other cardiovascular acute emergencies. We review the data on chronobiology of acute aortic rupture or dissection, and discuss various pathophysiologic mechanisms that account for this variability. It is likely that identification of consistent recurring patterns in the underlying risk mechanisms could provide potential new insights for more precise diagnosis and efficacious therapeutic intervention.