The impact of time and day on the presentation of acute coronary syndromes

Association between holiday and weekend admissions and mortality outcomes among patients with acute myocardial infarction receiving percutaneous coronary intervention in Taiwan

There is a lack of studies that concurrently differentiate the effect of the holiday season from the weekend effect on mortality risk in patients with acute myocardial infarction (AMI). We evaluated the mortality risk among patients admitted with AMI who underwent percutaneous coronary intervention, using data from the Taiwan National Health Insurance Research Database. Adult AMI patients admitted during January and February between 2013 and 2020 were enrolled and classified into the holiday season (using the Chinese New Year holiday seasons as an indicator) (n = 1729), weekend (n = 4725), and weekday (n = 14,583) groups according to the first day of admission. A multivariable logistic regression model was used to assess the risk. With the weekday group or the weekend group as the reference, the holiday season group did not have increased risks of in-hospital mortality (adjusted odds ratio [aOR] 1.15; 95% confidence intervals [CI] 0.93-1.42 or aOR 1.23; 95% CI 0.96-1.56) and 7-day mortality (aOR 1.20; 95% CI 0.90-1.58 or aOR 1.24; 95% CI 0.90-1.70). Stratified and subgroup analyses showed similar trends. We conclude that holiday season-initiated admissions were not associated with higher mortality risks in AMI admission cases than weekday or weekend admissions.

Impact of day of admission on in-hospital outcomes of cardiogenic shock

BACKGROUND

The management of cardiogenic shock (CS) requires attentiveness to details and in some cases, invasive interventions. In the past, studies have shown relationships between the day of admission and cardiovascular outcomes. We aim to analyze the trends and in-hospital outcomes of patients admitted with CS over the weekends compared to weekdays.

METHOD

We identified all patients with CS from the National Inpatient Sample (NIS) database between 2016 and 2020. Using multivariate logistic regression analysis, baseline demographics and in-hospital outcomes were obtained and compared by weekend or weekday admission.

RESULTS

Out of 854,684 CS admissions, 199,255 (23.6%) occurred on weekends. Patients admitted over the weekend had worse outcomes, including higher rates of mortality (aOR 1.09 CI 1.05 - 1.11, p<0.001), cardiac arrest (aOR 1.09 CI 1.04 -1.14, p<0.001), and respiratory failure. We also noted higher percutaneous coronary intervention (PCI) rates (aOR 1.2 CI 1.16 - 1.25, p<0.001) but lower rates of pulmonary artery catheterization (PAC) and post-procedure pneumothorax. Weekend admissions had shorter hospital lengths of stay, and they incurred lower charges ($223,222 vs. $247,908). Between 2016 and 2020, we observed a consistent downward trend in the mortality rates of the weekend and weekday CS admissions, with consistently higher weekend than weekday admissions.

CONCLUSION

Weekend admissions for CS are associated with worse outcomes, which have persisted for years. This now begs the question of whether physician dissatisfaction, understaffing, or burn-out are responsible for this finding.

Acute coronary syndrome in a hospital in southern Brazil: peak of hospitalizations on Mondays and severe cases on weekends and at night

INTRODUCTION

Ischemic heart disease is the leading cause of death in Brazil and worldwide. The term acute coronary syndrome (ACS) generically represents the acute myocardial ischemic events. These events are clinically divided into three types: acute myocardial infarction (AMI) with ST-segment elevation, AMI without ST-segment elevation, and unstable angina. Although cardiovascular ischemic events occur acutely, studies describe cyclic patterns of ACS, mainly on circadian and weekly variation.

OBJECTIVE

The aim of this study was to analyze the circadian and weekly variation of hospitalizations for ACS in a hospital in southern Brazil in 2019.

METHODS

Observational, cross-sectional type study. The population was the patients hospitalized at the Nossa Senhora da Conceição Hospital (NSCH) in Tubarão (SC, Brazil) with the international classification of diseases (ICD) code referring to ACS in the year 2019, corresponding to 579 patients.

RESULTS

After applying the exclusion criteria, 512 patients hospitalized for ACS were analyzed, 55.1% were male with a median (p25-p75) age of 62.0 (56.0-69.0) years. The main ICDs of hospitalization were: I20.0 (76.2%), I21.9 (16.6%), I21.3 (3.1%) and the most prevalent comorbidities were high blood pressure (82.6%), diabetes (30.1%) and previous AMI (23.6%). The median (p25-p75) time of admission was 14 h (10-18) h and length of stay was 5 (3-9) days. Death occurred in 18 hospitalizations (3.5%) of cases.

CONCLUSION

We conclude that in the present study there was a peak of hospitalizations for ACS on Mondays, proportionally reducing throughout the week and with a significant decrease on the weekend.

Chronobiology and Chronotherapy in Inflammatory Joint Diseases

Circadian rhythm perturbations can impact the evolution of different conditions, including autoimmune diseases. This narrative review summarizes the current understanding of circadian biology in inflammatory joint diseases and discusses the potential application of chronotherapy. Proinflammatory cytokines are key players in the development and progression of rheumatoid arthritis (RA), regulating cell survival/apoptosis, differentiation, and proliferation. The production and secretion of inflammatory cytokines show a dependence on the human day–night cycle, resulting in changing cytokine plasma levels over 24 h. Moreover, beyond the circadian rhythm of cytokine secretion, disturbances in timekeeping mechanisms have been proposed in RA. Taking into consideration chronotherapy concepts, modified-release (MR) prednisone tablets have been introduced to counteract the negative effects of night-time peaks of proinflammatory cytokines. Low-dose MR prednisone seems to be able to improve the course of RA, reduce morning stiffness and morning serum levels of IL-6, and induce significant clinical benefits. Additionally, methotrexate (MTX) chronotherapy has been reported to be associated with a significant improvement in RA activity score. Similar effects have been described for polymyalgia rheumatica and gout, although the available literature is still limited. Growing knowledge of chronobiology applied to inflammatory joint diseases could stimulate the development of new drug strategies to treat patients in accordance with biological rhythms and minimize side effects.

Extreme weather conditions as a gender-specific risk factor for acute myocardial infarction

BACKGROUND

Acute coronary syndrome is a disease with high prevalence and high mortality. Exposure to heat or cold increases the risks of myocardial infarction significantly. Gender-specific effects of this have not yet been examined. Our goal was to determine whether extreme weather conditions, which become more and more frequent, are gender-specific risk factors for myocardial infarction, in order to help provide faster diagnosis and revascularization therapy for patients.

METHODS

We analysed the incidence of ST-elevation myocardial infarction (STEMI) in a large urban area over a 65-months period in a cohort study. A day was the unit of analysis. Incidence rate ratios (IRR) with Poisson regression models were calculated. All patients with STEMI on Saturdays and Sundays were included. Gender, high or low perceived temperatures (PT), a function of temperature, wind speed and humidity, and meteorological cold and heat warnings by the Austrian Central Institute for Meteorology and Geodynamics (ZAMG) were considered as risk factors.

RESULTS

During the 562 days of the study period, a total of 1109 patients with STEMI (803; 72% men, mean age 61;14 years) were included. The gender difference between men and women was much more pronounced on cold (0 °C) days (85% of patients male; 1.8 per day) than on hot (20 °C) days (71% male; 1.4 per day) or days without extreme temperatures (72% male; 1.4 per day). We found significant interaction between gender and cold days (IRR of the interaction term 2.3 (95% CI 1.2-4.6), p = 0.02). No gender-specific effect was observed on warm days (IRR for interaction 0.9 (95% CI 0.6-1.3), p = 0.3).

CONCLUSION

Low perceived temperature pronouncedly increases the already elevated risk for STEMI in males. Whether this effect is based on gender alone, or on one of the cardiovascular risk factors which are more common in men, is up to further study.

Weekend Effect and in-Hospital Mortality in Elderly Patients with Acute Kidney Injury: A Retrospective Analysis of a National Hospital Database in Italy

Background: The aim of this study was to relate the weekend (WE) effect and acute kidney injury (AKI) in elderly patients by using the Italian National Hospital Database (NHD). Methods: Hospitalizations with AKI of subjects aged ≥ 65 years from 2000–2015 who were identified by the ICD-9-CM were included. Admissions from Friday to Sunday were considered as WE, while all the other days were weekdays (WD). In-hospital mortality (IHM) was our outcome, and the comorbidity burden was calculated by the modified Elixhauser Index (mEI), based on ICD-9-CM codes. Results: 760,664 hospitalizations were analyzed. Mean age was 80.5 ± 7.8 years and 52.2% were males. Of the studied patients, 9% underwent dialysis treatment, 24.3% were admitted during WE, and IHM was 27.7%. Deceased patients were more frequently comorbid males, with higher age, treated with dialysis more frequently, and had higher admission during WE. WE hospitalizations were more frequent in males, and in older patients with higher mEI. IHM was independently associated with dialysis-dependent AKI (OR 2.711; 95%CI 2.667–2.755, p < 0.001), WE admission (OR 1.113; 95%CI 1.100–1.126, p < 0.001), and mEI (OR 1.056; 95% CI 1.055–1.057, p < 0.001). Discussion: Italian elderly patients admitted during WE with AKI are exposed to a higher risk of IHM, especially if they need dialysis treatment and have high comorbidity burden.

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.

Lack of a “Weekend Effect” for Renal Transplant Recipients

The “weekend (WE) effect” defines the association between WE hospital admissions and higher rate of mortality. The aim of this study was to evaluate the relationship between WE effect and renal transplant recipients (RTRs) using the database of the Emilia-Romagna region (ERR), Italy. We included ERR admissions of RTRs ( International Classification of Diseases, Ninth Revision, Clinical Modification [ ICD-9-CM] code V420) between 2000 and 2013. In-hospital mortality, admissions due to cardiovascular events (CVEs), and the Elixhauser score were evaluated on the basis of ICD-9-CM codification. Out of 9063 hospital admissions related to 3648 RTRs (mean age 53 ± 13 years, 62.9% male), 1491 (16.5%) were recorded during the WE. During the follow-up period, 1581 (17.4%) patients deceased and 366 (4%) had CVEs. Length of hospital stay (LOS) was 9.7 ± 12.1 days. Logistic regression analysis showed that only LOS was independently associated with WE admissions (odds ratio: 1594, confidence interval: 1.385-1.833; P < .001). Renal transplant recipients are not exposed to higher risk of adverse outcome during WE admissions. However, WE admissions were characterized by an increased duration of hospitalization.

Effects of weather conditions on emergency ambulance calls for acute coronary syndromes

The aim of this study was to evaluate the relationship between weather conditions and daily emergency ambulance calls for acute coronary syndromes (ACS). The study included data on 3631 patients who called the ambulance for chest pain and were admitted to the department of cardiology as patients with ACS. We investigated the effect of daily air temperature (T), barometric pressure (BP), relative humidity, and wind speed (WS) to detect the risk areas for low and high daily volume (DV) of emergency calls. We used the classification and regression tree method as well as cluster analysis. The clusters were created by applying the k-means cluster algorithm using the standardized daily weather variables. The analysis was performed separately during cold (October-April) and warm (May-September) seasons. During the cold period, the greatest DV was observed on days of low T during the 3-day sequence, on cold and windy days, and on days of low BP and high WS during the 3-day sequence; low DV was associated with high BP and decreased WS on the previous day. During June-September, a lower DV was associated with low BP, windless days, and high BP and low WS during the 3-day sequence. During the warm period, the greatest DV was associated with increased BP and changing WS during the 3-day sequence. These results suggest that daily T, BP, and WS on the day of the ambulance call and on the two previous days may be prognostic variables for the risk of ACS.

Diurnal and twenty-four hour patterning of human diseases: cardiac, vascular, and respiratory diseases, conditions, and syndromes

Various medical conditions, disorders, and syndromes exhibit predictable-in-time diurnal and 24 h patterning in the signs, symptoms, and grave nonfatal and fatal events, e.g., respiratory ones of viral and allergic rhinorrhea, reversible (asthma) and non-reversible (bronchitis and emphysema) chronic obstructive pulmonary disease, cystic fibrosis, high altitude pulmonary edema, and decompression sickness; cardiac ones of atrial premature beats and tachycardia, paroxysmal atrial fibrillation, 3rd degree atrial-ventricular block, paroxysmal supraventricular tachycardia, ventricular premature beats, ventricular tachyarrhythmia, symptomatic and non-symptomatic angina pectoris, Prinzmetal vasospastic variant angina, acute (non-fatal and fatal) incidents of myocardial infarction, sudden cardiac arrest, in-bed sudden death syndrome of type-1 diabetes, acute cardiogenic pulmonary edema, and heart failure; vascular and circulatory system ones of hypertension, acute orthostatic postprandial, micturition, and defecation hypotension/syncope, intermittent claudication, venous insufficiency, standing occupation leg edema, arterial and venous branch occlusion of the eye, menopausal hot flash, sickle cell syndrome, abdominal, aortic, and thoracic dissections, pulmonary thromboembolism, and deep venous thrombosis, and cerebrovascular transient ischemic attack and hemorrhagic and ischemic stroke. Knowledge of these temporal patterns not only helps guide patient care but research of their underlying endogenous mechanisms, i.e., circadian and others, and external triggers plus informs the development and application of effective chronopreventive and chronotherapeutic strategies.

The weekend effect: does time of admission impact management and outcomes of small bowel obstruction?

Aims: To determine whether day and time of admission influences the practice patterns of the admitting general surgeon and subsequent outcomes for patients diagnosed with small bowel obstruction.

Methods: A retrospective database review was carried out, covering patients admitted with the presumed diagnosis of partial small bowel obstruction from 2004–2011.

Results: A total of 404 patients met the inclusion criteria. One hundred and thirty-nine were admitted during the day, 93 at night and 172 on the weekend. Overall 30.2% of the patients were managed operatively with no significant difference between the groups (P = 0.89); however, of patients taken to the operating room, patients admitted during the day received operative intervention over 24 hours earlier than those admitted at a weekend, 0.79 days vs 1.90 days, respectively (P = 0.05). Overall mortality was low at 1.7%, with no difference noted between the groups (P = 0.35). Likewise there was no difference in morbidity rates between the three groups (P = 0.90).

Conclusions: Despite a faster time to operative intervention in those patients admitted during the day, our study revealed that time of admission does not appear to correlate to patient outcome or mortality.

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.

Effect of Hurricane Katrina on chronobiology at onset of acute myocardial infarction during the subsequent three years

The onset of acute myocardial infarction (AMI) has been shown to occur in a nonrandom pattern, with peaks in midmorning and on weekdays (especially Monday). The incidence of AMI has been shown to increase locally after natural disasters, but the effect of catastrophic events on AMI biorhythms is largely unknown. To assess the differences in the chronobiology of AMI in residents of New Orleans before and after Hurricane Katrina, the onset of AMI in patients at Tulane University Health Sciences Center in the 6 years before and the 3 years after Hurricane Katrina was retrospectively examined. Compared to the pre-Katrina group, the post-Katrina cohort demonstrated significant decreases in the onset of AMI during mornings (p = 0.002), Mondays (p <0.0001), and weekdays (p <0.0001) and significant increases in onset during weekends (p <0.0001) and nights (p <0.0001). These changes persisted during all 3 years after the storm. In conclusion, the normal pattern of AMI onset was altered after Hurricane Katrina, and expected morning, weekday, and Monday peaks were eliminated.

Twenty-four-hour patterns in occurrence and pathophysiology of acute cardiovascular events and ischemic heart disease

The scientific literature clearly establishes the occurrence of cardiovascular (CV) accidents and myocardial ischemic episodes is unevenly distributed during the 24 h. Such temporal patterns result from corresponding temporal variation in pathophysiologic mechanisms and cyclic environmental triggers that elicit the onset of clinical events. Moreover, both the pharmacokinetics and pharmacodynamics of many, though not all, CV medications have been shown to be influenced by the circadian time of their administration, even though further studies are necessary to better clarify the mechanisms of such influence on different drug classes, drug molecules, and pharmaceutical preparations. Twenty-four-hour rhythmic organization of CV functions is such that defense mechanisms against acute events are incapable of providing the same degree of protection during the day and night. Instead, temporal gates of excessive susceptibility exist, particularly in the morning and to a lesser extent evening (in diurnally active persons), to aggressive mechanisms through which overt clinical manifestations may be triggered. When peak levels of critical physiologic variables, such as blood pressure (BP), heart rate (HR), rate pressure product (systolic BP × HR, surrogate measure of myocardial oxygen demand), sympathetic activation, and plasma levels of endogenous vasoconstricting substances, are aligned together at the same circadian time, the risk of acute events becomes significantly elevated such that even relatively minor and usually harmless physical and mental stress and environmental phenomena can precipitate dramatic life-threatening clinical manifestations. Hence, the delivery of CV medications needs to be synchronized in time, i.e., circadian time, in proportion to need as determined by established temporal patterns in risk of CV events, and in a manner that averts or minimizes undesired side effects.

Weekend versus weekday, morning versus evening admission in relationship to mortality in acute coronary syndrome patients in 6 middle eastern countries: results from gulf race 2 registry

We used prospective cohort data of patients with acute coronary syndrome (ACS) to compare their management on weekdays/mornings with weekends/nights, and the possible impact of this on 1-month and 1-year mortality. Analyses were evaluated using univariate and multivariate statistics. Of the 4,616 patients admitted to hospitals with ACS, 76% were on weekdays. There were no significant differences in 1-month (odds ratio (OR), 0.88; 95% CI: 0.68-1.14) and 1-year mortality (OR, 0.88; 95% CI: 0.70-1.10), respectively, between weekday and weekend admissions. Similarly, there were no significant differences in 1-month (OR, 0.92; 95% CI: 0.73-1.15) and 1-year mortality (OR, 0.98; 95% CI: 0.80-1.20), respectively, between nights and day admissions. In conclusion, apart from lower utilization of angiography (P < .001) at weekends, there were largely no significant discrepancies in the management and care of patients admitted with ACS on weekdays and during morning hours compared with patients admitted on weekends and night hours, and the overall 30-day and 1-year mortality was similar between both the cohorts.

Higher mortality in patients hospitalized for acute aortic rupture or dissection during weekends

BACKGROUND

The management of acute aortic aneurysm rupture or dissection (AARD) requires specific medical expertise, diagnostic techniques, and therapeutic options, not always available in all hospitals through the entire week. The aim of our study was to evaluate whether an association exists between weekday (WD) or weekend (WE) admission and mortality for patients with ARRD.

METHODS

Based on the database of routinely collected hospital admissions of the region of Emilia Romagna (RER) of Italy, we examined the discharge sheets of all patients with AARD (January 1999 to December 2009). The risk of in-hospital death was calculated for admissions on the WE compared with the admissions during a WD.

RESULTS

The analysis considered 4559 events in 4461 patients. AARD admissions were most frequent on Monday (14.7%) and Friday (14.8%) and less frequent on Saturday (12.6%). The percentage of events admitted on Sunday/holiday was 15.0%, whereas the distribution of death rate with respect to day of admission was significantly different (χ(2) = 23.472; P < .001) with the highest frequency peak on Sunday/holiday (17.4%) and the lowest on Tuesday (12.9%). WE admissions were associated with significantly higher in-hospital mortality (43.4%) than WD admissions (36.9%, P < .001). Multivariate regression analysis showed that WE admission was an independent risk factor for increased in-hospital mortality odds ratio 1.318; 95% confidence interval, 1.144-1.517; P < .001).

CONCLUSIONS

Our findings show that hospitalization for AARD on WE is associated with a significantly higher mortality rate than hospitalization on WD. Further studies are needed to investigate whether ensuring optimal diagnostic and therapeutic approaches during the entire week might improve the overall survival of patients with ARRD.

Stroke Mortality, Clinical Presentation and Day of Arrival: The Atherosclerosis Risk in Communities (ARIC) Study

Background. Recent studies report that acute stroke patients who present to the hospital on weekends have higher rates of 28-day mortality than similar patients who arrive during the week. However, how this association is related to clinical presentation and stroke type has not been systematically investigated. Methods and Results. We examined the association between day of arrival and 28-day mortality in 929 validated stroke events in the ARIC cohort from 1987-2004. Weekend arrival was defined as any arrival time from midnight Friday until midnight Sunday. Mortality was defined as all-cause fatal events from the day of arrival through the 28th day of followup. The presence or absence of thirteen stroke signs and symptoms were obtained through medical record review for each event. Binomial logistic regression was used to estimate odds ratios and 95% confidence intervals (OR; 95% CI) for the association between weekend arrival and 28-day mortality for all stroke events and for stroke subtypes. The overall risk of 28-day mortality was 9.6% for weekday strokes and 10.1% for weekend strokes. In models controlling for patient demographics, clinical risk factors, and event year, weekend arrival was not associated with 28-day mortality (0.87; 0.51, 1.50). When stratified by stroke type, weekend arrival was not associated with increased odds of mortality for ischemic (1.17, 0.62, 2.23) or hemorrhagic (0.37; 0.11, 1.26) stroke patients. Conclusions. Presence or absence of thirteen signs and symptoms was similar for weekday patients and weekend patients when stratified by stroke type. Weekend arrival was not associated with 28-day all-cause mortality or differences in symptom presentation for strokes in this cohort.

Effect of weekend admission on in-hospital mortality after subarachnoid hemorrhage in Chongqing China

BACKGROUND

Medical resources are usually not the same throughout the week. It is reported that the mortality rate of some disease was higher in patients admitted on weekends than on weekdays. Our study will try to evaluate whether this "weekend effect" acts on in-hospital mortality rate after SAH.

METHODS

We performed a retrospective study of patients with SAH admitted to our hospital from January 2006-2009. Patients were classified according to their admission days. The following information, including patient demographics,living habits,systemic complications and Charlson comorbidity index, were documented. Descriptive statistics were used to assess the characteristics between patients admitted on weekends and weekdays. The comparison of mortality between the two groups was carried out by chi-square test. Multivariable regression model was used to analyze the influence of weekend admission on in-hospital mortality and adjust for potential confounders.

RESULTS

Weekend admission accounted for about 29% of the 183 patients with SAH. There were no differences in general characteristics between patients admitted on weekends and those on weekdays. The chi-square test showed the mortality between two groups was not significantly different (0.082). In logistic regression model, weekend admission was not an independent predictor of higher in-hospital mortality (OR 1.77, 95% CI 0.83-3.77) after SAH.

CONCLUSION

Weekend admission was not closely related to higher in-hospital mortality. There was no weekend effect observed in our hospital in Chongqing, China.

Circadian rhythms in patients with ST-elevation myocardial infarction

BACKGROUND

Circadian rhythms with regard to time of symptom onset for patients with acute myocardial infarction have been observed, although their relationship to outcomes has been debated. We evaluated these rhythms in patients with ST-elevation myocardial infarction as a function of the 24-hour circadian cycle.

METHODS AND RESULTS

The relationship between onset of symptoms during the 24-hour circadian cycle and prehospital delays from symptom onset to hospital arrival, timeliness of reperfusion, and in-hospital death was assessed in 2143 patients with ST-elevation myocardial infarction presenting from 2004-2008 at 1 of 3 tertiary-care healthcare ST-elevation myocardial infarction systems. There was a significant association between time of onset and the circadian cycle, with the greatest percentage (39%) of patients experiencing onset between 8 AM and 3 PM (P<0.001). Time of onset was associated with prehospital delay and timeliness of reperfusion. Patients with onset from 12 AM to 5:59 AM had median prehospital delays of 121 minutes versus 70 minutes from 12 PM to 5:59 PM (P<0.001). Patients with onset time from 12 AM to 5:59 AM had median door-to-balloon times of 75 minutes versus 60 minutes from 6 AM to 11:59 AM (P<0.001). Using multivariable modeling to control for baseline patient characteristics, prehospital delay, and timeliness of reperfusion, there was no significant association between time of symptom onset with in-hospital death.

CONCLUSIONS

Patients with ST-elevation myocardial infarction exhibit significant circadian patterns in symptom onset, prehospital delay, and timeliness of reperfusion. Patients who develop symptoms from 12 AM to 5:59 AM present with longer prehospital delays and have longer door-to-balloon times. After multivariable adjustment, there was no significant association between circadian patterns of time of onset and in-hospital death.

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.

Influence of weekend versus weekday hospital admission on mortality following subarachnoid hemorrhage

Object

Several studies have indicated that short-term mortality risk is higher among patients who are admitted on the weekends. This “weekend effect” has been observed among patients admitted with a variety of diagnoses, including myocardial infarction, pulmonary embolism, ruptured abdominal aortic aneurysm, and stroke. This study examines the relationship between short-term mortality risk and weekend admission among patients hospitalized following subarachnoid hemorrhage (SAH).

Methods

This retrospective cohort study examines mortality outcomes among patients included in the Nationwide Inpatient Sample (NIS) for 2004. Patients included in the cohort were identified using the International Classification of Diseases, 9th revision, Clinical Modification (ICD-9-CM) code for SAH. Multivariable logistic regression analyses and Cox proportional hazard regression analyses are used to measure the association of weekend admission on mortality for patients with SAH, adjusted for differences in patient characteristics that also contribute to mortality risk.

Results

Weekend admissions occurred among 27.5% of the 5667 patients with SAH in the NIS database. Weekend admission was not a statistically significant independent predictor of death in the SAH study population at 7 days (OR 1.07, 95% CI 0.91–1.25), 14 days (OR 1.01, 95% CI 0.87–1.17), or 30 days (OR 1.03, 95% CI 0.89–1.19).

Conclusions

Weekend admission is not associated with significantly increased short-term mortality risk among patients hospitalized with SAH.

Influence of Weekend Hospital Admission on Short-Term Mortality After Intracerebral Hemorrhage

Background and Purpose— There is expanding literature to show that certain patients admitted during the weekend have worse outcomes than similar patients admitted during the week. Although many clinicians have hypothesized the presence of this “weekend effect” with patients with intracerebral hemorrhage, there is a paucity of studies validating this conjecture.

Methods— We performed a retrospective cohort study of patients with intracerebral hemorrhage (International Classification of Diseases, 9th Revision, Clinical Modification=431) extracted from the 2004 Nationwide Inpatient Sample. Multivariable logistic regression analyses and Cox proportional hazards regression were conducted to calculate the odds of death (within 7, 14, and 30 days) and the hazard ratio of death for patients with weekend intracerebral hemorrhage admissions compared with weekday intracerebral hemorrhage admissions. All analyses were adjusted for concurrent differences in length of stay, patient demographics, and comorbid disease.

Results— Weekend hospital admissions accounted for 26.8% of the 13 821 patients with a diagnosis of intracerebral hemorrhage in the National Inpatient Sample. Admission during the weekend was a statistically significant independent predictor of death within 7 days (OR, 1.14; 95% CI, 1.05 to 1.25), within 14 days (OR, 1.15; 95% CI, 1.05 to 1.25), and within 30 days (OR, 1.15; 95% CI, 1.05 to 1.25). The adjusted hazard of in-hospital death (hazard ratio, 1.12; CI, 1.05 to 1.20) indicates that the overall risk of in-hospital death with intracerebral hemorrhage is 12% higher with weekend admission.

Conclusion— Weekend admission for intracerebral hemorrhage was associated with increased risk-adjusted mortality when compared with admission during the remainder of the week.

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.

Can comprehensive stroke centers erase the 'weekend effect'?

BACKGROUND

Prior epidemiological work has shown higher mortality in ischemic stroke patients admitted on weekends, which has been termed the 'weekend effect'. Our aim was to assess stroke patient outcomes in order to determine the significance of the 'weekend effect' at 2 comprehensive stroke centers.

METHODS

Consecutive stroke patients were identified using prospective databases. Patients were categorized into 4 groups: intracerebral hemorrhage (ICH group), ischemic strokes not treated with IV t-PA (intravenous tissue plasminogen activator; IS group), acute ischemic strokes treated with IV t-PA (AIS-TPA group), and transient ischemic attack (TIA group). Weekend admission was defined as the period from Friday, 17:01, to Monday, 08:59. Patients treated beyond the 3-hour window, receiving intra-arterial therapy, or enrolled in nonobservational clinical trials were excluded. Patient demographics, NIHSS scores, and admission glucose levels were examined. Adverse events, poor functional outcome (modified Rankin scale, mRS, 3-6), and mortality were compared.

RESULTS

A total of 2,211 patients were included (1,407 site 1, 804 site 2). Thirty-six percent (800/2,211) arrived on a weekend. No significant differences were found in the ICH, IS, AIS-TPA, or TIA groups with respect to the rate of symptomatic ICH, mRS on discharge, discharge disposition, 90-day mRS, or 90-day mortality when comparing weekend and weekday groups. Using multivariate logistic regression to adjust for site, age, admission NIHSS, and blood glucose, weekend admission was not a significant independent predictive factor for in-hospital mortality in all strokes (OR = 1.10, 95% CI 0.74-1.63, p = 0.631).

CONCLUSIONS

Our results suggest that comprehensive stroke centers (CSC) may ameliorate the 'weekend effect' in stroke patients. These results may be due to 24/7 availability of stroke specialists, advanced neuroimaging, or ongoing training and surveillance of specialized nursing care available at CSC. While encouraging, these results require confirmation in prospective studies.

Circadian, daily, and seasonal distributions of ventricular tachyarrhythmias in patients with implantable cardioverter-defibrillators

This study investigated the circadian, daily, and seasonal distributions of ventricular arrhythmias in patients with new implantable cardioverter-defibrillator placement at Creighton University Medical Center from January 2000 to December 2004. The incidence and distribution of ventricular tachyarrhythmias as recorded by implantable cardioverter-defibrillators were analyzed with respect to season, month, day of the week, and average daily temperature. Data from 154 consecutive patients (mean age 67 +/- 14 years; 78% men, 71% with ischemic heart disease [IHD], mean left ventricular ejection fraction 34 +/- 15%) were analyzed. During a mean follow-up of 35 +/- 19 months, a total of 1,055 episodes of spontaneously terminated ventricular tachycardia (VT) and 612 episodes of VT or ventricular fibrillation with appropriate device therapy occurred. Distributions in the incidence of VT and VT or ventricular fibrillation receiving appropriate therapy were similar in patients with IHD and non-IHD. Spontaneously terminated VT and appropriately treated VT or ventricular fibrillation episodes occurred with the greatest incidence in the winter months and the lowest incidence in summer, spring, and fall. A linear regression between the number of episodes and the average daily temperature showed a greater likelihood of the 2 events occurring on cooler days, irrespective of the cause of cardiac disease. A weekly distribution was also observed, with the greatest proportion of episodes occurring on Fridays and the lowest on Saturdays and Sundays. A bimodal circadian distribution was present, with the greatest peak occurring from 8 a.m. to 1 p.m. and a smaller peak occurring from 5 p.m. to 10 p.m. In conclusion, the occurrence of ventricular tachyarrhythmias appears to follow circadian, daily, and seasonal distributions that are similar in patients with IHD and non-IHD. The incidence inversely correlates with average daily temperatures.