Circadian variation in onset of acute cardiogenic pulmonary edema is independent of patients' features and underlying pathophysiological causes

Sleep and Cardiovascular Risk

Sleep is essential for healthy being and healthy functioning of human body as a whole, as well as each organ and system. Sleep disorders, such as sleep-disordered breathing, insomnia, sleep fragmentation, and sleep deprivation are associated with the deterioration in human body functioning and increased cardiovascular risks. However, owing to the complex regulation and heterogeneous state sleep per se can be associated with cardiovascular dysfunction in susceptible subjects. The understanding of sleep as a multidimensional concept is important for better prevention and treatment of cardiovascular diseases.

Day vs night: Does time of presentation matter in acute heart failure? A secondary analysis from the RELAX-AHF trial

BACKGROUND

Signs and symptoms of heart failure can occur at any time. Differences between acute heart failure (AHF) patients who present at nighttime vs daytime and their outcomes have not been well studied. Our objective was to determine if there are differences in baseline characteristics and clinical outcomes between AHF patients presenting during daytime vs nighttime hours within an international, clinical trial.

METHODS

This is a post hoc analysis of the RELAX AHF trial, which randomized 1,161 AHF patients to serelaxin vs placebo, both in addition to usual AHF therapy. Prespecified end points of the primary trial were used: dyspnea, 60-day heart failure/renal failure rehospitalization or cardiovascular (CV) death, and 180-day CV death. Both unadjusted and adjusted analyses for outcomes stratified by daytime vs nighttime presentation were performed.

RESULTS

Of the 1,161 RELAX-AHF patients, 775 (66.8%) patients presented during daytime and 386 (33.2%) at nighttime. Baseline characteristics were largely similar, although daytime patients were more likely to be male, have greater baseline body weight, have higher New York Heart Association class, have history of atrial fibrillation, and have more peripheral edema compared with nighttime patients. No differences in dyspnea relief or 60-day outcomes were observed. However, daytime presentation was associated with greater risk for 180-day CV death after adjustment (hazard ratio 2.28, 95% CI 1.34-3.86; c statistic = 0.82, 95% CI 0.78-0.86).

CONCLUSION

In this secondary analysis of the RELAX-AHF trial, baseline characteristics suggest that daytime-presenting patients may have more gradual worsening of chronic HF. Patients with AHF who presented at night had less risk for 180-day CV death, but similar risk for 60-day CV death or rehospitalization and symptom improvement for patients who presented during the daytime.

Ambulatory Blood Pressure Parameters and Heart Failure With Reduced or Preserved Ejection Fraction in Elderly Treated Hypertensive Patients

BACKGROUND

The association between ambulatory blood pressure (BP) and future risk of heart failure (HF) is unclear. We investigated the association between ambulatory BP parameters and risk of HF with reduced ejection fraction (HFREF) or preserved ejection fraction (HFPEF) in elderly treated hypertensive patients.

METHODS

The occurrence of HFREF and HFPEF was evaluated in 1,191 elderly treated hypertensive patients who underwent clinical and instrumental evaluation, including ambulatory BP monitoring to evaluate daytime, nighttime, and 24-hour BP, dipping status, and morning surge (MS) of BP.

RESULTS

During the follow-up (9.1±4.9 years, range 0.4-20 years), 123 patients developed HF, of whom 56 had HFREF and 67 had HFPEF. After adjustment for other covariates, Cox regression analysis showed that 24-hour systolic BP, but not clinic BP, was independently associated with risk of both HFREF (hazard ratio (HR): 1.36, 95% confidence interval (CI): 1.14-1.63, per 10mm Hg increment) and HFPEF (HR: 1.35, 95% CI: 1.13-1.61, per 10mm Hg increment); moreover, high MS of BP (>23mm Hg) in dippers was independently associated with risk of HFREF (HR: 2.27, 95% CI: 1.00-5.15) and nondipping was independently associated with risk of HFPEF (HR: 2.78, 95% CI: 1.38-5.63).

CONCLUSIONS

In elderly treated hypertensive patients, 24-hour systolic BP is independently associated with future risk of both HFREF and HFPEF, whereas high MS is independently associated with risk of HFREF and nondipping is independently associated with risk of HFPEF.

Circadian variation of cardiogenic pulmonary oedema

INTRODUCTION

Circadian variation of in-hospital acute cardiogenic pulmonary oedema (CPE) with the highest occurrence in the early morning has been reported repeatedly. However, no study evaluating circadian variation of CPE in the field has been published. Therefore, we decided to evaluate the circadian variation of CPE in the Central Bohemian Region of the Czech Republic in the patients treated by regional emergency medical service (EMS) and analyse its association with baseline blood pressure in the field.

METHODS

We extracted all dispatches to CPE cases from EMS database for the period from 1.11.2008 to 30.6.2014 and analysed for circadian variation. We identified the patients presenting with CPE coupled with arterial hypertension (systolic blood pressure >140mmHg) and hypotension (systolic blood pressure <90mmHg) and compared the subgroups (both subgroups include 2744 subjects).

RESULTS

In 4747 episodes of CPE, maximal occurrence was detected in the ninth hour in the morning, representing 7.7% of all CPE episodes (p<0.05). While CPE with hypertension (2463 subjects) reached maximal occurrence also in the ninth hour (7.4% of all cases, p<0.05), CPE with hypotension (281 patients) was most frequent in the fourteenth hour (8.6% of all cases, p<0.05).

CONCLUSION

The highest occurrence of CPE was observed in the ninth hour in the morning in our study. Moreover, differences in circadian variation between CPE with hypertension and hypotension were identified. Knowledge of these patterns may have an impact on the logistic of prehospital emergency care and on preventive measures in the patients who have previously undergone CPE.

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.

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.

Circadian aspects of post-operative morbidity and mortality

It has been well established that there exists a circadian concentration of cardiovascular, cerebrovascular and cardiopulmonary events. The aim was to describe aspects of circadian variation in relation to cardiovascular, cerebrovascular and thromboembolic diseases and to describe the literature concerning post-operative circadian disturbances. We also present the literature concerning circadian variation in post-operative morbidity and mortality. PubMed and the Cochrane database were searched for papers using a combination of 'circadian,''surgery,''post-operative,''mortality' and 'morbidity.' Eleven relevant studies were found, and seven of these were excluded due to the use of time of surgery and not time of morbidity or mortality as the main variable. The results from the four articles showed a circadian distribution of morbidity and mortality that mimics the one seen without surgery. There is a peak incidence of myocardial ischemia, fatal thromboembolism and sudden unexpected death in the morning hours. A circadian variation exists in post-operative morbidity and mortality. The observed circadian variation in post-operative morbidity and mortality may warrant a chronopharmacological approach to patients in the perioperative period. The underlying pathophysiological mechanisms should be the focus for future studies.

Circadian study of decompression sickness symptoms and response-associated variables in rats

In order to study circadian rhythms and decompression sickness (DCS), we determined: 1) the baseline circadian time structure in noncompressed rats of potential response variables to compression/decompression (C/D), and 2) whether rats subjected to C/D display a circadian time-dependent difference in inflammatory response intensity and biological tolerance. Subgroups of male rats, standardized to a 12 h light/12 h dark schedule, were evaluated every 4 h over 24 h after they were either compressed to 683 kPa (group E) or remained at sea level (group C). During 60 min recovery, evaluation included gross DCS symptoms and pulmonary edema in all E rats, and cell counts, nitric oxide, protein, thromboxane B(2,) and leukotriene E(4) levels in survivors. Chi-square, ANOVA, and 24 h cosinor analyses were used to test for time-of-day effects. C/D exposures near the end of dark/activity or during light/resting were generally better tolerated, with lowest signs of DCS symptoms and lowest responses by most of the variables monitored. More deaths were observed in the first half of the dark/activity span. Of the 16 subsets of inflammatory-associated variables, overall increases were observed in 13 and decreases in 2. Significant or borderline significant circadian time effects were found in 14 variables in group C, 12 variables in group E, and 13 variables in response (E%C). Thus, nearly all baseline indices of DCS demonstrated circadian time-dependencies in the sea-level exposed control rats (group C), and nearly all were modified by the circadian time of C/D. Such time-of-day effects of DCS are potentially relevant to the operational concerns of occupations involving decompression exposures and the investigation of prevention and treatment intervention strategies of DCS.

Influence of circadian rhythm on mortality after myocardial infarction: Data from a prospective cohort of emergency calls

Myocardial infarction (MI) occurs more frequently in the morning as a result of the concomitant unfavorable timing of several physiological parameters and/or biochemical conditions. However, little is known about the possible influence of this circadian pattern on prognosis. To evaluate whether the time of symptom onset could potentially influence mortality from acute MI, this prospective study considered all consecutive MIs admitted to the ED of Ferrara, Italy, after a call to the Emergency Coordinating Unit from January 1, 1998, to December 31, 2001. The total sample consisted of 442 MIs (mean age, 68.7 years; males, 72%). Eighty patients (males, 82.5%) died in the ED; the remaining 362 were admitted to the hospital. Of these, 50 (males, 60%) died during their hospital stay. Based on the timing of their symptom onset, cases were categorized both into 24 1-hour intervals and four 6-hour intervals (midnight to 5:59 am, 6:00 am to 11:59 am, noon to 5:59 pm, and 6:00 pm to 11:59 pm), and the circadian distributions of fatal versus nonfatal MIs were compared. The circadian variation of MI peaked between 6:00 am and noon (P < .001), and in this period, there was a trend toward a higher frequency of fatal cases (41.5% vs. 35.2%; chi(2) = 1.911, P = .167). To verify whether this higher frequency of fatal events in the morning hours could be related to possible higher severity of cases observed in that hours, a further separate analysis considering age, infarct site, and peak levels of MB was made. Again, no significant temporal differences among the four 6-hour intervals were found between fatal and nonfatal Mis, although a trend toward older age was observed in morning MIs. Not only the frequency, but also the mortality, of acute MI could be increased in the morning hours. This could be of practical interest for emergency doctors and could have significant implications for acute treatment, because several studies have reported a lowered efficacy of thrombolytic drugs in the morning hours.

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.

Circadian pattern of emergency calls: implications for ED organization

A circadian variation has been shown in the onset of acute medical diseases and we postulate that there is a circadian variation in emergency calls. We reviewed the 20,858 emergency calls addressed to the Emergency Coordinating Unit of the Hospital of Ferrara, Italy, from January 1 to December 31, 1998. Precise determination of the time of calls was available from the recordings. Total calls and subgroups by different diseases were categorized into 24 one-hour increments and analyzed for circadian rhythmicity by applying a partial Fourier series. A circadian variation was found for all subgroups, except for alcoholic intoxication. There was a peak frequency of calls in the morning hours for cardiologic, respiratory, and neurologic disease. There was a peak frequency of calls in the afternoon for trauma, neoplastic diseases, and acute poisoning. Organization of quantity and quality of Emergency Department (ED) staff should take into account the increased demand of specific facilities during certain hours of the day.