Factores de riesgo cardiovascular en el ritmo circadiano del infarto agudo de miocardio

Circadian Variations and Associated Factors in Patients with Ischaemic Heart Disease

Circadian rhythms have been identified in cardiovascular diseases, and cardiovascular risk factors can modify the circadian rhythm. The purpose of this study was to describe the onset of ischaemic heart disease symptomatology in relation to the date and time, the day of the week of presentation, the season, AMI location and severity and the level of influence of individual patient characteristics in a retrospective cross-sectional study involving 244 ischaemic heart disease patients from the intensive care unit of La Ribera Hospital (Spain). The onset of pain was more frequent in the morning, the season with the highest frequency of ischaemic events was winter, and the lowest incidence was during weekends. Regarding the severity of ischaemic heart disease, the circadian rhythm variables of weekdays vs. weekends and seasons did not show a significant association. The length of hospital stay was associated with the onset of pain in the afternoon. The onset of pain at night was associated with the subendocardial location of the infarction. In conclusion, living in a Mediterranean country, the Spanish population showed a circadian pattern of AMI, where the onset of pain has an influence on AMI location and on the length of hospital stay and is the same in patients with different individual risk factors.

Circadian and seasonal variation in onset of acute myocardial infarction

The aim was to investigate the circadian and seasonal variation of acute myocardial infarction (AMI). Clinical data of 3867 AMI patients hospitalized from November 2010 to October 2019 in the Border Yanbian Minority Autonomous Prefecture, China were collected, and 3158 patients with definite AMI onset times were analyzed. The clinical data analyzed included the time of onset, nationality, age, laboratory data. We divided the patients into 4 groups based on the timepoint of their AMI onsets: 00:00-05:59, 06:00-11:59, 12:00-17:59, and 18:00-23:59. We also divided the patients based on nationality: Chinese Korean and Han groups. We observed that there is a circadian rhythm in the incidence of AMI, and the peak of AMI is in the morning (7:00-9:00). Unexpectedly, the incidence of AMI was significantly lower in the cold winter than that of other 3 warm seasons (P < 0.01) and the peak of AMI presented at the months of the large contrast between day and night temperature difference (over 20°C) like May of Spring and October of Fall. Finally, there was no difference in circadian rhythm between Chinese Korean and Han, although these groups differed in age, body mass index, and the inflammatory cell level. These findings have shown a different seasonal and circadian variation in onset of AMI. Further studies are required to determine the pathophysiological mechanism(s) underlying these differences and to guide prevention of AMI for reducing its mortality and disability.

Postnatal Deletion of Bmal1 in Cardiomyocyte Promotes Pressure Overload Induced Cardiac Remodeling in Mice

Background Mice with cardiomyocyte-specific deletion of Bmal1, a core clock gene, had spontaneous abnormal cardiac metabolism, dilated cardiomyopathy, and shortened lifespan. However, the role of cardiomyocyte Bmal1 in pressure overload induced cardiac remodeling is unknown. Here we aimed to understand the contribution of cardiomyocyte Bmal1 to cardiac remodeling in response to pressure overload induced by transverse aortic constriction or chronic angiotensin Ⅱ (AngⅡ) infusion. Methods and Results By generating a tamoxifen-inducible cardiomyocyte-specific Bmal1 knockout mouse line (cKO) and challenging the mice with transverse aortic constriction or AngⅡ, we found that compared to littermate controls, the cKO mice displayed remarkably increased cardiac hypertrophy and augmented fibrosis both after transverse aortic constriction and AngⅡ induction, as assessed by echocardiographic, gravimetric, histologic, and molecular analyses. Mechanistically, RNA-sequencing analysis of the heart after transverse aortic constriction exposure revealed that the PI3K/AKT signaling pathway was significantly activated in the cKOs. Consistent with the in vivo findings, in vitro study showed that knockdown of Bmal1 in cardiomyocytes significantly promoted phenylephrine-induced cardiomyocyte hypertrophy and triggered fibroblast-to-myofibroblast differentiation, while inhibition of AKT remarkedly reversed the pro-hypertrophy and pro-fibrosis effects of Bmal1 knocking down. Conclusions These results suggest that postnatal deletion of Bmal1 in cardiomyocytes may promote pressure overload-induced cardiac remodeling. Moreover, we identified PI3K/AKT signaling pathway as the potential mechanistic ties between Bmal1 and cardiac remodeling.

Comparison of clinical outcomes in STEMI patients treated with primary PCI according to day-time of medical attention and its relationship with circadian pattern

OBJECTIVE

Relationship between STEMI time of presentation, its circadian pattern and cardiovascular outcomes is unclear. Our objective is to analyze clinical outcomes of STEMI according to time of presentation and circadian pattern.

METHODS

We analyzed data from patients treated within the regional STEMI Network from January 2010 to December 2015. On-hour group included patients treated between 8:00 h and 19:59 h on weekdays, the rest were catalogued as off-hour group. The primary endpoint was 1-year all-cause mortality. Secondary endpoints were 30-day all-cause mortality and in-hospital complications.

RESULTS

A total of 8608 patients were included, 44.1% in the on-hour group and 55.9% in the off-hour group. We observed a shorter patient delay and longer system delay in the off-hour group compared to on-hour group with no difference in total ischemic time. At 30-day and 1-year follow-up there were no differences in adjusted all-cause mortality between groups [OR 0.91 (CI95%: 0.73-1.12; p = 0.35) and OR 0.99 (CI95%: 0.83-1.17; p = 0.87), respectively]. A circadian pattern was observed between 9:00 am and 12:30 pm, with no differences in 30-day and 1-year mortality between patients included in this time interval [OR 1.02 (IC95%: 0.81-1.30; p = 0.85) and OR 1.12 (IC95%: 0.92-1.36; p = 0.25) respectively].

CONCLUSIONS

Off-hour STEMI presentation was associated with a shorter patient delay and longer system delay without an increase in total ischemic time. The off-hour presentation was not related to an increase in 1-year all-cause mortality when compared to on-hour. A circadian pattern was found, without differences in 30-day and 1-year mortality.

Cultural factors and the circadian rhythm of ST elevation myocardial infarction in patients in a Mediterranean island

INTRODUCTION

The circadian rhythm of onset of myocardial infarction shows an increased risk during the morning hours. However, it is not clear whether habits, culture and sunshine hours differentiate circadian rhythm. The aim of this study was to investigate the influence of cultural factors on the circadian rhythm of acute myocardial infarction with ST segment elevation in a Mediterranean island.

METHOD

The study was a retrospective correlational survey. It included 123 patients with ST elevation myocardial infarction (mean age 60.7±12.6; 82% men). The 24 h of a day were divided into four six-hour periods of time for study purposes (00:01-06:00; 06:01-12:00; 12:01-18:00; and 18:01-24:00) and the chi-square test was used for the analysis.

RESULTS

A morning peak of symptoms onset of ST-elevation myocardial infarction was detected during the period 06:01-12:00 (p=0.044). In patients who were smokers, a bimodal pattern involving a morning (06:01-12:00) and an afternoon-to-night peak (18:01-24:00) (p=0.005) was detected. For patients with a history of hypertension, a morning peak of their symptoms was also detected (p=0.028). Different circadian variations were found between patients over the age of 60 years old and patients under the age of 60 years old (p=0.025).

CONCLUSIONS

Patients with ST elevation myocardial infarction seem to follow a circadian rhythm with a peak of onset of symptoms in the morning. In the smokers' subgroup, a different circadian pattern was found. The habit of smoking is likely to affect the circadian rhythm of the onset of ST elevation myocardial infarction in the Mediterranean area and culture.

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.

Myocardial potency of Bio-tea against Isoproterenol induced myocardial damage in rats

Kombucha (Bio-tea) is a beverage produced by the fermentation of sugared black tea using a symbiotic association of bacteria and yeasts. Traditional claims about Kombucha report beneficial effects such as antibiotic properties, gastric regulation, relief from joint rheumatism and positive influence on the cholesterol level, arteriosclerosis, diabetes, and aging problems. The present investigation was carried out to understand the preventive effect of Kombucha on heart weight, blood glucose, total protein, lipid profile and cardiac markers in rats with myocardial damage induced using Isoproterenol. As Bio-tea is produced by fermenting tea, the parameters were compared in rats pre-treated with normal black tea and Bio-tea for 30 days followed by subcutaneous injection of Isoproterenol (85 mg/kg body weight). Normal rats as well as Isoproterenol induced myocardial infarcted rats were also used, which served as controls. Isoproterenol induced myocardial infarcted control rats showed a significant increase in heart weight, blood glucose and cardiac markers and a decrease in plasma protein. Increased levels of cholesterol, triglycerides, low density lipids (LDL) and very low density lipids (VLDL) were also observed, while the high density lipid (HDL) content decreased. Bio-tea showed a higher preventive effect against myocardial infarction when compared to tea, as was observed by the significant reduction in heart weight, and blood glucose and increase in plasma albumin levels. Bio-tea significantly decreased cholesterol, triglycerides, LDL and VLDL while simultaneously increasing the levels of HDL. Similarly a decrease in leakage of cardiac markers from the myocardium was also observed.

A biochemical and 2, 3, 5-triphenyl tetrazolium chloride staining study on the preventive effects of zingerone (vanillyl acetone) in experimentally induced myocardial infarcted rats

Myocardial infarction continues to be a major public health problem, not only in western countries but also increasingly in developing countries and makes significant contribution to the mortality statistics. Reduction in mortality rate and prevention of myocardial infarction are of utmost importance. Tachycardia, left ventricular hypertrophy (LVH), altered adenosine triphosphatases (ATPases), and shifts in electrolyte balance play a vital role in the pathogenesis of myocardial infarction. This study was designed to evaluate the preventive effects of zingerone (vanillyl acetone) on tachycardia, LVH, altered electrocardiogram (ECG), altered activities of membrane bound ATPases, electrolyte imbalance and myocardial infarct size in isoproterenol induced myocardial infarcted rats. Rats were pretreated with zingerone (vanillyl acetone) 6 mg/kg body weight daily for a period of 14 days and were then induced myocardial infarction with isoproterenol (100 mg/kg body weight) on 15th and 16th day. Isoproterenol induced myocardial infarcted rats showed tachycardia, LVH, altered ECG, serum cardiac troponin-T, plasma myoglobin, heart ATPases, heart sodium ion, calcium ion, potassium ion, and increased myocardial infarct size. Pretreatment with zingerone (vanillyl acetone) revealed preventive effects on tachycardia, LVH, ECG, and all the above mentioned biochemical parameters evaluated in isoproterenol induced myocardial infarcted rats. The 2, 3, 5-triphenyl tetrazolium chloride staining on myocardial infarct size confirmed the prevention of myocardial infarction. Further, the in vitro study revealed a very convincing free radical scavenging of zingerone (vanillyl acetone). Thus, the observed effects of zingerone (vanillyl acetone) are due to its antioxidant and free radical scavenging activities in isoproterenol induced myocardial infarcted rats.

Chronobiology of death in heart failure

INTRODUCTION AND OBJECTIVES

In the general population, heart events occur more often during early morning, on Mondays, and during winter. However, the chronobiology of death in heart failure has not been analyzed. The aim of this study was to determine the circadian, day of the week, and seasonal variability of all-cause mortality in chronic heart failure.

METHODS

This was an analysis of all consecutive heart failure patients followed in a heart failure unit from January 2003 to December 2008. The circadian moment of death was analyzed at 6-h intervals and was determined by reviewing medical records and by information provided by the relatives.

RESULTS

Of 1196 patients (mean [standard deviation] age, 69 [13] years; 62% male), 418 (34.9%) died during a mean (standard deviation) follow-up of 29 (21) months. Survivors were younger, had higher body mass index, left ventricular ejection fraction, glomerular filtration rate, hemoglobin and sodium levels, and lower Framingham risk scores, amino-terminal pro-B type natriuretic peptide, troponin T, and urate values. They were more frequently treated with angiotensin receptor blockers, beta-blockers, mineralocorticoids receptor antagonists, digoxin, nitrates, hydralazine, statins, loop diuretics, and thiazides. The analysis of the circadian and weekly variability did not reveal significant differences between the four 6-h intervals or the days of the week. Mortality occurred more frequently during the winter (30.6%) compared with the other seasons (P = .024).

CONCLUSIONS

All cause mortality does not follow a circadian pattern, but a seasonal rhythm in patients with heart failure. This finding is in contrast to the circadian rhythmicity of cardiovascular events reported in the general population.

[Relation between myocardial infarction and circadian rhythm in patients attended in a prehospital emergency service]

BACKGROUND AND OBJECTIVES

The aim of this study is to analyze the presence of circadian rhythm in the time of onset of symptoms of acute myocardial infarction treated by a prehospital emergency system and the influence of modifiable cardiovascular risk factors and non-modifiable as modulators of that circadian rhythm.

PATIENTS AND METHODS

Retrospective analysis of 709 patients clinically diagnosed with acute myocardial infarction on-site in the prehospital setting. The variables were time to onset of symptoms, age, sex, previous ischemic heart disease, hypertension, diabetes mellitus, hyperlipidemia and smoking. We analyzed the rhythm with cosinor multiple sinusoid method, with 3 harmonics (24, 12 and 8h) for the adjustment.

RESULTS

The time of onset of pain showed circadian rhythm (P <,001), peaking at 10.39 and a valley at 4.28, showing a sinusoidal curve fitting bimodal aspect with a predominant morning peak and another evening one of lower amplitude. All subgroups categorized by the study variables showed circadian rhythm, with a cosine curve similar to the global infarction. Smokers had a predominantly evening peak.

CONCLUSIONS

Acute myocardial infarction shows a circadian rhythm. Smoking and diabetes mellitus can modify the standard incidence rate of occurrence of myocardial infarction.