Chronobiologic Aspects of Venous Thromboembolism

Alterations in visible light exposure modulate platelet function and regulate thrombus formation

BACKGROUND

Variations in light exposure are associated with changes in inflammation and coagulation. The impact of light spectra on venous thrombosis (VT) and arterial thrombosis is largely unexplored.

OBJECTIVES

To investigate the impact of altering light spectrum on platelet function in thrombosis.

METHODS

Wild-type C57BL/6J mice were exposed to ambient (micewhite, 400 lux), blue (miceblue, 442 nm, 1400 lux), or red light (micered, 617 nm, 1400 lux) with 12:12 hour light:dark cycle for 72 hours. After 72 hours of light exposure, platelet aggregation, activation, transcriptomic, and metabolomic changes were measured. The ability of released products of platelet activation to induce thrombosis-generating neutrophil extracellular trap formation was quantified. Subsequent thrombosis was measured using murine models of VT and stroke. To translate our findings to human patients, light-filtering cataract patients were evaluated over an 8-year period for rate of venous thromboembolism with multivariable logistic regression clustered by hospital.

RESULTS

Exposure to long-wavelength red light resulted in reduced platelet aggregation and activation. RNA-seq analysis demonstrated no significant transcriptomic changes between micered and micewhite. However, there were global metabolomic changes in platelets from micered compared with micewhite. Releasate from activated platelets resulted in reduced neutrophil extracellular trap formation. Micered also had reduced VT weight and brain infarct size following stroke. On subgroup analysis of cataract patients, patients with a history of cancer had a lower lifetime risk of venous thromboembolism after implantation with lenses that filter low-wavelength light.

CONCLUSION

Light therapy may be a promising approach to thrombus prophylaxis by specifically targeting the intersection between innate immune function and coagulation.

Frequency and severity of idiopathic epistaxis relative to time of day

This study investigated the frequency of idiopathic epistaxis onset and its severity relative to the time of day. Idiopathic epistaxis was defined as epistaxis in the emergency department, with no epistaxis diagnosis in any hospital 12 months before incident epistaxis. The timing of epistaxis onset was divided into four categories: morning (6:01-12:00), afternoon (12:01-18:00), evening (18:01-24:00), and overnight (00:01-6:00). The chi-square test was used to analyse the time distribution of epistaxis (p ≤ .05).. During the study period, a total of 1684 patients with a median age of 56 years developed epistaxis. Epistaxis incidence was highest in December (n = 213), lowest in July (n = 95), and highest in winter, followed by fall, spring, and summer. Epistaxis occurred most frequently overnight (n = 823, 48.8%), followed by evening (n = 410, 24.3%), morning (n = 254, 15.1%), and afternoon (n = 197, 11.7%; p < .001). Afternoon was selected as the reference. After adjustment for covariates, odds ratios (ORs) and 95% confidence intervals (CIs) of the risk of epistaxis were 1.34 (95% CI, 1.26-1.43), 1.47 (1.38-1.56), and 3.52 (3.14-3.91) in the evening, morning, and overnight, respectively. Epistaxis rates overnight were significantly strongest and positively proportional to blood pressure levels between 0:01 am and 6:00 am (r = 18.1, p < .001), followed by overnight rates (r = 11.5, p = .017). Patients who developed epistaxis overnight were more likely to develop posterior epistaxis and to receive endoscopic electrocoagulation haemostasis (p < .001). In this cohort, these results suggest that adult idiopathic epistaxis occurred most frequently at overnight, especially in the winter, and more need management to immediately control the bleeding in ENT emergency departments. In addition, this study found that high frequent of epistaxis at overnight associated with serious blood pressure between 0:01 am and 6:00 am. This analysis supports that health care professionals and caregiver should be aware of individuals with hypertension, and the status of blood pressure at overnight should be considered in preventing nasal bleeding's risk.

Redox Regulatory Changes of Circadian Rhythm by the Environmental Risk Factors Traffic Noise and Air Pollution

Significance: Risk factors in the environment such as air pollution and traffic noise contribute to the development of chronic noncommunicable diseases. Recent Advances: Epidemiological data suggest that air pollution and traffic noise are associated with a higher risk for cardiovascular, metabolic, and mental disease, including hypertension, heart failure, myocardial infarction, diabetes, arrhythmia, stroke, neurodegeneration, depression, and anxiety disorders, mainly by activation of stress hormone signaling, inflammation, and oxidative stress. Critical Issues: We here provide an in-depth review on the impact of the environmental risk factors air pollution and traffic noise exposure (components of the external exposome) on cardiovascular health, with special emphasis on the role of environmentally triggered oxidative stress and dysregulation of the circadian clock. Also, a general introduction on the contribution of circadian rhythms to cardiovascular health and disease as well as a detailed mechanistic discussion of redox regulatory pathways of the circadian clock system is provided. Future Directions: Finally, we discuss the potential of preventive strategies or "chrono" therapy for cardioprotection. Antioxid. Redox Signal. 37, 679-703.

Association between air temperature, air pollution and hospital admissions for pulmonary embolism and venous thrombosis in Italy

BACKGROUND

Previous studies reported a link between short-term exposure to environmental stressors (air pollution and air temperature) and atherothrombotic cardiovascular diseases. However, only few of them reported consistent associations with venous thromboembolism (VTE). Our aim was to estimate the association between daily air temperature and particulate matter (PM) air pollution with hospital admissions for pulmonary embolism (PE) and venous thrombosis (VT) at national level in Italy.

METHODS

We collected daily hospital PE and VT admissions from the Italian Ministry of Health during 2006-2015 in all the 8,084 municipalities of Italy, and we merged them with air temperature and daily PM10 concentrations estimated by satellite-based spatiotemporal models. First, we applied multivariate Poisson regression models at province level. Then, we obtained national overall effects by random-effects meta-analysis.

RESULTS

This analysis was conducted on 219,952 PE and 275,506 VT hospitalizations. Meta-analytical results showed weak associations between the two exposures and the study outcomes in the full year analysis. During autumn and winter, PE hospital admissions increased by 1.07% (95% confidence intervals [CI]: 0.21%; 1.92%) and 0.96% (95% CI: 0.07%; 1.83%) respectively, per 1 °C decrement of air temperature in the previous 10 days (lag 0-10). In summer we observed adverse effects at high temperatures, with a 1% (95% CI: 0.10%; 1.91%) increasing risk per 1 °C increment. We found no association between VT and cold temperatures.

CONCLUSION

Results show a significant effect of air temperature on PE hospitalizations in the cold seasons and summer. No effect of particulate matter was detected.

Temporal fluctuations of post-tonsillectomy haemorrhage

Purpose

Although haemorrhage is a common and in some cases life-threatening complication after tonsillectomy, surprisingly little is known about the temporal fluctuations of the onset of bleeding. The purpose of this study was to assess circadian and seasonal rhythms of post-tonsillectomy haemorrhage (PTH) and potential ramifications to educate patients and health care staff.

Methods

This retrospective study carried out at a tertiary referral hospital included paediatric and adult patients requiring emergency surgery due to severe PTH between 1993 and 2019. Medical records were reviewed and patient demographics, details regarding the initial procedure, postoperative day of haemorrhage, and start time of emergency surgery were extracted. Descriptive statistics, Kruskal–Wallis test, Mann–Whitney U test, and Chi-square goodness of fit tests were used to detect potential differences.

Results

A total of 300 patients with severe PTH and subsequent emergency surgery were identified. The median postoperative duration until PTH was 6 (range: < 1–19) days. 64.7% (n = 194) of all emergency surgeries had to be performed during evening and night hours (6 pm—6 am) (p < 0.0001). Compared to diurnal incidents, the risk of a nocturnal PTH event increased, the longer ago the initial surgery was (p < 0.0001). No seasonal variations were identified. Age, sex, and details of the initial procedure had no significant influence on the start time according to the surgical protocol.

Conclusion

The discovered temporal fluctuations of PTH are of relevance for patient awareness and preoperative education. Due to possible life-threatening complications, management of severe PTH requires specific resources and trained medical staff on call.

Influence of mental stress and environmental toxins on circadian clocks: Implications for redox regulation of the heart and cardioprotection

Risk factors in the environment such as air pollution and mental stress contribute to the development of chronic non-communicable disease. Air pollution was identified as the leading health risk factor in the physical environment, followed by water pollution, soil pollution/heavy metals/chemicals and occupational exposures, however neglecting the non-chemical environmental health risk factors (e.g. mental stress and noise). Epidemiological data suggest that environmental risk factors are associated with higher risk for cardiovascular, metabolic and mental diseases, including hypertension, heart failure, myocardial infarction, diabetes, arrhythmia, stroke, depression and anxiety disorders. We provide an overview on the impact of the external exposome comprising risk factors/exposures on cardiovascular health with a focus on dysregulation of stress hormones, mitochondrial function, redox balance and inflammation with special emphasis on the circadian clock. Finally, we assess the impact of circadian clock dysregulation on cardiovascular health and the potential of environment-specific preventive strategies or "chrono" therapy for cardioprotection. LINKED ARTICLES: This article is part of a themed issue on Risk factors, comorbidities, and comedications in cardioprotection. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.23/issuetoc.

Frequency of post-tonsillectomy hemorrhage relative to time of day

OBJECTIVES

Postoperative hemorrhage is a serious complication of tonsillectomy, with secondary bleeding rates affecting up to 0.8% to 3% of patients. Although these bleeds are anecdotally perceived as occurring more frequently at night, the occurrence of hemorrhage relative to the time of day has not been investigated. We measured the frequency of post-tonsillectomy hemorrhage onset relative to the time of day.

METHODS

We reviewed electronic medical records of all patients who experienced postprocedural hemorrhage (International Classification of Disease, Ninth Edition [ICD-9] 998.11, ICD-10 J95.830 at two hospitals within a tertiary academic health system in a 10-year period). Patient demographics, time of bleed onset, emergency room [ED] arrival time, and management (operating room vs. observation) were abstracted. Patients without a recorded bleeding time were excluded. Time of bleed onset was categorized as morning (6:01 am-12 pm), afternoon (12:01 pm-6 pm), evening (6:01 pm-12 am), or overnight (12:01 am-6 am). Chi-square goodness of fit test was used to assess the distribution of hemorrhage timing (P ≤ 0.05).

RESULTS

A total of 7,396 patients underwent tonsillectomy May 2008 through May 2018, among whom 121 (2%) post-tonsillectomy hemorrhage patients were identified. Among the 104 patients with ED arrival times, 29 (28%) arrived in the morning; 15 (14%) arrived in the afternoon; 40 (38%) arrived in the evening; and 20 (19%) arrived overnight (P = 0.003). Sixty patients (mean age 17.1 years, standard deviation 16.6) had a recorded timing of bleed onset. Bleed onset occurred most commonly overnight (24, 40%), followed by evening (21, 35%), afternoon (11, 18%), and morning (4, 7%) (P = 0.0007).

CONCLUSION

In this cohort, post-tonsillectomy hemorrhage occurred most frequently between midnight and 6 am. Our findings confirm anecdotal experience and provide data in setting caregiver expectations.

LEVEL OF EVIDENCE

4 Laryngoscope, 130:1823-1827, 2020.

Venous Thromboembolism in Denmark: Seasonality in Occurrence and Mortality

Background  Many cardiovascular conditions exhibit seasonality in occurrence and mortality, but little is known about the seasonality of venous thromboembolism.

Methods  Using Danish registries, we identified all patients with deep vein thrombosis, pulmonary embolism, splanchnic vein thrombosis, cerebral vein thrombosis, and retinal vein thrombosis during 1977–2016. We tallied monthly deaths occurring within 90 days of the venous thromboembolism diagnosis. We estimated peak-to-trough ratios and timing of the peak of both diagnoses and deaths summed over all years of the study period. The departure from 1.0 of the peak-to-trough ratio measures the intensity of any seasonal pattern.

Results  We estimated a peak-to-trough ratio of 1.09 (95% confidence interval: 1.07–1.11) for deep vein thrombosis and 1.22 (1.19–1.24) for pulmonary embolism occurrence. The peak-to-trough ratios for splanchnic vein thrombosis, cerebral vein thrombosis, and retinal vein thrombosis occurrence were 1.10 (1.01–1.20), 1.19 (1.00–1.40), and 1.12 (1.07–1.17), respectively. The occurrence of all conditions peaked during winter or fall. In time trend analyses, the peak-to-trough ratio increased considerably for splanchnic vein thrombosis, cerebral vein thrombosis, and retinal vein thrombosis occurrence. In associated mortality, the peak-to-trough ratio for deep vein thrombosis was larger (1.15, 1.07–1.23) than that for pulmonary embolism (1.04, 1.01–1.08).

Discussion  Excess winter risks were modest, but more marked for pulmonary embolism occurrence than for deep vein thrombosis occurrence. The seasonal pattern intensified throughout the study period for splanchnic vein thrombosis, cerebral vein thrombosis, and retinal vein thrombosis. The winter peak in mortality following pulmonary embolism was smaller than that for deep vein thrombosis.

Semiautomatic intermittent pneumatic compression device applied to deep vein thrombosis in major orthopedic surgery

Objective

To investigate the effect of additional semiautomatic intermittent pneumatic compression device (IPCD) in the prevention of deep vein thrombosis (DVT) of lower extremity in these patients undergoing major orthopedic surgery, when compared with the conventional graduated compression stockings alone.

Methods

The data of 112 patients undergoing major orthopedic surgery were retrospectively analyzed. 51 patients who ever received IPCD and graduated compression stockings during major orthopedic surgery were taken as the experimental group, and 61 patients who only received the conventional graduated compression stockings during surgery were taken as the observation group. The Doppler sonography was utilized to detect the presence of DVT and pulmonary embolism pre- and postoperatively. Besides, the mean and peak velocity of blood flow in femoral vein were recorded before and after surgery. And then, the comparisons between the two groups were made, respectively.

Results

When compared with the conventional graduated compression stockings alone, the intraoperative application of IPCD and stockings contributed the significant reduction of DVT (3.92%, 2/51 versus 9.84%, 6/61, X² = 5.632, P = 0.034). In terms of the mean and peak velocity of blood flow in femoral vein, the postoperative difference was higher in the observation group than those in the control group (149.56 ± 26.35 versus 130.15 ± 22.56 mm/s, P < 0.05). With respect to perioperative blood loss, the difference between the two groups was statistically significant (800.5 ± 320.7 versus 950.1 ± 305.9 ml, P = 0.031).

Conclusions

Intraoperative application of IPCD could promote blood circulation of lower limbs, and significantly decrease the incidence of potentially fatal DVT in patients undergoing major orthopedic surgery, when compared with the conventional graduated compression stockings.