Tobacco smoke-induced hypercoagulation in human plasma: role of carbon monoxide

The Modified Risk of Paradoxical Embolism Score Is Associated with Patent Foramen Ovale in Patients with Ischemic Stroke: A Nationwide US Analysis

BACKGROUND

The Risk of Paradoxical Embolism (RoPE) score was developed to identify stroke-related patent foramen ovale (PFO) in patients with cryptogenic stroke.

METHODS

We conducted a retrospective analysis of the 2016 to 2020 National Inpatient Sample to determine the performance of the modified RoPE score in identifying the presence of a PFO in patients with acute ischemic stroke (AIS).

RESULTS

A total of 3,338,805 hospital admissions for AIS were analysed and 3.0% had PFO. Patients with PFO were younger compared to those without a PFO (median 63 years vs. 71 years, p < 0.001) and fewer were female (46.1% vs. 49.7%, p < 0.001). The patients with PFO had greater mean modified RoPE scores (4.0 vs. 3.3, p < 0.001). The area under the curve for the RoPE score in predicting PFOs was 0.625 (95%CI 0.620-0.629). The best diagnostic power of the RoPE score was achieved with a cut-off point of ≥4 where the sensitivity was 55% and the specificity was 64.2%. A cut-off point of ≥5 increased the specificity (83.1%) at the expense of sensitivity (35.8%). The strongest predictor of PFOs was deep vein thrombosis (OR 3.97, 95%CI 3.76-4.20).

CONCLUSIONS

The modified RoPE score had modest predictive value in identifying patients with PFO among patients admitted with AIS.

Assessing Barriers to Primary Prevention of Cardiovascular Diseases in Low and Middle-Income Countries: A Systematic Review

The incidence of cardiovascular diseases (CVDs) in low- and middle-income countries (LMICs) has greatly increased. Previously dominated by infectious diseases, LMICs are the new epicentre of CVDs. CVD is a common problem amongst the population in the African continent; however, many countries in LMICs lack the resources to stem the rise of CVDs. A systematic review was conducted between March and July 2023 to assess barriers to the primary prevention of CVDs in studies conducted in LMICs. Online databases, such as Embase, Cochrane, Scopus, and MEDLINE, were consulted. Keywords included primary prevention, cardiovascular diseases, diabetes, weight loss, and physical fitness, all of which focused on LMICs. To enrich the literature review, efforts were made to check other listed references and more papers were retrieved. The inclusion criteria were countries in LMICs, CVD, full-text, and peer-reviewed journals. Qualitative and quantitative studies were included. Exclusion criteria included high-income countries, secondary prevention, and research unrelated to CVDs, such as barriers in oncology or mental health. A total of 1089 papers were retrieved from the search engines. After applying the exclusion criteria for LMICs, only 186 papers were retained. A further search for quality, relevance, and duplicity reduced the qualifying number to 50 papers. Further efforts to retrieve the data and examine the quality of the studies resulted in 18 final selected studies. Three categories emerged based on the type of barriers: physician barriers, patient barriers, and health system barriers. Evidently, in several LMICs, guidelines for CVD prevention were lacking, and too much emphasis was placed on secondary prevention at the expense of primary prevention, a lack of human resources, and inadequate infrastructure. Overworked healthcare providers were unable to allocate adequate time to the patients. There was no shared decision-making process. Patient barriers included lack of motivation, no symptoms, low level of education, no insurance, long physical distances to the facilities, and inadequate medication or stock out. Some of the major barriers included closing and opening hours, poor operating space, inadequate funding from the government or donors, and lack of electronic medical services. There are many barriers to accessing primary prevention services for CVDs. These barriers can be divided into patient, physician, or health system barriers. More research needs to be conducted in LMICs to address the increasing risk factors for CVDs. Greater investment is required by national governments to provide more resources. Task shifting and shared decision-making are some of the quick wins.

Lung microvascular occlusion by platelet-rich neutrophil-platelet aggregates promotes cigarette smoke-induced severe flu

Cigarette smoking is associated with a higher risk of ICU admissions among patients with flu. However, the etiological mechanism by which cigarette smoke (CS) exacerbates flu remains poorly understood. Here, we show that a mild dose of influenza A virus promotes a severe lung injury in mice preexposed to CS but not room air for 4 weeks. Real-time intravital (in vivo) lung imaging revealed that the development of acute severe respiratory dysfunction in CS- and flu-exposed mice was associated with the accumulation of platelet-rich neutrophil-platelet aggregates (NPAs) in the lung microcirculation within 2 days following flu infection. These platelet-rich NPAs formed in situ and grew larger over time to occlude the lung microvasculature, leading to the development of pulmonary ischemia followed by the infiltration of NPAs and vascular leakage into the alveolar air space. These findings suggest, for the first time to our knowledge, that an acute onset of platelet-driven thrombo-inflammatory response in the lung contributes to the development of CS-induced severe flu.

Whole blood PT/aPTT assay based on non-contact drop-of-sample acoustic tweezing spectroscopy

Most coagulation tests are photo-optical turbidimetric assays that require the removal of cellular components from whole blood for optical clearing. If the resulting blood plasma samples are hemolyzed, they may become unsuitable for turbidimetric analysis. To resolve this issue, whole-blood analogs to plasma turbidimetric assays need to be developed. Using samples collected from non-smokers (normal group), smokers (thrombotic group), and hemophilia A (bleeding group) patients, we demonstrate that the reaction time assessed from whole blood viscosity data of the drop-of-blood acoustic tweezing spectroscopy (ATS) technique strongly correlates (Rp ≥ 0.95) with PT/aPTT values obtained from plasma turbidimetric data. Linear correlation (Rp ≥ 0.88) was also obtained between the viscous and elastic outputs of the ATS technique and the fibrinogen concentration. The integration of ATS data enabled the assessment of the functional level of fibrin cross-linkers such as factor XIII. Overall, ATS allows comprehensive sample-sparing analysis of whole blood coagulation for reliable and safe diagnosis of bleeding/thrombosis risks.

Update of HDL in atherosclerotic cardiovascular disease

Epidemiologic evidence supported an inverse association between HDL (high-density lipoprotein) cholesterol (HDL-C) levels and atherosclerotic cardiovascular disease (ASCVD), identifying HDL-C as a major cardiovascular risk factor and postulating diverse HDL vascular- and cardioprotective functions beyond their ability to drive reverse cholesterol transport. However, the failure of several clinical trials aimed at increasing HDL-C in patients with overt cardiovascular disease brought into question whether increasing the cholesterol cargo of HDL was an effective strategy to enhance their protective properties. In parallel, substantial evidence supports that HDLs are complex and heterogeneous particles whose composition is essential for maintaining their protective functions, subsequently strengthening the "HDL quality over quantity" hypothesis. The following state-of-the-art review covers the latest understanding as per the roles of HDL in ASCVD, delves into recent advances in understanding the complexity of HDL particle composition, including proteins, lipids and other HDL-transported components and discusses on the clinical outcomes after the administration of HDL-C raising drugs with particular attention to CETP (cholesteryl ester transfer protein) inhibitors.

Postpartum haemorrhage occurring in UK midwifery units: A national population-based case-control study to investigate incidence, risk factors and outcomes

OBJECTIVES

To estimate the incidence of, and investigate risk factors for, postpartum haemorrhage (PPH) requiring transfer to obstetric care following birth in midwifery units (MU) in the UK; to describe outcomes for women who experience PPH requiring transfer to obstetric care.

METHODS

We conducted a national population-based case-control study in all MUs in the UK using the UK Midwifery Study System (UKMidSS). Between September 2019 and February 2020, 1501 women with PPH requiring transfer to obstetric care following birth in an MU, and 1475 control women were identified. We used multivariable logistic regression, generating adjusted odds ratios (aORs) and 95% confidence intervals (CIs) to investigate risk factors for PPH requiring transfer to obstetric care.

RESULTS

The incidence of PPH requiring transfer to obstetric care following birth in an MU was 3.7% (95% CI 3.6%-3.9%). Factors independently associated with PPH requiring transfer to obstetric care were smoking during pregnancy (aOR = 0.73; 95% CI 0.56-0.94), nulliparity (aOR = 1.96; 95% CI 1.66-2.30), previous PPH (aOR = 2.67; 95% CI 1.67-4.25), complications in a previous pregnancy other than PPH (aOR = 2.40; 95% CI 1.25-4.60), gestational age ≥41 weeks (aOR = 1.36; 95% CI 1.10-1.69), instrumental birth (aOR = 2.69; 95% CI 1.53-4.72), third stage of labour ≥60 minutes (aOR = 5.56; 95% CI 3.93-7.88), perineal trauma (aOR = 4.67; 95% CI 3.16-6.90), and birthweight 3500-3999g (aOR = 1.71; 95% CI 1.42-2.07) or ≥4000g (aOR = 2.31; 95% CI 1.78-3.00). One in ten (10.6%) cases received a blood transfusion and one in five (21.0%) were admitted to higher level care.

CONCLUSIONS

The risk factors identified in this study align with those identified in previous research and with current guidelines for women planning birth in an MU in the UK. Maternal outcomes after PPH were broadly reassuring and indicative of appropriate management. NHS organisations should ensure that robust guidelines are in place to support management of PPH in MUs.

CIGARETTE SMOKING IS ASSOCIATED WITH DECREASED MORTALITY IN CRITICALLY ILL TRAUMA PATIENTS

ABSTRACT

Background: Smoking may offer pathophysiologic adaptations that increase survivability in certain patients with cardiovascular disease. We sought to identify if smoking increases survivability in trauma patients, hypothesizing that critically ill trauma patients who smoke have a decreased risk of mortality compared with non-smokers. Methods: The Trauma Quality Improvement Program (2010-2016) database was queried for trauma patients with intensive care unit admissions. A multivariable logistic regression model was performed. Results: From the 630,278 critically ill trauma patients identified, 116,068 (18.4%) were current cigarette smokers. Critically ill trauma smokers, compared with non-smokers, had a higher rate of pneumonia (7.8% vs. 6.9%, P< 0.001) and lower mortality rate (4.0% vs. 8.0%, P< 0.001). After controlling for covariates, smokers had a decreased associated risk of mortality compared with non-smokers (OR = 0.55, CI = 0.51-0.60, P< 0.001), and no difference in the risk of major complications (OR = 0.98, CI = 0.931.03, P = 0.44). The same analysis was performed using age as a continuous variable with associated decreased risk of mortality (OR 0.57 (CI 0.53-0.62), P< 0.001). Conclusion: Critically ill trauma smokers had a decreased associated mortality risk compared with non-smokers possibly due to biologic adaptations such as increased oxygen delivery developed from smoking. Future basic science and translational studies are needed to pursue potential novel therapeutic benefits without the deleterious long-term side effects of smoking.

Physiology, pathology and the biomolecular corona: the confounding factors in nanomedicine design

The biomolecular corona that forms on nanomedicines in different physiological and pathological environments confers a new biological identity. How the recipient biological system's state can potentially affect nanomedicine corona formation, and how this can be modulated, remains obscure. With this perspective, this review summarizes the current knowledge about the content of biological fluids in various compartments and how they can be affected by pathological states, thus impacting biomolecular corona formation. The content of representative biological fluids is explored, and the urgency of integrating corona formation, as an essential component of nanomedicine designs for effective cargo delivery, is highlighted.

Retrospective study on rib fractures: smoking and alcohol matter for mortality and complications

Background

Rib fractures and substance use are both common in trauma patients, but there is little data on how smoking and alcohol use may be associated with outcomes in these patients. We assessed the association between smoking or alcohol use disorder (AUD) and outcomes in patients with rib fractures.

Methods

We used institutional databases to conduct a retrospective review of patients with rib fractures at the only American College of Surgeons-verified adult level 1 trauma center in a rural state between 2015 and 2019. The key exposure variables were smoking and AUD. The key outcome variables were mortality and pulmonary complications (pneumonia, adult respiratory distress syndrome, and pneumothorax). We used multivariable regression for analysis and directed acyclic graphs to identify variables for adjustment.

Results

We identified 1880 eligible patients with rib fractures, including 693 (37%) who were smokers and 204 (11%) who had AUD. Compared with non-smokers, smokers were younger, more often male, and had lower mortality rates. Regression showed that smokers had a lower likelihood of mortality (OR 0.48; 95% CI 0.27 to 0.87; p=014). Likelihood of pneumonia, ARDS, and pneumothorax was not different between smokers and non-smokers. Compared with patients without AUD, patients with AUD were older, more often male, and had higher likelihood of pneumonia and lower likelihood of pneumothorax. Regression showed that patients with AUD had higher likelihood of pneumonia (OR 1.82; 95% CI 1.24 to 2.68; p=0.002) and lower likelihood of pneumothorax (OR 0.51; 95% CI 0.33 to 0.75; p=0.002).

Discussion

In trauma patients with rib fractures treated at a level 1 trauma center over 5 years, smoking was associated with decreased risk of mortality. These findings have implications for risk stratification and clinical decision-making for patients with rib fractures.

Level of evidence

III

Clinical Risk Factors Associated with Ambulatory Outcome in Acute Ischemic Stroke Patients Smokers Treated with Thrombolytic Therapy

BACKGROUND

Patients who have suffered an acute ischemic stroke (AIS) and are smokers may have a better outcome following thrombolytic therapy when compared with non-smokers. While this finding is controversial, data on baseline clinical risk factors to predict treatment efficacy of thrombolytic therapy using ambulatory status in patients who suffered AIS and are smokers is not common.

METHODS

Between 2010 and 2016, retrospective data on patients who have suffered an AIS and received recombinant tissue plasminogen activator (rtPA) were obtained from Greenville health system registry. Assessment of clinical risk factors and the likelihood of an improvement in post-stroke ambulation among smokers and non-smokers was carried out using multivariate logistic regression.

RESULTS

Of 1001 patients, 70.8% were smokers and 29.2% non-smokers. Among the smokers and non-smokers, 74.6% and 84.6% improvement in ambulation respectively at discharge. The odds of improved ambulation decrease among smokers as age group increases compared to those below 50 [(60-69 years, aOR, 0.30, 95% C.I, 0.108-0.850, p < 0.05), (70-79 years aOR, 0.27, 95% C.I, 0.096-0.734, p < 0.05), (80+ years aOR, 0.16, 95% C.I, 0.057-0.430, P < 0.01). Patients with National Institute of Health Stroke Scale Score (NIHSS) score > 7 (reference <7) were 91% less likely to have improved ambulation among smokers and non-smokers (aOR, 0.09, 95% C.I, 0.055-0.155, P = 0.01), and (aOR, 0.08, 95% C.I, 0.027-0.214, P = 0.01) respectively. Atrial fibrillation was an independent predictor of decreased improvement in ambulation only among smokers (aOR, 0.58, 95% C.I, 0.356-0.928 P < 0.05).

CONCLUSION

Our findings suggest that elderly smokers with atrial fibrillation would benefit more from aggressive management of atrial fibrillation than non-smokers.

Postpartum haemorrhage and risk of long-term hypertension and cardiovascular disease: an English population-based longitudinal study using linked primary and secondary care databases

OBJECTIVE

To investigate the long-term risk of developing hypertension and cardiovascular disease (CVD) among those women who suffered a postpartum haemorrhage (PPH) compared with those women who did not.

DESIGN

Population-based longitudinal open cohort study.

SETTING

English primary care (The Health Improvement Network (THIN)) and secondary care (Hospital Episode Statistics (HES)) databases.

POPULATION

Women exposed to PPH during the study period matched for age and date of delivery, and unexposed.

METHODS

We conducted an open cohort study using linked primary care THIN and HES Databases, from 1 January 1997 to 31 January 2018. A total of 42 327 women were included: 14 109 of them exposed to PPH during the study period and 28 218 matched for age and date of delivery, and unexposed to PPH. HRs for cardiovascular outcomes among women who had and did not have PPH were estimated after controlling for covariates using multivariate Cox regression models.

OUTCOME MEASURES

Risk of hypertensive disease, ischaemic heart disease, heart failure, stroke or transient ischaemic attack.

RESULTS

During a median follow-up of over 4 years, there was no significant difference in the risk of hypertensive disease after adjustment for covariates (adjusted HR (aHR): 1.03 (95% CI: 0.87 to 1.22); p=0.71). We also did not observe a statistically significant difference in the risk of composite CVD (ischaemic heart disease, heart failure, stroke or transient ischaemic attack) between the exposed and the unexposed cohort (aHR: 0.86 (95% CI: 0.52 to 1.43; p=0.57).

CONCLUSION

Over a median follow-up of 4 years, we did not observe an association between PPH and hypertension or CVD.

A 20-Year-Old Man with e-Cigarette or Vaping Product Use-Associated Lung Injury (EVALI) and Thrombotic Coagulopathy

BACKGROUND In 2019, the US Centers for Disease Control and Prevention (CDC) described the criteria for the diagnosis of e-cigarette or vaping product use-associated lung injury (EVALI), which may be caused by contamination of delta-9-tetrahydrocannabinoid (THC) e-liquids with vitamin E acetate. This report describes a case of a 20-year-old man with a history of recreational drug use that included vaping, who presented with EVALI and a coagulopathy associated with thrombotic events. CASE REPORT We present a 20-year-old patient who worked at a cannabidiol (CBD) manufacturing facility with a history of e-cigarette use and polysubstance abuse in remission who presented with respiratory and gastrointestinal symptoms accompanied by 50-pound weight loss over 6 months. The patient had been vaping with nicotine and THC-containing e-cigarettes multiple times per day for 1.5 years. He met the CDC surveillance criteria for EVALI, consisting of respiratory symptoms and infiltrates on imaging within 90 days of vaping, and was found to have eosinophilic pneumonia secondary to THC-containing e-cigarette use. Additionally, thrombi were detected in the pulmonary arteries, right saphenous vein, and right ventricle. A segmental infarct was noted in the inferior pole of the left kidney. CONCLUSIONS We present the second case report potentially linking e-cigarette use with clinically significant thrombogenesis, the first with both arterial and venous thromboses. This report demonstrates the importance of taking a history of e-cigarette use in patients presenting with lung injury. Although EVALI and the diagnostic criteria have only recently been described, systemic effects, including coagulopathy, are now being reported.

Risk Factors and Outcomes for Preoperative Asymptomatic Pulmonary Embolism in Patients Aged 60 Years and Over with Hip Fracture

Objective

To investigate the risk factors for, and outcomes of, preoperative asymptomatic pulmonary embolism (PE) in patients ≥60 years old following delayed operation for hip fracture.

Methods

From March 2017 to December 2018, 90 patients aged ≥60 years with hip fracture who suffered a delay in surgery were recruited to this prospective study following admission to our hospital. Computed tomography pulmonary angiography (CTPA) was used to detect preoperative asymptomatic PE and calculated its incidence. Time from injury to admission, baseline characteristics, medical comorbidities, and blood biomarker levels were evaluated as potential risk factors. Logistic regression analysis was used to identify risk factors. Mortality and major bleeding events were recorded and compared between individuals with PE and without. Data were analyzed by t‐test, Mann–Whitney U test, χ² test, Fisher's exact test, and logistic regression analysis.

Results

The incidence of preoperative asymptomatic PE was 18.9% (17/90 patients). In the univariate analysis, the risk factors for preoperative asymptomatic PE were male sex, hypertension, cerebrovascular accident, smoking, plasma D‐dimer level, potassium level, urea level, creatinine level, and cysteine level. Multivariate logistic regression analysis showed that the risk of preoperative asymptomatic PE was higher in patients with hypertension (odds ratio [OR] = 10.048; 95% confidence interval [CI], 1.118–90.333), cerebrovascular accident (OR = 20.135; 95% CI, 1.875–216.164), smoking (OR = 48.741; 95% CI, 4.155–571.788), high plasma D‐dimer levels (OR = 1.200; 95% CI, 1.062–157.300), and high plasma potassium levels (OR = 12.928; 95% CI, 1.062–157.300). All patients were followed up for 21.0 months (range, 2 to 36 months). Mortality within the first year postoperatively was higher in patients with PE (29.41% vs 9.59%, P = 0.046).

Conclusions

In view of the high incidence of preoperative asymptomatic PE and the inferior prognosis in individuals with PE, routine CTPA examination for preoperative asymptomatic PE could be useful for patients aged ≥60 years with hip fracture for whom surgery is delayed.

Three-dimensional aneurysm volume measurements show no correlation between coil packing density and recurrence

Objective

Endovascular treatment is the mainstay therapy for brain aneurysms. About 15% of patients need re-treatment within six months due to early recanalization. In this study, we investigate risk factors associated with treatment failure.

Methods

This retrospective cohort study includes endovascularly treated aneurysm cases between July 2012 and December 2015 at the University of California Davis Medical Center with pre-treatment and early post-treatment imaging. Thin cut 3D aneurysm volume rendering was used for morphologic analyses. Univariate and bivariate analyses were conducted to evaluate differences between patients and clinical factors by treatment failure.

Results

Of the 50 patients who met the inclusion criteria, 41 (82.0%) were female, with an average age of 61 years. Most aneurysms were on the anterior communicating artery (40%) or posterior communicating artery (22.0%), and 34 (68%) aneurysms were ruptured. Early treatment failure was observed in 14 (28.0%) of endovascularly treated patients. Raymond-Roy class (RRC) was significantly associated with treatment failure (p = 0.0052), with 10 out of the 14 cases (71.4%) with early recanalization having an RRC of 3. Coil packing density did not associate with aneurysm recanalization (p = 0.61).

Conclusion

In our single institution series, patient characteristics, aneurysm characteristics, or coil packing density did not affect early aneurysm recanalization. RRC was the best predictor of early recanalization; however, further confirmation with additional studies are required. Although this study focused on early treatment failure, late recanalization has been shown with longer follow up. Further investigation into factors associated with late treatment failure will need further investigation. New intrasaccular devices and flow diverters will also likely play a role in reducing recurrence in the future as these treatments gain usage.

In acute ischemic stroke patients with smoking incidence, are more women than men more likely to be included or excluded from thrombolysis therapy?

Background:

Clinical factors associated with exclusion from recombinant tissue plasminogen activator in both men and women are not completely understood. The aim of this study is to determine whether there is a gender difference in clinical risk factors that excluded ischemic stroke patients with a history of smoking from recombinant tissue plasminogen activator.

Methods:

Retrospective data from a stroke registry were analyzed, and multivariable linear regression models were used to determine gender differences. Logistic regression models determined exclusion clinical risk factors for thrombolysis in male and female acute ischemic stroke patients with a history of smoking, while sequentially adjusting for sociodemographic, clinical, and stroke-related variables. The Kaplan–Meier survival analysis was used to determine the exclusion probabilities of men and women with a history of smoking within the stroke population.

Results:

Of the 1,446 acute ischemic stroke patients eligible for recombinant tissue plasminogen activator, 379 patients with a history of smoking were examined, of which 181 received recombinant tissue plasminogen activator while 198 were excluded from receiving recombinant tissue plasminogen activator. Of the 198 patients, 75 females and 123 males were excluded from receiving recombinant tissue plasminogen activator. After multivariable adjustment for age, National Institutes of Health scores, and stroke-related factors, females who present with weakness/paresis on initial examination (OR = 0.117, 95% CI, 0.025–0.548) and men who present with a history of previous transient ischemic attack (OR = 0.169, 95% CI, 0.044–0.655), antiplatelet medication use (OR = 0.456, 95% CI, 0.230–0.906), and weakness/paresis on initial examination (OR = 0.171, 95% CI, 0.056–0.521) were less likely to be excluded from recombinant tissue plasminogen activator (thrombolysis therapy).

Conclusions:

In an ischemic stroke population with a history of smoking, female smokers are more likely to be excluded from thrombolysis therapy in comparison to men, even after adjustment for confounding variables.

Cardiovascular risk of smoking and benefits of smoking cessation

Smoking increases mortality from all causes and has a crucial role in atherosclerotic cardiovascular disease (ASCVD). Active smoking and secondhand smoke exposure determine more than 30% of coronary heart disease (CHD) mortality. The exact mechanisms of cardiovascular damages are not well known, but the detrimental effect of smoking on endothelial function has long been recognized. Smoking elicits oxidative processes, negatively affects platelet function, fibrinolysis, inflammation and vasomotor function; all these proatherogenic effects double the 10-year risk of fatal events in smokers compared to non smokers. An intriguing issue about smoking is the vulnerability of female gender. The mortality from cardiovascular diseases (CVDs) is higher in female than male smokers and female smokers show a 25% higher risk of developing CHD than men with the same exposure to tobacco smoke. This female vulnerability seems to be related to genes involved in thrombin signaling. The effects of smoking cessation have also been extensively studied. Cessation at an early age (40 years) has an impressive 90% reduction in the excess risk of death. In this review we report recent data about the causal link between smoking and CVDs and about the benefits of smoking cessation.

Statistical analysis plan for "A randomised, controlled study to evaluate the effects of switching from cigarette smoking to using a tobacco heating product on health effect indicators in healthy subjects"

Tobacco harm reduction strategies aim to substitute smoking with potentially reduced risk products (PRRPs) such as e-cigarettes and tobacco-heating products (THPs). The health benefits of switching from smoking to PRRPs is unknown. A randomised controlled trial is being conducted to increase understanding of the health effects of switching from smoking to a THP in a 12-month long ambulatory study (ISRCTN81075760). Here we describe the study endpoints and the statistical analysis plan. Endpoints are divided into biomarkers of exposure (BoE) to tobacco smoke constituents and health effect indicators related to risk of lung cancer, cardiovascular and obstructive lung disease. These have been selected on the basis of extensive literature evidence. Three primary endpoints, augmentation index (risk factor for cardiovascular disease), total NNAL (linked to lung cancer) and 8-Epi-PGF2α type III (indicator of oxidative stress linked to various diseases), and multiple secondary endpoints will be analysed at 90, 180, and 360 days. Changes from baseline will be compared between study arms by specific contrasts in mixed models. Study wise multiple comparisons adjustments will be performed to account for multiplicity of timepoints and comparisons within timepoints. Generalisability of outcomes will be tested by a sensitivity analysis adjusting for age and gender. Importantly, an ancillary analysis will be performed to assess product compliance during the study based on plasma levels of CEVal, a surrogate marker for acrylonitrile exposure. The rationale underlying the selection of BoEs and health effect indicators, coupled with the statistical analysis plan will be central to understanding the potential health effects of replacing smoking with THP use for one year.

Clinical Characteristics of Driving-related Stroke Occurring as a Recurrent Stroke

BACKGROUND

Although the number of seemingly healthy subjects who suffer a minor stroke increases, there are no data on how frequently they sustain another stroke while driving.

METHODS

A single-center, retrospective study was conducted to clarify the clinical characteristics of driving-related stroke occurring as a recurrent stroke by analyzing data prospectively acquired between January 2009 and June 2019 on 3452 acute stroke patients.

RESULTS

One hundred-thirty five patients (85 ischemic stroke [IS] and 50 hemorrhagic stroke [HS]) had suffered a driving-related stroke. Of them, 22 (16%) had suffered a prior stroke (recurrent stroke group), while 113 had never suffered a stroke before (first-time stroke group). While the use of anti-thrombotics was significantly more common in the RS group, other variables including the frequency of road traffic accidents, did not differ significantly. The first stroke-recurrent stroke interval ranged from 0.2 to 18 years. The stroke type at the time of recurrence was IS in the majority of patients with prior IS. When compared to 432 patients with recurrent IS unrelated to driving, patients with recurrent IS related to driving (n = 16) had significantly higher frequency of lacunar strokes (56% vs 27%, P = .02) and lower frequency of cardioembolic strokes (6% vs 29%, P = .04).

CONCLUSION

The current finding that 16% of patients who presented with driving-related stroke had previously suffered a stroke indicates that drivers with a prior stroke may be at increased risk for recurrent stroke while driving, and prolonged follow-up be necessary for minor stroke patients who resume driving.

Inherited Thrombophilia in a Lebanese Family of Four Generations: A Case Report of Recurrent Miscarriage

Introduction

Factor V Leiden (G1691A), prothrombin (G20210A) and MTHFR (C677T) gene mutations were investigated in many studies for their association with Deep Venous Thrombosis.

Case Presentation

A North Lebanese family has been examined, from an index case, a 40-year-old woman, who had a history of venous thrombosis with unexplained recurrent miscarriage. The index case was found to be heterozygous for factor V Leiden G1691A, prothrombin G20210A, and methylenetetrahydrofolate reductase C677T gene variants. Her family members were heterozygous for at least two of the three-point mutations, and multiple risk factors associated with thrombophilia were identified.

Conclusion

Our findings emphasize the need for clarifying the utility and futility of thrombophilia testing in the era of molecular diagnostics.

Risk of Venous Thromboembolism After Carbon Monoxide Poisoning: A Nationwide Population-Based Study

STUDY OBJECTIVE

Few studies have investigated the association between carbon monoxide (CO) poisoning and risk of venous thromboembolism. We aim to identify the risk of pulmonary embolism and deep venous thrombosis after CO poisoning.

METHODS

We conducted a nationwide cohort-crossover study using administrative claims data in Korea. We compared the risk of venous thromboembolism (pulmonary embolism or deep venous thrombosis) in the cohort period after CO poisoning to that of the same period 1 year later (crossover period), using conditional logistic regression analysis.

RESULTS

We included 22,699 patients with a diagnosis of CO poisoning during the study period between 2004 and 2015. The risk of venous thromboembolism was significantly elevated during days 0 to 90 after CO poisoning (odds ratio 3.96; 95% confidence interval 2.50 to 6.25). However, this risk was not significantly elevated during subsequent postexposure periods through 360 days. During days 0 to 30 after CO poisoning, the risks of pulmonary embolism (odds ratio 22.00; 95% confidence interval 5.33 to 90.75) and deep venous thrombosis (odds ratio 10.33; 95% confidence interval 3.16 to 33.80) were significantly elevated.

CONCLUSION

We found that the risk of venous thromboembolism persisted for up to 90 days after CO poisoning. The risk was increased 22-fold for pulmonary embolism and 10-fold for deep venous thrombosis, especially in the first month after CO poisoning. Patients should be monitored for venous thromboembolism risk after CO poisoning.

Karma of Cardiovascular Disease Risk Factors for Prevention and Management of Major Cardiovascular Events in the Context of Acute Exacerbations of Chronic Obstructive Pulmonary Disease

There is compelling epidemiological evidence that airway exposure to cigarette smoke, air pollution particles, as well as bacterial and viral pathogens is strongly related to acute ischemic events. Over the years, there have been important animal and human studies that have provided experimental evidence to support a causal link. Studies show that patients with cardiovascular diseases (CVDs) or risk factors for CVD are more likely to have major adverse cardiovascular events (MACEs) after an acute exacerbation of chronic obstructive pulmonary disease (COPD), and patients with more severe COPD have higher cardiovascular mortality and morbidity than those with less severe COPD. The risk of MACEs in acute exacerbation of COPD is determined by the complex interactions between genetics, behavioral, metabolic, infectious, and environmental risk factors. To date, there are no guidelines regarding the prevention, screening, and management of the modifiable risk factors for MACEs in the context of COPD or COPD exacerbations, and there is insufficient CVD risk control in those with COPD. A deeper insight of the modifiable risk factors shared by CVD, COPD, and acute exacerbations of COPD may improve the strategies for reduction of MACEs in patients with COPD through vaccination, tight control of traditional CV risk factors and modifying lifestyle. This review summarizes the most recent studies regarding the pathophysiology and epidemiology of modifiable risk factors shared by CVD, COPD, and COPD exacerbations that could influence overall morbidity and mortality due to MACEs in patients with acute exacerbations of COPD.

Early Versus Late Pulmonary Embolism in Trauma Patients: Not All Pulmonary Embolisms are Created Similarly

BACKGROUND

Pulmonary embolism (PE) is an uncommon complication occurring in up to 5% of trauma patients. In small previous studies, patients with long-bone fractures were associated with a higher risk of early PE while those with severe head injuries were at higher risk for late PE.

MATERIALS AND METHODS

This was a retrospective analysis at a single level I trauma center from 2010 to 2017. Patients with early PE (≤4 d) were compared to those with late PE (>4 d) using bivariate analysis and multivariable logistic regression analysis. We sought to confirm risk factors for early and late PE, hypothesizing that early PE is associated with long-bone fractures and late PE is associated with above-the-knee deep venous thrombosis (DVT).

RESULTS

From 12,833 trauma admissions, 76 patients (0.6%) had a PE. Of these, 33 (43.4%) had an early PE and 43 (54.6%) were diagnosed with late PE. After adjusting for covariates, independent risk factors for late PE included above-the-knee DVT (odds ratio [OR] = 12.01, confidence interval [CI] = 1.34-107.52, P = 0.03), blood transfusion (OR = 8.99, CI = 1.75-46.22, P = 0.009), and craniotomy (OR = 8.82, CI = 1.03-75.97, P = 0.04), while the only independent risk factor for early PE was smoking (OR = 4.56, CI 1.06-19.66, P = 0.04). Severe head injury and long-bone fractures were not risk factors for early or late PE (P > 0.05) CONCLUSIONS: The strongest risk factor for late PE is above-the-knee DVT. Contrary to previous reports, long-bone extremity fractures and severe head injuries are not associated with early or late PE. The only risk factor for early PE was a history of smoking.

De Novo Assessment and Review of Pan-American Pit Viper Anticoagulant and Procoagulant Venom Activities via Kinetomic Analyses

Snakebite with hemotoxic venom continues to be a major source of morbidity and mortality worldwide. Our laboratory has characterized the coagulopathy that occurs in vitro in human plasma via specialized thrombelastographic methods to determine if venoms are predominantly anticoagulant or procoagulant in nature. Further, the exposure of venoms to carbon monoxide (CO) or O-phenylhydroxylamine (PHA) modulate putative heme groups attached to key enzymes has also provided mechanistic insight into the multiple different activities contained in one venom. The present investigation used these techniques to characterize fourteen different venoms obtained from snakes from North, Central, and South America. Further, we review and present previous thrombelastographic-based analyses of eighteen other species from the Americas. Venoms were found to be anticoagulant and procoagulant (thrombin-like activity, thrombin-generating activity). All prospectively assessed venom activities were determined to be heme-modulated except two, wherein both CO and its carrier molecule were found to inhibit activity, while PHA did not affect activity (Bothriechis schlegelii and Crotalus organus abyssus). When divided by continent, North and Central America contained venoms with mostly anticoagulant activities, several thrombin-like activities, with only two thrombin-generating activity containing venoms. In contrast, most venoms with thrombin-generating activity were located in South America, derived from Bothrops species. In conclusion, the kinetomic profiles of venoms obtained from thirty-two Pan-American Pit Viper species are presented. It is anticipated that this approach will be utilized to identify clinically relevant hemotoxic venom enzymatic activity and assess the efficacy of locally delivered CO or systemically administered antivenoms.

Late coronary ischemıc syndromes assocıated wıth transcatheter aortıc valve ımplantatıon: A revıew of mechanıstıc and clınıcal aspects

In the past years, transcatheter aortic valve implantation (TAVI) has emerged as a promising option for the treatment of aortic valve pathologies particularly in the the presence of surgically high-risk situations. Importantly, a variety of specific procedural complications including acute coronary osteal occlusion, though very rare, has been reported in major clinical studies. However, little is known about the late impact of TAVI on coronary system at the macro and microvascular levels.

On the other hand, clinical studies as well as real life experiences have shown variable rates of acute coronary syndrome (ACS) readmissions among TAVI recipients in the short and long terms. Within this context, it may be suggested that even though late coronary ischemic events arising after TAVI, to some extent, appears to be spontaneous or attributable to certain stressors, TAVI may also have the potential to directly account for, accelerate or contribute to the evolution of these ischemic events on follow-up. Accordingly, the present review primarily focuses on potential association of TAVI with late coronary ischemic syndromes along with a particular emphasis on its mechanistic basis and clinical implications among TAVI recipients.

Effects of Heme Modulation on Ovophis and Trimeresurus Venom Activity in Human Plasma

Geographic isolation and other factors result in evolution-driven diversity of the enzymatic composition of venom of pit vipers in the same genus. The present investigation sought to characterize venoms obtained from such genetically diverse Ovophis and Trimeresurus pit vipers utilizing thrombelastographic coagulation kinetic analyses. The coagulation kinetics of human plasma were assessed after exposure to venom obtained from two Ovophis and three Trimeresurus species. The potency of each venom was defined (µg/mL required to equivalently change coagulation); additionally, venoms were exposed to carbon monoxide (CO) or a metheme-inducing agent to modulate any enzyme-associated heme. All venoms had fibrinogenolytic activity, with four being CO-inhibitable. While Ovophis venoms had similar potency, one demonstrated the presence of a thrombin-like activity, whereas the other demonstrated a thrombin-generating activity. There was a 10-fold difference in potency and 10-fold different vulnerability to CO inhibition between the Trimeresurus species. Metheme formation enhanced fibrinogenolytic-like activity in both Ovophis species venoms, whereas the three Trimeresurus species venoms had fibrinogenolytic-like activity enhanced, inhibited, or not changed. This novel “venom kinetomic” approach has potential to identify clinically relevant enzymatic activity and assess efficacy of antivenoms between genetically and geographically diverse species.

Role of heme modulation in inhibition of Atheris, Atractaspis, Causus, Cerastes, Echis, and Macrovipera hemotoxic venom activity

Venomous snake bite and subsequent coagulopathy is a significant source of morbidity and mortality worldwide. The gold standard to treat coagulopathy caused by these venoms is the administration of antivenom; however, despite this therapy, coagulopathy still occurs and recurs. Of interest, our laboratory has demonstrated in vitro and in vivo that coagulopathy-inducing venom exposed to carbon monoxide (CO) is inhibited, potentially by an attached heme. The present investigation sought to determine if venoms derived from snakes of the African genera Atheris, Atractaspis, Causus, Cerastes, Echis, and Macrovipera that have no or limited antivenoms available could be inhibited with CO or with the metheme-inducing agent, O-phenylhydroxylamine (PHA). Assessing changes in coagulation kinetics of human plasma with thrombelastography, venoms were exposed in isolation to CO or PHA. Eight species were found to have procoagulant activity consistent with the generation of human thrombin, while one was likely fibrinogenolytic. All venoms were significantly inhibited by CO/PHA with species-specific variation noted. These data demonstrate indirectly that the heme is likely bound to these disparate venoms as an intermediary modulatory molecule. In conclusion, future investigation is warranted to determine if heme could serve as a potential therapeutic target to be modulated during treatment of envenomation by hemotoxic enzymes.

Acute coronary syndromes occurring while driving: frequency and patient characteristics

Background

Acute coronary syndrome (ACS) may occur during any human activity, including driving. The objectives of this study were to report the frequency of ACS occurring while driving, clarify patient characteristics, and analyze the behavioral patterns of drivers who sustained ACS.

Methods

A single-center, retrospective observational study was conducted using prospectively acquired data. Among 1605 ACS patients admitted between January 2011 and December 2016, 65 (60 men/5 women) patients who sustained ACS while driving were identified. Clinical variables were compared between these 65 patients and 1540 patients who sustained ACS while performing other activities. Furthermore, multivariable regression analysis was performed to identify variables associated with ACS.

Results

The frequency of ACS occurring while driving was 4.0% (65/1605). Compared with patients who sustained ACS while performing other activities, those who sustained ACS while driving were significantly younger (66.2 ± 13.0 vs. 57.5 ± 12.2 years, p < 0.001) and more likely to smoke (34.2 vs. 60.0%, p < 0.001). Multivariable regression analysis showed that age (OR 0.961; 95% CI 0.940–0.982) and current smoking (OR 1.978; 95% CI 1.145–3.417) were associated with ACS. While 55 drivers (85%) who remained conscious after ACS could seek medical attention without causing accidents, the other 10 (15%) who sustained cardiac arrest caused accidents.

Conclusions

The association between current smoking and ACS occurring while driving suggests that smoking cessation is advised for smokers who drive from the standpoint of driving safety. We expect that prospective studies be conducted to verify our findings and identify individuals at risk for ACS while driving.

Electronic supplementary material

The online version of this article (10.1186/s12199-017-0689-5) contains supplementary material, which is available to authorized users.

Carbon monoxide inhibits hemotoxic activity of Elapidae venoms: potential role of heme

Envenomation by hemotoxic enzymes continues to be a major cause of morbidity and mortality throughout the world. With regard to treatment, the gold standard to abrogate coagulopathy caused by these venoms is still the administration of antivenom; however, despite antivenom therapy, coagulopathy still occurs and recurs. Of interest, this laboratory has demonstrated in vitro and in vivo that coagulopathy inducing venom derived from snakes of the family Viperidae exposed to carbon monoxide (CO) is inhibited, potentially by an attached heme. The present investigation sought to determine if venoms derived from snakes of the Elapidae family (taipans and cobras) could also be inhibited with CO or with the metheme inducing agent, O-phenylhydroxylamine (PHA). Assessing changes in coagulation kinetics of human plasma with thrombelastography, venoms from Elapidae snakes were exposed in isolation to CO (five species) or PHA (one specie) and placed in human plasma to assess changes in procoagulant or anticoagulant activity. The procoagulant activity of two taipan venoms and anticoagulant activity of three cobra venoms were significantly inhibited by CO. The venom of the inland taipan was also inhibited by PHA. In sum, these data demonstrate indirectly that the biometal heme is likely bound to these disparate venoms as an intermediary modulatory molecule. In conclusion, CO may not just be a potential therapeutic agent to treat envenomation but also may be a potential modulator of heme as a protective mechanism for venomous snakes against injury from their own proteolytic venoms.

Characterisation of clot microstructure properties in stable coronary artery disease

Background

Coronary artery disease (CAD) is associated with an increased prothrombotic tendency and is also linked to unfavourably altered clot microstructure. We have previously described a biomarker of clot microstructure (d_f) that is unfavourably altered in acute myocardial infarction. The d_f biomarker assesses whether the blood will form denser or looser microstructures when it clots. In this study we assessed in patients with stable chest pain whether d_f can differentiate between obstructed and unobstructed CAD.

Methods

A blood sample prior to angiography was obtained from 251 consecutive patients undergoing diagnostic coronary angiography. Patients were categorised based on angiographic findings as presence or absence of obstructive CAD (stenosis ≥50%). The blood sample was assessed using the d_f biomarker, standard laboratory markers and platelet aggregometry (Multiplate).

Results

A significant difference (p=0.028) in d_f was observed between obstructive CAD (1.748±0.057, n=83) and unobstructive CAD (1.732±0.052, n=168), where patients with significant CAD produce denser, more tightly packed clots. d_f was also raised in men with obstructive CAD compared with women (1.745±0.055 vs 1.723±0.052, p=0.007). Additionally d_f significantly correlated with the platelets response to arachidonic acid as measured by the ASPItest area under the curve readings from platelet aggregometry (correlation coefficient=0.166, p=0.008), a low value of the ASPItest indicating effective aspirin use was associated with looser, less dense clots.

Conclusions

For the first time, we characterise clot microstructure, as measured by d_f, in patients with stable CAD. d_f can potentially be used to risk-stratify patients with stable CAD and assess the efficacy of therapeutic interventions by measuring changes in clot microstructure.

Stirred, shaken, or stagnant: What goes on at the blood-biomaterial interface

There is a widely recognized need to improve the performance of vascular implants and external medical devices that come into contact with blood by reducing adverse reactions they cause, such as thrombosis and inflammation. These reactions lead to major adverse cardiovascular events such as heart attacks and strokes. Currently, they are managed therapeutically. This need remains unmet by the biomaterials research community. Recognized stagnation of the blood-biomaterial interface research translates into waning interest from clinicians, funding agencies, and practitioners of adjacent fields. The purpose of this contribution is to stir things up. It follows the 2014 BloodSurf meeting (74th International IUVSTA Workshop on Blood-Biomaterial Interactions), offers reflections on the situation in the field, and a three-pronged strategy integrating different perspectives on the biological mechanisms underlying blood-biomaterial interactions. The success of this strategy depends on reengaging clinicians and on the renewed cooperation of the funding agencies to support long-term efforts.

Left Ventricular Assist Device-Associated Carbon Monoxide and Iron-Enhanced Hypercoagulation: Impact of Concurrent Disease

Left ventricular assist device (LVAD) therapy is associated with thrombophilia despite anticoagulation. Of interest, LVAD patients have increased carboxyhemoglobin, a measure of upregulated heme oxygenase (Hmox) activity that releases carbon monoxide (CO) and iron. Given that CO and iron enhance plasmatic coagulation, we determined if LVAD patients had hypercoagulability and decreased fibrinolytic vulnerability with measurable CO and iron-mediated effects. Blood samples were obtained a month or more after implantation of the LVAD. Thrombelastographic methods to assess coagulation kinetics, fibrinolytic kinetics, formation of carboxyhemefibrinogen, and iron-mediated enhancement of clot growth were utilized. Coagulation and fibrinolytic parameter normal individual (n = 30) plasma values were determined. Sixteen LVAD patients were studied. CO and iron enhancement of coagulation were observed in the majority of LVAD patients, contributing to hypercoagulation. However, most patients demonstrated abnormally increased rates of clot lysis. Critically, hemolysis as assessed by circulating lactate dehydrogenase activity was small in this cohort, and only four patients without comorbid states (e.g., obesity, diabetes, sleep apnea) were hypercoagulable with evidence of Hmox upregulation. However, seven patients with comorbidities were hypercoagulable with Hmox upregulation. Future investigation of CO and iron-related thrombophilia and comorbid disease is warranted to define its role in LVAD-related thrombosis.

Association between thyroid dysfunction and venous thromboembolism in the elderly: a prospective cohort study

BACKGROUND

Venous thromboembolism (VTE) and subclinical thyroid dysfunction (SCTD) are both common in elderly patients. SCTD has been related to a hypercoagulable state and an increased thromboembolic risk. However, prospective data on the relationship between SCTD and VTE are lacking.

OBJECTIVES

To investigate the relationship between SCTD and recurrent VTE (rVTE), all-cause mortality, and thrombophilic biomarkers. Patients Elderly patients with VTE were studied.

METHODS

In a prospective multicenter cohort, thyroid hormones and thrombophilic biomarkers were measured 1 year after acute VTE, as both may be influenced by acute thrombosis. We defined subclinical hypothyroidism (SHypo) as elevated thyroid-stimulating hormone (TSH) levels (4.50-19.99 mIU L(-1) ), and subclinical hyperthyroidism (SHyper) as TSH levels of < 0.45 mIU L(-1) , both with normal free thyroxine levels. Outcomes were incidence of rVTE and overall mortality during follow-up starting after the 1-year blood sampling.

RESULTS

Of 561 participants (58% with anticoagulation), 6% had SHypo and 5% had SHyper. After 20.8 months of mean follow-up, 9% developed rVTE and 10% died. The rVTE incidence rate was 7.2 (95% confidence interval [CI] 2.7-19.2) per 100 patient-years in SHypo participants, 0.0 (95% CI 0.0-7.6) in SHyper participants, and 5.9 (95% CI 4.4-7.8) in euthyroid participants. In multivariate analyses, the sub-hazard ratio for rVTE was 0.00 (95% CI 0.00-0.58) in SHyper participants and 1.50 (95% CI 0.52-4.34) in SHypo participants as compared with euthyroid participants, without increased levels of thrombophilic biomarkers. SHyper (hazard ratio [HR] 0.80, 95% CI 0.23-2.81) and SHypo (HR 0.99, 95% CI 0.30-3.29) were not associated with mortality.

CONCLUSION

In elderly patients, SHyper may be associated with lower rVTE risks. SHypo showed a non-statistically significant pattern of an association with rVTE, without increased mortality or differences in thrombophilic biomarkers.

Carbon monoxide attenuates the effects of snake venoms containing metalloproteinases with fibrinogenase or thrombin-like activity on plasmatic coagulation

Carbon monoxide released from CORM-2 inhibitsCrotalus atroxsnake venom metalloproteinase mediated decreases in human plasma velocity of coagulation.

Bariatric patients have plasmatic hypercoagulability and systemic upregulation of heme oxygenase activity

Morbid obesity is associated with significant thrombophilia. Of interest, adipocytes obtained from obese patients have increased heme oxygenase (Hmox) activity, the endogenous enzyme responsible for carbon monoxide (CO) production. Given that CO enhances plasmatic coagulation, we determined whether morbidly obese patients undergoing bariatric surgery had an increase in endogenous CO and plasmatic hypercoagulability. CO was determined by noninvasive pulse oximetry measurement of carboxyhemoglobin (COHb). A thrombelastographic method to assess plasma coagulation kinetics and formation of carboxyhemefibrinogen (COHF) was utilized. Nonsmoking bariatric patients (n = 20, BMI 47 ± 8 kg/m, mean ± SD) had abnormally increased COHb concentrations of 2.7 ± 1.9%, indicative of Hmox upregulation. When coagulation kinetics of these bariatric patients were compared with values obtained from normal individuals' (n = 30) plasma, 70% (95% confidence interval 45.7-88.1%) had abnormally great velocity of clot formation, abnormally large clot strength, and COHF formation. Future investigation of Hmox-derived CO in the pathogenesis of obesity-related thrombophilia is warranted.

Risk of Peripheral Artery Disease in Patients With Carbon Monoxide Poisoning: A Population-Based Retrospective Cohort Study

Carbon monoxide (CO) poisoning can cause several life-threatening complications, particularly in cardiovascular and neurological systems. However, no studies have been performed to investigate the association between peripheral artery disease (PAD) and CO poisoning. We constructed a population-based retrospective cohort study to clarify the risks between PAD and CO poisoning. This population-based cohort study involved analyzing data from 1998 to 2010 obtained from the Taiwanese National Health Insurance Research Database, with a follow-up period extending to the end of 2011. We identified patients with CO poisoning and selected a comparison cohort that was frequency matched according to age, sex, and year of diagnosis of CO poisoning at a ratio of 1 patient to 4 control patients. We analyzed the risks for patients with CO poisoning and PAD by using Cox proportional hazards regression models. In this study, 9046 patients with CO poisoning and 36,183 controls were included. The overall risks for developing PAD were 1.85-fold in the patients with CO poisoning compared with the comparison cohort after adjusting for age, sex, and comorbidities. Our long-term cohort study results showed a higher risk for PAD development among patients with CO poisoning.

Hemodialysis patients have plasmatic hypercoagulability and decreased fibrinolytic vulnerability: role of carbon monoxide

Chronic hemodialysis is associated with significant thrombophilia. Of interest, hemodialysis patients have increased carboxyhemoglobin (COHb) and exhaled carbon monoxide (CO), signs of upregulated heme oxygenase (Hmox) activity. Given that CO enhances plasmatic coagulation, we determined whether patients requiring chronic hemodialysis had an increase in endogenous CO, plasmatic hypercoagulability and decreased fibrinolytic vulnerability. Carbon monoxide was determined by noninvasive pulse oximetry measurement of COHb. Blood samples were obtained just before hemodialysis. Thrombelastographic methods to assess plasma coagulation kinetics, fibrinolytic kinetics, and formation of carboxyhemefibrinogen (COHF) were used. Hemodialysis patients (n = 45) had abnormally increased COHb concentrations of 2.2 ± 1.9%, indicative of Hmox upregulation. Coagulation and fibrinolytic parameter normal values were determined with normal individual (n = 30) plasma. Thirty-seven patients of the hemodialysis cohort had COHF formation (82.2%, [67.9%-92.0%]; mean, [95% confidence interval]), and many of this group of patients had abnormally great velocity of clot growth (73.3%, [58.1%-85.4%]) and strength (75.6%, [60.5%-87.1%]). Furthermore, over half of COHF positive patients had a hypofibrinolytic state, evidenced by an abnormally prolonged time to maximum rate of lysis (53.3%, [37.9%-68.6%]) and clot lysis time (64.4%, [48.8%-78.1%]). Carbon monoxide enhanced coagulation and diminished fibrinolytic vulnerability in hemodialysis patients. Future investigation of hemodialysis, CO-related thrombophilia is warranted.

Colon and pancreas tumors enhance coagulation: role of hemeoxygenase-1

Colon and pancreatic cancer are associated with significant thrombophilia. Colon and pancreas tumor cells have an increase in hemeoxygenase-1 (HO-1) activity, the endogenous enzyme responsible for carbon monoxide production. Given that carbon monoxide enhances plasmatic coagulation, we determined if patients undergoing resection of colon and pancreatic tumors had an increase in endogenous carbon monoxide and plasmatic hypercoagulability. Patients with colon (n = 17) and pancreatic (n = 10) tumors were studied. Carbon monoxide was determined by the measurement of carboxyhemoglobin (COHb). A thrombelastographic method to assess plasma coagulation kinetics and formation of carboxyhemefibrinogen (COHF) was utilized. Nonsmoking patients with colon and pancreatic tumors had abnormally increased COHb concentrations of 1.4 ± 0.9 and 1.9 ± 0.7%, respectively, indicative of HO-1 upregulation. Coagulation analyses comparing both tumor groups demonstrated no significant differences in any parameter; thus the data were combined for the tumor groups for comparison with 95% confidence interval values obtained from normal individuals (n = 30) plasma. Seventy percent of tumor patients had a velocity of clot formation greater than the 95% confidence interval value of normal individuals, with 53% of this hypercoagulable group also having COHF formation. Further, 67% of tumor patients had clot strength that exceeded the normal 95% confidence interval value, and 56% of this subgroup had COHF formation. Finally, 63% of all tumor patients had COHF formation. Future investigation of HO-1-derived carbon monoxide in the pathogenesis of colon and pancreatic tumor-related thrombophilia is warranted.

Iron and carbon monoxide enhance coagulation and attenuate fibrinolysis by different mechanisms

Two parallel lines of investigation elucidating novel mechanisms by which iron (scanning electron microscopy-based) and carbon monoxide (viscoelastic-based) enhance coagulation and diminish fibrinolysis have emerged over the past few years. However, a multimodal approach to ascertain the effects of iron and carbon monoxide remained to be performed. Such investigation could be important, as iron and carbon monoxide are two of the products of heme catabolism via heme oxygenase-1, an enzyme upregulated in a variety of disease states associated with thrombophilia. Human plasma was exposed to ferric chloride, carbon monoxide derived from carbon monoxide-releasing molecule-2, or their combination. Viscoelastic studies demonstrated ferric chloride and carbon monoxide mediated enhancement of velocity of growth, and final clot strength, with the combination of the two molecules noted to have all the prothrombotic kinetic effects of either separately. Parallel ultrastructural studies demonstrated separate types of fibrin polymer cross-linking and matting in plasma exposed to ferric chloride and carbon monoxide, with the combination sharing features of each molecule. In conclusion, we present the first evidence that iron and carbon monoxide interact with key coagulation and fibrinolytic processes, resulting in thrombi that begin to form more quickly, grow faster, become stronger, and are more resistant to lysis.

Effect of exercise training on clot strength in patients with peripheral artery disease and intermittent claudication: An ancillary study

Objectives:

Patients with peripheral artery disease have walking impairment, greater thrombotic risk, and are often treated with exercise training. We sought to determine the effect of a 3-month-long exercise program on clot strength among patients with peripheral artery disease and intermittent claudication.

Methods:

Twenty-three symptomatic peripheral artery disease patients were randomly assigned to a walking exercise program or to an attention control group who performed light resistance exercise. We investigated the effect of exercise training on clot strength and time to clot formation was assessed by thromboelastography.

Results:

After 3 months of exercise, clot strength (maximal amplitude) and time to clot formation (R) did not change significantly from baseline, even after improvements in claudication onset time (p < 0.01) and peak walking time (p < 0.05). Furthermore, changes in clot formation parameters were not significantly different between groups. Among the 10 individuals demonstrating a reduction in clot strength (reduced maximal amplitude), one was a smoker (10%) compared to 9 of 13 non-responders (69%) whose maximal amplitude was unchanged or increased (p = 0.0097).

Conclusion:

In this ancillary study, a 12-week walking program improved ambulatory function in peripheral artery disease patients with claudication, but does not modify clot strength or time to clot formation. Larger studies are needed to confirm these hypothesis generating findings and to determine whether a different amount or type of exercise may induce a change in clotting in this patient population.

Cholecystectomy and wound complications: smoking worsens risk

BACKGROUND

In the United States, approximately 800,000 cholecystectomies are performed annually. We sought to determine the influence of preoperative smoking on postcholecystectomy wound complication rates.

MATERIALS AND METHODS

Using the National Surgical Quality Improvement Program database (2005-2011), patients aged ≥18 y who underwent elective open or laparoscopic cholecystectomy (LC) for benign gallbladder disease were identified using current procedural terminology codes. Multivariate regression was performed to determine the association between smoking status and wound complications, by surgical approach.

RESULTS

Of 143,753 identified patients, 128,692 (89.5%) underwent LC, 27,788 (19.3%) were active smokers, and 100,710 (70.2%) were females. Active smokers were younger than nonsmokers (mean + standard deviation age: 44.2 (14.9) versus 51.6 (17.9) years); P < 0.001) and had fewer comorbidities. Within 30-d postcholecystectomy, wound complications were reported in 2011 (1.4%) patients. Compared with nonsmokers, active smokers demonstrated increased odds of wound complications after both open cholecystectomy (odds ratio 1.28; P = 0.010) and LC (odds ratio 1.20; P = 0.020) after adjustment for demographic and clinical characteristics. Having wound complications increased the average postoperative length of stay by 2-4 d (P <0.001).

CONCLUSIONS

Active smokers are more likely to develop wound complications after cholecystectomy, regardless of surgical approach. Occurrence of wound complications consequently increases postoperative length of stay. Smoking abstinence before cholecystectomy may reduce the burden associated with wound complications.

Brain tumors enhance plasmatic coagulation: the role of hemeoxygenase-1

BACKGROUND

Patients with brain tumors suffer significant thrombotic morbidity and mortality. In addition to increased thrombin generation via tumor release of tissue factor-bearing microparticles and hyperfibrinogenemia, brain tumors and surrounding normal brain likely generate endogenous carbon monoxide (CO) via the hemeoxygenase-1 (HO-1) system. CO has been shown to enhance plasmatic coagulation via formation of carboxyhemefibrinogen (COHF). Thus, our goals in this study were to determine whether patients with brain tumors had increased HO-1 upregulation/CO production, plasmatic hypercoagulability, and formation of COHF.

METHODS

Patients with brain tumors (N = 20) undergoing craniotomy had blood collected for determination of carboxyhemoglobin as a marker of HO-1 activity, plasmatic hypercoagulability (defined as clot strength > 95% confidence interval value of normal subject plasma), and COHF formation (determined with a thrombelastograph-based assay). Plasma obtained from commercially available normal subjects (N = 30) was used for comparison with brain tumor patient samples.

RESULTS

Brain tumor patients had carboxyhemoglobin concentrations of 1.5% ± 0.5% (mean ± SD), indicative of HO-1 upregulation. Compared with normal subject plasma, brain tumor patient plasma had significantly (P < 0.0001) greater clot formation velocity (5.2 ± 1.5 vs 9.5 ± 2.3 dynes/cm/s, respectively) and significantly (P = 0.00016) stronger final clot strength (166 ± 28 vs 230 ± 78 dynes/cm, respectively). Ten of the brain tumor patients had plasma clot strength that exceeded the 95% confidence interval value observed in normal subjects, and 12 of the brain tumor patients had COHF formation. Five of the brain tumor patients in the hypercoagulable subgroup had COHF formation. Last, 5 of the hypercoagulable patients had primary brain tumors, whereas the other 5 patients had metastatic tumors or an inflammatory mass lesion.

CONCLUSIONS

A subset of patients with brain tumors has increased endogenous CO production, plasmatic hypercoagulability, and COHF formation. Future investigation of the role played by HO-1 derived CO in the pathogenesis of brain tumor-associated thrombophilia is warranted.

Symptomatic internal carotid artery thrombosis in acute carbon monoxide intoxication

Stroke has been rarely associated with carbon monoxide (CO) intoxication. We report a symptomatic internal carotid artery (ICA) thrombosis in a patient with acute CO intoxication.

Carbon monoxide: Anticoagulant or procoagulant?

Within the past decade there have been several investigations attempting to define the impact of exogenous and endogenous carbon monoxide exposure on hemostasis. Critically, two bodies of literature have emerged, with carbon monoxide mediated platelet inhibition cited as a cause of in vitro human and in vitro/in vivo rodent anticoagulation. In contrast, interaction with heme groups associated with fibrinogen, α₂-antiplasmin and plasmin by carbon monoxide has resulted in enhanced coagulation and decreased fibrinolysis in vitro in human and other species, and in vivo in rabbits. Of interest, the ultrastructure of platelet rich plasma thrombi demonstrates an abnormal increase in fine fiber formation and matting that are obtained from humans exposed to carbon monoxide. Further, thrombi obtained from humans and rabbits have very similar ultrastructures, whereas mice and rats have more fine fibers and matting present. In sum, there may be species specific differences with regard to hemostatic response to carbon monoxide. Carbon monoxide may be a Janus-faced molecule, with potential to attenuate or exacerbate thrombophilic disease.

Effect of tobacco smoking and smoking cessation on plasma lipoproteins and associated major cardiovascular risk factors: a narrative review

Cigarette smoking, active or passive, kills about 6 million people each year worldwide. Cardiovascular disease (CVD) is responsible for 40% of all smoking-related deaths, lung cancer accounts for 20% of all smoking-related deaths, and chronic obstructive pulmonary disease is related to another 20% of deaths. In this narrative review we consider the relationship between cigarette smoking and CVD. We discuss disease states and/or CVD risk factors related to smoking, such as dyslipidaemia, vascular inflammation, endothelial dysfunction, arterial stiffness, insulin resistance, type 2 diabetes mellitus (T2DM), chronic kidney disease (CKD), and non-alcoholic fatty liver disease (NAFLD) as well as their complex interrelations. Smoking cessation can correct abnormalities related to smoking; however, success rates are relatively low. In cases of inability to quit, measures to minimize the adverse effects of smoking specifically related to CVD should be taken. Smokers should receive best practice treatment, according to guidelines, as for non-smokers.