Trends in the incidence of deep vein thrombosis and pulmonary embolism: a 25-year population-based study

BACKGROUND

The incidence of venous thromboembolism has not been well described, and there are no studies of long-term trends in the incidence of venous thromboembolism.

OBJECTIVES

To estimate the incidence of deep vein thrombosis and pulmonary embolism and to describe trends in incidence.

METHODS

We performed a retrospective review of the complete medical records from a population-based inception cohort of 2218 patients who resided within Olmsted County, Minnesota, and had an incident deep vein thrombosis or pulmonary embolism during the 25-year period from 1966 through 1990.

RESULTS

The overall average age- and sex-adjusted annual incidence of venous thromboembolism was 117 per 100000 (deep vein thrombosis, 48 per 100000; pulmonary embolism, 69 per 100000), with higher age-adjusted rates among males than females (130 vs 110 per 100000, respectively). The incidence of venous thromboembolism rose markedly with increasing age for both sexes, with pulmonary embolism accounting for most of the increase. The incidence of pulmonary embolism was approximately 45% lower during the last 15 years of the study for both sexes and all age strata, while the incidence of deep vein thrombosis remained constant for males across all age strata, decreased for females younger than 55 years, and increased for women older than 60 years.

CONCLUSIONS

Venous thromboembolism is a major national health problem, especially among the elderly. While the incidence of pulmonary embolism has decreased over time, the incidence of deep vein thrombosis remains unchanged for men and is increasing for older women. These findings emphasize the need for more accurate identification of patients at risk for venous thromboembolism, as well as a safe and effective prophylaxis.

Guidelines for the prevention of stroke in patients with stroke or transient ischemic attack: a guideline for healthcare professionals from the american heart association/american stroke association

The aim of this updated statement is to provide comprehensive and timely evidence-based recommendations on the prevention of ischemic stroke among survivors of ischemic stroke or transient ischemic attack. Evidence-based recommendations are included for the control of risk factors, interventional approaches for atherosclerotic disease, antithrombotic treatments for cardioembolism, and the use of antiplatelet agents for noncardioembolic stroke. Further recommendations are provided for the prevention of recurrent stroke in a variety of other specific circumstances, including arterial dissections; patent foramen ovale; hyperhomocysteinemia; hypercoagulable states; sickle cell disease; cerebral venous sinus thrombosis; stroke among women, particularly with regard to pregnancy and the use of postmenopausal hormones; the use of anticoagulation after cerebral hemorrhage; and special approaches to the implementation of guidelines and their use in high-risk populations.

Neutrophil extracellular traps contribute to immunothrombosis in COVID-19 acute respiratory distress syndrome

COVID-19 affects millions of patients worldwide, with clinical presentation ranging from isolated thrombosis to acute respiratory distress syndrome (ARDS) requiring ventilator support. Neutrophil extracellular traps (NETs) originate from decondensed chromatin released to immobilize pathogens, and they can trigger immunothrombosis. We studied the connection between NETs and COVID-19 severity and progression. We conducted a prospective cohort study of COVID-19 patients (n = 33) and age- and sex-matched controls (n = 17). We measured plasma myeloperoxidase (MPO)-DNA complexes (NETs), platelet factor 4, RANTES, and selected cytokines. Three COVID-19 lung autopsies were examined for NETs and platelet involvement. We assessed NET formation ex vivo in COVID-19 neutrophils and in healthy neutrophils incubated with COVID-19 plasma. We also tested the ability of neonatal NET-inhibitory factor (nNIF) to block NET formation induced by COVID-19 plasma. Plasma MPO-DNA complexes increased in COVID-19, with intubation (P < .0001) and death (P < .0005) as outcome. Illness severity correlated directly with plasma MPO-DNA complexes (P = .0360), whereas Pao2/fraction of inspired oxygen correlated inversely (P = .0340). Soluble and cellular factors triggering NETs were significantly increased in COVID-19, and pulmonary autopsies confirmed NET-containing microthrombi with neutrophil-platelet infiltration. Finally, COVID-19 neutrophils ex vivo displayed excessive NETs at baseline, and COVID-19 plasma triggered NET formation, which was blocked by nNIF. Thus, NETs triggering immunothrombosis may, in part, explain the prothrombotic clinical presentations in COVID-19, and NETs may represent targets for therapeutic intervention.

One-year cardiovascular event rates in outpatients with atherothrombosis

CONTEXT

Few data document current cardiovascular (CV) event rates in stable patients with atherothrombosis in a community setting. Differential event rates for patients with documented coronary artery disease (CAD), cerebrovascular disease (CVD), or peripheral arterial disease (PAD) or those at risk of these diseases have not been previously evaluated in a single international cohort.

OBJECTIVE

To establish contemporary, international, 1-year CV event rates in outpatients with established arterial disease or with multiple risk factors for atherothrombosis.

DESIGN, SETTING, AND PARTICIPANTS

The Reduction of Atherothrombosis for Continued Health (REACH) Registry is an international, prospective cohort of 68 236 patients with either established atherosclerotic arterial disease (CAD, PAD, CVD; n = 55 814) or at least 3 risk factors for atherothrombosis (n = 12 422), who were enrolled from 5587 physician practices in 44 countries in 2003-2004.

MAIN OUTCOME MEASURES

Rates of CV death, myocardial infarction (MI), and stroke.

RESULTS

As of July 2006, 1-year outcomes were available for 95.22% (n = 64 977) of participants. Cardiovascular death, MI, or stroke rates were 4.24% overall: 4.69% for those with established atherosclerotic arterial disease vs 2.15% for patients with multiple risk factors only. Among patients with established disease, CV death, MI, or stroke rates were 4.52% for patients with CAD, 6.47% for patients with CVD, and 5.35% for patients with PAD. The incidences of the end point of CV death, MI, or stroke or of hospitalization for atherothrombotic event(s) were 15.20% for CAD, 14.53% for CVD, and 21.14% for PAD patients with established disease. These event rates increased with the number of symptomatic arterial disease locations, ranging from 5.31% for patients with risk factors only to 12.58% for patients with 1, 21.14% for patients with 2, and 26.27% for patients with 3 symptomatic arterial disease locations (P<.001 for trend).

CONCLUSIONS

In this large, contemporary, international study, outpatients with established atherosclerotic arterial disease, or at risk of atherothrombosis, experienced relatively high annual CV event rates. Multiple disease locations increased the 1-year risk of CV events.

Triggers, targets and treatments for thrombosis

Thrombosis--localized clotting of the blood--can occur in the arterial or the venous circulation and has a major medical impact. Acute arterial thrombosis is the proximal cause of most cases of myocardial infarction (heart attack) and of about 80% of strokes, collectively the most common cause of death in the developed world. Venous thromboembolism is the third leading cause of cardiovascular-associated death. The pathogenic changes that occur in the blood vessel wall and in the blood itself resulting in thrombosis are not fully understood. Understanding these processes is crucial for developing safer and more effective antithrombotic drugs.

Induction of reproducible brain infarction by photochemically initiated thrombosis

We have used a photochemical reaction in vivo to induce reproducible thrombosis leading to cerebral infarction in rats. After the intravenous injection of rose bengal, a potent photosensitizing dye, an ischemic lesion was formed by irradiating the left parietal convexity of the exposed skull for 20 minutes with green light (560 nm) from a filtered xenon arc lamp. Animals were allowed to survive from 30 minutes to 15 days after irradiation. Early microscopic alterations within the irradiated zone included the formation of thrombotic plugs and adjacent red blood cell stasis within pial and parenchymal vessels. Scanning electron microscopy revealed frequent platelet aggregates adhering to the vascular endothelium, often resulting in vascular occlusion. Carbon-black brain perfusion demonstrated that occlusion of vascular channels progressed after irradiation and was complete within 4 hours. Histopathological examination at 1, 5, and 15 days revealed that the associated infarct evolved reproducibly through several characteristic stages, including a phase of massive macrophage infiltration. Although cerebral infarction in this model is initiated by thrombosis of small blood vessels, the fact that the main pathological features of stroke are consistently reproduced should permit its use in assessing treatment regimens. Further, the capability of producing infarction in preselected cortical regions may facilitate the study of behavioral, functional, and structural consequences of acute and chronic stroke.

Comparative determinants of 4-year cardiovascular event rates in stable outpatients at risk of or with atherothrombosis

CONTEXT

Clinicians and trialists have difficulty with identifying which patients are highest risk for cardiovascular events. Prior ischemic events, polyvascular disease, and diabetes mellitus have all been identified as predictors of ischemic events, but their comparative contributions to future risk remain unclear.

OBJECTIVE

To categorize the risk of cardiovascular events in stable outpatients with various initial manifestations of atherothrombosis using simple clinical descriptors.

DESIGN, SETTING, AND PATIENTS

Outpatients with coronary artery disease, cerebrovascular disease, or peripheral arterial disease or with multiple risk factors for atherothrombosis were enrolled in the global Reduction of Atherothrombosis for Continued Health (REACH) Registry and were followed up for as long as 4 years. Patients from 3647 centers in 29 countries were enrolled between 2003 and 2004 and followed up until 2008. Final database lock was in April 2009.

MAIN OUTCOME MEASURES

Rates of cardiovascular death, myocardial infarction, and stroke.

RESULTS

A total of 45,227 patients with baseline data were included in this 4-year analysis. During the follow-up period, a total of 5481 patients experienced at least 1 event, including 2315 with cardiovascular death, 1228 with myocardial infarction, 1898 with stroke, and 40 with both a myocardial infarction and stroke on the same day. Among patients with atherothrombosis, those with a prior history of ischemic events at baseline (n = 21,890) had the highest rate of subsequent ischemic events (18.3%; 95% confidence interval [CI], 17.4%-19.1%); patients with stable coronary, cerebrovascular, or peripheral artery disease (n = 15,264) had a lower risk (12.2%; 95% CI, 11.4%-12.9%); and patients without established atherothrombosis but with risk factors only (n = 8073) had the lowest risk (9.1%; 95% CI, 8.3%-9.9%) (P < .001 for all comparisons). In addition, in multivariable modeling, the presence of diabetes (hazard ratio [HR], 1.44; 95% CI, 1.36-1.53; P < .001), an ischemic event in the previous year (HR, 1.71; 95% CI, 1.57-1.85; P < .001), and polyvascular disease (HR, 1.99; 95% CI, 1.78-2.24; P < .001) each were associated with a significantly higher risk of the primary end point.

CONCLUSION

Clinical descriptors can assist clinicians in identifying high-risk patients within the broad range of risk for outpatients with atherothrombosis.

Relations between left atrial appendage blood flow velocity, spontaneous echocardiographic contrast and thromboembolic risk in vivo

OBJECTIVES

The aim of this study was to determine the relations between spontaneous echo contrast, left atrial appendage blood flow velocity and thromboembolism.

BACKGROUND

Left atrial thrombus and spontaneous echo contrast, a putative marker of thromboembolic risk, are frequently located in the left atrial appendage. Measurement of left atrial appendage outflow Doppler velocity by transesophageal echocardiography is a recent technique for assessment of left atrial appendage function, which may be important in thrombus formation.

METHODS

Transthoracic and transesophageal echocardiographic studies were performed in 140 patients with atrial fibrillation (chronic in 80 patients, paroxysmal in 50 patients, first episode < 2 weeks in 10 patients). The left atrium and appendage were inspected for thrombus and spontaneous echo contrast, which was graded from 0 (none) to 4+ (severe). Outflow velocity profiles were obtained by pulsed wave Doppler at the orifice of the left atrial appendage.

RESULTS

Left atrial spontaneous echo contrast was present in 78 patients (56%). In multivariate logistic regression analysis, spontaneous echo contrast was the only significant correlate of left atrial thrombus and was present in 14 (93%) of 15 patients. Spontaneous echo contrast and age were associated positively, and anticoagulant therapy was associated negatively, with previous thromboembolic events. Increasing grades of spontaneous echo contrast were associated with decreasing left atrial appendage blood velocity. The velocity in patients with thrombus was not significantly different from that in patients with 4+ spontaneous echo contrast. In multivariate linear regression analysis, the grade of spontaneous echo contrast was significantly and negatively associated with left atrial appendage velocity (p = -0.0001) and mitral regurgitation (p = -0.0002) and significantly and positively associated with left atrial area (p = 0.0005). The odds ratio for spontaneous echo contrast was 28:1 for low left atrial appendage blood flow velocity (< 35 cm/s) and 96:1 for low velocity and the absence of mitral regurgitation.

CONCLUSIONS

Spontaneous echo contrast is the cardiac factor most strongly associated with left atrial appendage thrombus and embolic events. Spontaneous echo contrast formation is promoted by reduced blood flow velocity and increased left atrial size but is diminished by mitral regurgitation.

Effect of cisternal and ventricular blood on risk of delayed cerebral ischemia after subarachnoid hemorrhage: the Fisher scale revisited

BACKGROUND AND PURPOSE

Thick cisternal clot on CT is a well-recognized risk factor for delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (SAH). Whether intraventricular hemorrhage (IVH) or intracerebral hemorrhage (ICH) predisposes to DCI is unclear. The Fisher CT grading scale identifies thick SAH but does not separately account for IVH or ICH.

METHODS

We studied 276 consecutively admitted patients with an available admission CT scan performed within 72 hours of onset. Demographic, clinical, laboratory, and neuroimaging data were recorded, and the amount and location of SAH, IVH, and ICH on admission CT scans were quantified. The relationship between these variables and DCI was analyzed separately and in combination with multiple logistic regression.

RESULTS

DCI developed in 20% of patients (54 of 276). Among SAH variables, thick clot completely filling any cistern or fissure was the best predictor of DCI (P=0.008), and among IVH variables, blood in both lateral ventricles was most predictive (P=0.001). These variables had independent predictive value for DCI in a multivariate analysis of CT findings, and both were included in a final multivariate model when evaluated in conjunction with other clinical risk factors: IVH (OR 4.1, 95% CI 1.7 to 9.8), SAH (OR 2.3, 95% CI 1.5 to 9.5), mean arterial pressure >112 mm Hg (OR 4.9, 95% CI 2.1 to 11.4), and transcranial Doppler mean velocity >140 cm/s within 5 days of hemorrhage (OR 3.8, 95% CI 1.5 to 9.5). Similar results were obtained in a repeat analysis with infarction due to vasospasm as the dependent variable.

CONCLUSIONS

SAH completely filling any cistern or fissure and IVH in the lateral ventricles are both risk factors for DCI, and their risk is additive. We propose a new SAH rating scale that accounts for the independent predictive value of subarachnoid and ventricular blood for DCI.

Atherothrombosis and high-risk plaque: part I: evolving concepts

Atherothrombosis is a complex disease in which cholesterol deposition, inflammation, and thrombus formation play a major role. Rupture of high-risk, vulnerable plaques is responsible for coronary thrombosis, the main cause of unstable angina, acute myocardial infarction, and sudden cardiac death. In addition to rupture, plaque erosion may also lead to occlusive thrombosis and acute coronary events. Atherothrombosis can be evaluated according to histologic criteria, most commonly categorized by the American Heart Association (AHA) classification. However, this classification does not include the thin cap fibroatheroma, the most common form of high-risk, vulnerable plaque. Furthermore, the AHA classification does not include plaque erosion. As a result, new classifications have emerged and are reviewed in this article. The disease is asymptomatic during a long period and dramatically changes its course when complicated by thrombosis. This is summarized in five phases, from early lesions to plaque rupture, followed by plaque healing and fibrocalcification. For the early phases, the role of endothelial dysfunction, cholesterol transport, high-density lipoprotein, and proteoglycans are discussed. Furthermore, the innate and adaptive immune response to autoantigens, the Toll-like receptors, and the mechanisms of calcification are carefully analyzed. For the advanced phases, the role of eccentric remodeling, vasa vasorum neovascularization, and mechanisms of plaque rupture are systematically evaluated. In the final thrombosis section, focal and circulating tissue factor associated with apoptotic macrophages and circulatory monocytes is examined, closing the link between inflammation, plaque rupture, and blood thrombogenicity.

Antithrombotic and thrombolytic therapy for valvular disease: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

BACKGROUND

Antithrombotic therapy in valvular disease is important to mitigate thromboembolism, but the hemorrhagic risk imposed must be considered.

METHODS

The methods of this guideline follow those described in Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines. Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines in this supplement.

RESULTS

In rheumatic mitral disease, we recommend vitamin K antagonist (VKA) therapy when the left atrial diameter is > 55 mm (Grade 2C) or when complicated by left atrial thrombus (Grade 1A). In candidates for percutaneous mitral valvotomy with left atrial thrombus, we recommend VKA therapy until thrombus resolution, and we recommend abandoning valvotomy if the thrombus fails to resolve (Grade 1A). In patients with patent foramen ovale (PFO) and stroke or transient ischemic attack, we recommend initial aspirin therapy (Grade 1B) and suggest substitution of VKA if recurrence (Grade 2C). In patients with cryptogenic stroke and DVT and a PFO, we recommend VKA therapy for 3 months (Grade 1B) and consideration of PFO closure (Grade 2C). We recommend against the use of anticoagulant (Grade 1C) and antiplatelet therapy (Grade 1B) for native valve endocarditis. We suggest holding VKA therapy until the patient is stabilized without neurologic complications for infective endocarditis of a prosthetic valve (Grade 2C). In the first 3 months after bioprosthetic valve implantation, we recommend aspirin for aortic valves (Grade 2C), the addition of clopidogrel to aspirin if the aortic valve is transcatheter (Grade 2C), and VKA therapy with a target international normalized ratio (INR) of 2.5 for mitral valves (Grade 2C). After 3 months, we suggest aspirin therapy (Grade 2C). We recommend early bridging of mechanical valve patients to VKA therapy with unfractionated heparin (DVT dosing) or low-molecular-weight heparin (Grade 2C). We recommend long-term VKA therapy for all mechanical valves (Grade 1B): target INR 2.5 for aortic (Grade 1B) and 3.0 for mitral or double valve (Grade 2C). In patients with mechanical valves at low bleeding risk, we suggest the addition of low-dose aspirin (50-100 mg/d) (Grade 1B). In valve repair patients, we suggest aspirin therapy (Grade 2C). In patients with thrombosed prosthetic valve, we recommend fibrinolysis for right-sided valves and left-sided valves with thrombus area < 0.8 cm(2) (Grade 2C). For patients with left-sided prosthetic valve thrombosis and thrombus area ≥ 0.8 cm(2), we recommend early surgery (Grade 2C).

CONCLUSIONS

These antithrombotic guidelines provide recommendations based on the optimal balance of thrombotic and hemorrhagic risk.

The causes and risk of stroke in patients with asymptomatic internal-carotid-artery stenosis. North American Symptomatic Carotid Endarterectomy Trial Collaborators

BACKGROUND

The causes of stroke in patients with asymptomatic carotid-artery stenosis have not been carefully studied. Information about causes might influence decisions about the use of carotid endarterectomy in such patients.

METHODS

We studied patients with unilateral symptomatic carotid-artery stenosis and asymptomatic contralateral stenosis from 1988 to 1997. The causes, severity, risk, and predictors of stroke in the territory of the asymptomatic artery were examined and quantified.

RESULTS

The risk of stroke at five years after study entry in a total of 1820 patients increased with the severity of stenosis. Among 1604 patients with stenosis of less than 60 percent of the luminal diameter, the risk of a first stroke was 8.0 percent (1.6 percent annually), as compared with 16.2 percent (3.2 percent annually) among 216 patients with 60 to 99 percent stenosis. In the group with 60 to 99 percent stenosis, the five-year risk of stroke in the territory of a large artery was 9.9 percent, that of lacunar stroke was 6.0 percent, and that of cardioembolic stroke 2.1 percent. Some patients had more than one stroke of more than one cause. In the territory of an asymptomatic occluded artery (as was identified in 86 patients), the annualized risk of stroke was 1.9 percent. Strokes with different causes had different risk factors. The risk factors for large-artery stroke were silent brain infarction, a history of diabetes, and a higher degree of stenosis; for cardioembolic stroke, a history of myocardial infarction or angina and hypertension; for lacunar stroke, age of 75 years or older, hypertension, diabetes, and a higher degree of stenosis.

CONCLUSIONS

The risk of stroke among patients with asymptomatic carotid-artery stenosis is relatively low. Forty-five percent of strokes in patients with asymptomatic stenosis of 60 to 99 percent are attributable to lacunes or cardioembolism. These observations have implications for the use of endarterectomy in asymptomatic patients. Without analysis of the risk of stroke according to cause, the absolute benefit associated with endarterectomy may be overestimated.

Induction of reproducible brain infarction by photochemically initiated thrombosis

We have used a photochemical reaction in vivo to induce reproducible thrombosis leading to cerebral infarction in rats. After the intravenous injection of rose bengal, a potent photosensitizing dye, an ischemic lesion was formed by irradiating the left parietal convexity of the exposed skull for 20 minutes with green light (560 nm) from a filtered xenon arc lamp. Animals were allowed to survive from 30 minutes to 15 days after irradiation. Early microscopic alterations within the irradiated zone included the formation of thrombotic plugs and adjacent red blood cell stasis within pial and parenchymal vessels. Scanning electron microscopy revealed frequent platelet aggregates adhering to the vascular endothelium, often resulting in vascular occlusion. Carbon-black brain perfusion demonstrated that occlusion of vascular channels progressed after irradiation and was complete within 4 hours. Histopathological examination at 1, 5, and 15 days revealed that the associated infarct evolved reproducibly through several characteristic stages, including a phase of massive macrophage infiltration. Although cerebral infarction in this model is initiated by thrombosis of small blood vessels, the fact that the main pathological features of stroke are consistently reproduced should permit its use in assessing treatment regimens. Further, the capability of producing infarction in preselected cortical regions may facilitate the study of behavioral, functional, and structural consequences of acute and chronic stroke.

IL-6 inhibition with ziltivekimab in patients at high atherosclerotic risk (RESCUE): a double-blind, randomised, placebo-controlled, phase 2 trial

BACKGROUND

IL-6 has emerged as a pivotal factor in atherothrombosis. Yet, the safety and efficacy of IL-6 inhibition among individuals at high atherosclerotic risk but without a systemic inflammatory disorder is unknown. We therefore addressed whether ziltivekimab, a fully human monoclonal antibody directed against the IL-6 ligand, safely and effectively reduces biomarkers of inflammation and thrombosis among patients with high cardiovascular risk. We focused on individuals with elevated high-sensitivity CRP and chronic kidney disease, a group with substantial unmet clinical need in whom previous studies in inflammation inhibition have shown efficacy for cardiovascular event reduction.

METHODS

RESCUE is a randomised, double-blind, phase 2 trial done at 40 clinical sites in the USA. Inclusion criteria were age 18 years or older, moderate to severe chronic kidney disease, and high-sensitivity CRP of at least 2 mg/L. Participants were randomly allocated (1:1:1:1) to subcutaneous administration of placebo or ziltivekimab 7·5 mg, 15 mg, or 30 mg every 4 weeks up to 24 weeks. The primary outcome was percentage change from baseline in high-sensitivity CRP after 12 weeks of treatment with ziltivekimab compared with placebo, with additional biomarker and safety data collected over 24 weeks of treatment. Primary analyses were done in the intention-to-treat population. Safety was assessed in all patients who received at least one dose of assigned treatment. The trial is registered with ClinicalTrials.gov, NCT03926117.

FINDINGS

Between June 17, 2019, and Jan 14, 2020, 264 participants were enrolled into the trial, of whom 66 were randomly assigned to each of the four treatment groups. At 12 weeks after randomisation, median high-sensitivity CRP levels were reduced by 77% for the 7·5 mg group, 88% for the 15 mg group, and 92% for the 30 mg group compared with 4% for the placebo group. As such, the median pairwise differences in percentage change in high-sensitivity CRP between the ziltivekimab and placebo groups, after aligning for strata, were -66·2% for the 7·5 mg group, -77·7% for the 15 mg group, and -87·8% for the 30 mg group (all p<0·0001). Effects were stable over the 24-week treatment period. Dose-dependent reductions were also observed for fibrinogen, serum amyloid A, haptoglobin, secretory phospholipase A2, and lipoprotein(a). Ziltivekimab was well tolerated, did not affect the total cholesterol to HDL cholesterol ratio, and there were no serious injection-site reactions, sustained grade 3 or 4 neutropenia or thrombocytopenia.

INTERPRETATION

Ziltivekimab markedly reduced biomarkers of inflammation and thrombosis relevant to atherosclerosis. On the basis of these data, a large-scale cardiovascular outcomes trial will investigate the effect of ziltivekimab in patients with chronic kidney disease, increased high-sensitivity CRP, and established cardiovascular disease.

FUNDING

Novo Nordisk.

Vascular access for hemodialysis. Patency rates and results of revision

Over a 4-year interval, 324 arteriovenous conduits were created in 256 patients with end-stage renal disease as access for chronic hemodialysis. These included 154 Cimino fistulae, 163 polytetrafluoroethylene (PTFE) grafts, and seven miscellaneous grafts. Satisfactory patency rates were demonstrated for as long as 4 years for both Cimino fistulae and PTFE grafts by life-table analysis. Failures of Cimino fistulae usually occurred early in the postoperative period, secondary to attempts to use inadequate veins. Thrombosis caused the majority of PTFE graft failures and was generally the result of venous stenosis. Correction of such venous stenosis is mandatory to restore graft patency and can result in prolonged graft survival.

Association of intraluminal thrombus in abdominal aortic aneurysm with local hypoxia and wall weakening

PURPOSE

Our previous computer models suggested that intraluminal thrombus (ILT) within an abdominal aortic aneurysm (AAA) attenuates oxygen diffusion to the AAA wall, possibly causing localized hypoxia and contributing to wall weakening. The purpose of this work was to investigate this possibility.

METHODS

In one arm of this study, patients with AAA were placed in one of two groups: (1) those with an ILT of 4-mm or greater thickness on the anterior surface or (2) those with little (< 4 mm) or no ILT at this site. During surgical resection but before aortic cross-clamping, a needle-type polarographic partial pressure of oxygen (PO2) electrode was inserted into the wall of the exposed AAA, and the PO2 was measured. The probe was advanced, and measurements were made midway through the thrombus and in the lumen. Mural and mid-ILT PO2 measurements were normalized by the intraluminal PO2 measurement to account for patient variability. In the second arm of this study, two AAA wall specimens were obtained from two different sites of the same aneurysm at the time of surgical resection: group I specimens had thick adherent ILT, and group II specimens had thinner or no adherent ILT. Nonaneurysmal tissue was also obtained from the infrarenal aorta of organ donors. Specimens were subjected to histologic, immunohistochemical, and tensile strength analyses to provide data on degree of inflammation (% area inflammatory cells), neovascularization (number of capillaries per high-power field), and tensile strength (peak attainable load). Additional specimens were subjected to Western blotting and immunohistochemistry for qualitative evaluation of expression of the cellular hypoxia marker oxygen-regulated protein.

RESULTS

The PO2 measured within the AAA wall in group I (n = 4) and group II (n = 7) patients was 18% +/- 9% luminal value versus 60% +/- 6% (mean +/- SEM; P <.01). The normalized PO2 within the ILT of group I patients was 39% +/- 10% (P =.08 with respect to the group I wall value). Group I tissue specimens showed greater inflammation (P <.05) compared with both group II specimens and nonaneurysmal tissue: 2.9% +/- 0.6% area (n = 7) versus 1.7% +/- 0.3% area (n = 7) versus 0.2% +/- 0.1% area (n = 3), respectively. We found similar differences for neovascularization (number of vessels/high-power field), but only group I versus control was significantly different (P <.05): 16.9 +/- 1.6 (n = 7) vs 13.0 +/- 2.3 (n = 7) vs 8.7 +/- 2.0 (n = 3), respectively. Both Western blotting and immunohistochemistry results suggest that oxygen-regulated protein is more abundantly expressed in group I versus group II specimens. Tensile strength of group I specimens was significantly less (P <.05) than that for group II specimens: 138 +/- 19 N/cm2 (n = 7) versus 216 +/- 34 N/cm2 (n = 7), respectively.

CONCLUSION

Our results suggest that localized hypoxia occurs in regions of thicker ILT in AAA. This may lead to increased, localized mural neovascularization and inflammation, as well as regional wall weakening. We conclude that ILT may play an important role in the pathology and natural history of AAA.

Underlying disorders associated with severe early-onset preeclampsia

OBJECTIVE

Our purpose was to determine whether patients with severe early-onset preeclampsia have hemostatic or metabolic abnormalities that are associated with a tendency to vascular thrombosis.

STUDY DESIGN

A total of 101 patients with a history of severe early-onset preeclampsia were tested at least 10 weeks post partum for the presence of hyperhomocysteinemia (methionine loading test), protein C, protein S, and antithrombin III deficiency, activated protein C resistance, lupus anticoagulant, and immunoglobulin G and/or M anticardiolipin antibodies.

RESULTS

Of the 101 patients, 39 (38.6%) had chronic hypertension. Of the 85 patients tested for coagulation disturbances, 21 (24.7%) had protein S deficiency. Of the 50 patients tested for activated protein C resistance, 8 (16.0%) were positive. Of the 79 patients tested for hyperhomocysteinemia, 14 (17.7%) had a positive methionine loading test. Finally, 95 patients were tested for anticardiolipin antibodies; 27 (29.4%) had detectable immunoglobulin G and/or M anticardiolipin antibodies.

CONCLUSION

Patients with a history of severe early-onset preeclampsia should be screened for protein S deficiency, activated protein C resistance, hyperhomocysteinemia, and anticardiolipin antibodies, since these results may have an impact on counseling for and pharmacologic management in future pregnancies.

Epidemiology of Peripheral Artery Disease and Polyvascular Disease

Atherosclerotic lower extremity peripheral artery disease (PAD) is increasingly recognized as an important cause of cardiovascular morbidity and mortality that affects >230 million people worldwide. Traditional cardiovascular risk factors, including advanced age, smoking, and diabetes, are strongly linked to an increase risk of PAD. Although PAD has been historically underappreciated compared with coronary artery disease and stroke, greater attention on PAD in recent years has led to important new epidemiological insights in the areas of thrombosis, inflammation, dyslipidemia, and microvascular disease. In addition, the concept of polyvascular disease, or clinically evident atherosclerosis in multiple arterial beds, is increasingly identified as a particularly malignant cardiovascular disease worthy of special clinical attention and further study. It is noteworthy that PAD may increase the risk of adverse outcomes in similar or even greater magnitude than coronary disease or stroke. In this review, we highlight important new advances in the epidemiology of PAD with a particular focus on polyvascular disease, emerging biomarkers, and differential risk pathways for PAD compared with other atherosclerotic diseases.

Extracranial thrombotically active carotid plaque as a risk factor for ischemic stroke

CONTEXT

Recent studies suggest that factors other than the degree of carotid stenosis are involved in ischemic stroke pathogenesis, especially modifications of plaque composition and related complications.

OBJECTIVE

To examine the role of carotid plaque rupture and thrombosis in ischemic stroke pathogenesis in patients undergoing carotid endarterectomy, excluding those with possible cardiac embolization or with severe stenosis of the circle of Willis.

DESIGN, SETTING, AND PATIENTS

A total of 269 carotid plaques selected from an Interinstitutional Carotid Tissue Bank were studied by histology after surgical endarterectomy between January 1995 and December 2002. A total of 96 plaques were from patients with ipsilateral major stroke, 91 plaques from patients with transient ischemic attack (TIA), and 82 plaques from patients without symptoms.

MAIN OUTCOME MEASURES

Differences in the frequency of thrombosis, cap rupture, cap erosion, inflammatory infiltrate, and major cardiovascular risk factors between study groups.

RESULTS

A thrombotically active carotid plaque associated with high inflammatory infiltrate was observed in 71 (74.0%) of 96 patients with ipsilateral major stroke (and in all 32 plaques from patients operated within 2 months of symptom onset) compared with 32 (35.2%) of 91 patients with TIA (P < .001) or 12 (14.6%) of 82 patients who were without symptoms (P < .001). In addition, a fresh thrombus was observed in 53.8% of patients with stroke operated 13 to 24 months after the cerebrovascular event. An acute thrombus was associated with cap rupture in 64 (90.1%) of 71 thrombosed plaques from patients with stroke and with cap erosion in the remaining 7 cases (9.9%). Ruptured plaques of patients affected by stroke were characterized by the presence of a more severe inflammatory infiltrate, constituted by monocytes, macrophages, and T lymphocyte cells compared with that observed in the TIA and asymptomatic groups (P = .001). There was no significant difference between groups in major cardiovascular risk factors.

CONCLUSION

These results demonstrate a major role of carotid thrombosis and inflammation in ischemic stroke in patients affected by carotid atherosclerotic disease.

Right heart thrombi in pulmonary embolism: results from the International Cooperative Pulmonary Embolism Registry

OBJECTIVES

This study was designed to investigate the prevalence and prognostic significance of right heart thrombi (RHTh) in pulmonary embolism.

BACKGROUND

Most reports about patients with RHTh are small case series. We analyzed data referring to RHTh among 2,454 consecutive pulmonary embolism patients enrolled in the International Cooperative Pulmonary Embolism Registry.

METHODS

Of the 2,454 patients, 1,113 had results available from baseline echocardiography. We compared the 42 patients with RHTh versus 1,071 without RHTh.

RESULTS

Patients with RHTh had shorter duration of symptoms (2.2 +/- 2.9 days vs. 4.3 +/- 6.0 days, p = 0.013), lower systolic blood pressure (BP) (116.0 +/- 28.8 vs. 125.7 +/- 25.0 mm Hg, p = 0.008), and more frequent right ventricular hypokinesis (64% vs. 40%, p = 0.002) and congestive heart failure (26% vs. 13%, p = 0.024); but they had similar age (62.9 vs. 62.5 years), arterial oxygen pressure (71.3 +/- 26.0 vs. 69.5 +/- 30.5 mm Hg), and prevalence of cancer (14% vs. 19%). The overall mortality rate at 14 days and at three months was higher in patients with RHTh (21% vs. 11%, p = 0.032, and 29% vs. 16%, p = 0.036). The difference in early mortality was observed almost entirely within the subgroup of patients treated with heparin alone (23.5% vs. 8%, p = 0.02), despite similar clinical severity at presentation (systolic BP 122.2 +/- 24.2 vs. 127.8 +/- 24.1 mm Hg, hypotension in 5.9% vs. 3.4% patients).

CONCLUSIONS

Among patients with acute pulmonary embolism, RHTh is usually found in those more hemodynamically compromised but is also a marker of worse prognosis in initially apparently stable patients treated with heparin alone.

Paroxysmal nocturnal haemoglobinuria: long-term follow-up and prognostic factors. French Society of Haematology

BACKGROUND

Paroxysmal nocturnal haemoglobinuria (PNH) is a rare acquired disorder of haematopoietic stem cells. Although knowledge about the pathophysiology of the disease is increasing, no multivariate analysis of factors influencing survival has been undertaken, mainly because the disease is rare. We undertook such an investigation.

METHODS

Data were collected on 220 patients with PNH diagnosed over a 46-year period (1950-1995) from participating French centres. Diagnosis of the disease required, at least, an unequivocally positive Ham's test.

FINDINGS

The Kaplan-Meier survival estimate was 65% (SE 4) at 10 years and 48% (6) at 15 years after diagnosis. 8-year cumulative incidence rates of the main complications (pancytopenia, thrombosis, and myelodysplastic syndrome) were 15% (3), 28% (4), and 5% (2), respectively. Demographic data, presenting features, initial treatment, complications, and causes of death were similar to those previously reported. In multivariate analysis, seven factors were significantly associated with survival in patients with PNH. Poor survival was associated with the occurrence of thrombosis as a complication (relative risk 10.2 [95% CI 6-17], p < 0.0001), evolution to pancytopenia (5.5 [2.8-11], p < 0.0001), myelodysplastic syndrome or acute leukaemia (19.1 [7.3-50], p < 0.001), age over 55 years at diagnosis (4 [2.4-6.9], p < 0.0001), need for additional treatment (2.1 [1.3-3.6], p < 0.003), and thrombocytopenia at diagnosis (2.2 [1.3-3.8, p < 0.003). Better survival was shown for patients in whom aplastic anaemia antedated PNH (0.32 [0.14-0.72], p < 0.02). Factors associated in multivariate analysis with a high risk of thrombosis during the disease course were thrombosis at diagnosis (5.1 [2.5-10.6], p = 0.0002), age over 54 years (2.6 [1.5-4.6, p = 0.0014), and infection at diagnosis (2.6 [1.3-5.2], p = 0.0099). The risk factors for progression to pancytopenia were absence at diagnosis of anaemia (4.03 [1.3-12.2], p = 0.03) and neutropenia (2.45 [1.1-5.7], p = 0.03). The risk factors for development of myelodysplastic syndrome or acute leukaemia were abdominal pain crisis at presentation (10.5 [2.5-44.0], p = 0.004) and year of diagnosis after 1983 (8.45 [1.8-40.7], p = 0.004).

INTERPRETATION

This large number of cases permitted a detailed analysis of prognostic factors for the first time, in this rare disease. Estimates of PNH prognostic factors may serve as baseline data in the assessment of current and future treatments for this disease.