Silent Pulmonary Embolism Research Articles

Can Routine Investigation for Occult Pulmonary Embolism Be Justified in Patients with Deep Vein Thrombosis?

This study aims to investigate whether routine screening for silent pulmonary embolism (PE) can be justified in patients with deep vein thrombosis (DVT). We retrospectively analyzed the medical records of 201 patients with lower-extremity DVT admitted to the vascular surgery department of a single tertiary university center between 2019 and 2023. All patients underwent clinical evaluation, basic laboratory exams, a whole-leg colored duplex ultrasound, and a computed tomography pulmonary angiography (CTPA), to screen for an occult, underlying PE. The overall incidence of silent PE was 48.8%. The median admission D-dimer level was significantly higher in patients with silent PE than in those without PE (9.60 vs. 5.51 mg/L, P=0.001). A D-dimer value ≥5.14 mg/L was discriminant for predicting silent PE, with a sensitivity of 68.2% and a specificity of 59.3%. Silent PE was significantly more common on the right side, with the embolus located at the main pulmonary, lobar, segmental, and subsegmental arteries in 29.6%, 32.7%, 20.4%, and 17.3%, respectively. A higher incidence of occult PE was observed in patients with iliofemoral DVT (P=0.037), particularly when the thrombus extended to the inferior vena cava (P=0.003). Moreover, iliofemoral DVT was associated with a larger size and a more proximal location of the embolus (P=0.041). Multivariate logistic regression showed that male sex (odds ratio [OR]=2.46, 95% confidence interval [CI]: 1.39-3.53; P=0.026), cancer (OR=2.76, 95% CI: 1.45-4.07; P=0.017), previous venous thromboembolism (VTE) history (OR=2.67, 95% CI: 1.33-4.01; P=0.022), D-dimer value ≥5.14 mg/L (OR=2.24, 95% CI: 1.10-3.38; P=0.033), iliofemoral DVT (OR=2.13, 95% CI: 1.19-3.07; P=0.041), and thrombus extension to the IVC (OR=2.95, 95% CI: 1.43-4.47; P=0.009) served as independent predictors for silent PE. A high incidence of silent PE was observed in patients with lower-extremity DVT. Screening of patients with DVT who have the aforementioned predictive risk factors using CTPA for silent PE may be needed and justified for the efficient management of VTE and its long-term complications.

Nomogram for predicting pulmonary embolism in gynecologic inpatients with isolated distal deep venous thrombosis.

To investigate the incidence of isolated distal deep venous thrombosis (IDDVT) concurrent with pulmonary embolism (PE) in gynecologic inpatients, analyze the risk factors for IDDVT with PE, and establish a nomogram model for IDDVT patients with PE. A total of 260 patients were diagnosed with IDDVT between December 2017 and November 2020. The incidence of PE in these patients was determined using computed tomography pulmonary angiography. Logistic regression analysis was used to identify the related risk factors. On this basis, nomogram risk prediction models were established. Among 260 patients with IDDVT, 106 (40.8%) had concurrent PE, of whom 74 (28.5%) experienced silent PE. Univariate logistic analysis demonstrated statistical significance for body mass index (BMI; P = 0.044), glucocorticoid therapy (P = 0.009), hypertension (P < 0.001), and diabetes (P < 0.001). Multivariate logistic analysis revealed that these were independent risk factors for IDDVT with PE that retained statistical significance. A nomogram based on these factors was constructed to predict PE in patients with IDDVT. Its receiver operating characteristic (ROC) showed an area under the curve of 0.710 (95% confidence interval 0.642-0.779), with prediction sensitivity of 64.2% and prediction specificity of 76.6%. In the present study, a high prevalence of PE was found in gynecologic inpatients with IDDVT. Glucocorticoid therapy, hypertension, diabetes, and BMI were independent risk factors for IDDVT patients with PE. Taking these risk factors into account, a nomogram risk prediction model was developed to help facilitate early detection of concurrent PE.

Removal of inferior vena cava filter by open surgery after failure of endovenous retrieval.

The permanent placement of inferior vena cava (IVC) filters may lead to numerous complications and their removal is recommended once the risk of pulmonary embolism is reduced. Removal of IVC filters by endovenous means is preferred. But failure of endovenous removal happens when recycling hooks penetrate the vein wall and filters are left in place for too long time. In these scenarios, open surgery may be effective for removal of IVC filters. We aimed to describe the surgical approach, outcomes, and 6-month follow-up of the removal of IVC filter by open surgery, after the failure of removal via the endovenous method. A total of 1,285 patients with retrievable IVC filters were admitted from July 2019 to June 2021, including 1,176 (91.5%) endovenous filter removals, and 24 (1.9%) open surgical IVC filter removals after the failure by endovenous method, of whom 21 (1.6%) were followed-up and eligible for analysis of the study. Patient characteristics, filter type, filter removal rate, IVC patency rate, and complications were retrospectively analyzed. Twenty-one patients were left with IVC filters for 26 (10, 37) months, of which 17 (81.0%) patients had non-conical filters and 4 (19.0%) had conical filters; all 21 filters were successfully removed, with a 100% removal rate, no deaths, no serious complications, and no symptomatic pulmonary embolism. At the 3rd month follow-up after surgery and 3rd month follow-up after discontinuation of anticoagulation therapy, only 1 case (4.8%) had IVC occlusion, but without any occurrence of new lower limb deep venous thrombosis and silent pulmonary embolism. Open surgery can be used for the removal of IVC filters after failure of removal by endovenous method or when accompanied by complications without symptoms of pulmonary embolism. Open surgical approach can be used as an adjunctive clinical intervention for the removal of such filters.

Lead-related infective endocarditis with vegetations: Prevalence and impact of pulmonary embolism in patients undergoing transvenous lead extraction.

The prevalence and impact of pulmonary embolism (PE) in patients with lead-related infective endocarditis undergoing transvenous lead extraction (TLE) are unknown. Twenty-five consecutive patients with vegetations ≥10 mm at transoesophageal echocardiography were prospectively studied. Contrast-enhanced chest computed tomography (CT) was performed before (pre-TLE) and after (post-TLE) the lead extraction procedure. Pre-TLE CT identified 18 patients (72%) with subclinical PE. The size of vegetations in patients with PE did not differ significantly from those without (median 20.0 mm [interquartile range: 13.0-30.0] vs. 14.0 mm [6.0-18.0], p = 0.116). Complete TLE success was achieved in all patients with 3 (2-3) leads extracted per procedure. There were no postprocedure complications related to the presence of PE and no differences in terms of fluoroscopy time and need for advanced tools.In the group of positive pre-TLE CT, post-TLE scan confirmed the presence of silent PE in 14 patients (78%). There were no patients with new PE formation. Large vegetations (≥20 mm) tended to increase the risk of post-TLE subclinical PE (odds ratio 5.99 [95% confidence interval (CI): 0.93-38.6], p = 0.059).During a median 19.4 months follow-up, no re-infection of the implanted system was reported. Survival rates in patients with and without post-TLE PE were similar (hazard ratio: 1.11 [95% CI: 0.18-6.67], p = 0.909). Subclinical PE detected by CT was common in patients undergoing TLE with lead-related infective endocarditis and vegetations but was not associated with the complexity of the procedure or adverse outcomes. TLE procedure seems safe and feasible even in patients with large vegetations.

Silent Pulmonary Embolism in Deep Vein Thrombosis: Relationship and Risk Factors.

PurposeThis study aimed to evaluate risk factors for silent pulmonary embolism (PE) in symptomatic deep vein thrombosis (DVT) and investigate the relationship between DVT and silent PE.MethodsThis was a single-centre, retrospective cohort study. Between 5 January 2015 and 31 December 2021, consecutive patients with symptomatic DVT received CT pulmonary angiography and CT venography were analyzed. Patient demographics, comorbidities, risk factors, and image findings were analyzed. The group differences were compared using a Chi-square test, Fisher's exact test, independent t test, or Mann-Whitney U test. Multivariant regression was used to determine predictive factors for silent PE.ResultsA total of 355 patients (mean age, 60.5 ± 16.6 years) were included. The incidence of silent PE was 43.1%. The main or lobar pulmonary arteries were affected in 53.6% of patients, which is more often found in iliofemoral DVTs (56.6% vs 26.7%, p = .027). The multivariant analysis showed male patients (p = .042; OR 1.59; 95% CI, 1.02–2.50), inferior vena cava involvement (p = .043; OR 1.81; 95% CI, 1.02–3.20) and D-dimer value > 3.82 μg/ml (p < .001; OR 2.32; 95% CI, 1.43–3.77) were risk factors for silent PE. Unilateral DVT patients with ipsilateral iliac vein compression had a lower incidence of silent PE (28.8% vs 52.9%, p < .001).ConclusionIliofemoral DVT was associated with a more proximal PE. The male patients, inferior vena cava involvement, and D-dimer > 3.82 μg/ml were risk factors for silent PE. Ipsilateral iliac vein compression reduced the incidence of silent PE.

Pulmonary embolism secondary to deep venous thrombosis: A retrospective and observational study for clinical characteristics and risk stratification.

To investigate the risk factors, predilection sites in pulmonary embolism (PE) patients caused by deep venous thrombosis (DVT) and explore the value of scoring systems in assessing the risk of PE in DVT patients. A total of 692 DVT patients were enrolled, and divided into no pulmonary embolism (NPE, 226, 32.66%), silent pulmonary embolism (SPE, 330, 47.67%) and featuring pulmonary embolism (FPE, 136, 19.65%) groups. For each group, the differences of clinical data and PE locations were compared, and the risk factors of PE secondary to DVT were analyzed. The predictive value of the scoring system for the diagnosis of PE and FPE was evaluated. PE presented more in the bilateral pulmonary arteries (PAs) (249, 53.43%) and has no significant difference in PESI scores in different locations. Gender, DVT locations, and previous surgery were the independent risk factors of PE. DVT locations, previous history of COPD, and previous surgical interventions were the independent risk factors of FPE. The results for areas under the ROC curves were: AUC(Wells) = 0.675, AUC (Revised Geneva) = 0.601, AUC(D-dimer) = 0.595 in the PE group; AUC(Wells) = 0.722, AUC (Revised Geneva) = 0.643, AUC(D-dimer) = 0.557 in the FPE group. PE secondary to DVT mostly occurs in the bilateral PAs. Male gender, DVT locations, and previous surgery increased the risk of PE. The Wells scoring system was more advantageous for evaluating the diagnosis of PE in patients with DVT.

Is routine screening for silent pulmonary embolism justified in patients with deep vein thrombosis?

The incidence of asymptomatic pulmonary embolism (PE) exceeds 70% in patients with deep venous thrombosis (DVT), even in cases of distal deep vein thrombosis. We report the case of a patient with a diagnosis of DVT in the lower left limb associated with asymptomatic PE who presented late symptoms due to this same PE. The absence of acute symptoms and the late onset of symptoms could have provoked doubts about the most appropriate treatment, resulting in unnecessary interventions, if pulmonary embolism had not already been diagnosed with tomography. In the present case, we demonstrate that computed tomography angiography conducted at the time of DVT diagnosis accurately diagnosed PE and prevented any misinterpretation of recurrent DVT in a patient already being medicated, which could have been mistakenly interpreted as demonstrating failure of anticoagulant therapy. Such a situation could lead to unnecessary intervention to fit an inferior vena cava filter. We cannot suggest that a classic medical conduct should be reformulated simply on the basis of a case report. However, we would be remiss not to suggest that well-designed studies should be carried out in the future to assess the need for this examination in the acute phase.

Perm-Cath catheter-related atrial thrombus – Case series and management recommendations

Catheter-related atrial thrombus (CRAT) is frequent, with no clear guidelines available with regard to diagnosis and management. Here, we report five patients with Perm Cath related AT. We conclude and recommend that Perm Cath, when not needed or used needs to be removed as soon as possible. A majority of CRAT are detected incidentally. They commonly occur at inferior vena cava and right atrial junction and a transoesophageal echocardiogram is needed in most patients to clearly define the thrombus and see additional hidden thrombi. Differentiating CRAT versus vegetation is difficult and one needs to treat both if blood cultures are positive. Commonly these thrombi do not embolize and are fixed to atrial walls, but silent pulmonary embolism needs to be considered. All patients initially should be treated with intravenous or subcutaneous anticoagulation. Patients with “High Risk” features such as, “multiple thrombi > 2,” “mobile thrombi,” “extending or embolizing thrombi to pulmonary artery,” “infected thrombi,” and “failed anticoagulation” must be considered for thrombolysis followed by surgery if required.

Pulmonary embolism and coexisting deep vein thrombosis: A detrimental association?

Pulmonary embolism (PE) and deep vein thrombosis (DVT) are two replicates of the same pathology, frequently associated. Isolated DVT has lower complication rates than PE. One third of clinically-overt DVTs are associated with a silent PE while the reported rates of concomitant DVT in PE are ranging from 10 to 93%. Whether the association of DVT and PE has a poorer prognosis than isolated PE is not known. Literature analysis shows conflicting data regarding the association of DVT and outcomes such as death and recurrence and the prognostic significance of coexisting deep vein thrombosis (DVT) in acute pulmonary embolism (PE) remains controversial. This study aimed to provide routine patient care data on the impact of this association on PE severity and 3-month outcomes in a population presenting with symptomatic venous thromboembolism (VTE), from the REMOTEV registry. REMOTEV is a prospective, non-interventional study of patients with acute symptomatic VTE, treated with direct oral anticoagulants (DOACs) or standard anticoagulation (vitamin K antagonists (VKA) or parenteral heparin/fondaparinux alone) for at least 3 months with a follow-up of 1 year for VTE recurrence, death and bleeding complications. From November 1, 2013 to February 28, 2018, among 1241 consecutive patients included, 1192 had a follow-up of at least 3 months and, among them, 1037 had PE with (727) or without DVT (310). The median age was 69 (55–80, 25th–75th percentiles). Patients with PE-associated DVT had more severe forms of PE ( P < 0.0001). However, no significant difference in all-cause mortality rate [HR 1.36 (CI 95%: 0.69–2.92)], or in the composite criterion of all-cause mortality and recurrence rate [HR 1.56 (CI 95%: 0.83–3.10)] was noted at 3 months of follow-up. In REMOTEV, coexisting DVT was associated with a higher severity of PE, with no impact on short-term prognosis (death and VTE recurrence).

Pulmonary Embolism After Endovascular Aortic Repair, a Retrospective Cohort Study

Endovascular aortic repair (EVAR) is associated with an increased risk of pulmonary embolism, which is often clinically silent and therefore difficult to recognise. The aim was to investigate the incidence of pulmonary embolism after EVAR using routinely performed pre- and post-operative aortic computed tomography angiography (CTA), and the association between pulmonary embolism and mortality. This single centre retrospective cohort study included adult patients who underwent EVAR in the University Medical Centre Utrecht between January 2010 and July 2015 and who had a total aortic, thoracic aortic, or pulmonary CTA within one month post-operatively. Baseline and mortality data were obtained by reviewing hospital and general practitioner records. The primary outcome was pulmonary embolism within one month after surgery. Secondary outcomes were 30 day and six month mortality. During the study period, 526 EVARs were performed. Seventy-four of these procedures were included in the analysis of which there were 40 thoracic and 34 abdominal EVARs. In nine patients (12%, 95% CI 7-22) pulmonary embolism was observed of which one was central, two were segmental, and six were subsegmental. Seven were clinically silent and two were present on the pre-operative CTA. Thirty day mortality was significantly higher in patients with pulmonary embolism (relative risk 14.4, 95% CI 1.4-143, p=.037) though none of the deaths seemed directly attributable to it. This study, although preliminary, suggests that silent pulmonary embolism after EVAR occurs in approximately one in 10 patients, despite routine thrombo-embolism prophylaxis. Pulmonary embolism was associated with a higher 30 day mortality risk yet it was not the cause of death in any of these patients.

Unexpected Cardiac Computed Tomography Findings in Patients With Postoperative Myocardial Injury.

Postoperative myocardial injury (PMI) is a strong predictor of mortality after noncardiac surgery. PMI is believed to be attributable to coronary artery disease (CAD), yet its etiology is largely unclear. We aimed to quantify the prevalence of significant CAD in patients with and without PMI using coronary computed tomography angiography (CCTA). This prospective cohort study included patients of 60 years or older without a history of cardiac disease and with and without PMI after intermediate- to high-risk noncardiac surgery. PMI was defined as any serum troponin I level ≥60 ng/L on the first 3 postoperative days. Main exclusion criteria were known cardiac disease and postoperative ischemic symptoms or electrocardiography abnormalities. Noninvasive imaging consisted of a postoperative CCTA. Main outcome was CAD defined as >50% coronary stenosis on CCTA. The analysis included 66 patients. Median peak troponin levels in the PMI (n = 46) and control group (n = 20) were 150 (interquartile range, 120-298) vs 15 (interquartile range, 10-31) ng/L (P < .01). CAD was found in 23 patients with PMI (50%) vs 3 without PMI (15%; relative risk, 3.3; 95% confidence interval, 1.1-9.8). Remarkably, pulmonary embolism was present in 15 patients with PMI (33%) versus in 4 without PMI (20%; relative risk, 1.6; 95% confidence interval, 0.6-4.3). None of the patients died within 30 days. In patients without a history of cardiac disease, PMI after noncardiac surgery was associated with CAD. In addition, a clinically silent pulmonary embolism was found in one-third of patients with PMI. This urges further research to improve clinical workup using imaging and may have important clinical implications.

Updates of Pulmonary Embolism

Pulmonary embolism (PE) is the third most common cause of cardiovascular death worldwide, behind myocardial infarction and stroke. Due to pulmonary bed obstruction, PE can result in acute right ventricular (RV) failure which is a life-threatening condition. Because most patients ultimately die within the first hours of presentation, early diagnosis is very important (1). Mortality due to pulmonary embolism varies greatly, depending on various factors including age, comorbid conditions, and stability on presentation. Patients with low-risk PE have a 1-year survival rate over 95%. In contrast, patients presenting with high risk PE and hemodynamic instability have an approximately 40% mortality rate within 90-days. In this review, we will discuss the basic pathophysiology of PE, risk factors for developing PE, and standard diagnostic testing modalities. We will also cover risk stratification of patients presenting with PE and the implications for treatment and disposition. While no exact epidemiological data are available, the incidence of PE is estimated to be approximately 60 to 70 per 100,000, and that of venous thrombosis approximately 124 per 100,000 of the general population (2). The European guidelines for the diagnosis and management of PE report annual incidence rates of venous thrombosis and PE of approximately 0.5 to 1.0 per 1000 inhabitants (3). However, the actual figures are likely to be substantially higher because silent PE can develop in up to 40% to 50% of patients with deep vein thrombosis (DVT) (3)

SILENT PULMONARY EMBOLISM: INCIDENCE AND RISK FACTORS IN INDIAN PATIENTS WITH LOWER LIMB DVT

30Apr 2017 SILENT PULMONARY EMBOLISM: INCIDENCE AND RISK FACTORS IN INDIAN PATIENTS WITH LOWER LIMB DVT Shanmugavelayutham.C , Elancheralathan.K , Thulasikumar.G , Deepan kumar.B and Lakshmidharan. M. Department of Vascular Surgery, Stanley Medical College, Chennai. Department of Vascular Surgery, Thanjavur Medical College, Thanjavur.

Asymptomatic Pulmonary Embolism after Ablation

Background: Pulmonary embolism (PE) is a life-threatening event with a broad presentation spectrum ranging from asymptomatic cases to sudden cardiac arrest. It is unclear if right atrial emboli cause PE in patients with atrial fibrillation (AF) or if mild PE itself increases right cardiac pressure provoking AF. Objective: To determine the incidence and predictors of asymptomatic PE in patients undergoing AF ablation. Method and Results: Patients (n = 93) were screened and those with previous or current symptomatic PE or venous thromboembolism, pulmonary hypertension, increased right heart pressures detected on echocardiography, a history of stroke, transient ischemic attack, coagulopathy or cancer and inappropriate contrast for the evaluation of pulmonary arterial tree were excluded. The remaining AF patients (n = 71) underwent guided ablation controlled with 3-dimensional, left atrial and pulmonary venous computed tomography. The asymptomatic PE was defined by using the modified Miller score by 2 independent assessors in 6 patients. Univariate logistic regression showed that age (OR: 1.094, 95% CI 1.007-1.188, p = 0.033), diabetes (OR: 12.000, 95% CI 1.902-75.716, p = 0.008), CHA₂DS₂-VASc score (OR: 2.800, 95% CI 1.304-6.013, p = 0.008), and pulmonary artery diameter (OR: 1.221, 95% CI 1.033-1.444, p = 0.019) were significantly associated with PE. However, multivariate analysis revealed that the CHA₂DS₂-VASc score (p = 0.047) remained the exclusive significant predictor for asymptomatic PE. Conclusion: The incidence of random asymptomatic PE in AF patients is high (>8%). The CHA₂DS₂-VASc score can predict silent PE. Since patients with a high CHA₂DS₂-VASc score are already anticoagulated, our results do not change clinical practice but are noteworthy in terms of the cause-effect relationship between AF and PE.

Risk Factors Associated with Symptomatic Pulmonary Embolism of Catheter Directed Thrombolysis for Lower Extremity Deep Venous Thrombosis

The aim was to study the risk factors associated with symptomatic pulmonary embolism (PE) in patients with deep venous thrombosis (DVT) in the lower limbs treated by catheter directed thrombolysis (CDT) without inferior vena cava filter (IVCF) placement. A total 266 patients with acute/subacute ilio-femoral, ilio-femoropopliteal, and femoropopliteal thrombosis confirmed by computed tomography venography or ultrasound Doppler were studied. All patients were treated with CDT. CTPA (computed tomography pulmonary angiography) examination was performed in all patients before thrombolysis. Patients with clinically suspected symptomatic PE were confirmed by repeated CTPA after treatment. The major outcome of this study was the occurrence of symptomatic PE events during CDT. During CDT, the incidence of symptomatic PE events was 4.9% (13/266). Patients with silent PE had a higher risk of developing symptomatic PE (10/110, 9.1%) than those who had no prior PE (3/156, 1.9%); multivariate analysis confirmed this difference (OR 4.018, 95% CI 1.048-15.402). It was also found that patients with previous heart disease had a higher risk of developing symptomatic PE (11/90, 12.2%) than those with no prior heart disease (2/176, 1.1%). Multivariate analysis confirmed that previous heart disease increased the risk of developing symptomatic PE (OR 10.407, 95% CI 2.228-48.617). One patient who suffered from heart failure and silent PE before CDT died of symptomatic PE (1/13, 7.7%). The risk of developing symptomatic PE is most markedly increased in patients with previous silent PE and heart disease. Selective rather than routine IVCF placement is an appropriate approach.

Should we look for silent pulmonary embolism in patients with deep venous thrombosis?

BackgroundAsymptomatic or silent pulmonary embolism (S-PE) in patients with deep vein thrombosis has been the focus of numerous publications with the objective of determining the incidence of S-PE and assessing whether its existence has any clinical or therapeutic consequences that outweigh the risks associated with the diagnostic tests performed and the increased healthcare costs. The objectives were to assess the incidence of S-PE using computed tomography angiogram (CTA), to understand the epidemiological factors that might trigger embolism, and to assess whether D-dimer (DD) predicts the existence of S-PE’s.MethodsA prospective and consecutive assessment of 103 hospitalized patients with lower limb DVT in the absence of PE symptoms, using CT scan. DD was quantified before anticoagulation. The risk factors and characteristics of the DVT were studied. A three-year follow-up assessing risk recurrence and clinical outcome was performed.ResultsThe incidence of S-PE was 66%. In 77% of these cases, the main and lobar pulmonary arteries were affected. Iliac and femoral DVTs most often produced S-PE. ROC curve with a DD value higher than 578 ng/ml provided good sensitivity but low specificity to identify patients with S-PE. Diagnosis entailed higher hospitalization expenses. No significant recurrence rate of thrombotic events was observed in the S-PE group during the follow-up.ConclusionsThe incidence of S-PE in lower-limb DVT is high, but in the absence of symptoms, diagnosis does not appear to be necessary, as there are no short- or long-term clinical or therapeutic consequences.

Impact on Pulmonary Arterial Pressures after Repeated Endovascular Thrombectomy of Dialysis Grafts: A Prospective Follow-up Study

PurposeVascular access thrombosis is a common complication of arteriovenous dialysis grafts that results in silent pulmonary embolism (PE) in a substantial proportion of patients. However, the impact of repeated PE on the pulmonary vasculature remains unclear. Materials and MethodsFrom January 2010 to April 2012, 110 patients undergoing maintenance hemodialysis via arteriovenous grafts were recruited. Hemodynamic assessments, including transthoracic echocardiography and right heart catheterization, were performed at baseline and after 1 year to evaluate the changes in pulmonary artery (PA) pressures and heart function. ResultsFifty-two patients completed the follow-up hemodynamic assessment at a median duration of 535 days and had at least one endovascular thrombectomy procedure (median of seven). There was no significant difference in mean PA pressures between baseline and the end of follow-up (23.1 mm Hg ± 6.8 vs 21.6 mm Hg ± 6.1; P = .16). The change in mean PA pressure did not correlate with the number of thrombectomy procedures in the overall cohort (r = −0.02, P = .89) or in the subgroup with cardiopulmonary disease (r = −0.30, P = .14). The changes of mean PA pressure were not associated with number of thrombectomy procedures (β = −0.03, P = .89). ConclusionsRepeated endovascular thrombectomy procedures are not related to changes in PA pressure in the short term. The present results support the safety of endovascular thrombectomy in the pulmonary vasculature.

A patient who experienced thyroid storm complicated by rhabdomyolysis, deep vein thrombosis, and a silent pulmonary embolism: a case report

BackgroundThyroid storm is a serious condition of thyrotoxicosis. Hyperthyroidism often presents with thrombotic events, especially at cerebral sites; however, the possible association between a lower extremity deep vein thrombosis (LEDVT) and thyroid storm has not been previously reported. We encountered a patient who developed thyroid storm, associated with rhabdomyolysis, followed by LEDVT and a small silent pulmonary embolism (PE). The case is discussed with references to the pertinent literature.Case presentationA 50-year-old woman with no past medical history was referred to our hospital because of severe diarrhea, muscle weakness in her lower limbs (manual muscle testing: MMT 3), and disturbances of consciousness. She was diagnosed as having Graves’ disease based on the presence of struma, exophthalmos, and hyperthyroidism with TSH receptor antibody positivity; we further determined that the patient was experiencing thyroid storm based on the results of the Burch-Wartofsky scoring system and a Japanese diagnostic criteria. Treatment with steroids, iodine potassium, methimazole, and propranolol was initiated. Severe watery diarrhea continued, and the laboratory data revealed hypokalemia (2.0 meq/L). On day 14, a blood analysis showed a sudden elevation in her creatinine kinase (CK) level, leading to a diagnosis of rhabdomyolysis. Thereafter, the muscle weakness in her lower limbs advanced to a degree of MMT 1. Seven days after the diagnosis of rhabdomyolysis, pitting edema began to appear in bilateral lower extremities. Contrast-enhanced CT scans revealed a LEDVT involving the left common iliac vein, bilateral femoral veins, and left popliteal vein. Furthermore, a small PE was identified. Hyperthyroidism often presents with thrombotic events, especially at cerebral sites, but few reports of PE or LEDVT have been made.ConclusionThis case suggests that the occurrence of thyroid storm may be associated with a risk of LEDVT and/or PE. We suggest that DVT preventive measures are undertaken, and that a lower limb venous echo or contrast-enhanced CT examination would be considered if LEDVT is suspected.

Risk factors associated with the occurrence of silent pulmonary embolism in patients with deep venous thrombosis of the lower limb

The aim of our study is to investigate the prevalence of silent pulmonary embolism in patients with deep venous thrombosis in the lower limbs and to evaluate the associated risk factors. A total of 322 patients with acute deep venous thrombosis confirmed by CT venography or Doppler ultrasonography were studied. The diagnosis of silent pulmonary embolism was established by computed tomography pulmonary arteriography (CTPA). The association between covariates and the prevalence of silent pulmonary embolism in patients with deep venous thrombosis in lower limbs were assessed using chi-square test and multivariable regression. The incidence of silent pulmonary embolism was 33.5% (108 in 322 patients) in all patients with deep venous thrombosis in lower limbs. Chi-square test showed male gender, the right lower limb, proximal location of the thrombus, unprovoked venous thrombosis and coexisting heart diseases were related to a higher incidence of silent pulmonary embolism in patients with deep venous thrombosis in lower limbs. The multivariate regression analysis confirmed that the risk factors associated with silent pulmonary embolism in deep venous thrombosis patients included the right side and proximal location of the thrombus (odds ratio: 2.023, 95% CI: 1.215-3.368; odds ratio: 3.610, 95% CI: 1.772-7.354), unprovoked venous thrombosis (odds ratio: 2.037, 95% CI: 1.188-3.493), coexisting heart diseases (odds ratio: 4.507, 95% CI: 2.667-7.618). Silent pulmonary embolism occurred frequently in patients with deep venous thrombosis in lower limbs. The right side, the proximal location of the thrombus, unprovoked venous thrombosis and coexisting heart diseases increased the risk for the occurrence of silent pulmonary embolism.

Safety and efficacy of low-molecular-weight heparins in prophylaxis of deep vein thrombosis in postoperative/ICU patients: A comparative study

Background:Venous thromboembolism (VTE), although a very common problem in everyday clinical practice, remains asymptomatic in most cases. Clinical diagnosis helps identify those who are going to have thromboembolic episode. A combination of clinical scoring systems like Wells’ score and D-dimer assay provide a useful diagnostic tool. Trauma (surgical or accidental) and critically ill patients are found to have greatest risk. Enoxaparin and dalteparin are amongst the most common low-molecular-weight heparins (LMWHs) used for deep venous thrombosis (DVT) prophylaxis in such patients.Aim:The present study is designed to compare their role in preventing DVT in postoperative or critically ill patients and to determine their relative safety profiles.Materials and Methods:The study included 36 critically ill adult patients. All the patients were allocated into three groups of 12 patients each. Group I patients received no prophylaxis, group II received inj. enoxaparin s/c 0.6-0.8 mg/kg twice daily, and group III received inj. dalteparin s/c 125-250 units/kg once daily. Routine investigations and coagulation profile were recorded on admission to intensive care unit (ICU) and at every third day thereafter. Patients were daily assessed for pretest probability of DVT using Wells’ scoring, and D-dimer test was done on the 7th day. Occurrence of any bleeding (visible or occult) was noted, and incidence of DVT was determined in each group using positive results of D-dimer test and the clinical assessment with Wells’ score.Results:A significant difference in Wells’ score (P < 0.05) was found between groups I and III on day 5 and day 7. A lower, but insignificant difference in the incidence of DVT was found between the study and control groups. No significant difference in major bleeding or other side effects was found. Better hemodynamic status and arterial blood gases in the study groups may indirectly refer to absence of asymptomatic DVT or silent pulmonary embolism in this group.Conclusion:The present study suggests that LMWHs, namely, enoxaparin and dalteparin, provide effective means of preventing DVT in high-risk, critically ill or postoperative patients, without causing any significant increase in the risk of bleeding or other side effects. Dalteparin appears to be unaffected by low creatinine clearance as explained by its clearance by a non-saturable mechanism. Still, a more extensive study with larger population is needed to make the outcomes worthwhile.