Predictors of rehospitalization for symptomatic venous thromboembolism after total hip arthroplasty

Withholding of Hormone Replacement Therapy Prior to Total Joint Arthroplasty Surgery to Reduce the Risk of Postoperative Thromboembolic Events: Is It Justified?-A Systematic Review of Clinical Practice Guidelines

BACKGROUND

Hormone replacement therapy (HRT), menopausal hormone therapy (MHT), and estrogen-containing medications are frequently withheld before elective lower limb arthroplasty, based on a perceived risk of venous thromboembolism (VTE). However, evidence linking HRT, MHT, and an increased VTE risk is equivocal. This systematic review evaluated the concordance of international clinical practice guidelines (CPGs) on the withholding of HRT or MHT.

METHODS

The PubMed, Google Scholar, Cochrane, and Ovid databases were searched for CPGs for the preoperative, perioperative, and postoperative management of patients on HRT and MHT undergoing elective lower limb arthroplasty. This was supplemented by an internet search. There were 7 international CPGs in English, from Europe and North America, published between January 2000 and February 2023 reviewed against the Appraisal of Guidelines for Research & Evaluation Instrument (AGREE-II) criteria, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist.

RESULTS

The guidelines reviewed revealed a mixed picture on HRT or MHT withdrawal and use in arthroplasty, with some featuring detailed advice on the preoperative and postoperative management of HRT or MHT (Scottish Intercollegiate Guidelines Network), while others featured no guidance (American College of Chest Physicians). The evidence referenced in these guidelines highlighted studies showing HRT or MHT to play a limited role in increasing VTE risk, with most studies from the 1990s and 2000s.

CONCLUSIONS

Based on current evidence, non-estrogen-containing transdermal HRT or MHT should not be withheld in patients undergoing elective joint arthroplasty, though further evidence is required to justify withholding estrogen-containing forms.

An analysis of risk factors for venous thromboembolism in primary versus revision total joint arthroplasty

Background

One of the most serious complications after primary or revision lower extremity total joint arthroplasty (TJA) is venous thromboembolism disease (VTE). Identifying patients at high risk for VTE allows tailoring of prophylactic anticoagulation regimens to those most vulnerable. This study aimed to identify risk factors for VTE in primary and revision lower extremity TJA.

Methods

The Electronic Medical Record was queried from a single academic institution for all patients who underwent a lower extremity TJA between 2007 and 2020. Demographics, comorbid conditions, perioperative characteristics, and postoperative complications were identified. An Elastic Net Multiple Logistic Regression Model was used to assess 49 covariates and predict those associated with a significant risk of VTE.

Results

We identified 4900 primary and revision total knee arthroplasty (TKA) and total hip arthroplasty (THA) patients. There was no significant difference between primary and revision THA. Primary TKA had a higher rate of VTE than revision TKA. Significant risk factors identified for VTE in THA patients include histories of deep vein thrombosis (DVT), pulmonary embolism (PE), metastatic tumors, hemiplegia, and Hispanic ethnicity. Risk factors for VTE in TKA patients include histories of DVT, PE, metastatic tumors, and postoperative warfarin and heparin use. In all patients, age was a significant predictor of VTE risk.

Conclusion

Our work identifies many risk factors for VTE following TJA. While the increased rate of VTE in some populations may represent selection bias, it also highlights the incomplete understanding of the etiology and prevention of this complication in the joint arthroplasty population and requires further study.

The use of pre-operative Inferior Vena Cava filters for thromboprophylaxis in ultra-high-risk patients undergoing total hip and knee arthroplasty: a systematic review and narrative analysis

PURPOSE

Patients undergoing total hip (THA) or knee (TKA) arthroplasty are at high risk of venous thromboembolism (VTE). As the number performed annually increases, the population at risk of fatal pulmonary embolism (PE) also grows. Ultra-high-risk arthroplasty patients (UHRAPs) include those with additional comorbidities, or a history of VTE, for many of whom routine prophylaxis will previously have failed. Pre-operative insertion of Inferior Vena Cava filters (IVCFs) has been recommended for thromboprophylaxis in UHRAPs, and this review was performed to establish their results.

METHODS

A systematic search of MEDLINE and Embase databases was performed for studies reporting the use of Inferior Vena Cava filters in hip and knee arthroplasty patients.

RESULTS

Ten studies met the inclusion criteria, containing 718 IVCFs in Orthopaedic patients, 343 of which were permanent (47.8%), 369 potentially retrievable (51.4%), 5 absorbable (0.6%) and one of unknown design (0.1%). Patient age averaged 64.7yrs (17-95) and 56% were female. Pre-operatively, 415 prophylactic IVCFs were inserted in 409 UHRAPs, undergoing a total of 438 total joint arthroplasties (TJA). There were 11 cases of PE in the entire series (1.5%) only one of which was fatal (0.01%), with four non-fatal PE in the UHRAP group (0.96%). Removal was attempted for 283 of the retrievable filters (76.7%) and was successful in 280 (98.9%).

CONCLUSION

The use of IVCFs eliminated fatal PE in UHRAPs, but larger, high-quality studies, with standardised reporting, are still required to determine their absolute indications for use, complication profile, efficacy and optimum design.

Obesity and the Risk of Venous Thromboembolism after Major Lower Limb Orthopaedic Surgery: A Literature Review

The risk of venous thromboembolism following total joint arthroplasty is significantly greater than those of other types of elective orthopaedic procedures. This risk is increased in obesity due to the associated prothrombotic physiological and hematological changes that predispose to embolic events. The prevalence of obesity is increasing in the aging population, which contributes to a further increase in the risk of postoperative thrombosis in the older patients. There is a lack of clear evidence regarding dosing information for thromboprophylaxis medications in patients with obesity. As a result, the currently available thromboprophylaxis guidelines do not provide specific recommendations for this group. Suboptimal dosing regimens for these medications can place these patients at a risk of bleeding or clotting complications postsurgery. Hence any increase in dosage may require intensive surveillance for the residual anticoagulant effects and careful balancing of risks and benefits on an individual basis. Our review discusses the basis for increased thrombotic risk in obesity, the evidence supporting dosage recommendations, and the implications of the current guidelines for pharmacological thromboprophylaxis in patients with obesity undergoing lower limb arthroplasty.

Rivaroxaban Treatment for Patients With Unprovoked or Provoked Venous Thromboembolism ― Subanalysis of the J’xactly Study ―

Background: The efficacy and safety of direct oral anticoagulants (DOACs) in patients with unprovoked venous thromboembolism (VTE) remain unclear.

Methods and Results: In this subanalysis of the J’xactly study, a multicenter prospective observational study, we evaluated the safety and effectiveness of rivaroxaban in patients with acute VTE according to unprovoked (n=388) or provoked (n=557) VTE status. Median follow-up was 21.2 months. Compared with patients in the provoked group, patients in the unprovoked group were younger, less likely to be female, and had higher body weight. The incidence of symptomatic VTE recurrence was significantly higher in the unprovoked than provoked VTE group (3.54% vs. 1.77% per patient-year; P=0.032). There was no significant difference in the incidence of major bleeding events between rivaroxaban-treated patients with unprovoked and provoked VTE (2.31% vs. 3.75% per patient-year; P=0.289). Although the proportion of patients with a body mass index (BMI) ≥25 kg/m² who were non-users of antiplatelet agents was higher in the unprovoked VTE group, there was no interaction effect (BMI: 4.58% vs. 1.55% per patient-year [P=0.040; P for interaction=0.361]; concomitant antiplatelet agent non-users: 3.65% vs. 1.72% per patient-year [P=0.028; P for interaction=0.627]).

Conclusions: This subanalysis suggests the safety and effectiveness of rivaroxaban in patients with unprovoked VTE. In such patients, DOAC discontinuation should be considered carefully, particularly in those not using antiplatelet agents and those with a high BMI.

Effect of body mass index on symptomatic venous thromboembolism and prosthesis revision risk after total knee arthroplasty: a long-term study from China

OBJECTIVE

To investigate the effect of body mass index (BMI) on the risk of symptomatic VTE and prosthesis revision after total knee arthroplasty (TKA).

METHODS

Seven thousand one hundred eighty-two patients with primary unilateral TKA treated in our hospital from 2011 to 2020 were divided into four groups according to BMI: BMI < 25 kg/m², BMI 25 kg/m²-29.9 kg/m², BMI 30 kg/m²-34.9 kg/m² and BMI ≥ 35 kg/m². Incidence, Odds ratio and Kaplan-Meier survival analysis were used to evaluate the effects of BMI on symptomatic VTE and prosthesis revision risk after TKA.

RESULTS

The incidence of VTE after TKA was 8.9‰(64/7182). There was no significant difference in the incidence of VTE among different BMI groups(P = 0.452). Deep vein thrombosis mainly occurred in the distal lower extremities, especially in intermuscular veins. Revision rate of prosthesis after TKA was 6.4‰(46/7182). There was no significant difference in revision rate among different BMI groups(P = 0.718). In the univariate analysis of TKA, compared with patients with normal BMI, the risk of postoperative VTE and prosthesis revision in patients with overweight, obesity class I and obesity class II did not increase. Higher prosthesis revision rate and lower prosthesis survival rate were observed in BMI ≥ 35 kg/m² group, although the difference was not statistically significant.

CONCLUSIONS

Through such a retrospective large sample data of long-term follow-up, we believe that the higher BMI was not associated with the increased risk of symptomatic VTE and prosthesis revision after TKA. When TKA was used for appropriate indications, high BMI should not be considered as a contraindication.

Association between cardiovascular risk factors and venous thromboembolism in the elderly

Background

The preponderance of the evidence supports no association between traditional cardiovascular risk factors and venous thromboembolism (VTE), other than obesity. There are limited data in older people.

Objectives

To investigate whether cardiovascular risk factors (body mass index, smoking, alcohol intake, hypertension, and diabetes) are associated with the risk of VTE in elderly and to assess the combined effect between cardiovascular risk factors and genetic risk factors for VTE (factor V Leiden/prothrombin 20210A, positive family history of VTE, and non‐O blood group).

Methods

The Age and Thrombosis, Acquired and Genetic risk factors in the Elderly study is a multicenter case‐control study performed in Vermont, USA and Leiden, the Netherlands, comprising 401 cases with first VTE and 431 control subjects, all aged ≥70 years. To assess the risk of VTE, odds ratios (OR) with 95% confidence intervals (CIs) were calculated, adjusting for potential confounders.

Results

Both height and weight were positively associated with VTE risk: the ORs were 2.2 (95% CI, 1.2–3.9) and 1.5 (95% CI, 1.0–2.4) in the top quartile for height and weight separately. This risk was more pronounced for unprovoked VTE. Smoking, alcohol intake, and diabetes were not associated with VTE. Higher systolic and diastolic blood pressure and hypertension were associated with a decreased risk of VTE. In the presence of a genetic predisposition, height and weight further increased the risk of VTE.

Conclusions

In the elderly, height and weight are positively associated with the risk of VTE. With genetic predisposition, higher levels of height and weight further increase the risk of VTE.

Association between peripartum hysterectomy and venous thromboembolism

BACKGROUND

The risk of venous thromboembolism after delivery is modified by mode of delivery, with the risk of venous thromboembolism being higher after cesarean delivery than vaginal delivery. The risk of venous thromboembolism after peripartum hysterectomy is largely unknown.

OBJECTIVE

This study aimed to compare the incidence and risk of venous thromboembolism among women who had and did not have a peripartum hysterectomy. Furthermore, we sought to compare the risk of venous thromboembolism after hysterectomy with other patient, pregnancy, and delivery risk factors known to be associated with venous thromboembolism.

STUDY DESIGN

This was a cross-sectional study of women with delivery encounters identified in the Nationwide Readmissions Database from October 2015 to December 2017. Delivery encounters and all variables of interest were identified using the International Classification of Diseases, Tenth Revision diagnosis and procedure codes. The incidence of venous thromboembolism during delivery and rehospitalizations within 6 weeks after discharge was compared among women who had and did not have a peripartum hysterectomy. Multivariable logistic regressions were used to estimate associations between venous thromboembolism and hysterectomy, adjusted for the following characteristics: maternal age, payer at time of delivery, obesity, hypertension, diabetes mellitus, tobacco use, multifetal gestation, peripartum infection, and peripartum hemorrhage. Similarly, venous thromboembolism risk was compared by mode of delivery, including hysterectomy. Diagnoses that may have been indications for peripartum hysterectomy were identified among patients who underwent a hysterectomy and compared between those who did and did not have venous thromboembolism. Analyses used survey weights to obtain population estimates.

RESULTS

Of the 4,419,037 women with deliveries, 5098 (11.5 per 10,000 deliveries) underwent a hysterectomy. Moreover, 110 patients (215.8 per 10,000 deliveries) were diagnosed with venous thromboembolism after hysterectomy. The risk of venous thromboembolism was significantly higher in women who underwent a hysterectomy than in women who did not have a hysterectomy (unadjusted odds ratio, 25.1 [95% confidence interval, 20.0-31.5]; adjusted odds ratio, 11.2 [95% confidence interval, 8.7-14.5]; P<.001). Comparing the risk of venous thromboembolism by mode of delivery, the unadjusted and adjusted incidences of venous thromboembolism were 6.9 (95% confidence interval, 6.5-7.3) and 7.4 (95% confidence interval, 6.9-7.8) per 10,000 deliveries among women after vaginal delivery without peripartum hysterectomy, 12.5 (95% confidence interval, 11.8-13.1) and 11.3 (95% confidence interval, 10.7-12.0) per 10,000 deliveries after cesarean delivery without hysterectomy; and 217.2 (95% confidence interval, 169.1-265.2) and 96.9 (95% confidence interval 76.9-126.5) per 10,000 deliveries after hysterectomy, regardless of mode of delivery. Of the 110 diagnoses of venous thromboembolism with peripartum hysterectomy, 89 (81%) occurred during delivery admission. Of the remaining 21 cases, 50% occurred within the first 10 days after discharge from delivery, and 75% occurred within 25 days after discharge.

CONCLUSION

These findings have demonstrated that peripartum hysterectomy is associated with a markedly increased risk of venous thromboembolism in the postpartum period, even when controlling for other known risk factors for postpartum thromboembolic events. Here, the incidence of venous thromboembolism after peripartum hysterectomy (2.2%) met some guideline-based risk thresholds for routine thromboprophylaxis, potentially for at least 2 weeks after delivery. Further investigation into the role of routine venous thromboembolism prophylaxis during and after delivery is needed.

Efficacy and Safety of Mechanical IVC Filtration for Preventing Pulmonary Embolism in High-Risk Orthopedic Patients Undergoing Total Hip or Knee Arthroplasty

BACKGROUND

To determine the efficacy and safety of inferior vena cava (IVC) filters in preventing pulmonary embolism (PE) in high-risk patients undergoing hip or knee arthroplasty.

METHODS

2857 hip or knee arthroplasty procedures between January 2013 and December 2018 were retrospectively reviewed. Patients with a preoperative history of venous thromboembolism (VTE), either PE or deep venous thrombosis (DVT), were categorized as high-risk patients. The incidence of overall VTE, PE, and DVT were compared between patients with filters and those without. The subgroup analysis was also performed by patient risk, and filter status and the incidence of VTE, PE, and DVT were compared. Variables such as filter placement, history of hypercoagulability etcetra were evaluated as risk factors for the development of postoperative VTE.

RESULTS

In the high-risk group, the use of IVC filters was significantly associated with a lower incidence of pulmonary embolism (0.8% vs 5.5%, P = .028). When compared with the low-risk group, the high-risk group had significantly higher incidence of PE (3.8% vs 2.0%, P = .038), DVT (11.6% vs 5.3%, P < .001), and overall VTE (15.0% vs 6.8%, P < .001). The history of VTE was associated with postoperative VTE (P < .001), PE (P = .042), and DVT (P < .001). There was no significant correlation between filter placement and postoperative VTE, DVT, or PE in the low-risk group. Filter retrieval was successful in 100% (96/96) of attempted patients with no complications.

CONCLUSION

The use of IVC filters is significantly associated with a lower incidence in pulmonary embolism in high-risk arthroplasty patients. High-risk patients demonstrated an incidence of postoperative VTE over two times greater than other patients. Prophylactic placement of IVC filters in hip/knee arthroplasty is safe.

Clinical factors associated with adverse outcomes in the acute period of management of submassive pulmonary embolism

The majority of patients with intermediate-to-severe submassive pulmonary embolism are hemodynamically stable upon presentation. There is a lack of evidence for the clinical relevance and safety of initially employed therapies in this population. The objective of current analysis was to determine predictors associated with adverse outcomes in submassive pulmonary embolism patients. This was a single-center, retrospective chart review identifying patient characteristics and clinical factors associated with adverse outcomes within the management of patients presenting to the emergency department for submassive pulmonary embolism. A total of 122 admissions for submassive pulmonary embolism were included. Among these patients, 41% (n = 50) of admissions had an adverse outcomes. Fluid volume was associated with adverse events in an incremental manner (odds ratio 2.1, 95% confidence interval, 1.4-3.2). These findings demonstrate a significant incidence of adverse events in patients with submassive pulmonary embolism and an incremental increase in likelihood of adverse events with each liter of fluid.

Is Apixaban Safe and Effective for Venous Thromboembolism Prophylaxis After Primary Total Hip and Total Knee Arthroplasties?

BACKGROUND

Venous thromboembolism (VTE) is a serious complication of total hip arthroplasty (THA) and total knee arthroplasty (TKA). Apixaban is approved for VTE prophylaxis. This study seeks to ascertain the risk of VTE and bleeding complications in patients undergoing primary THA and TKA receiving apixaban for postoperative VTE prophylaxis for one of the following indications: high risk for VTE, previously on apixaban, and contraindication to the use of aspirin.

METHODS

This is a retrospective cohort study of patients who underwent primary THA or TKA over a 17-month period and were prescribed apixaban for thromboprophylaxis postoperatively.

RESULTS

230 patients were included in the study, 110 TKA and 120 THA. The primary reasons for high-risk VTE status included personal and family history of VTE, and 13% were taking apixaban preoperatively for atrial fibrillation. 1 patient (0.43%) who underwent TKA had a DVT with PE. 2.6% of patients had wound complications requiring operative treatment, and 0.87% of THA patients underwent revision arthroplasty.

CONCLUSION

The use of apixaban for VTE prophylaxis after primary THA and TKA in patients at high risk for VTE, in patients previously on apixaban, and in patients with a contraindication to the use of aspirin is associated with a low risk of VTE and bleeding complications.

Evaluation of the risk factors for venous thromboembolism post splenectomy - A ten year retrospective cohort study in St James's hospital

Background

Splenectomy is a surgical intervention for a variety of indications; benign and malignant. Complications of this procedure include Venous thromboembolism (VTE) and infection. The incidence of VTE post-surgery has been reported between 0.8%-3% depending on the type of surgery. A higher incidence of abdominal VTE was reported post splenectomy (6-11%). However, there is limited literature regarding the risk factors for post splenectomy VTE and the optimal strategy for thromboprophylaxis.

Objective

The primary objective of the study was to evaluate the incidence of VTE post splenectomy and to identify the pre-operative, intra-operative and post-operative risk factors. The secondary objective was to assess the local compliance with post-splenectomy prophylactic antibiotics and vaccination protocols.

Methods

We conducted a retrospective observational study. All patients who had a splenectomy in St James's Hospital between January 2007 and June 2017 were included and reviewed. Statistical analysis was carried out using SPSS statistical package.

Results

85 patients were involved in the study. The main indications for splenectomy were benign haematology, malignant haematology, solid tumours, traumatic and spontaneous rupture. 6/85 patients developed VTE (7.06%).High BMI ≥ 30 was associated with increased risk of VTE (p = 0.007), while the use of post-operative prophylactic anticoagulation was associated with reduced risk (p = 0.005). Other factors including age >50 years, female gender, presence of active malignancy and splenomegaly were associated with increased VTE risk with no statistical significance. All VTE's occurred in elective versus emergency splenectomy. Laparoscopic splenectomy was associated with higher risk of VTE than open splenectomy. 97% of patients were prescribed prophylactic antibiotics on discharge, but only 88% had received recommended vaccinations.

Conclusion

Venous thromboembolism is common post splenectomy. Our data showed that BMI ≥30 was associated with a statistically significant increased risk of VTE, while the use of prophylactic anticoagulation was associated with reduced risk. Further prospective studies with larger samples are warranted and a splenectomy care plan may be helpful.

Pediatric obesity and perioperative medicine

PURPOSE OF REVIEW

Childhood obesity is a public health emergency that has reached a pandemic level and imposed a massive economic burden on healthcare systems. Our objective was to provide an update on (1) challenges of obesity definition and classification in the perioperative setting, (2) challenges of perioperative patient positioning and vascular access, (3) perioperative implications of childhood obesity, (3) anesthetic medication dosing and opioid-sparing techniques in obese children, and (4) research gaps in perioperative childhood obesity research including a call to action.

RECENT FINDINGS

Despite the near axiomatic observation that obesity is a pervasive clinical problem with considerable impact on perioperative health, there have only been a handful of research into the many ramifications of childhood obesity in the perioperative setting. A nuanced understanding of the surgical and anesthetic risks associated with obesity is essential to inform patients' perioperative consultation and their parents' counseling, improve preoperative risk mitigation, and improve patients' rescue process when complications occur.

SUMMARY

Anesthesiologists and surgeons will continue to be confronted with an unprecedented number of obese or overweight children with a high risk of perioperative complications.

Venous thromboembolism prophylaxis practice and its association with outcomes in Australia and New Zealand burns patients

Background

Patients with burn injuries are considered to have an increased risk of venous thromboembolism (VTE). While untreated VTEs can be fatal, no studies have examined chemoprophylaxis effectiveness. This study aimed to quantify the variation in prevalence of VTE prophylaxis use in patients in Australian and New Zealand burns units and whether prophylaxis use is associated with in-hospital outcomes following burn injury.

Methods

Admission data for adult burns patients (aged ≥16 years) admitted between 1 July 2016 and 31 December 2018 were extracted from the Burns Registry of Australia and New Zealand. Mixed effects logistic regression modelling investigated whether VTE prophylaxis use was associated with the primary outcome of in-hospital mortality.

Results

There were 5066 admissions over the study period. Of these patients, 81% (n = 3799) with a valid response to the VTE prophylaxis data field received some form of VTE prophylaxis. Use of VTE prophylaxis ranged from 48.6% to 94.8% of patients between units. In-hospital death was recorded in <1% of patients (n = 33). After adjusting for confounders, receiving VTE prophylaxis was associated with a decrease in the adjusted odds of in-hospital mortality (adjusted odds ratio = 0.21; 95% CI, 0.07–0.63; p = 0.006).

Conclusions

Variation in the use of VTE prophylaxis was observed between the units, and prophylaxis use was associated with a decrease in the odds of mortality. These findings provide an opportunity to engage with units to further explore differences in prophylaxis use and develop future best practice guidelines.

Venous thromboembolism in orthopaedic oncology

AIMS

Malignancy and surgery are risk factors for venous thromboembolism (VTE). We undertook a systematic review of the literature concerning the prophylactic management of VTE in orthopaedic oncology patients.

METHODS

MEDLINE (PubMed), EMBASE (Ovid), Cochrane, and CINAHL databases were searched focusing on VTE, deep vein thrombosis (DVT), pulmonary embolism (PE), bleeding, or wound complication rates.

RESULTS

In all, 17 studies published from 1998 to 2018 met the inclusion criteria for the systematic review. The mean incidence of all VTE events in orthopaedic oncology patients was 10.7% (1.1% to 27.7%). The rate of PE was 2.4% (0.1% to 10.6%) while the rate of lethal PE was 0.6% (0.0% to 4.3%). The overall rate of DVT was 8.8% (1.1% to 22.3%) and the rate of symptomatic DVT was 2.9% (0.0% to 6.2%). From the studies that screened all patients prior to hospital discharge, the rate of asymptomatic DVT was 10.9% (2.0% to 20.2%). The most common risk factors identified for VTE were endoprosthetic replacements, hip and pelvic resections, presence of metastases, surgical procedures taking longer than three hours, and patients having chemotherapy. Mean incidence of VTE with and without chemical prophylaxis was 7.9% (1.1% to 21.8%) and 8.7% (2.0% to 23.4%; p = 0.11), respectively. No difference in the incidence of bleeding or wound complications between prophylaxis groups was reported.

CONCLUSION

Current evidence is limited to guide clinicians. It is our consensus opinion, based upon logic and deduction, that all patients be considered for both mechanical and chemical VTE prophylaxis, particularly in high-risk patients (pelvic or hip resections, prosthetic reconstruction, malignant diagnosis, presence of metastases, or surgical procedures longer than three hours). Additionally, the surgeon must determine, in each patient, if the risk of haemorrhage outweighs the risk of VTE. No individual pharmacological agent has been identified as being superior in the prevention of VTE events. Cite this article: Bone Joint J 2020;102-B(12)1743:-1751.

Obesity and hormonal contraception: an overview and a clinician's practical guide

BACKGROUND

The growing prevalence of obesity among the fertile female population poses a considerable problem to contraceptive providers. Obese women, who are more at risk for venous thromboembolism and cardiovascular events due to their condition, might be at an even higher risk of developing thromboembolic events when on medical contraception. Combined hormonal contraceptives might be less effective in obese women and may lead to unacceptable metabolic side effects for this population. In addition, the lack of safety data for weight loss drugs and the higher risk for complications during and after pregnancy require a close surveillance of the fertility status of obese patients.

OBJECTIVE

The aim of this narrative review is to summarize the available medical contraceptive options and to give the readers a practical guidance for a wise contraceptive choice with regards to obesity.

METHODS

A general literature review of peer-reviewed publications on the topic "obesity and contraception" was performed using the PubMed database.

RESULTS

Nowadays, there are many useful tools that help clinicians in choosing among the wide range of therapeutic possibilities, such as the World Health Organization (WHO) Medical Eligibility Criteria for contraceptive use. Furthermore, the great diversity of hormonal contraceptive formulations (combined hormonal formulations; progestin-only methods) and active substances (different estrogens and progestins) allow physicians to tailor therapies to patients' clinical peculiarities.

CONCLUSION

Long-acting reversible contraceptives [progestin-only implants, levonorgestrel-intra-uterine devices (IUDs) and copper IUDs] and progestin-only methods in general are excellent options for many categories of patients, including obese ones.

LEVEL OF EVIDENCE

V, narrative review.

Use and Removal of Inferior Vena Cava Filters in Patients With Acute Brain Injury

Background

Few data exist regarding the rate of inferior vena cava (IVC) filter retrieval among brain-injured patients.

Methods

We conducted a retrospective cohort study using inpatient claims between 2009 and 2015 from a nationally representative 5% sample of Medicare beneficiaries. We included patients aged ≥65 years who were hospitalized with acute brain injury. The primary outcome was the retrieval of IVC filter at 12 months and the secondary outcomes were the association with 30-day mortality and 12-month freedom from pulmonary embolism (PE). We used Current Procedural Terminology codes to ascertain filter placement and retrieval and International Classification of Diseases, Ninth Revision, Clinical Modification codes to ascertain venous thromboembolism (VTE) diagnoses. We used standard descriptive statistics to calculate the crude rate of filter placement. We used Cox proportional hazards analysis to examine the association between IVC filter placement and mortality and the occurrence of PE after adjustment for demographics, comorbidities, and mechanical ventilation. We used Kaplan-Meier survival statistics to calculate cumulative rates of retrieval 12 months after filter placement.

Results

Among 44 641 Medicare beneficiaries, 1068 (2.4%; 95% confidence interval [CI], 2.3%-2.5) received an IVC filter, of whom 452 (42.3%; 95% CI, 39.3%-45.3) had a diagnosis of VTE. After adjusting for demographics, comorbidities, and mechanical ventilation, filter placement was not associated with a reduced risk of mortality (hazard ratio [HR], 1.0; 95% CI, 0.8-1.3) regardless of documented VTE. The occurrence of pulmonary embolism at 12 months was associated with IVC filter placement (HR, 3.19; 95% CI, 1.3-3.3) in the most adjusted model. The cumulative rate of filter retrieval at 12 months was 4.4% (95% CI, 3.1%-6.1%); there was no significant difference in retrieval rates between those with and without VTE.

Conclusions

In a large cohort of Medicare beneficiaries hospitalized with acute brain injury, IVC filter placement was uncommon, but once placed, very few filters were removed. IVC filter placement was not associated with a reduced risk of mortality and did not prevent future PE.

Type 1 diabetes is associated with an increased risk of venous thromboembolism: A retrospective population-based cohort study

Background

It has been unclear whether diabetes mellitus (DM) is positively associated with a risk of venous thromboembolism (VTE). In addition, whether the risk of VTE is altered in patients with type 1 diabetes (T1DM) has rarely been explored.

Aim

We investigated whether patients with T1DM are at a relatively high risk of VTE development.

Methods

We retrieved data from the National Health Insurance Research Database of Taiwan to conduct this retrospective cohort study. The T1DM group consisted of 4967 patients diagnosed as having T1DM before 2003. The non-T1DM group comprised 19 868 age- and sex-matched enrollees without T1DM. Cox proportional hazard regression analysis was used to investigate the hazard ratio of VTE in patients with T1DM relative to those without T1DM.

Results

During a mean follow-up period of 8.61 years, the risk of VTE in the T1DM group was 5.33-fold higher than in the non-T1DM group after adjusting for dyslipidemia, hypertension, stroke, lower leg fracture or surgery, and obesity. Further stratified analysis revealed that the risk of VTE was significantly high in both sexes and in all age groups below the age of 60.

Conclusion

T1DM appears to be an independent risk factor for VTE development.

Completion of the Updated Caprini Risk Assessment Model (2013 Version)

The Caprini risk assessment model (RAM) has been validated in over 250 000 patients in more than 100 clinical trials worldwide. Ultimately, appropriate treatment options are dependent on precise completion of the Caprini RAM. As the numerical score increases, the clinical venous thromboembolism rate rises exponentially in every patient group where it has been properly tested. The 2013 Caprini RAM was completed by specially trained medical students via review of the presurgical assessment history, medical clearances, and medical consults. The Caprini RAM was completed for every participant both preoperatively and predischarge to ensure that any changes in the patient’s postoperative course were captured by the tool. This process led to the development of completion guidelines to ensure consistency and accuracy of scoring. The 2013 Caprini scoring system provides a consistent, thorough, and efficacious method for risk stratification and selection of prophylaxis for the prevention of venous thrombosis.

[Short-term effectiveness of unicompartmental knee arthroplasty for knee osteoarthritis in super-age patients]

Objective

To investigate the short-term effectiveness of unicompartmental knee arthroplasty (UKA) in the treatment of knee osteoarthritis of super-age patients over 85 years old.

Methods

Senile patients with unilateral compartment osteoarthritis of the knee who received UKA between November 2013 and May 2017 and met the inclusion criteria were enrolled as the research objects. Among them, 40 patients (50 knees) were more than 85 years old (super-age group) and 44 patients (50 knees) were 52-81 years old (control group). There was significant difference in age between the two groups ( t=17.33, P=0.00). There was no significant difference in body mass index, degenerative classification of medial and lateral compartments, varus deformity of knee, disease duration, complicating diseases, and preoperative hemoglobin, hematocrit (HCT), American Hospital for Special Surgery (HSS) score, range of motion (ROM) of knee, visual analogue scale (VAS) score, and femoral-tibial angle (FTA) between the two groups ( P>0.05). Hospital stay, hemoglobin, and HCT of the two groups were recorded before operation and on the first day after operation. The changes of hemoglobin and HCT after operation were calculated. During follow-up period, the ROM of the knee, HSS score, and VAS score were measured; the position of the prosthesis and FTA were observed by X-ray films.

Results

There was no significant difference in hospital stay between the two groups ( t=1.05, P=0.29). Hemoglobin and HCT of the two groups on the first day after operation were significantly lower than those before operation ( P<0.05). There was no significant difference in the postoperative changes of hemoglobin and HCT between the two groups ( P>0.05). All the patients were followed up completely except 4 cases (5 knees) in the super-age group. The follow-up time ranged from 14 to 44 months of super-age group (mean, 29 months) and 21 to 33 months of control group (mean, 24 months). There were significant differences in HSS score, VAS score, ROM of the knee, and FTA between pre-operation and last follow-up in the two groups ( P<0.05). There was significant difference in HSS score between the two groups ( P<0.05), and no significant difference was found in ROM, VAS score, and FTA between the two groups ( P>0.05). X-ray film showed no adverse position of the prosthesis, infection around the prosthesis, prosthesis loosening, or pathological bright lines.

Conclusion

UKA combined with reasonable perioperative management in the treatment of super-age patients over 85 years with knee osteoarthritis is safe and feasible, and can obtain satisfactory short-term effectiveness.

Incidence and risk of venous thromboembolism in patients following appendectomy: a nationwide cohort study

Surgery may lead to poor blood flow and hypercoagulation. Few studies have investigated the incidence of venous thromboembolism (VTE) in Asian patients following appendectomy. We conducted a nationwide cohort study to investigate the risk of VTE in patients who underwent appendectomy compared with those who did not in Taiwan. We studied the entire hospitalized population in Taiwan from 2000 to 2012, with a follow-up period extending to the end of 2013. We identified patients who underwent appendectomy in Taiwan's National Health Insurance Research Database as the appendectomy cohort, and selected a nonappendectomy cohort from the general population that was 4:1 frequency-matched by age (5-year interval), sex, and index year for each appendectomy case. We used Cox models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for symptomatic VTE in the appendectomy cohort for comparison with the nonappendectomy cohort. The appendectomy cohort exhibited a higher incidence of symptomatic VTE than the nonappendectomy cohort (5.90 vs. 3.29 per 10,000 person-years). After adjustment for covariates, a 1.68-fold HR for symptomatic VTE was observed in the appendectomy cohort (95% CI 1.56-1.81). Compared with the nonappendectomy cohort, the patients who underwent open appendectomy had a 1.73-fold increased adjusted HR for symptomatic VTE (95% CI 1.61-1.87). Laparoscopic appendectomy was not significantly associated with symptomatic VTE. An 8.15-fold higher adjusted HR for VTE was observed in patients who underwent appendectomy within the first month after surgery compared with the nonappendectomy cohort. Open appendectomy carried an increased risk of symptomatic VTE. Laparoscopic appendectomy was not significantly associated with symptomatic VTE.

The incidence of symptomatic in-hospital VTEs in Asian patients undergoing joint arthroplasty was low: a prospective, multicenter, 17,660-patient-enrolled cohort study

PURPOSE

The aim of this study was to determine the real incidence of symptomatic in-hospital venous thromboembolism (VTE) and identify risk factors for VTEs in Asian patients undergoing total hip (THA) and total knee arthroplasty (TKA).

METHODS

A total of 17,660 patients (20,078 hips and knees) undergoing THA and TKA at 78 hospitals were enrolled. The composite incidence of symptomatic in-hospital DVT and PE was identified as the primary effectiveness outcomes. The primary safety outcomes were the incidences of postoperative complications, especially for major or minor bleeding. Secondary analyses were assessed to identify the risk factors for postoperative VTE.

RESULTS

The overall rates of symptomatic in-hospital DVT in patients undergoing THA and TKA were 0.21% (19/9022) and 0.36% (31/8638), respectively. Symptomatic PE was confirmed in one TKA patient. Safety analysis showed that the incidence of bleeding during hospital stays in patients undergoing THA and TKA was 0.10% (18/17,660). Increased VTE risks were associated with old age, high BMI index, hypertension, cerebrovascular disease, history of venous thromboembolism and no medical prophylaxis usage.

CONCLUSIONS

The incidence of symptomatic VTEs in Asian regions was low compared with that reported in studies targeting Western populations. Approximately 1 in 500 patients undergoing THA and approximately 1 in 300 patients undergoing TKA developed symptomatic VTEs prior to hospital discharge. Old age, high BMI, history of venous thromboembolism, hypertension, cerebrovascular disease, and no medication prophylaxis were risk factors identified in this study.

LEVEL OF EVIDENCE

Prospective cohort study; Level 2.

Is Obesity Associated With Increased Risk of Deep Vein Thrombosis or Pulmonary Embolism After Hip and Knee Arthroplasty? A Large Database Study

BACKGROUND

Deep venous thrombosis (DVT) and pulmonary embolus (PE) remain an important cause of morbidity and mortality after THA and TKA. Prior recommendations have advocated for more aggressive prophylaxis for patients with obesity, whereas the evidence supporting these recommendations is conflicting and often based on underpowered studies.

QUESTIONS/PURPOSES

(1) What is the association between obesity and DVT and PE after primary and revision THA and TKA? (2) Is there a body mass index (BMI) threshold beyond which DVT and PE risk is elevated?

METHODS

We reviewed the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database from 2008 to 2016 to evaluate the reported 30-day rates of DVT, PE, and combined venous thromboembolism (VTE) after primary THA, primary TKA, revision THA, and revision TKA according to BMI as a continuous variable and a categorical variable as defined by the World Health Organization cutoffs for underweight, normal weight, overweight, and obesity. This database is risk-adjusted and designed to capture complications after surgery, thus making it ideal for this study. The diagnosis of DVT and PE is included in the ACS-NSQIP database for any DVT or PE requiring treatment. Proximal versus distal DVT is not specified within the database. Multivariate logistic regression was performed to determine if obesity was independently associated with DVT and PE risk by controlling for age, sex, race, American Society of Anesthesiologists score, diabetes, hypertension, smoking status, general anesthesia, and hypoalbuminemia.

RESULTS

After controlling for potential confounding variables such as medical comorbidities and procedure type, patients undergoing primary and revision THA and TKA with World Health Organization classification as underweight (BMI < 18.5 kg/m), overweight (BMI 25-29.9 kg/m), Class I obese (BMI 30-34.9 kg/m), Class II obese (BMI 35-39.9 kg/m), or Class III obese (BMI ≥ 40 kg/m) did not demonstrate an association with increased risk of DVT compared with patients classified as normal weight (BMI 18.5-25 kg/m). Compared with patients undergoing primary THA classified as normal weight, the risk of PE was elevated in patients with Class II obesity (odds ratio [OR], 2.36; 95% confidence interval [CI], 1.23-4.50; p = 0.009) and all heavier categories. Compared with patients undergoing TKA classified as normal weight, the risk of PE was elevated in patients classified as overweight (OR, 1.56; 95% CI, 1.03-2.36; p = 0.035) and all heavier categories.

CONCLUSIONS

This large administrative database study suggests that patient classification as overweight or obese is associated with increased risk of development of PE but not DVT after primary THA or TKA. Because aggressive pharmacologic anticoagulation regimens can decrease the DVT rate but have not been shown to affect the rate of PE or death, the data do not currently support increased anticoagulation in patients with obesity without other risk factors for VTE undergoing THA or TKA. Additional studies are required to refine VTE prophylaxis protocols to reduce PE risk while maintaining acceptable postoperative bleeding risk.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Whose Benchmark Is Right? Validating Venous Thromboembolism Events Between Trauma Registries and Hospital Administrative Databases

BACKGROUND

Venous thromboembolism (VTE) events are tracked in trauma registries and by administrative data sets. Both databases are used to assess outcomes, despite having varying processes for data capture.

STUDY DESIGN

This study was performed at an urban, university-based, Level I trauma center from 2004 to 2014. Retrospective review of the trauma registry and the hospital's administrative database was performed querying for all VTEs. Each VTE was then validated through manual chart review. Confirmed events were those with radiographic evidence of VTE by ultrasound, CT, and/or ventilation-perfusion scan. Sensitivity, specificity, and predictive values were calculated and compared between databases.

RESULTS

There were 19,353 trauma patients admitted during the study period; 656 VTEs were identified in the registry and 890 were identified via administrative data; 527 potential events were identified by both databases; 129 events were only in registry; and 363 were only found in the administrative database. We confirmed 636 of 656 events in registry (positive predictive value, 97%; 95% CI, 95.6% to 98.3%) vs 815 of 890 events in administrative data (positive predictive value, 91.6%; 95% CI, 89.75% to 93.4%; p < 0.001). Sensitivity was higher for administrative (87.2% vs 68.0%; p < 0.001), as 299 confirmed VTE events were not in the registry. Differences between the 2 databases were diminished when the analysis excluded untreated events and those present on admission. Twenty-three percent of validated deep vein thrombosis events in the registry were upper extremity events.

CONCLUSIONS

The trauma registry showed higher specificity and lower sensitivity compared with administrative data. The low false-positive rate of the trauma registry supports its validity in VTE outcomes research. Additional investigation is needed to evaluate the relevance of the variable sensitivity, likely due to definitional differences. Supplementation of trauma registry data with administrative data can strengthen its completeness.

Venous thromboembolism prophylaxis using the Caprini score

Venous thromboembolism (VTE) including pulmonary embolism (PE) and deep vein thrombosis (DVT) is one of the leading causes of preventable cardiovascular disease in the United States (US) and is the number one preventable cause of death following a surgical procedure. Post-operative VTE is associated with multiple short and long-term complications. We will focus on reviewing the many faces of VTE in detail as they represent common challenging scenarios in clinical practice.

Thromboembolism prophylaxis in orthopaedics: an update

Venous thromboembolism (VTE) is a serious complication during and after hospitalization, yet is a preventable cause of in-hospital death.

Without VTE prophylaxis, the overall VTE incidence in medical and general surgery hospitalized patients is in the range of 10% to 40%, while it ranges up to 40% to 60% in major orthopaedic surgery. With routine VTE prophylaxis, fatal pulmonary embolism is uncommon in orthopaedic patients and the rates of symptomatic VTE within three months are in the range of 1.3% to 10%.

VTE prophylaxis methods are divided into mechanical and pharmacological. The former include mobilization, graduated compression stockings, intermittent pneumatic compression device and venous foot pumps; the latter include aspirin, unfractionated heparin, low molecular weight heparin (LMWH), adjusted dose vitamin K antagonists, synthetic pentasaccharid factor Xa inhibitor (fondaparinux) and newer oral anticoagulants. LMWH seems to be more efficient overall compared with the other available agents. We remain sceptical about the use of aspirin as a sole method of prophylaxis in total hip and knee replacement and hip fracture surgery, while controversy still exists regarding the use of VTE prophylaxis in knee arthroscopy, lower leg injuries and upper extremity surgery.

Cite this article: EFORT Open Rev 2018;3:136-148. DOI: 10.1302/2058-5241.3.170018

Interaction of a genetic risk score with physical activity, physical inactivity, and body mass index in relation to venous thromboembolism risk

INTRODUCTION

Venous thromboembolism (VTE) is highly heritable. Physical activity, physical inactivity and body mass index (BMI) are also risk factors, but evidence of interaction between genetic and environmental risk factors is limited.

METHODS

Data on 2,134 VTE cases and 3,890 matched controls were obtained from the Nurses' Health Study (NHS), Nurses' Health Study II (NHS II), and Health Professionals Follow-up Study (HPFS). We calculated a weighted genetic risk score (wGRS) using 16 single nucleotide polymorphisms associated with VTE risk in published genome-wide association studies (GWAS). Data on three risk factors, physical activity (metabolic equivalent [MET] hours per week), physical inactivity (sitting hours per week) and BMI, were obtained from biennial questionnaires. VTE cases were incident since cohort inception; controls were matched to cases on age, cohort, and genotype array. Using conditional logistic regression, we assessed joint effects and interaction effects on both additive and multiplicative scales. We also ran models using continuous wGRS stratified by risk-factor categories.

RESULTS

We observed a supra-additive interaction between wGRS and BMI. Having both high wGRS and high BMI was associated with a 3.4-fold greater risk of VTE (relative excess risk due to interaction = 0.69, p = 0.046). However, we did not find evidence for a multiplicative interaction with BMI. No interactions were observed for physical activity or inactivity.

CONCLUSION

We found a synergetic effect between a genetic risk score and high BMI on the risk of VTE. Intervention efforts lowering BMI to decrease VTE risk may have particularly large beneficial effects among individuals with high genetic risk.

The Prophylaxis of Venous Thromboembolism

BACKGROUND

Venous thromboembolism (VTE) is the third most common cardiovascular condition, after myocardial infarction and stroke. Prophylactic measures in accordance with current guidelines can significantly reduce the risk of VTE and the associated morbidity and mortality. Until now, the German interdisciplinary, evidence- and consensus-based (S3) clinical practice guideline on VTE prophylaxis was based on a complete review of all pertinent literature available in MEDLINE up to January 2008. More recent publications and drug approvals have made a thorough revision necessary.

METHODS

A systematic search was carried out in the MEDLINE and Embase databases for publications that appeared from 1 January 2008 to 7 August 2013. Updates of 5 national and international reference guidelines and 2 new Health Technology Assessment (HTA) reports were considered as well. A structured consensus-finding process was carried out with delegates from 27 scientific medical societies and from the Union of Medical Specialist Associations.

RESULTS

46 randomized controlled trials (RCTs) were included for critical appraisal. New findings led to re-evaluation of the value of compression stockings in combination with pharmacological prophylaxis (open recommendation), and suggest equal value of non-vitamin K antagonist oral anticoagulants (NOACs) and low molecular weight heparins (LMWH) or fondaparinux in elective hip and knee replacement (strong recommendation). For patients undergoing hip fracture surgery, we recommend LMWH or fondaparinux.

CONCLUSION

Further research is needed to assess the value of NOACs for pharmacological prophylaxis in orthopedic/trauma patients undergoing surgical procedures other than the ones mentioned above, and into the benefit and harm of new devices available for mechanical prophylaxis. The stringent implementation of basic measures such as early mobilization, movement exercises, and patient instruction is a key point to prevent venous thrombo - embolism.

Chart validation of inpatient International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) administrative diagnosis codes for venous thromboembolism (VTE) among intravenous immune globulin (IGIV) users in the Sentinel Distributed Database

The Sentinel Distributed Database (SDD) is a database of patient administrative healthcare records, derived from insurance claims and electronic health records, sponsored by the US Food and Drug Administration for evaluation of medical product outcomes. There is limited information on the validity of diagnosis codes for acute venous thromboembolism (VTE) in the SDD and administrative healthcare data more generally.In this chart validation study, we report on the positive predictive value (PPV) of inpatient administrative diagnosis codes for acute VTE-pulmonary embolism (PE) or lower-extremity or site-unspecified deep vein thrombosis (DVT)-within the SDD. As part of an assessment of thromboembolic adverse event risk following treatment with intravenous immune globulin (IGIV), charts were obtained for 75 potential VTE cases, abstracted, and physician-adjudicated.VTE status was determined for 62 potential cases. PPVs for lower-extremity DVT and/or PE were 90% (95% CI: 73-98%) for principal-position diagnoses, 80% (95% CI: 28-99%) for secondary diagnoses, and 26% (95% CI: 11-46%) for position-unspecified diagnoses (originating from physician claims associated with an inpatient stay). Average symptom onset was 1.5 days prior to hospital admission (range: 19 days prior to 4 days after admission).PPVs for principal and secondary VTE discharge diagnoses were similar to prior study estimates. Position-unspecified diagnoses were less likely to represent true acute VTE cases.

What Is the Timing of General Health Adverse Events That Occur After Total Joint Arthroplasty?

BACKGROUND

Despite extensive research regarding risk factors for adverse events after total joint arthroplasty (TJA), there are few publications describing the timing at which such adverse events occur.

QUESTIONS/PURPOSES

(1) On which postoperative day do certain adverse events occur? (2) What adverse events occur earlier after TKA than after THA? (3) For each adverse event, what proportion occurred after hospital discharge?

METHODS

We screened the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) to identify all patients undergoing primary THA and primary TKA between 2005 and 2013, resulting in a study population of 124,657 patients evaluated as part of this retrospective database analysis. For each of eight different adverse events, the median postoperative day of diagnosis, interquartile range for day of diagnosis, and middle 80% for day of diagnosis were determined. Multivariate Cox proportional hazards modeling was used to test whether there is a difference of timing for each adverse event as stratified by TKA or THA. The proportion of adverse events occurring after versus before discharge was also calculated.

RESULTS

The median day of diagnosis (and interquartile range; middle 80%) for stroke was 2 (1-10; 1-19), myocardial infarction 3 (2-6; 1-15), pulmonary embolism 3 (2-7; 1-19), pneumonia 4 (2-9; 2-17), deep vein thrombosis 6 (3-14; 2-23), urinary tract infection 8 (3-16; 2-24), sepsis 10 (5-19; 2-24), and surgical site infection 17 (11-23; 6-28). For the later occurring adverse events (surgical site infection, sepsis), the rate of occurrence remained high at the end of the 30-day postoperative period. Timing was earlier in patients undergoing TKA for pulmonary embolism (day 3 [interquartile range 2-6] versus 5 [3-17], p < 0.001) and deep vein thrombosis (day 5 [2-11] versus 13 [6-22], p < 0.001). The proportion of events occurring after discharge for myocardial infarction was 97 of 283 (34%), stroke 42 of 118 (36%), pulmonary embolism 223 of 625 (36%), pneumonia 171 of 426 (40%), deep vein thrombosis 576 of 956 (60%), urinary tract infection 958 of 1406 (68%), sepsis 284 of 416 (68%), and surgical site infection 1147 of 1212 (95%).

CONCLUSIONS

As lengths of hospital stay after TJA continue to decrease, our findings suggest that caution is in order because several acute and immediately life-threatening findings, including myocardial infarction and pulmonary embolism, might occur after discharge. Furthermore, the timing of surgical site infection and sepsis suggests that even the 30-day followup afforded by the ACS-NSQIP may not be sufficient to study the latest occurring adverse events. Additionally, both pulmonary embolism and deep vein thrombosis tend to occur earlier after TKA than THA, and this should guide clinical surveillance efforts in patients undergoing those procedures. These findings also indicate that inpatient-only databases (such as the Nationwide Inpatient Sample) may fail to capture a very large proportion of postoperative adverse events, weakening the conclusions of many published studies using those databases.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Safety Outcomes After Percutaneous Transcatheter Closure of Patent Foramen Ovale

BACKGROUND AND PURPOSE

We sought to evaluate the real-world rate of safety outcomes after patent foramen ovale (PFO) closure in patients with ischemic stroke or transient ischemic attack (TIA).

METHODS

We performed a retrospective cohort study using administrative claims data on all hospitalizations from 2005 to 2013 in New York, California, and Florida. Using International Classification of Diseases, Ninth Revision, Clinical Modification codes, we identified patients who underwent percutaneous transcatheter PFO closure within 1 year of ischemic stroke or TIA. Our outcome was an adverse event occurring during the hospitalization for PFO closure, defined as in prior studies as atrial fibrillation or flutter, cardiac tamponade, pneumothorax, hemothorax, a vascular access complication, or death. Crude rates were reported with exact confidence intervals.

RESULTS

We identified 1887 patients who underwent PFO closure after ischemic stroke or TIA. The rate of any adverse outcome during the hospitalization for PFO closure was 7.0% (95% confidence interval [CI], 5.9%-8.2%). Rates of adverse outcomes varied by age and type of preceding cerebrovascular event. In patients >60 years of age, the rate of adverse outcomes was 10.9% (95% CI, 8.6%-13.6%) versus 4.9% (95% CI, 3.8%-6.3%) in patients ≤60 years of age. The rate of adverse outcomes was 9.9% (95% CI, 7.3%-12.5%) in patients with preceding ischemic stroke versus 5.9% (95% CI, 4.7%-7.1%) after TIA.

CONCLUSIONS

Approximately 1 in 14 patients who underwent percutaneous transcatheter PFO closure after ischemic stroke or TIA experienced a serious periprocedural adverse outcome or death. The risk of adverse outcomes was highest in older patients and in those with preceding ischemic stroke.

Qualitative Slow Blood Flow in Lower Extremity Deep Veins on Doppler Sonography: Quantitative Assessment and Preliminary Evaluation of Correlation With Subsequent Deep Venous Thrombosis Development in a Tertiary Care Oncology Center

OBJECTIVES

To determine whether the qualitative sonographic appearance of slow deep venous flow in the lower extremities correlates with quantitative slow flow and an increased risk of deep venous thrombosis (DVT) in oncology patients.

METHODS

In this Institutional Review Board-approved retrospective study, we reviewed lower extremity venous Doppler sonographic examinations of 975 consecutive patients: 482 with slow flow and 493 with normal flow. The subjective slow venous flow and absence of initial DVT were confirmed by 2 radiologists. Peak velocities were recorded at 3 levels. Each patient was followed for DVT development. The associations between DVT and the presence of slow venous flow were examined by the Fisher exact test; a 2-sample t test was used for peak velocity and DVT group comparisons. The optimal cutoff peak velocity for correlation with the radiologists' perceived slow flow was determined by the Youden index.

RESULTS

Deep venous thrombosis development in the slow-flow group (21 of 482 [4.36%]) was almost doubled compared with patients who had normal flow (11 of 493 [2.23%]; P = .0456). Measured peak venous velocities were lower in the slow-venous flow group (P < .001). Patients with subsequent DVT did not have a significant difference in venous velocities compared with their respective patient groups. The sum of 3 venous level velocities resulted in the best cutoff for dichotomizing groups into normal versus slow venous flow.

CONCLUSIONS

Qualitative slow venous flow in the lower extremities on Doppler sonography accurately correlates with quantitatively slower flow, and this preliminary evaluation suggests an associated mildly increased rate of subsequent DVT development in oncology patients.

Recurrent venous thrombosis related to overweight and obesity: results from the MEGA follow-up study

Essentials Whether excess body weight influences recurrent venous thrombosis (VT) risk is uncertain. We included 3889 VT patients, classified into body mass index (BMI) strata to estimate recurrent VT risk. No evidence of an increased risk for excess body weight was found. Measuring BMI is not a good tool to identify patients at high risk of VT recurrence.

SUMMARY

Background Studies on the risk of recurrent venous thrombosis in patients with excess body weight have yielded conflicting results. Objective To estimate whether excess body weight increases the risk of recurrent venous thrombosis. Patients/Methods We included 3889 patients, followed after a first venous thrombosis for a median of 5.6 years. Body mass index (BMI) was calculated as weight in kilograms/height in meters squared, and classified according to three a priori-defined categories (normal weight, overweight, and obesity), as well as by percentiles. Crude incidence rates with 95% confidence intervals (CIs) of recurrent venous thrombosis were estimated as the number of events over the accumulated follow-up time in each BMI category. Cox regression models were used to compare groups, adjusted for age and sex. Results The incidence rate of recurrent venous thrombosis was 3.3 per 100 patient-years. Adjusted hazard ratios of recurrent venous thrombosis in overweight or obese patients in comparison with patients with normal weight were 1.05 (95% CI 0.88-1.27) and 0.94 (95% CI 0.74-1.19), respectively. Stratification by BMI percentile categories yielded similar results. The association between BMI and recurrent venous thrombosis was also absent after stratification by sex, (although a small effect for overweight, but not for obese women, was found), or into those with a first provoked or unprovoked event, or deep vein thrombosis and pulmonary embolism. Conclusions We found no evidence of an association between excess body weight and recurrent venous thrombosis. Measuring BMI is not a useful tool to identify patients at high risk of recurrence.

Long-Term Effects of Unprovoked Venous Thromboembolism on Mortality and Major Cardiovascular Events

Background

Patients with unprovoked venous thromboembolism (VTE) are at an increased risk of mortality, but whether their cardiovascular risks also increase remains to be determined. We aimed to investigate the factors associated with overall mortality and major adverse cardiovascular events in patients with unprovoked VTE.

Methods and Results

We identified 2154 patients newly diagnosed with unprovoked VTE from Taiwan's National Health Insurance Database between 2000 and 2013, excluding those with reversible etiologies, underlying cancer, or autoimmune diseases. These patients with VTE were compared with an age‐, sex‐, and cardiovascular risk‐matched cohort of 4308 controls. The risk of mortality and major adverse cardiovascular events in patients with VTE was 2.23 (CI, 1.93–2.57; P<0.0001) and 1.86 (CI, 1.65–2.09; P<0.0001) times, respectively, higher than that of the conditions in controls. These events mostly occurred during the first year after the diagnosis of unprovoked VTE. Among patients with VTE, advanced age, male sex, and comorbid diabetes mellitus indicated a higher incidence of mortality and major adverse cardiovascular events. Conversely, comorbid hyperlipidemia attenuated these risks.

Conclusions

This nation‐wide cohort study revealed that patients with unprovoked VTE, particularly older males with diabetes mellitus, had an elevated risk of both mortality and cardiovascular events. Risk of mortality and major adverse cardiovascular events were highest within the first year after diagnosis and persisted during the 10 years of follow‐up.

The Incidence and Economic Burden of In-Hospital Venous Thromboembolism in the United States

BACKGROUND

Venous thromboembolism (VTE) is a potentially preventable and costly complication after total hip arthroplasty (THA) and total knee arthroplasty (TKA). The in-hospital incidence and economic burden of VTE following total joint arthroplasty (TJA) in the United States is unknown. The aim of this study was to examine this issue.

METHODS

The Nationwide Inpatient Sample was used to estimate the total number of THA, TKA, and VTE events using International Classification of Diseases, Ninth Revision procedure codes from years 2002 to 2011. The rate of in-hospital deep vein thrombosis (DVT) and pulmonary embolism (PE), associated length of hospitalization, and current and projected in-hospital charges were obtained.

RESULTS

Revision arthroplasties had higher rates of in-hospital VTE compared to primary TJAs (2.5% vs 1.6%, P < .0001). Among primary TJAs, the median rate of in-hospital VTE was 0.59% (0.55%-0.63%) for primary THA and 1.01% (0.94%-1.08%) for primary TKA. Revision THAs developed more VTE events compared to revision TKAs (1.35% [1.25%-1.46%] vs 1.16% [1.07%-1.26%]). Patients with a VTE have longer hospitalizations (median primary TKA: 7 vs 3; median primary THA: 6 vs 3, P < .0001). The overall rate of VTE decreased over the last decade; however, the PE rates have remained relatively constant. Moreover, the associated costs with VTE events have increased significantly over the last decade.

CONCLUSION

Based on the analysis of the Nationwide Inpatient Sample database, the rate of in-hospital DVT following TJA appears to have declined over the last decade while the incidence of PE has remained constant. This may indicate that the current recommendations by the American Academy of Orthopaedic Surgeons for VTE prophylaxis are adequate for preventing DVT without increasing the rate of PE or that institutional screening and reporting of DVT has been reduced because DVTs became a "never" event.

Risk of Pulmonary Embolism After Cerebral Venous Thrombosis

BACKGROUND AND PURPOSE

Cerebral vein thrombosis (CVT) is a type of venous thromboembolism. Whether the risk of pulmonary embolism (PE) after CVT is similar to the risk after deep venous thrombosis (DVT) is unknown.

METHODS

We performed a retrospective cohort study using administrative data from all emergency department visits and hospitalizations in California, New York, and Florida from 2005 to 2013. We identified patients with CVT or DVT and the outcome of PE using previously validated International Classification of Diseases, Ninth Revision, Clinical Modification codes. Kaplan-Meier survival statistics and Cox proportional hazards models were used to compare the risk of PE after CVT versus PE after DVT.

RESULTS

We identified 4754 patients with CVT and 241 276 with DVT. During a mean follow-up of 3.4 (±2.4) years, 138 patients with CVT and 23 063 with DVT developed PE. CVT patients were younger, more often female, and had fewer risk factors for thromboembolism than patients with DVT. During the index hospitalization, the rate of PE was 1.4% (95% confidence interval [CI], 1.1%-1.8%) in patients with CVT and 6.6% (95% CI, 6.5%-6.7%) in patients with DVT. By 5 years, the cumulative rate of PE after CVT was 3.4% (95% CI, 2.9%-4.0%) compared with 10.9% (95% CI, 10.8%-11.0%; P<0.001) after DVT. CVT was associated with a lower adjusted hazard of PE than DVT (hazard ratio, 0.26; 95% CI, 0.22-0.31).

CONCLUSION

The risk of PE after CVT was significantly lower than the risk after DVT. Among patients with CVT, the greatest risk for PE was during the index hospitalization.

Characterizing the Acute Phase Response in Healthy Patients Following Total Joint Arthroplasty: Predictable and Consistent

BACKGROUND

During surgery, trauma to musculoskeletal tissue induces a systemic reaction known as the acute phase response (APR). When excessive or prolonged, the APR has been implicated as an underlying cause of surgical complications. The purpose of this study was to determine the typical APR following total joint arthroplasty in a healthy population defined by the Charlson Comorbidity Index (CCI).

METHODS

This retrospective study identified 180 healthy patients (CCI < 2) who underwent total joint arthroplasty by a single surgeon for primary osteoarthritis from 2013 to 2015. Serial measurements of C-reactive protein (CRP) and fibrinogen were obtained preoperative, perioperative, and at 2 and 6 weeks postoperative.

RESULTS

Postoperative CRP peaked during the inpatient period and returned to baseline by 2 weeks. Fibrinogen peaked after CRP and returned to baseline by 6 weeks. Elevated preoperative CRP correlated with a more robust postoperative APR for both total hip arthroplasty and total knee arthroplasty, suggesting that a patient's preoperative inflammatory state correlates with the magnitude of the postoperative APR.

CONCLUSION

Measurement of preoperative acute phase reactants may provide an objective means to predict a patient's risk of postoperative dysregulation of the APR and complications.

Development and Validation of a Risk Stratification System for Pulmonary Embolism After Elective Primary Total Joint Arthroplasty

INTRODUCTION

Stratification of patients into different risk categories for pulmonary embolism (PE) after total joint arthroplasty (TJA) may allow clinicians to individualize venous thromboembolism prophylaxis based on an appropriate risk-benefit scale.

METHODS

Patients undergoing primary total hip arthroplasty (THA) or total knee arthroplasty (TKA) as part of the American College of Surgeons National Surgical Quality Improvement Program were identified. Independent risk factors for PE within 30 days of surgery were identified and used to develop a point-scoring system to estimate the relative risk for PE. For validation, the system was tested on patients undergoing TJA at a single institution.

RESULTS

A total of 118,473 patients were identified, including 72,673 (61.3%) undergoing TKA and 45,800 (38.7%) undergoing THA. The incidence of PE within 30 days of the index arthroplasty was 0.50%. The risk factors associated with PE were age ≥70, female gender, higher body mass index (25-30 kg/m(2) and ≥30 kg/m(2)), and TKA (vs THA); anemia was protective. The point scores derived for each of these factors were as follows: anemia: -2; female: +1; body mass index 25-30 kg/m(2): +2; body mass index ≥30 kg/m(2): +3; age ≥70 years: +3; TKA: +5. The point-scoring system was then applied to 17,384 patients from a single institution. Single-institution patients categorized as low risk using the point-scoring system had a 0.44% 90-day risk for PE (95% CI = 0.29%-0.58%); medium risk, 1.51% (95% CI = 1.18%-1.84%); and high risk, 2.60% (95% CI = 2.09%-3.10%).

CONCLUSION

This point-scoring system predicts risk for PE after TJA and may help surgeons to optimize selection of chemical prophylaxis.

Dabigatran etexilate for thromboprophylaxis in over 5000 hip or knee replacement patients in a real-world clinical setting

BACKGROUND

Thromboprophylaxis is recommended for patients undergoing total hip or total knee replacement (THR, TKR). An international, open-label, prospective, observational, single-arm study in a routine clinical setting was performed to assess the safety and efficacy of dabigatran etexilate 220 mg once daily in patients undergoing THR or TKR, and in subgroups of patients with potentially increased risk of bleeding or venous thromboembolism (VTE).

MATERIALS AND METHODS

Patients were ≥18 years and required to be eligible to receive dabigatran 220 mg once daily (first dose 110 mg 1-4 h after THR/TKR surgery) according to the European Summary of Product Characteristics. The primary safety and efficacy outcomes were incidence of major bleeding events (MBEs), and the composite incidence of symptomatic VTE events and all-cause mortality, respectively.

RESULTS

In total, 5292 patients (median age 64 years) were enrolled and received dabigatran (2734 THR and 2558 TKR). Median drug exposure was 31 days (THR 34 days; TKR 27 days). Overall incidence of MBEs was 0.72 % (95 % confidence interval [CI] 0.51, 0.98), and this rate was comparable between types of surgery and was not significantly affected by protocol-defined risk factors. The overall incidence of symptomatic VTE and all-cause mortality was 1.04 % (95 % CI 0.78, 1.35); the only significant risk factor was history of VTE events (odds ratio 5.59; 95 % CI 2.53, 11.08). A post-hoc analysis showed that the incidence of MBEs in this observational study was similar to or lower than those reported in previous phase 3 trials.

CONCLUSIONS

Results from this observational study of dabigatran etexilate administered to patients undergoing THR or TKR surgery are reassuring and supportive of those obtained in dabigatran phase 3 trials.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00846807.

Incidence and risk factors for venous thromboembolism following surgical treatment of fractures below the hip: a meta-analysis

Venous thromboembolism (VTE) is a common complication after surgical treatment of fractures, which is associated with significant morbidity and mortality. Identifying the risk factors for VTE is important for preventive strategies to reduce the incidence of VTE. Therefore, we conducted a meta-analysis to evaluate the incidence of VTE and the risk factors influencing the development of VTE in patients who underwent surgery for fractures below the hip. PubMed, Embase, Web of Science, SinoMed (Chinese BioMedical Literature Service System, China) and CNKI (National Knowledge Infrastructure, China) databases were systematically searched to identify cohort or case-control studies that investigated the incidence and risk factors for VTE following surgical treatment of fractures below the hip. VTE risk ratios (RRs) were pooled by use of a fixed-effect model or a random-effect model, depending on the heterogeneity among the included studies. Heterogeneity between the studies was assessed by I² statistics. Twenty-three studies with a total of 191 294 patients who met the inclusion criteria were included in this meta-analysis. Our results demonstrated that age (≥60 years) (RR = 1·85, 95% confidence interval (CI): 1·34, 2·55; P = 0·000), previous VTE(RR = 5·25, 95% CI: 2·77, 9·96; P = 0·000), heart failure (RR = 1·74, 95% CI: 1·34, 2·27; P = 0·000), current smoking status (RR = 1·23, 95% CI: 1·07, 1·41; P = 0·004), hypertension (RR = 1·62, 95% CI: 1·27, 2·06; P = 0·000), hyperlipidaemia (RR = 2·16, 95% CI: 1·79, 2·62; P = 0·000), diabetes mellitus (RR = 1·46, 95% CI: 1·27, 1·68; P = 0·000), obesity (RR = 1·58, 95% CI: 1·35,·1·85; P = 0·000), multiple fractures (RR = 2·14, 95% CI: 1·00, 4·60; P = 0·050), varicose veins (RR = 3·07, 95% CI: 1·12, 8·47; P = 0·030), prolonged operation time (weighted mean differences (WMD) = 1·22, 95% CI: 0·63, 1·81; P = 0·000) and prolonged bed rest time (WMD = 3·12, 95% CI: 2·96, 3·29; P = 0·000) were associated with an increased risk of developing VTE. The other variables, including age (<60 years), previous smoking, immobility, pregnancy, cancer, open fractures and combination with trauma were not identified as significant risk factors for VTE. Almost all the risk factors mentioned above are in line with the known risk factors for VTE following surgery for fractures below the hip. Thus, surgeons should pay close attention to patients with these medical conditions in order to reduce the incidence of VTE following surgical treatment of fractures below the hip.

The epidemiology of venous thromboembolism

Venous thromboembolism (VTE) is categorized by the U.S. Surgeon General as a major public health problem. VTE is relatively common and associated with reduced survival and substantial health-care costs, and recurs frequently. VTE is a complex (multifactorial) disease, involving interactions between acquired or inherited predispositions to thrombosis and VTE risk factors, including increasing patient age and obesity, hospitalization for surgery or acute illness, nursing-home confinement, active cancer, trauma or fracture, immobility or leg paresis, superficial vein thrombosis, and, in women, pregnancy and puerperium, oral contraception, and hormone therapy. Although independent VTE risk factors and predictors of VTE recurrence have been identified, and effective primary and secondary prophylaxis is available, the occurrence of VTE seems to be relatively constant, or even increasing.

External validation of the In-hospital Mortality for PulmonAry embolism using Claims daTa (IMPACT) multivariable prediction rule

OBJECTIVE

To validate the In-hospital Mortality for PulmonAry embolism using Claims daTa (IMPACT) multivariable prediction rule using admission claims data.

STUDY DESIGN

Retrospective claims database analysis.

METHODS

This analysis was performed using Humana admission claims data from January 2007 to March 2014. We included adult patients admitted for their first PE during this period (International Classification of Diseases, ninth edition, Clinical Modification code of 415.1x in in the primary position or secondary position when accompanied by a primary code for a PE complication). The IMPACT rule, consisting of age plus 11 comorbidities, was used to estimate patients' probability of in-hospital mortality and classify risk. Low risk was defined as in-hospital mortality ≤ 1.5%. IMPACT was evaluated by evaluating prognostic test characteristic values and 95% confidence intervals (CIs).

RESULTS

A total of 23,858 patients admitted for PE were included, and 3.3% died in-hospital. The IMPACT prediction rule classified 2371 (9.9%) as low-risk; with a sensitivity of 97.6%, 95% CI: 96.1-98.5, specificity of 10.2%, 95% CI: 9.8-10.6, negative and positive predictive values of 99.2% (95% CI: 98.7-99.5) and 3.5% (95% CI: 3.3-3.8) and c-statistic of 0.70, 95% CI: 0.0.68-0.72, for in-hospital mortality. IMPACT classified 42.7% of patients < 65 years old as low-risk; with a sensitivity, specificity and c-statistic of 85.0%, 95% CI: 77.4-90.5, 43.3%, 95% CI: 42.0-44.7 and 0.74, 95% CI: 0.69-0.78, respectively.

CONCLUSION

The IMPACT prediction rule was valid when implemented in a database consisting largely of Medicare claims. Following further external validation and direct comparison to commonly used clinical prediction rules, IMPACT may become a valuable tool for payers and hospitals wishing to retrospectively assess whether their PE patients are being kept hospitalized for the optimal period of time.

The Role of Potentially Retrievable Inferior Vena Cava Filters in High-Risk Patients Undergoing Joint Arthroplasty

INTRODUCTION

Some patients undergoing total joint arthroplasty are at increased risk for venous thromboembolism (VTE). The aim of the present study was to evaluate the safety and efficacy of prIVCF in preventing PE in patients undergoing joint replacement surgery who are at high-risk for VTE.

MATERIALS AND METHODS

In this prospective, IRB-approved study, prIVCF were placed in consecutive patients who met specific high-risk criteria (history of VTE or hypercoaguable state) prior to total joint arthroplasty. Patients were followed until the IVC filter was removed. Outcomes and complications were recorded per Society of Interventional Radiology guidelines.

RESULTS

One hundred and nine potentially retrievable IVC filters were placed in 105 patients, who all subsequently underwent joint arthroplasty. One hundred eight IVC filters (98.9%) were retrieved successfully in a mean time of 44.1 days (range 13-183 days). There was 1 failed IVC filter retrieval attempt (0.9%) at 46 days post implantation. Two patients (1.9%) presented with recurrent PE and were successfully treated with anticoagulation prior to IVC filter retrieval. There were no fatalities from perioperative PE. In 1 patient (0.9%), a fractured filter leg had embolized during retrieval.

CONCLUSION

Potentially retrievable IVC filters are safe and effective for prophylaxis against PE in patients at high-risk for VTE undergoing joint arthroplasty.

Adjusted-Dose Enoxaparin for VTE Prevention in the Morbidly Obese

Background: Venous thromboembolism (VTE) is a major health problem and common cause of morbidity and mortality in hospitalized patients. While trials in both surgical and medically ill patients have demonstrated efficacy and safety of enoxaparin for VTE prophylaxis (VTEP), they failed to adequately represent morbidly obese (body mass index > 40 kg/m2) patients. Objective: To assess the impact of a weight-adjusted enoxaparin dosing algorithm on anti-factor Xa levels, thrombosis, and bleeding in morbidly obese patients. Methods: A retrospective chart review was conducted, which included morbidly obese patients receiving VTEP with adjusted-dose enoxaparin. Patients received enoxaparin 0.5 mg/kg subcutaneously once or twice daily based on VTE risk. An anti-factor Xa level was drawn 3 to 5 hours after 2 or more consecutive doses. The primary outcome was the percentage of patients achieving target anti-factor Xa levels, defined as 0.2 to 0.6 IU/mL. Secondary outcomes included the incidence of symptomatic VTE and major bleeding. Results: Of the 182 charts reviewed, 141 anti-factor Xa levels from 130 patients met inclusion criteria. The study population was 44% male, and the median body mass index was 45.6 kg/m2. A total of 120 anti-factor Xa levels (85.1%) were within the target prophylactic range. Sixteen anti-factor Xa levels (11.3%) were below target range, and 5 (3.4%) were above range. The only significant difference among the 3 groups was baseline renal function (P = .035). There were 2 thromboembolic events and 1 major bleed in the study population. Conclusion: A weight-based VTEP dosing strategy for morbidly obese patients is effective without an apparent increase in adverse events.

PROPHYLAXIS OF VENOUS THROMBOEMBOLISM IN ORTHOPAEDIC SURGERY

The relevance of prophylaxis of venous thromboembolism and its complications in orthopedic surgery is increasingly significant. This review discusses the pathophysiology of thrombus formation in general and orthopedic surgery, its incidence, predisposing factors and complications. It also presents an updated presentation and critique of prophylaxis currently available in our environment.

Predictors of costs from the hospital perspective of primary pulmonary embolism

The objective of this study was to estimate the total hospital cost per patient admitted through the emergency department with a primary diagnosis of pulmonary embolism (PE), and to identify the main components and predictors of costs.Actual costs of care of 652 consecutive patients hospitalised in 10 general hospitals in Belgium, including 31 outlier patients in terms of length of stay (4.8%), were obtained by aggregating all cost components contributing to care of each patient.In both inlier and outlier patients, the mean total cost per patient increased linearly with the degree of severity of illness classes related to the All Patient Refined Diagnosis Related Group (p<0.0001). Medical procedures, nursing activities and hospitalisation accommodation were the main cost components. We identified six independent predictors of costs in inliers: age group, chronic pulmonary heart disease, heart failure, admission to intensive care unit, initial thrombolysis treatment and type of hospital. There was a statistically significant linear trend between age groups and costs (p<0.0001).An increasing burden of comorbid illness was strongly associated with increasing actual cost for caring hospitalised patients for PE. Increasing age was associated with an increase in all main cost components.