Incidence Of VTE Research Articles

Development of venous thromboembolic event risk calculator for metabolic and bariatric surgery patients to reduce mortality

IntroductionVenous thromboembolic events (VTEs) after Metabolic and Bariatric Surgery (MBS) result in significant morbidity and are the leading cause of mortality. The objective of this study was to identify patients who are at a high risk for developing VTE and who may benefit from extended chemoprophylaxis following MBS. MethodsUsing the 2015-2019 Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) participant user file (PUF), we identified 696,069 patients who completed 30-day follow-up data and met the inclusion criteria. Using logistic regression analysis, we identified preoperative and postoperative risk factors associated with VTE and validated our model externally using the MBSAQIP 2020-2021 datasets (N = 273,692). The Hosmer–Lemeshow test was used for goodness of fit and calibration. We also compared our model’s discriminatory capability with that of other VTE risk assessment tools. We then used these risk factors to create an online open source application. ResultsThe overall incidence of VTE after MBS in the 696,069 (MBSAQIP 2015-2019 database) patients included in our analysis was .40% (2759 patients). Our model had a good predictive capability, with a C-statistic of .66. Our model also demonstrated good fit with a Hosmer–Lemeshow chi-square of 11.06 (P = .198). A cut-off point of .4% resulted in a sensitivity of 48.28%, with 24% of patients having a VTE risk greater than .4% within the 2015-2019 MBSAQIP dataset. Among all the perioperative factors selected in the PUF, high risk for VTE included African American race (AOR 1.625, P < .0001), operation length in minutes (AOR: 1.003, P < .0001), preop functional status (AOR 1.012, P = .007), procedure type (RYGB; AOR .768, P < .0001 and RBS; AOR .758, P = .019 with respect to sleeve), preop body mass index (BMI) (AOR 1.012, P < .001), history of pre-op vein thrombosis requiring therapy (AOR 5.041, P < .0001), post-op superficial or organ space surgical site infection (AOR 2.713, P < .0001), preop venous stasis (AOR 1.425, P = .019),at least one readmission within 30 days(AOR 1.583, P < .0001), or at least one reoperation within 30 days (AOR 4.399, P < .0001). ConclusionVTE after MBS can result in increased mortality rates. High-risk patients might benefit from extended chemoprophylaxis. Our model suggests that patients with a VTE risk ≥ .4% in the first 30 days following surgery may benefit from extended chemoprophylaxis.

Short-Term Bed Rest is not a Risk Factor for Venous Thromboembolism After Endoscopic Skull Base Surgery

IntroductionDeep venous thromboembolisms (DVT) increase morbidity in postoperative patients, and no current guidelines identify which patients undergoing endoscopic endonasal approach (EEA) to the skull base may be at increased risk. Postoperative care for these patients often includes a period of inactivity to prevent transient ICP shifts which may impact skull base reconstruction. We seek to characterize if postoperative bedrest puts EEA patients at increased risk of developing thromboembolic complications. MethodsRetrospective chart review of patients undergoing intradural surgery with primary skull base reconstruction for intraoperative CSF leak via EEA for any skull base pathology between July 2018 and May 2024 was performed yielding 221 patients who met inclusion criteria. Univariate and multivariable regression were performed with patient demographics, extent of approach, intraoperative leak flow rate, bedrest duration, presence and length of postoperative lumbar drainage (LD), and use of postoperative mechanical VT prophylaxis. ResultsThe mean age of included patients was 52.6 ± 16.8 years, 48% were male, and 3.6% of patients had DVTs. Age (OR 1.01, 95% CI 0.96-1.06, p=0.83), sex (OR 0.40, 95% CI 0.05-2.19, p=0.31), BMI (OR 0.98, 95% CI 0.87-1.07, p=0.74), extended approach (OR 0.80, 95% CI 0.13-4.36, p=0.80), CSF leak flow rate (OR 5.71, 95% CI 0.77-118.90, p=0.14), bedrest duration (OR 1.06, 95% CI 0.77-1.27, p=0.60), and presence of LD (OR 1.10, 95% CI 0.55-2.02, p=0.76) were not significant predictors of postoperative VTE incidence on multivariable analysis. ConclusionShort-term bedrest after EEA is not a risk factor for development of VTE in the immediate postoperative period.

Venous thromboembolism risk in amyotrophic lateral sclerosis: a hospital record-linkage study

BackgroundVenous thromboembolism (VTE) can occur in amyotrophic lateral sclerosis (ALS) and pulmonary embolism causes death in a minority of cases. The benefits of preventing VTE must be weighed against the...

Low pneumoperitoneum pressure on venous thromboembolism in laparoscopic colorectal cancer surgery: A randomized controlled study

IntroductionVenous thromboembolism (VTE) poses a significant risk in colorectal cancer surgeries due to hypercoagulability and the anatomical challenges of the pelvic cavity. With the advancement of minimally invasive techniques, intraoperative strategies for preventing VTE may prove to be effective. This study explores the effects of intraoperative pneumoperitoneum pressures on VTE incidence following colorectal cancer surgeries. MethodsThis single center parallel randomized controlled double-blind, trial involved 302 patients undergoing elective laparoscopic or robotic colorectal surgery. Patients were randomized to either a standard pneumoperitoneum pressure group (SP: 15 mmHg) or a low-pressure group (LP: 10 mmHg). Primary outcomes measured were the incidence of VTE, including symptomatic and asymptomatic DVT and PE. Secondary outcomes included postoperative D-dimer levels, surgery duration, blood loss, surgeon satisfaction, and oncological quality. ResultsOut of 302 randomized patients, 275 were evaluable post exclusions, with 138 in the SP group and 137 in the LP group. The incidence of VTE was 10.9 % in the SP and 13.9 % in the LP group, with no significant difference between the two (P = 0.450). Secondary outcomes such as D-dimer levels, surgery duration, and blood loss showed no significant differences between two groups. Surgeon satisfaction and oncological outcomes were similarly comparable. ConclusionsThe trial demonstrated no significant difference in the incidence of VTE between standard and low pneumoperitoneum pressures. This suggests that lower pressures may not necessarily provide a benefit in reducing postoperative VTE in colorectal cancer surgeries.

Thrombotic Consequences of COVID-19 Infection on Microsurgical Reconstruction.

Evidence has shown increased morbidity and mortality for patients with COVID-19 infection within 7 weeks of surgery. However, no studies have specifically investigated the effects of COVID-19 in microsurgical outcomes. This study evaluated thrombotic and overall complications after free tissue transfer for a variety of indications in patients with and without previous COVID-19 infection. A retrospective cohort study was performed in adult patients with or without a history of COVID-19 infection who underwent microsurgical reconstruction between 2017 and 2022. Patients with a history of COVID-19 infection were matched to controls based on age, gender, race, body mass index, history of diabetes, coronary artery disease, hypertension, Caprini score, tobacco use, and flap indication. From 2017 to 2022, 35 patients had a documented history of COVID-19. Matched case analysis determined a 4.8 times increased odds ratio of postoperative complications in the COVID-19 group compared with controls (p = 0.002). Significantly, more patients with COVID-19 experienced total or partial flap loss and anastomotic issues (COVID-19: 7/35, Control: 0/35; p < 0.001). There was no significant difference in incidence of VTE (COVID-19: 1/35, Control: 0/35; p = 0.493). Of note, 62.9% of the COVID-19 group were discharged on anticoagulants (versus 14.3% in the control group [p < 0.001]). COVID-19 has dire, long-lasting effects on virtually every organ system, chief among them, the microcirculation. Further studies are needed to fully determine the extent and influence of COVID-19 on complex procedures such as free tissue transfer and how to optimize the screening, workup, and postoperative care to guard against the associated thrombotic consequences.

Venous Thromboembolism Prophylaxis in High-Risk Pediatric Trauma Patients

The indications, safety, and efficacy of chemical venous thromboembolism prophylaxis (cVTE) in pediatric trauma patients remain unclear. A set of high-risk criteria to guide cVTE use was recently recommended; however, these criteria have not been evaluated prospectively. To examine high-risk criteria and cVTE use in a prospective multi-institutional study of pediatric trauma patients. This cohort study was completed between October 2019 and October 2022 in 8 free-standing pediatric hospitals designated as American College of Surgeons level I pediatric trauma centers. Participants were pediatric trauma patients younger than 18 years who met defined high-risk criteria on admission. It was hypothesized that cVTE would be safe and reduce the incidence of VTE. Receipt and timing of chemical VTE prophylaxis. The primary outcome was overall VTE rate stratified by receipt and timing of cVTE. The secondary outcome was safety of cVTE as measured by bleeding or other complications from anticoagulation. Among 460 high-risk pediatric trauma patients, the median (IQR) age was 14.5 years (10.4-16.2 years); 313 patients (68%) were male and 147 female (32%). The median (IQR) Injury Severity Score (ISS) was 23 (16-30), and median (IQR) number of high-risk factors was 3 (2-4). A total of 251 (54.5%) patients received cVTE; 62 (13.5%) received cVTE within 24 hours of admission. Patients who received cVTE after 24 hours had more high-risk factors and higher ISS. The most common reason for delayed cVTE was central nervous system bleed (120 patients; 30.2%). There were 28 VTE events among 25 patients (5.4%). VTE occurred in 1 of 62 patients (1.6%) receiving cVTE within 24 hours, 13 of 189 patients (6.9%) receiving cVTE after 24 hours, and 11 of 209 (5.3%) who had no cVTE (P = .31). Increasing time between admission and cVTE initiation was significantly associated with VTE (odds ratio, 1.01; 95% CI, 1.00-1.01; P = .01). No bleeding complications were observed while patients received cVTE. In this prospective study, use of cVTE based on a set of high-risk criteria was safe and did not lead to bleeding complications. Delay to initiation of cVTE was significantly associated with development of VTE. Quality improvement in pediatric VTE prevention may center on timing of prophylaxis and barriers to implementation.

Aspirin is an Effective Prophylaxis for Venous Thromboembolism After Revision Hip and Knee Arthroplasty

BackgroundVenous thromboembolism (VTE) following revision total joint arthroplasty (TJA) poses significant risks despite prophylactic measures. The optimal VTE prophylaxis agent for revision TJA remains unclear. This study aimed to compare aspirin against various anticoagulant agents regarding efficacy and safety in preventing symptomatic VTE events after revision TJA. MethodsA retrospective analysis included 4,575 patients undergoing revision TJA between 2008 and 2020. Of these, 2,091 received aspirin, while 2,484 received other anticoagulants. Demographic, procedural, and outcome data were collected. Logistic regression models were used to identify predictors of symptomatic VTE. ResultsThe aspirin group showed a significantly lower incidence of symptomatic VTE compared to the other anticoagulant group (0.53 versus 2.54%, P < .001). Logistic regression confirmed a higher risk of VTE with other anticoagulants (odds ratio: 0.2 to 0.26, P < .001), while blood transfusion (odds ratio: 2.72, P = .001) were identified as risk factors. ConclusionsThis study demonstrated that aspirin is a viable and potentially safer option than other anticoagulants, exhibiting comparable efficacy in preventing VTE events in revision TJA. Balancing effectiveness and safety is crucial, considering patient-specific risk factors and bleeding tendencies. This large cohort study demonstrated that aspirin was associated with a more effective and safer VTE prophylaxis agent, compared to other anticoagulants, in patients undergoing revision TJA.

Venous and Arterial Thromboembolism in Lung Cancer Patients: A Retrospective Analysis.

Background: Patients with lung cancer face an increased incidence of venous (VTE) and arterial (ATE) thromboembolism. Risk factors for thrombosis remain unclear, particularly the impact of the use of immune checkpoint inhibitors (ICIs). We sought to compare the incidence of VTE and ATE in lung cancer patients receiving platinum-based therapy versus those receiving ICIs alone or in combination with chemotherapy and to validate the Khorana risk score for predicting VTE in the era of ICIs. Methods: A retrospective single-institution data analysis of 173 patients diagnosed with locally advanced or metastatic lung cancer at the Jena University hospital between 2015 and 2021. Results: The study revealed a high incidence of VTE (17.9%) and ATE (5.8%). The VTE risk was higher in patients diagnosed with adenocarcinoma (OR 0.29, 95% CI 0.09-0.93) than in patients with other histological types. A prior venous event was associated with an increased risk of recurrent VTE (OR 4.46, 95% CI 1.20-16.63). The incidence of thrombosis under first-line platinum-based chemotherapy did not differ from the incidence under ICIs (p = 0.19). There were no differences in the subgroup of patients who received ICIs alone or combined immunochemotherapy (p = 0.43). The Khorana score failed to predict the risk of VTE correctly. Conclusions: We did not find evidence supporting the theory that ICI therapy (alone or combined) increases the risk of thrombotic events. Adenocarcinoma and a prior history of VTE were strongly associated with an increased risk of VTE. Other scores for thrombotic risk assessment in lung cancer patients should be tested in prospective studies.

Incidence of venous thromboembolism and bleeding in patients with malignant central nervous system neoplasm: Systematic review and meta-analysis.

This systematic review and meta-analysis (PROSPERO CRD42023423949) were based on a standardized search of PubMed, Virtual Health Library and Cochrane (n = 1653) in July 2023. After duplicate removal, data screening and collection were conducted by independent reviewers. The combined rates and 95% confidence intervals for the incidence of VTE and bleeding were calculated using the random effects model with double arcsine transformation. Subgroup analyses were performed based on sex, age, income, and type of tumor. Heterogeneity was calculated using Cochran's Q test and I2 statistics. Egger's test and funnel graphs were used to assess publication bias. Only 36 studies were included, mainly retrospective cohorts (n = 30, 83.3%) from North America (n = 20). Most studies included were published in high-income countries. The sample size of studies varied between 34 and 21,384 adult patients, mostly based on gliomas (n = 30,045). For overall malignant primary CNS neoplasm, the pooled incidence was 13.68% (95%CI 9.79; 18.79) and 11.60% (95%CI 6.16; 18.41) for VTE and bleeding, respectively. The subgroup with elderly people aged 60 or over had the highest incidence of VTE (32.27% - 95%CI 14.40;53.31). The studies presented few biases, being mostly high quality. Despite some variability among the studies, we observed consistent results by performing sensitivity analysis, which highlight the robustness of our findings. Our study showed variability in the pooled incidence for both overall events and subgroup analyses. It was highlighted that individuals over 60 years old or diagnosed with GBM had a higher pooled incidence of VTE among those with overall CNS malignancies. It is important to note that the results of this meta-analysis refer mainly to studies carried out in high-income countries. This highlights the need for additional research in Latin America, and low- and middle-income countries.

THE INCIDENCE OF VTE IN FOOT AND ANKLE SURGERY IN THE UK: UK FOOT AND ANKLE THROMBO-EMBOLISM AUDIT (UK-FATE)

IntroductionVTE is a possible complication of foot and ankle surgery, however there is an absence of agreement on contributing risk factors in the development of VTE. The primary outcome of this study was to analyse the 90-day incidence of symptomatic VTE following foot and ankle surgery and to determine which factors may increase the risk of VTE.MethodsThis was a national, multi-centre prospective audit spanning a collection duration of 9 months (2022/2023). Primary outcomes included incidence of symptomatic VTE and VTE related mortality up to 90 days following foot and ankle surgery and Achilles tendon rupture, and analysis of risk factors.ResultsIn total 11,363 patients were available for analysis. 5,090 patients (44.79%) were elective procedures, 4,791 patients (42.16%) were trauma procedures (excluding Achilles ruptures), 398 patients (3.50%) were acute diabetic procedures, 277 patients (2.44%) were Achilles ruptures undergoing surgery and 807 patients (7.10%) were Achilles ruptures treated non-operatively. There were 99 cases of VTE within 90 days of admission across the whole group (Total incidence = 0.87%), with 3 cases of VTE related mortality (0.03%). On univariate analysis, increased age and ASA grade showedhigher odds of 90-day VTE, as did previous cancer, stroke, history of VTE, and type of foot and ankle procedure / injury (p&lt;0.05). However, on multivariate analysis, the only independent predictors for 90-day VTE were found to be the type of foot and ankle procedure (Achilles tendon rupture = Odd's Ratio 11.62, operative to 14.41, non-operative) and ASA grade (grade III/IV = Odd's Ratio 3.64).ConclusionThe incidence of 90-day post procedure VTE in foot and ankle surgery in this national audit was low. Significant, independent risk factors associated with the development of 90-day symptomatic VTE were Achilles tendon rupture management and high ASA grade.

Molecular mechanisms of thrombotic complications in glial tumors

Cancer patients are at increased risk of venous thromboembolic complications (VTE), which are the second leading cause of death in these patients. Moreover, the maximum incidence of VTE occurs in tumors of the central nervous system [1]. Research is being conducted to identify laboratory biomarkers of increased risk of VTE, but to date data on their role are ambiguous. Patients with a mutation in the isocitrate dehydrogenase (IDH) gene are at lower risk of VTE, and the IDH mutation is associated with suppression of the production of tissue factor (TF) and podoplanin, the most studied molecules responsible for the occurrence of thromboembolic complications [2]. The main specific markers of VTE are based on immunohistochemical methods, which are possible only with histological examination of the tumor material. Therefore, it is important to find noninvasive biomarkers that could be used to assess the risk of venous thromboembolic complications. In this review, we will focus on highlighting the accumulated knowledge on this theme.

Subcutaneous amivantamab vs intravenous amivantamab, both in combination with lazertinib, in refractory EGFR-mutated, advanced non-small cell lung cancer (NSCLC): Primary results, including overall survival (OS), from the global, phase 3, randomized controlled PALOMA-3 trial.

LBA8505 Background: Amivantamab (ami) plus lazertinib (laz) demonstrated antitumor activity in EGFR-mutated advanced NSCLC. Subcutaneous (SC) ami administration takes ≤7 mins and has low infusion-related reaction (IRR) rates. PALOMA-3 (NCT05388669) evaluated SC ami+laz vs IV ami+laz for pharmacokinetics (PK), efficacy, and safety among pts with EGFR Ex19del or L858R-mutated advanced NSCLC and disease progression on osimertinib and platinum-based chemotherapy. Methods: SC ami at 1600 mg (2240 mg, ≥80 kg) was manually injected weekly for the first 4 weeks, then every 2 weeks; IV ami was given at the approved dose of 1050 mg (1400 mg, ≥80 kg). Laz was orally dosed at 240 mg daily. Co-primary PK noninferiority endpoints were trough concentration (Ctrough on Cycle [C] 2 Day [D] 1 or C4D1) and C2 area under the curve (AUCD1-D15). Key secondary endpoints were objective response rate (ORR; noninferior) and progression-free survival (PFS). OS was a predefined exploratory endpoint. Prophylactic anticoagulation was recommended for the first 4 months (mo) of treatment. Results: In total, 418 patients (pts) were randomized (SC, n = 206; IV, n = 212); 416 received ≥1 dose. Overall, median age was 61 years, 67% were female, 61% Asian, and median 2 prior lines. At a median follow-up of 7.0 mo, PALOMA-3 met both co-primary endpoints. Geometric mean ratios (GMRs) comparing SC ami+laz vs IV for Ctrough were 1.15 (90% CI, 1.04–1.26) for C2D1 and 1.43 (90% CI, 1.27–1.61) for C4D1. GMR for C2 AUCD1-D15 was 1.03 (90% CI, 0.98–1.09). ORR was 30.1% (95% CI, 24–37) in the SC arm and 32.5% (95% CI, 26–39) for IV (relative risk, 0.92; P= 0.001), meeting the noninferiority criteria. Median duration of response (DoR) was longer for SC ami+laz vs IV (median, 11.2 vs 8.3 mo among confirmed responders). A favorable PFS trend was observed for SC ami+laz over IV (median, 6.1 vs 4.3 mo; HR, 0.84; P= 0.20). OS was notably longer for SC ami+laz vs IV (HR, 0.62; 95% CI, 0.42–0.92; nominal P= 0.017). At 12 mo, 65% were alive in the SC arm vs 51% for IV. IRRs were ~5-fold lower in the SC arm: 13% vs 66% for IV, primarily grade 1-2 (0.5% vs 4% grade ≥3, respectively). Overall, 81% received prophylactic anticoagulants, with VTE reported by 9% in the SC arm vs 14% for IV. Across both arms, VTE incidence was 10% for pts who received prophylactic anticoagulants vs 21% for pts who did not. Severe bleeding risk was low among all pts receiving anticoagulants (1% grade ≥3). Conclusions: SC ami demonstrated noninferior PK and ORR compared to IV. Unexpectedly, DoR, PFS, and OS were longer in the SC arm vs IV, suggesting that the route of administration or formulation may affect outcomes. The safety profile was improved for SC ami, with lower IRR and VTE rates. Prophylactic anticoagulation can be safely implemented and reduces VTE risk. Clinical trial information: NCT05388669 .

ACUTE VENOUS THROMBOEMBOLISM IS COMMON FOLLOWING ACUTE NECROTIZING PANCREATITIS AND IS ASSOCIATED WITH WORSE CLINICAL OUTCOMES.

While splanchnic vein thrombosis (SVT) is a well-known local complication of acute pancreatitis, extra-splanchnic VTE (ESVT) is inadequately studied. Here, we aim to explore the incidence of VTE in acute necrotizing pancreatitis (ANP) and the associated mortality. This is a retrospective cohort study utilizing an electronic health record database. Adults with a diagnosis of ANP from January 2017 to December 2022 were identified using appropriate ICD-10-CM codes. The primary outcome was development of acute ESVT within one month of ANP. Secondary outcomes were 90-day mortality, 30-day rehospitalization, and oral anticoagulant (OAC) use in patients with ESVT. Propensity score matching (1:1) was performed for baseline characteristics and common comorbidities. 17,942 (7.11%) patients were diagnosed with ANP during the study period and about 10% (1,737) of them had a diagnosis of ESVT. Of all VTE, 61% were ESVT with or without SVT, and 63% (N = 1,799) were SVT. 90-day mortality (16.3% vs. 5.7%, risk ration, RR 2.86 [95% CI 2.29-3.56]) and 30-day rehospitalization (31% Vs 19%, RR 1.63 [95% CI 1.49-1.79]) were higher in patients with ESVT compared to non-VTE patients. 60% of patients with ESVT were on OAC and OAC use was associated with lower 90-day mortality (8.9% vs. 19.4%, RR 0.46) without increased risk of adverse events, like - acute gastrointestinal bleeding, intracranial bleeding, or need for packed red cell transfusion. Systemic VTE is common in patients with ANP and may contribute to increased mortality and risk of readmissions. Prospective studies can confirm our findings and explore the role of aggressive VTE prophylaxis in patients with ANP during hospital stay, and in the immediate ambulatory period.

The variation of anticoagulation prescribed in foot and ankle surgery in the UK – UK foot and ankle thrombo-embolism audit (UK-FATE)

IntroductionVenous thrombo-embolism (VTE) is a recognised complication of foot and ankle surgery. There are multiple possible anticoagulation treatments available in the UK to mitigate the risk of developing VTE. Our primary objective was to assess the variability of chemical anticoagulation prescribed in patients undergoing foot and ankle procedures. MethodsThis was a UK-based national, multicenter, prospective audit spanning a collection duration of 9 months on all foot and ankle procedures, carried out in 68 UK centers between 1st June 2022 and 30th November 2022, with a further 3-month follow up period. All patients who underwent a foot and ankle surgical procedure (including Achilles tendon rupture treatment) were included in this study. ResultsData on a total of 13,569 patients was submitted. Following data cleansing, 11,363 patients were available for further analysis, with anticoagulation data available for 11,099 patients. There were eleven different chemical anticoagulation treatments recorded across the cohort. A total of 3630 (31.95 %) patients received no chemical anticoagulation. The patients receiving chemical anticoagulation medication could be split into 4 main groups. The most common chemical anticoagulation received was low molecular weight heparin (LMWH) (6303, 84.4 % of patients receiving chemical anticoagulation). Aspirin was given in 4.1 % (308 patients), a Factor Xa inhibitor in 10 % (744 patients) and other anticoagulants (e.g. Warfarin) in 1.5 % (114 patients). The overall VTE rate in this sub analysis of patients receiving chemical anticoagulation, was 1.1 % (83 cases out of 7469). There was no significant difference seen in incidence of VTE between types of anticoagulants, when confounding factors were considered. The duration of post-operative chemical prophylaxis used by participants for most chemical anticoagulants was 6 weeks (64.50 %). ConclusionThere was significant variability of chemical anticoagulants reported in the study, with five different categories of anticoagulants used (including no chemical anticoagulation), and none clearly superior/inferior. The duration of anticoagulation was consistent across types of thromboprophylaxis.

Amivantamab plus lazertinib in atypical EGFR-mutated advanced non-small cell lung cancer (NSCLC): Results from CHRYSALIS-2.

8516 Background: Afatinib is the only EGFR tyrosine kinase inhibitor (TKI) approved to treat patients (pts) with EGFR-mutated advanced NSCLC harboring atypical mutations (eg, S768I, L861Q, G719X), excluding exon 20 insertion mutations (Ex20ins). In a retrospective analysis of 38 TKI-naïve pts, 27 had a response to afatinib, with a median duration of response (mDoR) of 11.1 months (mo) and median progression-free survival (mPFS) of 10.7 mo (Yang Lancet Oncol 2015;16(7):830-8). Amivantamab (ami) is an EGFR- MET bispecific antibody with immune-cell directing activity. Lazertinib (laz) is a CNS-penetrant, 3rd-generation EGFR TKI. This combination was evaluated among pts with atypical EGFR-mutated advanced NSCLC. Methods: Cohort C of the CHRYSALIS-2 study (NCT04077463) enrolled pts with atypical EGFR mutations, excluding Ex20ins, who were treatment-naïve or had ≤2 prior lines, which may have included a 1st/2nd-generation EGFR TKI. Pts with Ex19del or L858R co-mutations were excluded. Ami was intravenously administered at 1050 mg (1400 mg, ≥80 kg) weekly for the first 4 weeks and then biweekly. Laz was given orally at 240 mg daily. Response was assessed by the investigator per RECIST v1.1. Results: As of 4 Dec 2023, 105 pts received ami+laz, with a median follow-up of 13.8 mo (range, 0.1–30.2). The median age was 64 years, 50% were female, 68% Asian, 30% White, and 35% had CNS lesions at baseline. The most common mutations were G719X (54%), L861Q (24%), and S768I (22%). The ORR was 51% (95% CI, 41–61). In the treatment-naïve subset (n = 49), ORR was 55% (95% CI, 40–69), with mDoR not estimable (NE; 95% CI, 9.9 mo–NE) and mPFS of 19.5 mo (95% CI, 11.0–NE). Among responders, 78% (21/27) had DoR ≥6 mo. The ORR for pts harboring solitary mutations at G719 (n = 13), L861 (n = 8), and S768 (n = 2) was 54%, 63%, and 100%, respectively. The ORR for pts with compound atypical mutations (n = 17) was 41%, with DoR ≥6 mo for all 7 responders. Among pts treated with prior afatinib (n = 40), ORR was 45% (95% CI, 29–62), with mDoR of 8.9 mo (95% CI, 2.8–NE) and mPFS of 5.7 mo (95% CI, 4.2–10.7). Among the 18 responders, 56% had DoR ≥6 mo. The most common AEs were primarily EGFR- and MET-related toxicities, primarily grade 1-2. Discontinuations of both ami and laz due to treatment-related AEs occurred in 9% of pts. The incidence of VTE was 30% (31/105), with the majority of events, 71% (22/31), occurring in the first 4 mo of treatment. The vast majority of pts, 97% (30/31), were not on anticoagulation at time of first VTE. The rate of pneumonitis/interstitial lung disease was 6%. Biomarker analyses are ongoing; updated results will be presented at time of meeting. Conclusions: In the largest, single-cohort, prospective study of atypical EGFR-mutated advanced NSCLC, ami+laz demonstrated clinically meaningful and durable antitumor activity in pts who were treatment-naïve or had disease progression on afatinib. Clinical trial information: NCT04077463 .

Contributors to post-operative venous thromboembolism risk after breast cancer surgery: A systematic review and meta-analysis

IntroductionVenous thromboembolism (VTE) events are a preventable complication for patients undergoing surgery for breast cancer. However, there is a lack of consistency in the existing literature regarding the potential risk factors affecting these individuals. MethodsThis study aimed to investigate the potential risk factors associated with an increased risk of VTE following surgery for breast cancer. Data on patient characteristics such as age, body mass index (BMI), existing comorbidities, smoking history, surgical interventions, duration of hospitalization, and post-operative complications were recorded and analyzed. ResultsThirty-one studies investigating the incidence of VTE following surgical interventions for breast cancer were included. This study included 22,155 female patients with a mean age of 50.8 ± 2.9 years. The weighted mean length of surgery and hospital stay were 382.1 ± 170.0 min and 4.5 ± 2.7 days, respectively. The patients were followed-up for a weighted mean duration of 13.8 ± 21.2 months. The total incidence of VTE events was 2.2% (n = 489). Meta-analysis showed that patients with post-operative VTE had a significantly higher mean age and BMI, as well as longer mean length of surgery (P < 0.05). Comparing the techniques of autologous breast reconstruction showed that the risk of post-operative VTE is significantly higher with deep inferior epigastric perforator (DIEP) flaps, compared with the transverse rectus abdominus myocutaneous and latissimus dorsi myocutaneous flaps (P < 0.05). Compared with delayed reconstruction, immediate reconstruction was associated with a significantly higher incidence of VTE (P < 0.05). Smoking history, length of hospital stay, and Caprini score did not correlate with increased incidence of post-operative VTE. ConclusionThe incidence rate of VTE events in patients receiving surgical treatment for breast cancer is 2.2%. Risk factors for developing post-operative VTE in this patient population were found to be older age, increased BMI, extended length of surgical procedures, and DIEP flap reconstruction.

763 Is Central Venous Catheter the Main Culprit for Clinically Significant Venous Thromboembolism in Burn Patients

Abstract Introduction Venous thromboembolism (VTE) is a significant clinical problem for burn patients. The incidence of VTE has been reported as 0.25% to 47.1%. Known risk factors include large burn size, increasing age, male gender, active smoker or alcohol use, blood transfusion and surgeries. Central venous line (CVL) use is also a known risk factor for VTE. With all the known factors, we retrospectively analyzed our patients with VTE. Methods Retrospective chart review was performed on a single institution burn center in the calendar year of 2022. Pediatric patients were excluded. Following data were collected: age, burn size, mechanism, length of hospital stays, VTE diagnosis, VTE chemoprophylaxis, and central venous line days. VTE diagnosis was made using CT venogram or ultrasound. This project was a quality improvement initiative. Results There were 420 patients in the study period. Of all the admitted patients, there were 6 patients diagnosed with 7 VTE. One patient had 2 separate diagnoses of VTE at 2 distinct period and anatomical site. The incidence of VTE is 1.7%. Upon further chart review, all the VTE were at the site of central venous catheters. All the patients were on VTE chemoprophylaxis. The correlation between burn size, age, length of hospital stay and VTE was not significant. Conclusions Risk of VTE is high in burn patients due to the correlation with the Virchow’s Triad. All the patients admitted to the burn unit are placed on chemoprophylaxis unless contraindicated. The 7 patients diagnosed with VTE were on chemoprophylaxis. All the VTE were at the site of central venous catheter insertion sites, which is a known complication of catheters. The incident of 1.7% is on par with VTE incidents of burn patients, but much less than VTE caused by central venous catheters in non-burn patients. Large multicenter data collection is needed to validate this finding. Applicability of Research to Practice Directly appliable

120 Venous Thromboembolism Prophylaxis in Burn Patients

Abstract Introduction Venous thromboembolism (VTE) is extensively studied in trauma patients, but burn patients require special consideration due to their unique pathophysiology and management strategies. Currently, there are no specific prophylaxis recommendations to help mitigate VTE in burn patients. Methods The US National Trauma Data Bank (NTDB) was analyzed to identify patients with burn encounters from 2017-2021 using ICD-10 event codes. Our primary outcome measure was incidence of VTE, which included deep venous thrombosis and pulmonary embolism. Secondary outcome measures included need for blood transfusion and need to return to the operating room due to hemorrhage from skin/soft tissues/extremities. Multivariable regressions were conducted to evaluate the relationship between various VTE prophylaxis types and timing of VTE prophylaxis and VTE incidence while controlling for age, sex, %TBSA and inhalation injury. Results A total of 326,614 patients with burn injuries were identified in the NTDB during the study period, of whom 5,604 (1.7%) had a VTE event during their hospital admission. The majority of patients did not receive VTE prophylaxis (54.1%). Of those that did, the most commonly used VTE prophylaxis was LMWH (37.9%), followed by unfractionated heparin (4.1%). When controlling for age, sex, inhalation injury, and %TBSA, unfractionated heparin and LMWH were significantly associated with an increased risk of VTE (heparin: OR=1.8 95% CI 1.3-2.5, p &amp;lt; .001; LMWH: OR=1.5 95% CI 1.2-1.8, p &amp;lt; .001). Longer time to VTE prophylaxis was significantly associated with increased odds of VTE when controlling for the same covariates (OR=1.04 95% CI 1.03=1.07, p &amp;lt; .001). Neither VTE prophylaxis type nor timing of VTE prophylaxis administration was significantly associated with an increased need for blood transfusion. Heparin was the only VTE prophylaxis type significantly associated with increased odds of returning to the OR for a bleeding-related complication (p &amp;lt; .001). Conclusions A majority of burn patients in the NTDB did not receive VTE chemoprophylaxis, and counterintuitively, patients who received VTE chemoprophylaxis had higher rates of VTE than patients who did not, despite controlling for known VTE risk factors. In patients who did get chemoprophylaxis, unfractionated heparin is associated with a higher rate of VTE and surgical bleeding complications when compared with LMWH. Delayed initiation of VTE prophylaxis correlates with a higher likelihood of VTE occurrence. These findings underscore the importance of better studying and developing specialized VTE prevention guidelines for burn patients to enhance their care and outcomes. Applicability of Research to Practice Prompt initiation of VTE prophylaxis is essential to reduce the risk of VTE among burn patients, highlighting the importance of timely interventions. Developing specialized VTE prevention guidelines for this population can enhance their care and outcomes.

Risk of Venous Thromboembolism in Patients With Stage III and IV Non–Small-Cell Lung Cancer: Nationwide Descriptive Cohort Study

BackgroundVenous thromboembolism (VTE) is a common complication in patients starting cancer therapies for non–small-cell lung cancer (NSCLC). We examined the risk and timing of VTE in patients with stage IIIA, IIIB to C, and stage IV NSCLC according to received cancer treatments. Materials and MethodsA nationwide registry-based cohort study of patients recorded in the Danish Lung Cancer Registry (2010-2021) followed for 1 year after entry into the registry to assess the incidence of VTE. The Aalen–Johansen estimator was used to calculate the risk of VTE after treatment commencement with chemotherapy, radiotherapy, chemoradiation, immunotherapy, and targeted therapy. ResultsAmong the 3475 patients with stage IIIA, 4047 with stage IIIB to C, and 18,082 patients with stage IV cancer, the 1-year risk of VTE was highest in the first 6 months and varied markedly by cancer stage and cancer treatment. In stage IIIA, VTE risk was highest with chemotherapy (3.9%) and chemoradiation (4.1%). In stage IIIB to C, risks increased with chemotherapy (5.2%), immunotherapy (9.4%), and targeted therapy (6.0%). Stage IV NSCLC showed high risk with targeted therapy (12.5%) and immunotherapy (12.2%). The risk was consistently higher for pulmonary embolism than deep vein thrombosis. ConclusionVTE risks vary substantially according to cancer treatments and cancer stages. The highest risk was observed in the initial 6 months of therapy initiation. These insights emphasize the need for tailored risk assessment and vigilance in managing VTE complications in patients with NSCLC. Further research is needed to optimize individual thromboprophylaxis strategies for patients with unresectable and metastatic NSCLC.

Perioperative Venous Thromboembolism Risk in Patients Undergoing Hysterectomy for Fibroids: A US Retrospective Cohort Study

ObjectivesVenous thromboembolism (VTE) occurs in 0.4%–0.7% of benign hysterectomies. Pelvic vascular compression secondary to fibroids may elevate VTE risk. We aimed to evaluate the incidence and timing of VTE among individuals undergoing hysterectomy for fibroids and other benign indications. MethodsRetrospective cohort study of patients who underwent a hysterectomy for fibroid and non-fibroid indications from January 2015 to December 2021. Main outcome measure was VTE consisting of pulmonary embolism or deep venous thrombosis diagnosed during 3 periods: (1) preoperative (1 year before surgery until day before surgery), (2) early postoperative (surgery date through 6 weeks after surgery), and (3) late postoperative (6 weeks to 1 year after surgery). Demographics, comorbidities, surgical characteristics, and VTE rates were compared by indication. ResultsA total of 263 844 individuals with fibroids and 203 183 without were identified. In total, 1.1% experienced VTE. On multivariable regression (adjusted demographic confounders and route of surgery), the presence of fibroids was associated with increased odds of preoperative (adjusted odds ratio [aOR] 1.12; 95% CI 1.03–1.22, P = 0.011) and reduced odds of late postoperative VTE (aOR 0.81; 95% CI 0.73–0.91, P < 0.001). For individuals with fibroids, uterine weight ≥250 g and undergoing laparotomy were independently associated with preoperative (aOR 1.29; 95% CI 1.09–1.52, P = 0.003 and aOR 2.32; 95% CI 2.10–2.56, P < 0.001) and early postoperative VTE (aOR 1.32; 95% CI 1.08–1.62, P = 0.006 and aOR 1.72; 95% CI 1.50–1.96, P < 0.001). ConclusionsPatients with fibroids were at increased odds of having VTE 1 year before hysterectomy. For those with fibroids, elevated uterine weight and laparotomy were associated with greater risk of preoperative and early postoperative VTEs.