Initial clinical experience with the Quantra QStat System in adult trauma patients.

BACKGROUND: Whole blood viscoelastic testing (VET) devices are routinely used in a variety of clinical settings to assess hemostasis. The Quantra QStat System is a cartridge-based point of care VET device that measures changes in clot stiffness during coagulation and fibrinolysis using ultrasound detection of resonance. The objective of this study was to assess the ability of the Quantra QStat System to detect coagulopathies in trauma patients. METHODS: A multicenter observational study was conducted on adult subjects at two level 1 trauma centers. For each subject, whole blood samples were drawn upon arrival to the emergency department and again, in some cases, after administration of blood products and/or antifibrinolytics. Samples were analyzed on the Quantra in parallel to ROTEM delta. The QStat cartridge provides measures of Clot Time (CT), Clot Stiffness (CS), Fibrinogen and Platelet Contributions to clot stiffness (FCS and PCS), and Clot Stability to Lysis (CSL). Data analyses included linear regression of Quantra and ROTEM parameters and an assessment of the concordance of the two devices for the assessment of hyperfibrinolysis. RESULTS: A total of 56 patients were analyzed. 42% of samples had a low QStat CS value suggestive of an hypocoagulable state. The low stiffness values could be attributed to either low PCS, FCS or combination. Additionally, 13% of samples showed evidence of hyperfibrinolysis based on the QStat CSL parameter. Samples analyzed with ROTEM assays showed a lower prevalence of low CS and hyperfibrinolysis based on EXTEM and FIBTEM results. The correlation of CS, FCS and CT versus equivalent ROTEM parameters was strong with r-values of 0.83, 0.79 and 0.79, respectively. DISCUSSION: This first clinical experience with the Quantra in trauma patients showed that the QStat Cartridge was strongly correlated with ROTEM parameters and that it could detect coagulopathies associated with critical bleeding. LEVEL OF EVIDENCE: Diagnostic test, Level II.

Multicenter Evaluation of the Quantra QPlus System in Adult Patients Undergoing Major Surgical Procedures.

BACKGROUND: The management of perioperative bleeding and the optimization of the available therapies are subjects of significant clinical interest. Clinical guidelines recommend the use of whole blood viscoelastic testing devices to target the utilization of blood products during major surgical procedures. The Quantra QPlus System is a new cartridge-based viscoelastic testing device based on an innovative ultrasound technology. The aim of this study was to evaluate this new system in a surgical population. METHODS: Two hundred seventy-seven adult subjects were enrolled in a multicenter, prospective observational study consisting primarily of patients undergoing cardiac and major orthopedic surgeries. Samples were obtained at multiple time points for testing on the Quantra QPlus System, the rotational thromboelastometry (ROTEM) delta, and standard coagulation tests. Quantra measurements included Clot Time (CT), Heparinase Clot Time (CTH), Clot Time Ratio (CTR), Clot Stiffness (CS), Fibrinogen (FCS), and Platelet (PCS) Contributions to CS. Data analyses included assessment of the concordance of Quantra parameters with a series of clinical composite indexes formed on the basis of standard coagulation tests in 3 domains representing increased, decreased, and normal/subclinical coagulation function. Linear regression and receiver operator characteristic (ROC) analyses of Quantra parameters with corresponding parameters from ROTEM assays were also performed. RESULTS: The accuracy (overall percent agreement or ratio of true positives and true negatives over the entire population) between the Quantra and the composite indexes was between 72% and 98% depending on the specific parameter. Linear regression analysis indicated that the correlation between ROTEM delta and Quantra was very strong with r values ranging between 0.84 and 0.89. Results from ROC analysis demonstrated sensitivities and specificities in the 80%-90% range when QPlus parameters were used to discriminate ROTEM threshold values currently used in goal-directed treatment algorithms. CONCLUSIONS: This study demonstrated that the Quantra QPlus System is strongly correlated with a well-established viscoelastic testing device and its parameters effectively represent the results from multiple standard laboratory assays. The Quantra has been designed to operate at the point of care with the potential to provide rapid and comprehensive results to aid in the management of coagulopathic patients.

Comparison of Coagulation Parameters in Arterial and Venous Blood in Cardiac Surgery Measured Using the Quantra System.

OBJECTIVE: Perioperative coagulation testing often is performed with arterial samples even though device reference ranges typically are established in venous samples. Although limited studies exist comparing coagulation parameters across sampling sites, viscoelastic testing devices have demonstrated some differences. The objective of this study was to compare coagulation parameters determined using the Quantra System for venous and arterial samples. DESIGN: Prospective, observational study. SETTING: Tertiary care university hospital. PARTICIPANTS: The study comprised 30 adult patients undergoing cardiac surgery. INTERVENTIONS: Paired arterial and venous samples were obtained at 2 of the following time points: baseline, during bypass, or after protamine reversal of heparin. Quantra measurements included Clot Time (CT), Heparinase Clot Time (CTH), Clot Time Ratio (CTR), Clot Stiffness (CS), and Fibrinogen (FCS) and Platelet (PCS) Contributions to clot stiffness. MEASUREMENTS AND MAIN RESULTS: The relationship and agreement between matched data pairs were established and statistical analysis was performed via paired t tests. CTR, CS, FCS, and PCS were unaffected by the sampling site, whereas CT and CTH demonstrated statistically significant differences between arterial and venous samples (p < 0.001). Arterial clot times were prolonged relative to the venous ones with a mean percent error of 14.2 % and 11.9 %, respectively. These results are in general agreement with those reported for other viscoelastic testing devices. CONCLUSIONS: This study demonstrates that Quantra clot stiffness-based parameters (CS, FCS, PCS) are unaffected by sampling site, whereas the clot time parameters (CT and CTH) show good correlation in the presence of a bias. CTR, a ratio of CT and CTH, also is unaffected.

Risk factors associated with mortality after Roux-en-Y gastric bypass surgery.

OBJECTIVE: We sought to identify the major risk factors associated with mortality in Roux-en-Y gastric bypass (RYGB) surgery. BACKGROUND: Bariatric surgery has become an established treatment for extreme obesity. Bariatric surgery mortality has steadily declined with current rates of less than 0.5%. However, significant variation in the mortality rates has been reported for specific patient cohorts and among bariatric centers. METHODS: Clinical outcome data from 185,315 bariatric surgery patients from the Bariatric Outcome Longitudinal Database were reviewed. Of these, 157,559 patients had either documented 30 or more day follow-up data, including mortality. Multiple demographic, socioeconomic, and clinical factors were analyzed by univariate analysis for their association with 30-day mortality after gastric bypass. Variables found to be significant were entered into a multiple logistic regression model to identify factors independently associated with 30-day mortality. On the basis of these results, a RYGB mortality risk score was developed. RESULTS: The overall 30-day mortality rate for the entire bariatric surgery cohort was 0.1%. Of the 81,751 RYGB patients, the mortality rate was 0.15%. Factors significantly associated with 30-day gastric bypass mortality included increasing body mass index (BMI) (P<0.0001), increasing age (P<0.005), male gender (P<0.001), pulmonary hypertension (P<0.0001), congestive heart failure (P=0.0008), and liver disease (P=0.038). When the RYGB risk score was applied, a significant trend (P<0.0001) between increasing risk score and mortality rate is found. CONCLUSIONS: Increasing BMI, increasing age, male gender, pulmonary hypertension, congestive heart failure, and liver disease are risk factors for 30-day mortality after RYGB. The RYGB risk score can be used to determine patients at greater risk for mortality after RYGB surgery.

Influence of ethnicity on the efficacy and utilization of bariatric surgery in the USA.

BACKGROUND: Ethnic disparities in patterns of utilization and outcomes after Roux-en-Y gastric bypass surgery (RYGB) were examined from Bariatric Outcomes Longitudinal Database. METHODS: Descriptive statistics were used for demographics of Whites, Blacks, or Hispanics undergoing RYGB with 1 year of follow-up, between June 2007 and October 2011. Multivariate logistic and normal regression models, controlling for baseline characteristics, examined relationships between race and outcomes. T tests were used for continuous variables and Pearson chi-square test for categorical variables. RESULTS: Study patients (108,333) were79 % White, 12 % Black, and 9 % Hispanic. Fewer Black males underwent surgery (15 %) compared to Whites or Hispanics (∼22 %). Blacks compared to Whites were younger (42.7 ± 10.6 vs. 46.4 ± 11.6 years), heavier BMI (50 ± 9.1 vs. 47.4 ± 8.0 kg/m(2)), and more often hypertensive (57 vs. 52 %). Other comorbidities were higher in Whites. Thirty-day mortality rate was equivalent (0.23-0.26 %), but serious adverse events were higher for Blacks (3.65 %) versus Whites (3.19 %) and Hispanics (2.01 %). At 1 year, weight and comorbidity burden declined significantly but less in Blacks despite adjustment for baseline characteristics. CONCLUSIONS: Fewer Black males underwent RYGB. Despite a smaller percent decline in BMI and comorbidities in Blacks, all races benefitted significantly from RYGB. Influence of other factors such as diet, culture, and genetics needs to be investigated further.

Is ambulatory laparoscopic Roux-en-Y gastric bypass associated with higher adverse events?

OBJECTIVE: To determine the impact of length of stay upon 30-day outcomes. BACKGROUND: It has been recommended the goal length of stay (LOS) after laparoscopic Roux-en-Y gastric bypass (LRYGB) should be 1 day to improve resource utilization. This study's aim was to assess LRYGB outcomes by LOS. METHODS: Data were obtained from the BOLD (Bariatric Outcomes Longitudinal Database) for 51,788 laparoscopic gastric bypass (LRYGB) procedures performed between 2007 and 2010. Logistic regression models were used to evaluate age, sex, race, body mass index, insurance status, comorbidities, and LOS as predictors for 30-day mortality, serious complications, and readmissions. RESULTS: Overall patient demographics were as follows: median age, 45 years; median body mass index, 46.3 kg/m; % female, 78.6; % white, 77.8; % private insurance, 86.2; and % comorbidities more than 5 (39.1%). Overall, 30-day outcomes included mortality, 0.1%; serious complications, 0.5%; and readmissions, 3.8%. median LOS was 2 days, and the distribution of LOS was as follows [n (%)]: 0 (1.0), 1 (18.4), 2 (59.0), 3 (17.5), and 4 (4.1). Using the median LOS 2 days as reference, the logistic regression analysis revealed that ambulatory LOS of was significantly associated with increased risk of 30-day mortality (odds ratio: 13.02; P < 0.0001) as was LOS 1 day (odds ratio: 2.02; P < 0.0552). For LOS of 0 day, there was a trend toward an increase in the rate of 30-day serious complications (odds ratio: 1.9; P < 0.16). There was no significant trend between LOS status and 30-day readmission rates. CONCLUSIONS: In this large, prospective, clinical database, LOS of 1 day or less for LRYGB patients was significantly associated with an increased risk of 30-day mortality and a trend toward increased risk of 30-day serious complications.

Effect of ethnicity on weight loss among adolescents 1 year after bariatric surgery.

AIM: To investigate whether or not bariatric surgery weight outcomes vary by ethnicity in a large, nationally representative sample of adolescents. METHODS: The Bariatric Outcomes Longitudinal Database was used for analysis and contains data on surgeries performed on adolescents from 2004 to 2010 from 423 surgeons at 360 facilities across the United States Adolescents (n = 827) between 11 and 19 years old who underwent either gastric bypass or adjustable gastric banding surgery were included in the analysis. Outcome measures included changes in anthropometric measurements [weight (kg) and body mass index] from baseline to 3 (n = 739), 6 (n = 512), and 12 (n = 247) mo after surgery. RESULTS: A year after patients underwent either gastric bypass (51%) or adjustable gastric banding (49%) surgery, mean estimated weight loss for all ethnic groups differed by a maximum of only 1.5 kg, being 34.3 kg (95%CI: 30.0-38.5 kg) for Hispanics, 33.8 kg (95%CI: 27.3-40.3 kg) for non-Hispanic blacks, and 32.8 kg (95%CI: 30.9-34.7 kg) for non-Hispanic whites. No overall pairwise group comparisons were significant, indicating that no ethnic group had better weight loss outcomes than did another. CONCLUSION: Bariatric surgery substantially reduces the weight of severely obese adolescents at 1 year post-procedure with little variation by ethnicity and/or gender. These results suggest that bariatric surgery is a safe and reasonable treatment for all severely obese adolescents with the appropriate indications.

Changes in weight and co-morbidities among adolescents undergoing bariatric surgery: 1-year results from the Bariatric Outcomes Longitudinal Database.

BACKGROUND: Bariatric surgery is 1 of the few effective treatments of morbid obesity. However, the weight loss and other health-related outcomes for this procedure in large, diverse adolescent patient populations have not been well characterized. Our objective was to analyze the prospective Bariatric Outcomes Longitudinal Database (BOLD) to determine the weight loss and health related outcomes in adolescents. The BOLD data are collected from 423 surgeons at 360 facilities in the United States. METHODS: The main outcome measures included the anthropometric and co-morbidity status at baseline (n = 890) and at 3 (n = 786), 6 (n = 541), and 12 (n = 259) months after surgery. Adolescents (75% female; 68% non-Hispanic white, 14% Hispanic, 11% non-Hispanic black, and 6% other) aged 11 to 19 years were included in the present analyses. RESULTS: The overall 1-year mean weight loss for those who underwent gastric bypass surgery was more than twice that of those who underwent adjustable gastric band surgery (48.6 versus 20 kg, P < .001). Similar results were found for all other anthropometric changes and comparisons within 1 year between surgery types (P < .001). In general, the gastric bypass patients reported more improvement than the adjustable gastric band patients in co-morbidities at 1 year after surgery. A total of 45 readmissions occurred among gastric bypass patients and 10 among adjustable gastric band patients, with 29 and 8 reoperations required, respectively. CONCLUSIONS: The weight loss at 3, 6, and 12 months after surgery is approximately double in adolescent males and females who underwent gastric bypass surgery versus those who underwent adjustable gastric band surgery. Bariatric surgery can safely and substantially reduce weight and related co-morbidities in morbidly obese adolescents for ≥1 year.

Risk stratification of serious adverse events after gastric bypass in the Bariatric Outcomes Longitudinal Database.

BACKGROUND: There is now sufficient demand for bariatric surgery to compare bariatric surgeons and bariatric centers according to their postsurgical outcomes, but few validated risk stratification measures are available to enable valid comparisons. The purpose of this study was to develop and validate a risk stratification model of composite adverse events related to Roux-en-Y gastric bypass (RYGB) surgery. METHODS: The study population included 36,254 patients from the Bariatric Outcomes Longitudinal Database (BOLD) registry who were 18-70 years old and had RYGB between June 11, 2007, and December 2, 2009. This population was randomly divided into a 50% testing sample and a 50% validation sample. The testing sample was used to identify significant predictors of 90-day composite adverse events and estimate odds ratios, while the validation sample was used to assess model calibration. After validating the fit of the risk stratification model, the testing and validation samples were combined to estimate the final odds ratios. RESULTS: The 90-day composite adverse event rate was 1.48%. The risk stratification model of 90-day composite adverse events included age (40-64, ≥ 65), indicators for male gender, body mass index (50-59.9, ≥ 60), obesity hypoventilation syndrome, back pain, diabetes, pulmonary hypertension, ischemic heart disease, functional status, and American Society of Anesthesiology classes 4 or 5. Our final gastric bypass model was predictive (c-statistic = .68) of serious adverse events 90 days after surgery. CONCLUSIONS: With additional validation, this risk model can inform both the patient and surgeon about the risks of bariatric surgery and its different procedures, as well as enable valid outcomes comparisons between surgeons and surgical programs.

Early outcomes of bariatric surgery in patients with metabolic syndrome: an analysis of the bariatric outcomes longitudinal database.

BACKGROUND: Metabolic syndrome (MetS) complicating obesity is endemic in the United States. STUDY DESIGN: Bariatric Outcomes Longitudinal Database, the national database for the American Society for Metabolic and Bariatric Surgery Bariatric Surgery Center of Excellence Program, was queried to identify patients undergoing bariatric surgery from June 2007 through November 2010. MetS was defined as the presence of hypertension, diabetes, and dyslipidemia at presentation for bariatric surgery. Ninety-day and 1-year outcomes were assessed to determine early outcomes in bariatric surgery patients with MetS. RESULTS: Among 186,576 research-consented patients, 23,106 (12%) were diagnosed with MetS. Patients with MetS were more likely to be male (35% vs 20%; p < 0.0001), older (mean age 54 vs 44 years; p < 0.0001), and Caucasian (81% vs 74%; p < 0.0001). Of the 23,106 MetS patients, more underwent gastric bypass (RYGB) (62%) compared with gastric banding (32%), sleeve gastrectomy (4.5%), and biliopancreactic diversion with duodenal switch (BPD/DS)(1.5%). MetS patients had an increase in serious complications (2.4% vs 1.0%; p < 0.0001), readmissions (6.2% vs 4.7%; p < 0.0001), and mortality (0.3% vs 0.1%; p < 0.0001) within 90 days of operation. After adjusting for sex, age, and body mass index, RYGB patients with MetS had an increased risk of 90-day serious complications compared to RYGB patients without MetS (odds ratio 1.43; 95% CI, 1.27 to 1.61; p < 0.0001). The 12-month remission rate of diabetes was least for gastric banding (28%) compared with the other procedures (RYGB 62%, sleeve gastrectomy 52%, BPD/DS 74%). CONCLUSIONS: Patients with MetS undergoing bariatric surgery showed dramatic improvement in diabetes 1-year after surgery; however, an adverse 90-day outcome was more common.

Venous thromboembolism after bariatric surgery performed by Bariatric Surgery Center of Excellence Participants: analysis of the Bariatric Outcomes Longitudinal Database.

BACKGROUND: Venous thromboembolism (VTE) is an uncommon complication of bariatric surgery but a leading cause of postoperative mortality. Studying the factors predictive of low-incidence complications requires the analysis of large cohorts. The Bariatric Outcomes Longitudinal Database, the world's largest prospective database for bariatric surgery, has provided a suitable medium for analyzing low-frequency events. METHODS: The data in the Bariatric Outcomes Longitudinal Database from 73,921 research-consented patients who had undergone bariatric surgery by a participant in the American Society for Metabolic and Bariatric Surgery Bariatric Surgery Center of Excellence program before September 22, 2009, were analyzed for VTE events within 90 days after surgery. RESULTS: The overall risk of VTE within 90 days after surgery was .42%, and 73% of these events occurred after discharge, most within 30 days after surgery. The risk of VTE was greater in the patients undergoing gastric bypass than in those undergoing adjustable gastric banding (.55% versus .16%). VTE was more frequent when the procedure was performed using an open than a laparoscopic approach (1.54% versus .34%). Patients with a VTE event were older (+4.9 yr), had had a greater preoperative body mass index (+3.9 kg/m(2)), and were more likely to have a history of VTE (16.5% versus 3.7%). The risk of VTE was greater in men (hazard ratio 2.32, 95% confidence interval 1.81-2.98) and in patients with an inferior vena cava filter (hazard ratio 7.66, 95% confidence interval 4.55-12.91). CONCLUSION: The overall risk of VTE was low in the population treated by participants in the Bariatric Surgery Center of Excellence program, where clinical pathways to prevent VTE have been mandated. Analysis of this large study population allowed the identification of patient characteristics correlating with increased risk of postoperative VTE and the variable effectiveness of VTE prophylaxis methods.

Early postoperative outcomes of metabolic surgery to treat diabetes from sites participating in the ASMBS bariatric surgery center of excellence program as reported in the Bariatric Outcomes Longitudinal Database.

OBJECTIVE: Small case series suggest bariatric surgery may be an effective treatment for type 2 diabetes mellitus in patients who do not meet body weight criteria for morbid obesity (body mass index [BMI], <35 kg/m), but large multi-institutional series, which allow better assessment of the safety and efficacy of treatment, have not been reported. METHODS: Data from 66,264 research-consented patients with a primary bariatric surgery encounter in the Bariatric Outcomes Longitudinal Database from June 2007 to June 2009 were queried to identify patients with a BMI > or =30 but <35 kg/m2 (1.2%, n = 794) and diabetes requiring any medication (29%). RESULTS: A total of 235 patients met inclusion criteria. The 2 most common procedures, adjustable gastric banding (n = 109) and gastric bypass (n = 109), were compared. Laparoscopic access was used in 92% of procedures. Gender (76.6% female), race (80.4% White), and age (mean 52.6 +/- 10.4 years) did not differ between procedure groups. Gastric bypass provided superior weight loss and diabetes remission but demonstrated more frequent complications (90-day complications: 18% vs. 3%, P < 0.05). No mortalities were reported, and most complications were minor. CONCLUSIONS: The data suggest early effectiveness of surgical treatment of diabetes in patients who do not meet criteria for morbid obesity. Gastric bypass provides more effective treatment for diabetes than adjustable gastric banding within 6 to 12 months.

Baseline data from American Society for Metabolic and Bariatric Surgery-designated Bariatric Surgery Centers of Excellence using the Bariatric Outcomes Longitudinal Database.

BACKGROUND: The Bariatric Outcomes Longitudinal Database (BOLD) is a registry of self-reported bariatric surgery patient information from the American Society for Metabolic and Bariatric Surgery Bariatric Surgery Center of Excellence participants. The present study was undertaken to define the baseline characteristics of the patients with data entered into BOLD. METHODS: The data submitted by >800 surgeons and >450 facilities using BOLD before May 20, 2009, were analyzed. RESULTS: A total of 57,918 research-consented patients with surgical procedure data were included. Of the 57,918 patients, 41,243 were adults aged 26-55 years, with few patients aged < or =18 years (.14%) or > or = 66 years (5.67%). Females constituted a significant majority of the study population (45,619 [78.76%]). Of the 57,918 patients, 78.12% registered were described as Caucasian, 10.52% as African-American, 6.02% as Hispanic, .20% as Asian, and .46% as Native American. The most common bariatric surgical procedure was some form of gastric bypass (31,668 [54.68%]), followed by some form of gastric banding (22,947 [39.62%]), sleeve gastrectomy (1,328 [2.29%]), and biliopancreatic diversion (517 [.89%]). The vast majority of index procedures were completed using laparoscopic surgery techniques, except for biliopancreatic diversion, which was primarily done with an open approach. Through May 2009, 78 deaths were reported at any point after the index procedure, for a mortality rate of .13%. The 90-day mortality rate was .11%, and the 30-day mortality rate was .09%. CONCLUSION: This is the first report of data from BOLD. The data have revealed important characteristics of patients undergoing bariatric surgery across the United States in centers participating in the Bariatric Surgery Center of Excellence program. Future analyses of BOLD data are likely to have a major effect on the specialty of bariatric surgery.

PPARgamma agonists diminish serum VEGF elevation in diet-induced insulin resistant SD rats and ZDF rats.

We investigated the effect of peroxisome proliferator-activated receptor gamma (PPARgamma) agonists on serum vascular endothelial growth factor (VEGF) in diet-induced insulin resistant SD rats and ZDF rats. SD rats fed a high fat/sucrose diet showed increases in serum insulin and VEGF (both p < 0.01). Treatment with a PPARgamma agonist GI262570 normalized the diet-elevated insulin and VEGF (both p < 0.01). There was a positive correlation between serum insulin and VEGF (p < 0.05) in SD rats. ZDF rats had higher serum glucose, insulin, and VEGF than Zucker lean rats (all p < 0.01). Treatment of ZDF rats with PPARgamma agonist pioglitazone decreased serum glucose and VEGF (both p <0.01). There was a positive correlation between glucose and VEGF in ZDF rats (p < 0.05). In 3T3-L1 adipocytes, GI262570 did not affect insulin-stimulated VEGF secretion. These studies demonstrated that hyperinsulinemia in SD rats and hyperglycemia in ZDF rats were associated with increased serum VEGF; PPARgamma agonists normalized serum insulin, glucose, and VEGF, but did not affect VEGF secretion in vitro.