Aortic root repair in a patient with acquired hemophilia A: case report.

BACKGROUND: Patients with acquired hemophilia A (AHA) who require open heart surgery have a life-threatening risk of hemorrhage. Limited data exist to guide perioperative management of these patients. CASE PRESENTATION: A 53-year-old female with rheumatoid arthritis, concomitant aortic valve endocarditis, and severe aortic regurgitation presented to our hospital. Bleeding and abnormal coagulation tests were noted during the initial workup, and she was diagnosed with AHA. The perioperative management plan included the use of pharmaceuticals, porcine recombinant factor VIII, and blood products. Extensive preoperative coagulation data were obtained, and factor VIII levels were continuously monitored to mitigate bleeding complications. The aortic valve replacement and root repair were uneventful. CONCLUSION: Cardiac surgery in patients with AHA is possible as long as complex perioperative hemostatic and hematology management is used.

D-dimer levels remain elevated in acute aortic dissection after 24 h.

BACKGROUND: D-dimer levels are elevated in patients with acute aortic dissection (AAD). Although D-dimer levels have been used to rule out AAD within 24 h of symptom onset, it is unknown whether they may be used reliably after 24 h but within the acute period. Here, we tested the hypothesis that D-dimer levels remain elevated in AAD patients for at least 10 d after dissection onset. MATERIALS AND METHODS: D-dimer levels were measured in preoperative heparinized plasma samples from 100 patients with confirmed AAD for up to 10 d after onset of dissection. When possible, serial samples were obtained for ≥2 d. D-dimer levels were measured in fibrinogen equivalent units using a BCS XP automated coagulation analyzer, which is approved for citrated samples. Therefore, we first validated our samples by comparing D-dimer levels in heparinized and citrated plasma samples from 29 individuals, including patients with and without aortic disease and healthy donors. RESULTS: The correlation between heparinized and citrated plasma samples was 0.991 (P ≤ 0.001). At a threshold of 1.6 µg/mL, the overall sensitivity of the D-dimer assay in AAD patients up to 10 d after onset of dissection was 95.3%. CONCLUSIONS: D-dimer levels remained elevated in AAD patients over a 10-d period after dissection onset and may be helpful in ruling out AAD in patients who seek treatment after the first 24 h but within the acute period. Heparinized plasma samples may be substituted for citrated samples when evaluating D-dimer levels using the BCS XP coagulation analyzer.

External quality assurance of fibrinogen assays using normal plasma: results of the 2008 College of American Pathologists proficiency testing program in coagulation.

CONTEXT: Proper diagnosis and therapy of fibrinogen deficiency requires high-quality fibrinogen assays. OBJECTIVE: To assess the interlaboratory bias, precision, and grading of fibrinogen assays used by laboratories participating in the United States College of American Pathologists proficiency testing program in coagulation. DESIGN: Two identical vials of normal plasma were sent to more than 3500 laboratories. Participants measured fibrinogen levels using local methods. RESULTS: Fifty different fibrinogen methods were evaluated. All-method bias was 8.3% (range of method-specific biases, 0.0%-27.0%) and all-method coefficient of variation was 7.7% (range of method-specific coefficients of variation, 0.7%-25.8%). After controlling for reagent/instrument type, mean fibrinogen levels were 11.6% higher for prothrombin time-based reagents compared to Clauss (P < .001), and coefficient of variation was 46% lower for mechanical endpoint instruments compared to photo-optical. Most testing events (97.4%) could be reliably graded as pass or fail using a target range of ±20% from the method mean (total pass rate, 98.8%). Total fail rate was 3.0-fold lower for mechanical instruments compared to photo-optical (0.5% versus 1.5%, P  =  .001). Nonetheless many photo-optical methods had very high precision and very low fail rates. CONCLUSIONS: Fibrinogen assays showed highly variable methodology and performance characteristics. Bias, precision, and grading were affected by the type of reagent or instrument used.

Subclinical changes in serum creatinine and mortality after coronary artery bypass grafting.

BACKGROUND: Changes in postoperative serum creatinine levels have been used to define acute renal injury in patients undergoing cardiac surgery with cardiopulmonary bypass. It remains unclear, however, whether subclinical increases in serum creatinine that do not meet current Acute Kidney Injury Network or RIFLE (risk, injury, failure, loss, and end-stage kidney disease) criteria for acute renal injury are predictive of mortality after cardiac surgery. METHODS: Multivariate logistic regression was performed in a retrospective cohort of 3914 consecutive patients undergoing primary, isolated coronary artery bypass grafting with cardiopulmonary bypass to determine whether postoperative serum creatinine change independently predicts 30-day all-cause mortality in patients with normal renal function and with varying levels of preoperative renal insufficiency. To control further for selection bias, multivariate logistic regression was performed on a propensity-matched cohort (n = 2042) to determine whether subclinical increases in serum creatinine predict mortality. RESULTS: Negative change in serum creatinine was associated with reduced 30-day all-cause mortality. Even subclinical increases in serum creatinine were associated with increased mortality relative to patients with negative changes in serum creatinine (odds ratio, 3.93; 95% confidence interval, 1.68-9.22; P < .01). After propensity matching, subclinical increases in serum creatinine were still associated with increased mortality (odds ratio, 4.13; 95% confidence interval, 1.37-12.45; P = .01). CONCLUSIONS: Subclinical increases in serum creatinine that do not meet acute renal injury criteria are independently associated with 30-day all-cause mortality in patients with normal renal function or preoperative renal insufficiency undergoing coronary artery bypass grafting.

External quality assurance of antithrombin, protein C, and protein s assays: results of the College of American Pathologists proficiency testing program in thrombophilia.

CONTEXT: Hereditary and acquired deficiencies of antithrombin (AT), protein C (PC), and protein S (PS) are risk factors for venous thromboembolism. Proper diagnosis requires high-quality assays for these proteins. OBJECTIVE: To determine the accuracy and interlaboratory precision of AT, PC, and PS assays used by laboratories participating in the United States College of American Pathologists proficiency testing program in thrombophilia and to grade the performance of laboratories. DESIGN: Standardized normal plasma with assigned analyte values was sent in 2 separate challenges to participating laboratories. Participants measured AT, PC, and PS levels using local methods. RESULTS: When compared with the assigned values for the international standard, the order of assay accuracy from highest to lowest was AT activity, PC antigen, AT antigen, total PS antigen, PC activity, PS activity, and free PS antigen (range of assay bias, 2.6%-8.8%). The order of assay precision from highest to lowest was PC activity, AT activity, AT antigen, total PS antigen, PS activity, free PS antigen, and PC antigen (range of assay coefficient of variation, 6.1%-20.0%). Most testing events (87.8%) could be graded as pass or fail using a target range of ±3 standard deviations from the method-specific mean. The pass rate was 98.2% for all AT, PC, and PS testing events combined. CONCLUSIONS: Accuracy and precision were higher for AT assays and lower for PC and PS assays. It was feasible to grade individual laboratory performance.

Clinical value of plasma hepatocyte growth factor measurement for the diagnosis of periampullary cancer and prognosis after pancreaticoduodenectomy.

BACKGROUND: Previous studies suggest that serum hepatocyte growth factor (HGF) level may be a useful diagnostic and prognostic biomarker for various tumors. We investigated the utility of plasma HGF level measurements in diagnosing periampullary cancer (PAC). METHODS: Of the patients enrolled in this pilot study (n = 118), 57 had PAC, 21 had benign pancreatic tumor (BPT), 20 had chronic pancreatitis (CP), and 20 were healthy controls. Plasma HGF was measured with ELISA kits. It was measured again at 10 days and 1, 2, 3, 6, and 12 months after pancreaticoduodenectomy (PD). RESULTS: Plasma HGF levels were significantly higher in PAC patients than in BPT patients, CP patients, or healthy controls. When a cutoff value of 1,120 pg/ml was used, 48/57 (84%) patients with PAC were positive for elevated HGF, but only 6/20 (30%) of patients with CP and none of the controls or patients with BPT were positive for elevated HGF. After PD, HGF levels were significantly elevated at day 10. CONCLUSIONS: Plasma HGF level discriminates well between PAC and other, benign diseases. Therefore, HGF measurement could be a useful addition to the existing array of diagnostic tools for PAC pancreatic cancer. The higher postoperative value may reflect the stress of surgery.

High incidence of thromboembolic events in left ventricular assist device patients treated with recombinant activated factor VII.

BACKGROUND: Dosing of recombinant activated factor VII (rFVIIa) is controversial and unstandardized, and there is growing concern about thromboembolic complications, especially in left ventricular assist device (LVAD)-supported patients. We reviewed our experience with rFVIIa administration in patients with LVADs and examined its effectiveness and adverse effects, including the incidence of thromboembolic events and its correlation with increasing doses. METHODS: We retrospectively reviewed the records of 62 patients who received an LVAD and rFVIIa at our center between January 2004 and November 2006. Patients who received a single dose of 10 to 20 microg/kg (n = 32; 52%) constituted the "low-dose" cohort, and patients who received 30 to 70 microg/kg (n = 30; 48%) constituted the "high-dose" cohort. Laboratory values obtained before and after rFVIIa administration, as well as patients' transfusion requirements, were compared to determine the effectiveness of rFVIIa in reversing coagulopathy and reducing blood loss. We also compared the incidence of thromboembolic events in the low- and high-dose groups. RESULTS: Administration of rFVIIa was associated with significant decreases in prothrombin time, activated partial thromboplastin time and transfusion requirements. This association was seen in both the low- and high-dose groups. In addition, the incidence of thromboembolic events was significantly higher in the high-dose group (36.7%) than in the low-dose group (9.4%) (p < or = 0.001). CONCLUSIONS: Although rFVIIa administration seemed helpful in controlling life-threatening hemorrhage, patients requiring higher doses (30 to 70 microg/kg) had a dramatically higher incidence of serious thromboembolic events.