Israel Medical Association Journal

Background: Factor VII (FVII) deficiency is characterized by normal activated partial thromboplastin time (aPTT) and prolonged prothrombin time (PT) values. It is diagnosed by determining protein level and coagulation activity (FVII:C). FVII:C measurements are expensive and time consuming.

Objectives: To analyze correlations between PT, international normalized ratio (INR), and FVII:C in pediatric patients before otolaryngology surgery and to establish alternative methods for identifying FVII deficiency.

Methods: FVII:C data were collected from 96 patients with normal aPTT and prolonged PT values during preoperative otolaryngology surgery coagulation workup between 2016 and 2020. We compared demographic and clinical parameters using Spearman correlation coefficient and receiver operating characteristic (ROC) curve analysis to determine the accuracy of PT and INR values to predict FVII deficiency.

Results: The median values of PT, INR and FVII:C were 13.5 seconds, 1.14, and 67.5%, respectively. In total, 65 participants (67.7%) displayed normal FVII:C compared to 31 (32.3%) with decreased FVII:C. A statistically significant negative correlation was observed between FVII:C and PT values and between FVII:C and INR. Despite statistically significant ROC of 0.653 for PT (P-value = 0.017, 95% confidence interval [95%CI] 0.529–0.776) and 0.669 for INR (P-value = 0.08, 95%CI 0.551–0.788), we were unable to determine an optimal cutoff point to predict FVII:C deficiency with high sensitivity and high specificity.

Conclusions: We could not identify a PT or INR threshold to best predict clinically relevant FVII:C levels. When PT is abnormal, determining FVII:C protein levels is needed for diagnosing FVII deficiency and considering surgical prophylactic treatment.

Endovascularly retrieved clots may be a potential resource for diagnosing stroke etiology. This method may influence secondary prevention treatment. We measure thrombin activity eluted by serially washing clots. We concluded that an assay measuring the change in thrombin in clots retrieved during acute stroke endovascular thrombectomy procedures may serve as a diagnostic marker of the origin of the clot. The suggested mechanism for these differences may be the clot location before its retrieval, with high blood flow causing thrombin washout in atherosclerotic clots, in contrast to atrium appendage low blood flow retaining high thrombin levels.

Background: Recurrent miscarriages are associated with a high prevalence of thrombophilia. Use of a calibrated automated thrombogram (CAT) can serve as a universal test for thrombophilia.

Objectives: To examine whether thrombin generation measured by CAT is elevated during the first trimester in women with unexplained recurrent miscarriages.

Methods: This study comprised 25 pregnant women with recurrent pregnancy loss referred for thrombophilia screening and treated with low-molecular-weight heparin (LMWH). Thrombin generation parameters were measured in women who had miscarriages or live births and who were diagnosed as positive or negative for thrombophilia.

Results: Of the pregnancies, 76% resulted in live birth and 24% ended in miscarriages. Among the women, 76% were positive for thrombophilia. Thrombin generation parameters between pregnancies that ended in miscarriage compared to live births were not significantly different, and CAT parameters failed to predict pregnancy outcome. Although the CAT parameters demonstrated a trend toward a hypercoagulable state in women with thrombophilia, there was no statistical significance (P > 0.05).

Conclusions: Women with unexplained pregnancy loss demonstrated similar thrombin generation in the first trimester, regardless of the pregnancy outcome. CAT parameters failed to predict pregnancy outcome in women with recurrent unexplained pregnancy loss. Our results should be interpreted with caution due to the small number of participants.

Objectives: To determine the prevalence of abnormal coagulation studies in ED[1] patients evaluated for suspected ACS[2], and to investigate whether abnormal international normalized ratio/partial thromboplastin time testing resulted in changes in patient management and whether abnormal results could be predicted by history and physical examination.

Methods: In this retrospective observational study, hospital and ED records were obtained for all patients with a diagnosis of ACS seen in the ED during a 3 month period. ED records were reviewed to identify all patients in whom the cardiac laboratory panel was performed. Other data included demographics, diagnosis and disposition, historical risk factors for abnormalities of coagulation, ED and inpatient management, INR[3]/PTT[4], platelet count and cardiac enzymes. Descriptive statistical analyses were performed.

Results: Complete data were available for 223 of the 227 patients (98.7%). Of these, 175 (78.5%) patients were admitted. The mean age was 64.2 years. Thirteen patients (5.8%) were diagnosed with acute myocardial infarction. Of the 223 patients, 29 (13%) and 23 (10%) had INR and PTT results respectively beyond the reference range. Seventy percent of patients with abnormal coagulation test results had risk factors for coagulation disorders. The abnormal results of the remaining patients included only a mild elevation and therefore no change in management was initiated.

Conclusions: Abnormal coagulation test results in patients presenting with suspected ACS are rare, they can usually be predicted by history, and they rarely affect management. Routine coagulation studies are not indicated in these patients.

Background: Venous thromboembolic diseases are treated initially with low molecular weight heparin followed by oral coumarins.

Objectives: To investigate an orally available direct thrombin inhibitor for the acute treatment of venous thromboembolism as well as for prophylaxis of recurrent events.

Methods: The direct thrombin inhibitor ximelagatran was compared with subcutaneous LMW[1] heparins followed by oral warfarin in a double-blind randomized prospective multicenter trial in patients with acute VTE[2]. A pharmacokinetic study was performed in the VTE patients. For assessing the prevention of recurrent VTE, double-blind prospective randomized studies were conducted as follows: a) ximelagatran compared to warfarin for 6 months, and b) prolonged anticoagulation of ximelagatran vs. placebo for 18 months after termination of 6 months coumarin therapy.

Results: Two dose-finding studies and the pharmacokinetic analysis of ximelagatran in acute VTE were completed. About 2,500 patients were randomized to investigate 2 x 36 mg ximelagatran versus 2 x 1 mg/kg body weight enoxaparin followed by warfarin. The study hypothesized that the efficacy was equal in both treatment regimens for recurrent VTE documented by objective methods. The second study, with 1,234 patients, aimed to demonstrate a reduced incidence of recurrent thromboembolic events documented by objective methods after 18 months of treatment with 2 x 24 mg ximelagatran daily compared to placebo.

Conclusion: These large-scale clinical trials will soon yield the results of the comparison between oral ximelagatran and subcutaneous LMW heparin for treatment of acute VTE, and of warfarin for prophylaxis of recurrent events for 6 months and for a prolonged prophylaxis for another 18 months.

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[1] LMW = low molecular weight

[2] VTE = venous thromboembolism

Background: Both diagnostic and therapeutic options in the management of iatrogenic false aneurysms have changed dramatically in the last decade, with surgery being required only rarely.

Objective: To describe our experience, techniques and results in treating pseudoaneurysms at a large medical center with frequent arterial interventions. We emphasize upper limb lesions.

Materials and Methods: We reviewed the data of all consecutive patients diagnosed by color-coded duplex Doppler between August 1992 and July 1998 as having upper limb and lower limb pseudoaneurysms (mainly post- catheterization). We accumulated 107 false aneurysms (mainly post- catheterization lesions): 5 were upper limb lesions and 102 were groin aneurysms.

Results: In the lower limb cases 94 of the 102 lesions were not operated upon (92.1%). Seventy lower limb cases were treated non-operatively by ultrasound-guided compression obliteration with a 95.7% success rate (67 cases). Two cases were treated by  percutaneous thrombin injection (2%) and 23 by observation only (22.5%). Altogether 12 patients underwent surgery (11.2%): 4 upper extremity and 8 lower extremity cases. None of the lower limb group suffered serious complications regardless of treatment, but all five upper limb cases did, four of them necessitating surgical intervention. Three of the five upper limb cases had a grave outcome with severe or permanent or neurological damage.

Conclusion: Most post- catheterization pseudoaneurysms can be managed non-surgically. False aneurysms in the upper extremity are rare, comprising less than 2% of all lesions. However, upper extremity pseudoaneurysms present a potentially more serious complication and require early diagnosis and prompt intervention to minimize the high complication rate and serious long-term sequelae. Prevention can be achieved by proper puncture technique and site selection, and correct post-procedure hemostatic compression with or without an external device. Some upper limb lesions are avoidable if the axillary artery is not punctured.
 

Background: inflammation is an important feature of atherosclerotic lesions and increased production of the actuephase reactant. The contribution of coagulation factor to the development of coronary artery disease has not yet been clearly established.

Objective: To test whether C-reactive protein, fibrinogen and antithrombin-III are associated with angiograpic CAD, history of myocardial infarction and extensive atherosclerotic involvement.

Methods: Blood samples were tested for CRP, fibrinogen and AT-III levels from 219 individuals undergoing coronary angiography.

Results: CRP was higher in patients with CAD (0.95 + 1.31, n=180, vs. 0.39 + 0.61 mg/dl, n=39, P<0.0001) and in those with a history of MI (1.07 + 1.64, n=96, vs. 0.65 + 0.72 mg/dl, n=84, P<0.05) than in control subjects. The patients who developed unstable angina had higher CRP levels than the patients with stable CAD (2.07 + 2/38, n=7, vs. 0.80 + 1.13 mg/dl, n=173, P<0.001).

Fibrinogen was significantly higher in patients with CAD (298 + 108 vs. 258 + 63 mg/dl, P<0.01). In patients with CAD, mean AT-III value was less than in patients without CAD, but this difference was found in CRP, fibrinogen and AT-III values among the patients with single, double or triple vessel disease.

Conclusion: CRP is elevated in patients with CAD and a history of MI. Elevated levels of CRP at the time of hospital admission is a predictive value for future ischemic events.

There is an association between higher levels of fibrinogen and CAD. The association of AT-III levels with CAD needs testing in further studies.