[Clinical observation of neutralizing heparin with protamine in carotid endarterectomy]

OBJECTIVE

To evaluate the effects of administrating protamine to reverse heparin on intraoperative hemostatic time, postoperative drainage and postoperative complications in carotid endarterectomy.

METHODS

A retrospective cohort study of 125 cases of carotid endarterectomy was undertaken at Department of Vascular Surgery, Peking Union Medical Hospital in 2012. They were divided into 2 groups: heparin (H group) and heparin + intra-operative administration of protamine (H+P group). Their medical history, preoperative clinical findings, intraoperative hemostatic time, postoperative drainage volume and complications were compared between two groups and statistically analyzed.

RESULTS

Fifty cases received heparin alone and 75 cases had heparin reversal with protamine. Drainage volumes at Day 1 postoperation were less in H+P group than those in H group with statistically significant difference ((14 ± 13) vs (19 ± 12) ml, P = 0.038). And total postoperative drainage volumes were less in H+P group with statistical significant difference ((20 ± 17) vs (26 ± 15) ml, P = 0.035). Intraoperative hemostatic time was less in H+P group than that in H group with statistical significant difference ((30 ± 11) vs (36 ± 11) min, P = 0.030). There was no mortality. Only one case was re-operated for cervical hematoma. Cerebral ischemic symptoms of one patient in the H+P group became worse postoperatively and recovered after conservative medical treatment.

CONCLUSIONS

During carotid endarterectomy, the application of protamine may significantly decrease intraoperative hemostatic time and postoperative wound drainage. And protamine has no effect of increasing the risks of perioperative stroke.

Hemoptysis caused by saphenous vein graft perforation during percutaneous coronary intervention

Percutaneous coronary intervention carries the risk of coronary artery perforation, which may lead to serious adverse effects such as cardiac tamponade, myocardial infarction, and even death. We describe a patient who developed hemoptysis immediately after saphenous vein graft rupture, which is a rare complication during coronary intervention. Stenting using a covered stent, along with simultaneous administration of protamine, helped seal the vein graft perforation and stop the hemoptysis.

Protamine sulfate induced bladder injury protects from distention induced bladder pain

PURPOSE

Bladder pain is a debilitating symptom of many urological conditions. There is no generally effective treatment. Abnormal urothelial turnover is common to multiple disease states but the specific components of urothelial injury and the resulting molecular signals that lead to bladder pain are unknown. We examined mouse models of bladder injury induced by uropathogenic Escherichia coli, protamine sulfate (Sigma®) and bacterial lipopolysaccharide to identify cellular and molecular correlates underlying pain sensitization in response to the stimuli.

MATERIALS AND METHODS

C57BL/6 female mice (Jackson Laboratory, Bar Harbor, Maine) were given intravesicular protamine sulfate, lipopolysaccharide or uropathogenic E. coli. The impact of each on nociception was determined by measuring the evoked visceromotor response to bladder distention 24 hours after inoculation. Levels of pyuria and tissue inflammation were examined by urinary cytology and tissue histology. Quantitative polymerase chain reaction and gene expression analysis were used to identify injury profiles associated with nociception.

RESULTS

Protamine sulfate treatment was significantly analgesic upon bladder distention. Protamine treated bladders did not show pyuria or extensive tissue damage. Protamine injury was associated with a global decrease in the expression of inflammation associated genes. In contrast, uropathogenic E. coli injury significantly increased the nociceptive response to bladder distention. Lipopolysaccharide treatment did not affect nociception. Finally, injury induced expression of inflammation associated genes correlated with nociceptive responses.

CONCLUSIONS

Protamine treatment of the bladder is analgesic and tissue protective, and it suppresses the inflammatory cytokine expression normally associated with nociception. Also, the injury modalities that result in differential tissue response patterns provide an innovative method for identifying mediators of visceral pain.

Pharmacokinetics and pharmacodynamics of insulin lispro protamine suspension compared with insulin glargine and insulin detemir in type 2 diabetes

OBJECTIVE

The primary aim was to evaluate duration of action of a single 0.8 U/kg dose of insulin lispro protamine suspension (ILPS) in type 2 diabetes (T2DM) patients; secondarily to compare onset and duration of action of ILPS, glargine (G), and detemir (D) (0.8 U/kg) and evaluate pharmacokinetic (PK) and pharmacodynamic (PD) dose responses of ILPS.

RESEARCH DESIGN AND METHODS

In a single-center, double-blind, five-arm crossover study, 34 patients were randomized to a treatment sequence which included a single subcutaneous 0.8 U/kg dose of G and D and three doses of ILPS (0.4 U/kg, 0.8 U/kg, and 1.2 U/kg) and were studied using 24-hour euglycemic glucose clamps.

PRIMARY OUTCOME MEASURE

Duration of action was determined as the time to the last measurable glucose infusion rate (tR(last)) during glucose clamps.

RESULTS

The duration of insulin action (tR(last)) for ILPS at 0.8 U/kg was >23 hours and was similar to G (p = 0.114) and D (p = 0.570). Post-hoc analysis demonstrated the probability of achieving 24 hours of glucose-lowering activity after a 0.8 U/kg dose: 48% (ILPS), 43% (G), and 26% (D). G(tot) and R(max) were significantly greater for ILPS versus G or D. The median ILPS time-dependent values demonstrated a significantly earlier maximum PD response (tR(max) and early 50% tR(max)) versus either G or D. ILPS demonstrated dose-dependent increases in PK and PD measures across the dose range.

CONCLUSIONS

Following a single 0.8 U/kg dose in T2DM patients, ILPS, G, and D demonstrated similar durations of glucose-lowering activity and ILPS demonstrated significantly greater glucose-lowering activity (R(max) and G(tot)) and earlier maximum PD response. These results potentially support once-daily dosing of ILPS in T2DM.

LIMITATIONS

The observed number of 24-hour censored observations was higher than expected and the wash-out period for basal insulin treated patients may have been too short to definitively rule out a carry-over effect; however, such an effect, if present, would potentially only affect onset of action and not the primary outcome measure.

[Postprandial glycemic control using insulin aspart with NPH in inadequately controlled diabetics]

OBJECTIVE

To compare the efficacy and safety of insulin aspart (IAsp) and human insulin (HI) when applied as meal-time insulin with neutral protamine Hagedorn insulin (NPH) at bedtime in diabetics.

METHODS

A total of 220 Chinese subjects with type 1 or type 2 diabetes from 5 different hospitals were randomized by a ratio of 1:1 into two groups accepting IAsp or HI combined with NPH respectively. The main endpoints were assessed by fasting plasma glucose (FPG), 2 hour postprandial plasma glucose (2 h PPG), HbAlc and hypoglycemia.

RESULTS

A greater reduction in mean 2 h PPG was achieved in the IAsp group [(14.6 +/- 5.3) mmol/L] as compared with the HI group [(8.4 +/- 4.1) mmol/L] (P < 0.01, adjusted for baseline value, center effect and diabetes type). Significantly more IAsp-treated subjects reached the 2 h PPG target (50.0% vs 25.5%, P < 0.01). HbA1c was reduced more in IAsp/NPH group [(9.3 +/- 1.4)% vs (7.7 +/- 1.3)%] than in HI/NPH group [(9.2 +/- 1.2)% vs (7.7 +/- 1.2)%]. HbA1c target was reached by 24.5% (IAsp) vs 14.5% (HI) of subjects (P < 0.05). No major hypoglycemia or serious adverse events were observed for the IAsp group. Lower incidence of nocturnal hypoglycemia (IAsp/NPH: 3% vs HI/NPH: 4%) was reported in the IAsp group. Average daily insulin doses were 0.60/0.23 (IAsp/NPH) and 0.65/0.24 (HI/NPH) IU/kg respectively.

CONCLUSION

Treatment of IAsp in basal-bolus therapy in combination with NPH provides a superior postprandial glucose control and allows more subjects to reach the glycemic target without elevating the nocturnal hypoglycemic risk or adverse events.

A pilot randomized controlled crossover study comparing regional heparinization to regional citrate anticoagulation for continuous venovenous hemofiltration

OBJECTIVE

To evaluate the efficacy and safety of a regional heparinization and a regional citrate method of anticoagulation in CVVH.

DESIGN

Randomized controlled cross-over study.

SUBJECTS

Ten critically ill patients with acute renal failure.

SETTING

ICU of tertiary hospital.

INTERVENTION

CVVH was performed with pre-filter fluid replacement at 2000 ml/h and a blood flow rate of 150 ml/min. Regional heparinization was by the administration of heparin pre-filter at 1500 IU/h and protamine post-filter at 15 mg/h. Regional citrate anticoagulation was by means of a citrate-based replacement fluid (14 mmol/L) administered pre-dilution.

RESULTS

We studied nine males and one female. The mean age and APACHE II score were 70.5 and 17 respectively. Median circuit life was 13 hours (IQR 9.28) for the regional heparinization method compared to 17 hours (IQR 12,19.5) for the regional citrate method (p=0.77). There were no episodes of bleeding in either group.

CONCLUSION

Regional heparinization and regional citrate anticoagulation achieve similar circuit life in critically ill patients receiving CVVH.

Heparin-like anticoagulant associated with multiple myeloma and neutralized with protamine sulfate

A 55-year-old man with multiple myeloma developed sustained bleeding after bone marrow aspiration and cutaneous bleeding. Routine coagulation studies revealed a prolonged activated partial thromboplastin time and thrombin time (> 60 s) with a normal reptilase time. Further evaluation showed failure of the activated partial thromboplastin time to correct completely in a 1: 1 mixture with normal plasma. Treatment of the patient's plasma in vitro with protamine sulfate normalized the thrombin time. The presence of a heparin-like anticoagulant was suspected. The plasma heparin level was 0.73 IU/ml. Intravenous infusion of protamine sulfate appeared to neutralize the anticoagulant activity and stop the bleeding. The cancer cells themselves or the invasive nature of this type of cancer might result in a massive release of a heparinoid. Such coagulopathy appears to be a rare mechanism of bleeding and it is an important entity to consider since it is potentially reversible with protamine sulfate.

Coronary perforation during percutaneous coronary intervention

Coronary perforation is an undesirable complication during percutaneous coronary intervention (PCI). We reviewed the cases of overt coronary perforation in our institute and analyzed their clinical backgrounds, the characteristics of the target lesion, management, and clinical outcomes. Between 1991 and 2005, we experienced 12 cases (0.35%) of coronary perforation in a total of 3415 PCI procedures. The perforation occurred during the use of debulking devices in 3 cases, immediately after stenting in 2, immediately after postdilatation of the stent in 2, and during wiring in 3 cases. Restoration was attempted by long inflation of a balloon in 7 cases, implantation of a covered stent graft in 1, and emergency surgical repair in 1 case. Subsequent cardiac tamponade occurred in 3 patients who required pericardiocentesis, and 1 patient died due to congestive heart failure. Administration of protamine was effective in stopping the bleeding in 6 patients, whereas continuation of antiplatelet therapy resulted in no overt rebleeding. Coronary perforation during PCI is a rare complication but is associated with significant morbidity and mortality. Intravenous administration of protamine is effective when it is used in conjunction with nonsurgical devices for initial management of perforation.

The use of protamine after radiofrequency catheter ablation: A pilot study

OBJECTIVE

Evaluate the effect of administering intravenous protamine immediately post-radiofrequency catheter ablation (RFCA) on thrombotic and bleeding complications in heparinized patients.

METHODS

Heparinized patients that had RFCA for atrial or ventricular arrhythmias at our institution between January 2001 and March 2006 and had a complete data set were included in this cohort evaluation. Patients receiving at least one dose of protamine within 15 min of RFCA were deemed the prophylactic group while those not receiving protamine within 15 min were the control group. Thrombotic (cerebrovascular event, transient ischemic attack, pulmonary embolism, deep vein thrombosis, or myocardial infarction) and bleeding events (blood loss requiring transfusion, hematoma requiring intervention, or intracranial hemorrhage) were compared between groups.

RESULTS

Overall, 158 patients (74% male, 55 +/- 13.5) met inclusion criteria. Of these, 73.4% received prophylactic protamine (average dose = 39 mg +/- 17). Only one patient (0.9%) in the prophylactic protamine group and zero patients in the control group experienced a thrombotic event (p > 0.99). Only two patients (1.7%) in the protamine group (n = 2 blood transfusions) and zero patients in the control group experienced bleeding events (p = 0.839).

CONCLUSIONS

Administering prophylactic intravenous protamine to allow for quicker catheter removal following RFCA in heparinized patients did not markedly impact thrombotic or bleeding complication rates in our population. The perceived benefit in our institution to protamine administration in this population is a reduction in postoperative patient immobilization and discomfort, reduced PACU nursing care, and earlier time to discharge. Given the low rate of thrombotic and bleeding events, a study of several thousand patients would be needed to fully evaluate the impact on these events.

[Measurement of activated clotting time during cardiopulmonary bypass in infective endocarditis patients]

OBJECTIVE

To investigate the proper dosage of heparin and protamin in treating the patients with infective endocarditis (IE) during the operation.

METHODS

Activated clotting time (ACT) was measured during and after cardiopulmonary bypass (CPB) in 30 patients with IE and 30 patients with rheumatic heart disease (RHD) respectively.

RESULTS

The dosage of heparin before bypass in IE group was significantly higher than that of RHD group (P<0.05); the dosage of protamin for neutralization after bypass in IE group was significantly higher than that of RHD group (P<0.05); the ratio of protamin and heparin were 0.76 +/-0.23 in IE group and 0.74 +/-0.12 in RHD group (P>0.05).

CONCLUSION

The dosage of protamin should be increased to 3 mg/kg as the heparin is over 400 U/kg before CPB in the patient with IE, but the ratio of protamin and heparin will not be obviously changed.

[Impact of protamine sulfate on hemostasis system after operations with artificial circulation]

Effects of different doses and lots of protamine sulfate on hemostasis system after cardiac operations with artificial circulation are analyzed. Overall 982 patients underwent cardiac operations with artificial circulation. Quality and purity of protamine may be the causes of side effects. Negative effect of high doses of protamine on hemostasis system is demonstrated. Thrombocyte dysfunction is the main cause of intensive postoperative bleeding after administration of protamine high doses.

A comparison of the beta-D-xyloside, odiparcil, to warfarin in a rat model of venous thrombosis

BACKGROUND

A significant need exists for new chronic oral anticoagulation therapies to replace warfarin. Previous studies have shown that beta-D-xylosides, which prime glycosaminoglycan (GAG) synthesis, have antithrombin and antithrombotic activity. In the following report, a new orally active beta-D-xyloside (odiparcil) has been characterized in a rat model of venous thrombosis and its efficacy and bleeding liability compared to warfarin. Additionally, studies were conducted to investigate odiparcil's ex vivo antithrombin and antiplatelet activity, and also to explore the potential utility of protamine sulfate as a neutralizing agent.

METHODS AND RESULTS

In vivo thrombosis studies were conducted in a rat inferior vena cava model, and bleeding studies in a rat tail transection model. Following oral dosing, warfarin and odiparcil produced dose-related suppression of thrombus formation. A therapeutically relevant dose of warfarin in this model (international normalized ratio; INR 3.0) achieved approximately 65% inhibition of thrombus formation. Warfarin caused dose-related significant increases in bleeding indices. Odiparcil antithrombotic activity was limited by its mechanism to a maximum suppression of thrombus formation of 65-70%, and did not prolong bleeding indices. Additionally, odiparcil-induced heparin cofactor II (HCII)-dependent antithrombin activity was shown to be a function of dermatan sulfate-like GAG production. Other than thrombin-related effects, no odiparcil effects on platelet function were observed. In antidote studies, it was demonstrated that odiparcil-induced antithrombotic activity could be partially neutralized by protamine sulfate.

CONCLUSIONS

These experiments suggest that an antithrombotic approach based upon xyloside induction of circulating GAGs may have the potential to approximate the efficacy of warfarin and yet with a reduced risk to hemostasis.

A comparison of bivalirudin to heparin with protamine reversal in patients undergoing cardiac surgery with cardiopulmonary bypass: The EVOLUTION-ON study

OBJECTIVES

Unfractionated heparin and its antidote, protamine sulfate, allow for rapid and reversible anticoagulation during cardiac surgery with cardiopulmonary bypass, yet limitations exist, including a variable dose-response, dependence on a cofactor for anticoagulant effect, and antigenic potential. This trial was performed to evaluate the safety and efficacy of bivalirudin as an alternative to heparin with protamine reversal in on-pump cardiac surgery.

METHODS

We conducted a randomized, open-label, multicenter trial comparing heparin with protamine reversal to bivalirudin in patients undergoing cardiac surgery with cardiopulmonary bypass. The primary objective was to demonstrate comparable rates of in-hospital procedural success defined as freedom from death, Q-wave myocardial infarction, stroke, or repeat revascularization. Twenty-one institutions enrolled 101 patients randomized to bivalirudin and 49 patients to heparin treatment.

RESULTS

The primary end point of procedural success was not significantly different between the bivalirudin arm and the heparin/protamine arms at 7 days, 30 days, or 12 weeks' follow-up. Adequate anticoagulation was achieved in all patients. Secondary end points including mortality, 24-hour blood loss, overall incidence of transfusions, and duration of surgery were similar between the two arms.

CONCLUSIONS

Bivalirudin is a safe and effective anticoagulant for patients undergoing a wide range of cardiac surgical procedures with cardiopulmonary bypass. Procedural success rates with bivalirudin were similar to rates in patients receiving heparin anticoagulation, with no difference in mortality. Avoidance of blood stasis and attention to the intraoperative medical management of patients is critical for successful use of bivalirudin during cardiopulmonary bypass.

[Inflammatory response and haematological disorders in cardiac surgery: toward a more physiological cardiopulmonary bypass]

The systemic inflammatory response in cardiac surgery is closely related to the haemostasis disturbances. It is responsible of a significant morbidity and mortality that was previously suspected to be caused by cardiopulmonary bypass alone. However, it is time now to clearly identify the factors that are material-dependent from that material-independent. From this point of view, off-pump surgery allowed for better comprehension of the multiple sources of the inflammatory response. Numerous pathways are activated, involving complement, platelets, neutrophiles and monocytes. The tissue pathway of the coagulation system, through tissue factor, is of major importance and has to be surgically considered in order to reduce the whole body inflammatory response postoperatively. The quality of the extracorporeal perfusion through its consequences on organ perfusion, particularly in the splanchnic area, also participates to this pathophysiological process. Beyond the progress of technology provided by the industry, particularly the minimally extracorporeal circulation derived from off-pump surgery evolution, the surgical approach is of major importance in the control of the systemic inflammatory response and must not be ignored yet.

Anticoagulation with bivalirudin for off-pump coronary artery bypass grafting: the results of the EVOLUTION-OFF study

OBJECTIVES

Unfractionated heparin has many shortcomings, including indirect and partial inhibition of thrombin, antibody formation, and platelet activation. Bivalirudin, a short-acting direct thrombin inhibitor, avoids these limitations and has superior outcomes during percutaneous revascularization. This trial was performed to evaluate the safety and efficacy of bivalirudin in off-pump coronary artery bypass grafting.

METHODS

An open-label, multicenter randomized trial compared heparin with protamine reversal to bivalirudin in patients undergoing off-pump coronary artery bypass. The primary objective was safety as demonstrated by similar rates of procedural success defined as freedom from a composite of death, myocardial infarction, stroke, and repeat revascularization. Twenty-one institutions randomized 105 patients to receive bivalirudin and 52 patients to receive heparin.

RESULTS

The mean age was 65 years for both groups. The bivalirudin group had more grafts: 3.0 +/- 1 versus 2.5 +/- 1. Procedural success rates at 30 days were identical in bivalirudin- and heparin-treated patients (93%). Operative times, total blood loss, reoperations for bleeding, and major adverse events were not significantly different. Strokes were more frequent in the heparin group: 5.5% versus 0; P = .05. Mortality was 2% in each group. Repeat revascularization was required in 3% of bivalirudin- and 2% of the heparin-treated patients.

CONCLUSIONS

For patients undergoing off-pump coronary artery bypass grafting, bivalirudin was an effective anticoagulant, without excessive bleeding and with a safety profile similar to that of heparin. Further trials are warranted to assess whether anticoagulation with bivalirudin improves clinical outcomes.

Liposome-polycation-DNA (LPD) particle as a carrier and adjuvant for protein-based vaccines: therapeutic effect against cervical cancer

With the successful identification of many tumor-specific antigens, tumor-associated antigens, and the potential of using unfractioned tumor cell derivatives as tumor antigens, a system and/or adjuvant that can deliver these antigens and help them to induce strong and effective anti-tumor immune responses is greatly needed. Previously, we reported that a MHC class I-restricted peptide epitope derived from human papillomavirus (HPV) 16 E7 protein, when incorporated into a clinically proven safe LPD (liposome-polycation-DNA) particle, was able to effectively eradicate tumors established in mice. Cervical cancer is the second most common cancer among women worldwide. HPV infection is clearly linked to this cancer. Vaccines based on the early (E) gene products of HPV could be effective in controlling it. However, besides the fact that epitope vaccines have many limitations particularly, concerning the diverse HLAs in humans, the use of the epitope as an antigen prevented us from fully characterizing the immune responses induced by the LPD as a vaccine carrier and/or adjuvant in previous studies. In the present study, by using the HPV 16 E7 protein as an antigen, we first showed that LPD, as a vaccine carrier and adjuvant induced strong and robust immune responses, both cellular and antibody. We then showed that immunization with LPD particles incorporated with either the wild type HPV 16 E7 protein or a potentially safer mutant induced strong immune responses that caused complete regressions of a model cervical cancer tumor established in murines. LPD could be a potent vaccine carrier and/or adjuvant for many antigens.

Role of platelet surface PF4 antigenic complexes in heparin-induced thrombocytopenia pathogenesis: diagnostic and therapeutic implications

Heparin-induced thrombocytopenia (HIT) antibodies recognize complexes between heparin and platelet factor 4 (PF4). Heparin and PF4 bind HIT antibodies only over a narrow molar ratio. We explored the involvement of platelet surface-bound PF4 as an antigen in the pathogenesis of experimental HIT. We show that cell-surface PF4 complexes are also antigenic only over a restricted concentration range of PF4. Heparin is not required for HIT antibody binding but shifts the concentration of PF4 needed for optimal surface antigenicity to higher levels. These data are supported by in vitro studies involving both human and murine platelets with exogenous recombinant human (h) PF4 and either an anti-PF4-heparin monoclonal antibody (KKO) or HIT immunoglobulin. Injection of KKO into transgenic mice expressing different levels of hPF4 demonstrates a correlation between the severity of the thrombocytopenia and platelet hPF4 expression. Therapeutic interventions in this model using high-dose heparin or protamine sulfate support the pathogenic role of surface PF4 antigenic complexes in the etiology of HIT. We believe that this focus on surface PF4 advances our understanding of the pathogenesis of HIT, suggests ways to identify patients at high risk to develop HIT upon heparin exposure, and offers new therapeutic strategies.