Complement activation from protamine sulfate administration after coronary angiography

Management and outcomes of coronary artery perforations during percutaneous treatment of acute coronary syndromes

BACKGROUND

Coronary artery perforation (CAP) is an infrequent and life-threatening complication of percutaneous coronary intervention (PCI), requiring prompt intervention. There is insufficient data about the prognosis and management of CAP in patients with acute coronary syndrome (ACS). The aim of this study was to investigate the management of CAP in patients with ACS.

METHODS

The results of 25 patients with CAP were retrospectively analyzed.

RESULTS

Of the 25 patients, 14 patients (56%) had ACS. According to the Ellis classification, the grade of perforation was type-I in 8 (32%) patients, type-II in 6 (24%) patients and type-III in 11 (44%) patients. Prolonged balloon inflation was performed to 20 (80%) cases of CAP. It successfully sealed the perforation in three cases of type-I, five cases of type-II CAP and in seven cases of type-III CAP. Seven patients underwent covered stent implantation. Emergent CABG was required in two patients with type-III CAP. In-hospital mortality was not observed in the patients.

CONCLUSION

The outcomes of CAP in patients with ACS were similar to patients with stable coronary disease. The continuation of anti-platelet agents after the successful management of CAP may be encouraged in these patients.

Safety of immediate reversal of anticoagulation by protamine to reduce bleeding complications after infarct artery stenting for acute myocardial infarction and adjunctive abciximab therapy

Infarct artery stenting with adjunctive abciximab therapy is widely used treatment for patients with acute myocardial infarction (AMI). However, bleeding complications have been associated with a worse clinical outcome. Randomized trials in elective patients have shown that postprocedural protamine administration is safe and associated with a significant reduction in bleeding complications. The aim of the current study was to evaluate in STEMI patients undergoing primary percutaneous coronary intervention (PCI) with abciximab and stenting whether immediate reversal of anticoagulation by protamine is safe and associated with a reduction in the occurrence of bleeding complications. From January 2004 to June 2005, 254 patients with STEMI had immediate reversal of anticoagulation by protamine administration after infarct artery stenting and received abciximab therapy without heparin infusion (Group 1). These patients were compared with a control group of 265 patients (June 2002-December 2003) treated with the standard heparin therapy: bolus in order to achieve an activated coagulation time of 250-300 s during PCI plus 12-h infusion (7 UI/kg/h; Group 2). We excluded patients undergoing IABP implantation. The two groups were similar in all baseline characteristics. There were no differences in in-hospital mortality, reinfarction, urgent target vessel revascularization, stroke or acute or subacute stent thrombosis, while Group 1 patients showed a lower incidence of major bleeding complications (ACUITY scale: 1.1 vs. 4.0%, P = 0.035) and a shorter length of hospital stay (3.5 ± 1.7 vs. 4.0 ± 1.6 days, P = 0.002) as compared with heparin treated patients. Among patients undergoing primary stenting with abciximab administration, immediate post-PCI reversal anticoagulation by protamine without associated heparin infusion is safe and associated with a significant reduction in major bleeding complications.

Safety and benefits of protamine administration to revert anticoagulation soon after coronary angioplasty. A meta-analysis

Recent studies suggests that bleeding complications are associated with worse clinical outcome and survival among patients undergoing coronary angioplasty. Thus, in the last years increasing interests have been focused on strategies to prevent bleeding complications. The administration of protamine after coronary stenting for early sheath removal seems very attractive to minimize local and systemic bleeding complications. Thus, the aim of the current study is to perform a meta-analysis of randomized and non-randomized trials evaluating the benefits and safety of protamine administration after coronary angioplasty. The literature was scanned by formal searches of electronic databases (MEDLINE and CENTRAL) from January 1990 to December 2009. The following key words were used: coronary angioplasty, primary angioplasty, coronary stenting, protamine, heparin neutralization, bleeding complications. Primary endpoints were death and major bleeding complications, respectively. Secondary endpoint was myocardial infarction. A total of 5 trials, 2 randomized and 3 non randomized were included in the meta-analysis, involving 6,762 patients (4,913 or 72.6% in the protamine group and 1,949 or 27.4% in the standard group). Protamine administration was not associated with difference in short-term mortality (2.8% vs. 2.7%, OR [95% CI] = 0.97 [0.69-1.37], P = 0.88, p(het) = 1.0), but with a significant reduction in major bleeding complications (2.4% vs. 4.1%, OR [95% CI] = 0.51 [0.37-0.69], P < 0.0001, p(het) = 0.53, NNT = 58.8). No difference was observed myocardial infarction (0.9% vs. 0.8%, OR [95% CI] = 1.14 [0.63-2.07], P = 0.66, p(het) = 0.89). This meta-analysis shows that protamine administration after percutaneous coronary intervention seems to be safe and associated with a significant reduction in major bleeding complications. Pending the results of larger randomized trials, its use may be considered after coronary angioplasty.

Serious anaphylactic reactions due to protamine sulfate: a systematic literature review

Anaphylactic reactions caused by injection of protamine sulfate during cardiac surgery are a well-known complication. A systematic literature review was therefore conducted to gather evidence of the knowledge concerning these side effects, and to see if any prospective randomized studies supported this. Studies investigating the effect of protamine sulfate in human beings were extracted from MEDLINE, Embase and the Cochrane Library, retrieving 487 articles. Abstracts were evaluated by both authors, and referred articles not found in the primary search were furthermore extracted from reviews and case reports, resulting in a total of 272 relevant articles. Of these, 9 retrospective studies and 16 prospective studies were performed in an evidence-based manner. However, only 3 of the 16 prospective articles had an optimal design as far as inclusion criteria, randomization, and description of symptoms were concerned. Incidence of anaphylactic reactions in the prospective studies was 0.69% compared to 0.19% in the retrospective studies, but caution should be taken due to a pronounced heterogeneity of those studies. One study found heparinase I unsuitable as replacement for protamine sulfate. Overall, our findings support the low incidence of anaphylactic reactions reported in previous studies, but of note only few prospective investigations was conducted on the subject. Our study also emphasizes the need for critical appraisal of many routine procedures: in all aspects of medical care, systematic literature review conducted in a well-structured, repeated manner should be given high priority.

Low molecular weight protamine as nontoxic heparin/low molecular weight heparin antidote (III): preliminary in vivo evaluation of efficacy and toxicity using a canine model

Heparin employed in cardiovascular surgeries often leads to a high incidence of bleeding complications. Protamine employed in heparin reversal, however, can cause severe adverse reactions. In an attempt to address this clinical problem, we developed low molecular weight protamine (LMWP) as a potentially effective and less toxic heparin antagonist. A homogeneous 1880-d peptide fragment, termed LMWP-TDSP5 and containing the amino acid sequence of VSRRRRRRGGRRRR, was derived directly from protamine by enzymatic digestion of protamine with thermolysin. In vitro studies demonstrated that TDSP5 was capable of neutralizing various anticoagulant functions of both heparin and commercial low molecular weight heparin preparations. In addition, TDSP5 exhibited significantly reduced crossreactivity toward mouse sera containing antiprotamine antibodies. TDSP5 showed a decrease in its potential in activating the complement system. All of these findings suggested the possibility of markedly reduced protamine toxicity for TDSP5. In this article, we conducted preliminary in vivo studies to further demonstrate the feasibility and utility of using LMWP as a nontoxic clinical protamine substitute. Dogs were chosen as test animals because they were known to magnify the typical human response to protamine. By using a full spectra of biological and clinical assays for heparin, including the anti-IIa and anti-Xa chromogenic assays and the activated partial, thromboplastin time and TCT clotting assays, TDSP5 showed that it could completely neutralize all these different anticoagulant functions of heparin in dogs. Although administration of protamine in dogs produced a significant reduction in mean arterial blood pressure (-14.9 mm Hg) and elevation in pulmonary artery systolic pressure (+5.0 mm Hg), the use of TDSP5 in dogs did not elicit any statistically significant change in any of the variables measured. Furthermore, the use of LMWP also significantly reduced the protamine-induced transient thrombocytopenic and granulocytopenic responses. The white blood cell counts and platelet counts decreased to 82.1% and 60.0% of baseline, respectively, in dogs given intravenous protamine compared to 97.8% and 88.6% of baseline in dogs receiving TDSP5. These preliminary findings indicated that LMWP could potentially provide an effective and safe means to control both heparin- and protamine-induced complications.

Administration of protamine after coronary stent deployment

BACKGROUND

Prompt reversal of anticoagulation by protamine administration could be an important therapeutic option to treat serious procedural complications such as vessel rupture or major bleeding from the puncture site during coronary stent implantation. However, this therapeutic option is rarely used because of the possible risk of stent thrombosis.

METHODS

We retrospectively analyzed the incidence of acute and subacute stent thrombosis and vascular complications in 90 patients who received protamine (protamine group) and 1763 patients who did not receive protamine (control group) after successful coronary stent implantation. The 2 groups were matched for clinical, angiographic, and procedure characteristics.

RESULTS

No patients in the protamine group had adverse effects such as hypotension or vascular collapse during protamine administration. Acute stent thrombosis did not occur in any protamine group patient but did occur in 12 patients in the control group (0.7%) (P =.47). Subacute stent thrombosis occurred in 2 patients in the protamine group (2.1%) and in 15 in the control group (0.8%) (P =.20). By logistic regression analysis, protamine was not a determinant of stent thrombosis.

CONCLUSIONS

Reversal of anticoagulation by protamine after stent implantation does not predispose to stent thrombosis. This result has important clinical consequences because it allows the use of protamine in the treatment of coronary perforation and serious bleeding complications that may occur during coronary stent deployment.

Extracorporeal heparin adsorption following cardiopulmonary bypass with a heparin removal device--an alternative to protamine

OBJECTIVES

To evaluate the therapeutic efficacy and applicability of a heparin removal device (HRD) based on plasma separation and poly-L-lysine (PLL) affinity adsorption as an alternative to protamine in reversing systemic heparinization following cardiopulmonary bypass (CPB).

DESIGN

A prospective study.

SETTING

University research laboratory.

SUBJECTS

Adult female swine (n=7).

INTERVENTIONS

Female Yorkshire swine (n=7, 67.3+/-3.5 [SEM] kg) were subjected to 60 mins of right atrium-to-aortic, hypothermic (28 degrees C) CPB. After weaning from CPB, the right atrium was recannulated with a two-stage, dual-lumen cannula which was connected to an HRD via extracorporeal circulation. Blood flow was drained at 1431.2+/-25.4 mL/min from the inferior vena cava, through the plasma separation chamber of the HRD (where heparin was bound to PLL), and reinfused into the right atrium. The HRD run time was determined by a previously established mathematical model of first-order exponential depletion.

MEASUREMENTS AND MAIN RESULTS

Heart rate, mean arterial pressure, pulmonary arterial pressure, central venous pressure, kaolin and celite activated clotting time (ACT), activated partial thromboplastin time (APTT), heparin concentration, and plasma free hemoglobin were obtained before, during, and after the use of the HRD. Pre-CPB ACT was 167+/-89 secs (kaolin) and 99+/-7 secs (celite), and APTT was 34+/-5 secs. The HRD run time averaged 27.4 +/-1.5 mins targeted to remove 90% total body heparin. Use of the HRD was not associated with any adverse hemodynamic reactions or increases in plasma free hemoglobin. The heparin concentration immediately following CPB was 4.85+/-0.24 units/mL, with ACT >1000 secs and APTT >150 secs in all animals. During heparin removal, total body heparin content followed first-order exponential depletion kinetics. At the end of the HRD run, heparin concentration decreased to 0.51+/-0.09 units/mL, with kaolin ACT returning to 177+/-22 secs, celite ACT returning to 179+/-17 secs, and APTT returning to 27+/-3 secs (p > .05 vs. pre-CPB baseline for all variables).

CONCLUSIONS

The HRD is capable of reversal of anticoagulation following CPB without significant blood cell damage or changes in hemodynamics. The HRD, therefore, can serve as an alternative to achieve heparin clearance in clinical situations where use of protamine may be contraindicated.

Protamine allergy reactions during cardiac catheterization and cardiac surgery: risk in patients taking protamine-insulin preparations

Protamine insulin use may immunologically sensitize patients to protamine, leading to anaphylactoid reactions upon subsequent exposure to protamine sulfate during cardiac catheterization or cardiovascular surgery. The risk of such reactions in protamine insulin-dependent patients is uncertain. One catheterization study reported a 50-fold greater risk while a second showed no increased risk! To clarify the risk, the records of 7,750 cardiac catheterization procedures between 1984 and 1987 were analyzed for presence of NPH or PZI insulin use, protamine administration, and any complications or adverse reactions. Protamine was administered in 3,341/7,750 procedures (43%), including 171 in diabetics receiving NPH insulin. Adverse reactions to protamine occurred in 2/3, 170 noninsulin patients, 0.06%, and adverse reactions due to probable NPH insulin sensitization occurred in 1/171, 0.6%, of NPH diabetics, p = .034. Meta-analysis of risk showed an odds ratio of 7.96 for the NPH diabetic patients, and combining these results with the other large series in the literature (269 NPH diabetics total) showed an odds ratio of 4.19 compared to a non-NPH insulin group. Meta-analysis of the surgical literature showed the risk in surgical patients to be 2.1% in NPH patients versus 0.12% with no NPH, with an odds ratio of 15.52. The greater incidence in surgical patients may be due to protamine sensitization at prior catheterization and to the larger dose of protamine administered to surgical patients.