A case of acute myocardial infarction with repetitive stent thrombosis during emergent percutaneous coronary intervention. Transient decrease in antithrombin III activity and heparin resistance

A Review of Systemic Hematological Manifestations and Stent Thrombosis

Stent thrombosis (ST) has significant morbidity and mortality following percutaneous coronary intervention (PCI). ST is uncommon making the identification of nonprocedural predictors challenging. Numerous case reports of ST in both benign and malignant hematological conditions exist. Given ST could be a Herald event of an undiagnosed condition and condition-specific treatment may be available, it is important to consider specialist testing in an unexplained ST. This review included a case presentation of ST in previously undiagnosed paroxysmal nocturnal hemoglobinuria (PNH) and a literature review of ST in other acquired thrombophilias including myeloproliferative disorders (MPNs), antiphospholipid syndrome, hematological malignancies, and heparin-induced thrombocytopenia (HIT). Inherited thrombophilias and common pitfalls in thrombophilia and coagulation testing are also discussed. The cardiac-hematology landscape is becoming increasingly complex and there is a paucity of how to best manage ST in these patients. There is clear variability in practice and the use of multidisciplinary input between cardiologists and hematologists is essential.

A Case of Intraprocedural Thrombotic Events During Percutaneous Coronary Intervention Due to Acquired Antithrombin Deficiency-related Heparin Resistance Successfully Treated with Antithrombin Gamma Supplementation

A 75-year-old man receiving treatment for necrotizing pancreatitis developed septic disseminated intravascular coagulation and acute coronary syndrome (ACS). During percutaneous coronary intervention (PCI), a large amount of fresh thrombi appeared after balloon dilatation for the ACS-culprit lesion. Given the low plasma AT activity and poorly prolonged activated clotting time (ACT), we suspected that acquired AT deficiency-related heparin resistance (HR) was responsible for the thrombus formation. Administration of AT gamma markedly improved ACT, and we successfully completed PCI. We suggest that AT gamma be considered a treatment option for AT deficiency-related HR and subsequent intraprocedural thrombotic events.

Atrial Fibrillation in a Patient with Heparin-induced Thrombocytopenia Successfully Treated by Radiofrequency Catheter Ablation Using a Direct Thrombin Inhibitor

A 74-year-old man was admitted to our hospital to undergo radiofrequency catheter ablation (RFCA) of persistent atrial fibrillation (AF). We found that he had a history of heparin-induced thrombocytopenia (HIT). Thus, a direct thrombin inhibitor, Argatroban Hydrate (Argatroban^®), was used instead of heparin as anticoagulation therapy during the RFCA procedure. Finally, the AF was successfully treated by RFCA without any complications. Given these findings, the direct thrombin inhibitor Argatroban^® may be effective and feasible for anticoagulation therapy during RFCA procedures for AF in patients with HIT, such as the present case.

New Hemostatic Agents: Perioperative Anesthetic Considerations

AIM

Pharmacologic agents with procoagulant effects and antidotes against antithrombotic drugs play an important role in the prevention and management of perioperative coagulopathic bleeding. The aim of this narrative review is knowledge transfer from new and renewed hemostatic agents to anesthesiologists and other physicians involved in perioperative medicine.

METHODS

The literature search was performed on PubMed and the Summaries of Product Characteristics of 6 pharmacologic agents of interest: fibrinogen concentrate, vonicog alfa, susoctocog alfa, idarucizumab, andexanet alfa, and argatroban.

RESULTS AND DISCUSSION

This review highlights renewed interest in fibrinogen concentrate, an old prohemostatic drug, in correcting hypofibrinogenemia which is a leading pathomechanism of perioperative bleeding. This review describes clinically relevant aspects for brand new recombinant prohemostatic drugs for their use in critical clinical situations: vonicog alfa for the prevention and correction of bleeding in von Willebrand syndrome, and susoctocog alfa in acquired hemophilia A. Clinical experience and increasing evidence broadened the field of applications of the old antithrombotic drug argatroban to heparin resistance. New antidotes against new antithrombotic agents revolutionized the safety of chronic antithrombotic therapy in the emergency situations of acute and trauma surgery. Information on dosing and handling of new hemostatic drugs is summarized.

CONCLUSION

New and potent hemostatic agents exist for perioperative use and may enrich the armamentarium of anesthesiologists. Implementation into clinical practice requires their availability and user knowledge. Sustainability of these new drugs depends on post-licensing research, cost-effectiveness, and clinical experience.

A case report of atrial fibrillation in a patient with heparin resistance associated with an antithrombin III deficiency successfully treated by radiofrequency catheter ablation using a direct thrombin inhibitor

Background

Pulmonary vein antrum isolation has proven to be a useful strategy for radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) worldwide. Anticoagulation therapies are necessary to avoid thromboembolic events before, during, and after RFCA of AF. During the RFCA procedure for AF, it is recommended that the activated coagulation time be maintained between 300 s and 400 s using heparin as an anticoagulation therapy.

Case summary

An 81-year-old man with symptomatic and drug-refractory paroxysmal AF underwent RFCA. We found that he had a severe heparin resistance during the RFCA procedure, and heparin had little effect on him. Thus, a direct thrombin inhibitor, Argatroban Hydrate^®, was used instead of heparin for anticoagulation therapy during the procedure. Finally, the AF was successfully treated by RFCA without any complications. With a post-procedural inspection, we found that he had a Type-1 antithrombin III (AT-III) deficiency.

Discussion

Atrial fibrillation is the most common clinical arrhythmia and is associated with significant clinical morbidity and increased mortality. An AT-III deficiency is a well-known autosomal dominant hereditary disease and congenital blood coagulation abnormality occurring in about 1:500–5000 live births that may sometimes cause thrombophilia. Thus, the physicians may occasionally come across patients with an AT-III deficiency in real-world clinical practice, even though they have no history of thrombophilia. Argatroban Hydrate^® may be effective and feasible for anticoagulation therapy during the RFCA procedure of AF in patients with heparin resistance such as in this present case.

Disseminated Intravascular Coagulation as a Possible Cause of Acute Coronary Stent Thrombosis: A Case Report and Literature Review

Disseminated intravascular coagulation (DIC), as a cause of acute coronary stent thrombosis, has not yet been reported to our knowledge. We report a case of 64-year-old male, who presented with non-ST-segment elevation myocardial infarction (NSTEMI). Coronary angiography revealed right coronary artery (RCA) stenosis and a drug eluting stent was deployed. Fifteen hours following the intervention, the patient developed an inferior wall ST elevation myocardial infarction. Repeat cardiac catheterization showed an acute in-stent thrombosis. Following thrombectomy, another stent was placed. The patient noted to have an acute drop in platelet count following the second intervention. Two hours following repeat intervention, the patient again developed chest pain and EKG showed recurrent ST-segment elevations in leads II, III, and aVF. Prior to repeat cardiac catheterization, the patient became unresponsive and developed cardiogenic shock. The patient was resuscitated and intubated, and repeat catheterization showed complete stent thrombosis. Intracoronary tissue plasminogen activator (tPA) was given. The platelet count further dropped. Additional studies confirmed the diagnosis of DIC. No further cardiac catheterization was done at this point. The patient then later had a cardiac arrest and unfortunately cardiopulmonary resuscitation could not revive him. Amongst the etiologies of acute stent thrombosis, DIC was deemed a possible cause.

Heparin responsiveness during off-pump coronary artery bypass graft surgery: predictors and clinical implications

AIM

To evaluate the clinical impact of reduced heparin responsiveness (HR(reduced)) on the incidence of myocardial infarction (MI) following off-pump coronary artery bypass graft surgery (OPCAB), and to identify the predictors of HR(reduced).

METHODS

A total of 199 patients scheduled for elective OPCAB were prospectively enrolled. During anastomosis, 150 U/kg of heparin was injected to achieve an activated clotting time (ACT) of ≥ 300 s, and the heparin sensitivity index (HSI) was calculated. HSIs below 1.0 were considered reduced (HR(reduced)). The relationships between the HSI and postoperative MI, cardiac enzyme levels and preoperative risk factors of HR(reduced) were investigated.

RESULTS

There was no significant relationship between the HSI and cardiac enzyme levels after OPCAB. The incidence of MI after OPCAB was not higher in HR(reduced) patients. HR(reduced) occurred more frequently in patients with low plasma albumin concentrations and high platelet counts.

CONCLUSION

HR(reduced) was not associated with adverse ischemic outcomes during the perioperative period in OPCAB patients, which seemed to be attributable to a tight prospective protocol for obtaining a target ACT regardless of the presence of HR(reduced).