Type II Heparin-Induced Thrombocytopenia Manifesting As Cardiac Arrest Following Intravenous Heparin Bolus During an Elective Procedure: A Case Report and Literature Review

Heparin-induced thrombocytopenia (HIT) is a rare and life-threatening autoimmune-mediated adverse drug reaction seen in patients who are exposed to various forms of pharmacological heparin, including unfractionated heparin (UFH) and low molecular weight heparin (LMWH). Despite the presence of thrombocytopenia, these patients face the risk of clot formation and bleeding simultaneously. Prompt cessation of heparin and the initiation of non-heparin anticoagulants are important for the patient's survival. Typically, clinical diagnosis of HIT is necessary, and waiting for lab test results, which can take days, may not be always feasible. Here, we present a case of an unusual presentation of type II HIT, complicated by significant thrombocytopenia, pulmonary hemorrhage, and cardiac arrest after receiving intravenous (IV) heparin bolus during an elective cardiac ablation procedure for paroxysmal atrial fibrillation.

Shake it off: A curious case of rigors

Heparin-induced Anaphylactoid reactions are rare systemic reactions to heparin exposure. Although the exact pathogenesis of the reaction is unclear, in vivo platelet activation from inflammation may play a role. The reaction involves anti-platelet factor 4, a common factor also noted to be involved in heparin-induced thrombocytopenia (HIT). Like HIT, prompt identification of the reaction, immediate discontinuation of heparin, and supportive care are the mainstays of treatment to avoid severe and potentially fatal outcomes. Previous cases have described heparin-induced anaphylactoid reactions in the setting of heparin-induced thrombocytopenia. However, we will present a case of an isolated heparin-induced anaphylactoid reaction without HIT.

Mesenteric Ischemia Caused by Heparin-induced Thrombocytopenia: A Case Report

Deep venous thrombosis (DVT) prophylaxis is the current standard of care in trauma patients. While most of the anticoagulation complications are obvious and can be promptly identified, heparin-induced thrombocytopenia (HIT) requires a high index of suspicion for early diagnosis to prevent a potentially fatal outcome. A 39-year-old female presented to our emergency room after sustaining a gunshot wound to her left flank and pelvis requiring a sigmoid colon and left fallopian tube and ovary resection with colostomy diversion. The patient did well in her early postoperative period; however, her condition rapidly deteriorated after that as a result of mesenteric ischemia caused by heparin-induced thrombocytopenia. After multiple visits to the operating room, the patient ended up with short bowel syndrome, necessitating a referral to a bowel transplant center. Our aim is to increase awareness of this potentially lethal complication with a mortality rate up to 30% of patients.

Early recognition is the key to success: pulseless electrical activity (PEA) as a manifestation of heparin-induced anaphylactoid reaction

A 64-year-old man underwent mitral valve replacement. He was hospitalised 9 days later because of slurring of speech and left-sided facial weakness. During hospitalisation, unfractionated heparin (UFH) bolus and drip were initiated due to subtherapeutic international normalised ratio. Within 5 min of UFH bolus, the patient began to experience symptoms of dyspnoea, followed by pulseless electrical activity arrest. He was successfully resuscitated. A decline in platelet count >50% was noted immediately after UFH bolus and cardiac arrest. A diagnosis of heparin-induced thrombocytopenia and anaphylactoid reaction was considered (4Ts score of 7). Heparin was discontinued and argatroban was started. A platelet factor 4 (PF4) assay was strongly positive. Platelet counts subsequently improved following discontinuation of heparin.

New oral anticoagulants in the treatment of heparin-induced thrombocytopenia

BACKGROUND

Heparin induced thrombocytopenia (HIT) is a potentially catastrophic syndrome with a high incidence of vascular thrombosis. There are little data on the efficacy of new oral anticoagulants (NOAC) in this setting. This study reports on the outcome of patients with HIT, treated with NOAC.

MATERIALS AND METHODS

We retrospectively identified 22 patients with HIT who were treated by our group with a combination of NOAC and a short course of argatroban. These patients were evaluated in a prospective fashion for development of outcomes at a mean follow up of 19±3 months.

RESULTS

There were a total of 5 deep and 2 superficial vein thromboses diagnosed at index hospitalization. No patient developed arterial thrombosis. All patients tolerated NOAC and their platelet count normalized before discharge. At 19 months of follow-up, 6 patients had died of non-thrombotic causes. There was no bleeding, limb loss or recurrent venous thromboembolism in any patient.

CONCLUSIONS

In patients with HIT, a short course of parenteral treatment with argatroban followed by administration of a NOAC is highly safe and effective in prevention of thrombosis and normalization of platelet count. Development of HIT however, portends a poor prognosis independent of vascular thrombosis.