Management of a Pediatric Patient on the Berlin Heart Excor Ventricular Assist Device With Argatroban After Heparin-Induced Thrombocytopenia

Orthotopic Heart Transplantation in a Patient With Gitelman Syndrome and Dilated Cardiomyopathy

Gitelman syndrome (GS) is a rare hereditary tubulopathy affecting the distal tubule leading to significant electrolyte disturbances.¹ Although generally a benign condition, rare associations with arrhythmias and sudden cardiac death have been reported.¹ A paucity of literature exists associating GS with cardiomyopathy. We present a child with dilated cardiomyopathy and GS who was successfully treated with orthotopic heart transplantation.

Use of an argatroban-based purge solution in a percutaneous ventricular assist device

PURPOSE

The use of an argatroban-based percutaneous ventricular assist device (pVAD) purge solution in a patient with suspected heparin-induced thrombocytopenia (HIT) is described.

SUMMARY

A 70-year-old woman in cardiogenic shock was admitted to a coronary care unit after being discovered unresponsive at home. A transthoracic echocardiogram revealed a low ejection fraction and findings consistent with takotsubo cardiomyopathy. Administration of multiple inotropes and vasopressors was initially required for hemodynamic support. The patient was implanted with an Impella pVAD (Abiomed, Inc., Danvers, MA) using a heparin-based purge solution; an i.v. heparin infusion was initiated for supplemental systemic anticoagulation. Over the next 24 hours, the patient's platelet count decreased from 168,000 to 37,000 cells/μL. Given a differential diagnosis that included HIT, the patient was transitioned to an argatroban-based purge solution. Due to prolonged activated partial thromboplastin times, a systemic argatroban infusion was not initiated, and the patient remained fully anticoagulated throughout pVAD support with only the argatroban-based purge solution. An HIT antibody test was negative. On hospitalization day 9 (day 6 of pVAD support with argatroban use), the patient became hemodynamically stable and was weaned off pVAD support. Three days later, the platelet count had recovered to 117,000 cells/μL (from a nadir of 21,000 cells/μL). During pVAD support, the patient developed hemolytic anemia with minimal bleeding complications.

CONCLUSION

Argatroban was used as a purge solution anticoagulant in a patient with an Impella pVAD and found to be a safe and effective alternative to heparin.

Challenging diagnosis and treatment of HIT in child with ventricular assistance device

HIT presents the clinician with unique diagnostic challenges, especially in the pediatric population. The HIT clinical sequelae of thrombocytopenia and thrombosis are secondary to the activation of platelets by heparin-antibody complexes. Diagnosis involves clinical observations and confirmatory laboratory testing using antibody detection and the functional SRA. As we describe in the following case of a six-yr-old female, the SRA may be difficult to interpret in the case of high-titer antibodies and illustrates the need for repeat testing in cases of high clinical suspicion.

Heparin-induced thrombocytopenia in the pediatric population: a review of current literature

Heparin-induced thrombocytopenia is a rare and serious reaction to unfractionated heparin and low-molecular-weight heparins in children. Quick recognition, discontinuation of heparin, and subsequent treatment with an alternative anticoagulant are essential steps to prevent serious complications such as thrombus and limb amputation. The purpose of this review is to describe the clinical features of heparin-induced thrombocytopenia in children and to summarize the data available for its management. This paper summarizes data and relates the use of direct thrombin inhibitors with clinical outcomes. A literature search was conducted with Ovid, using the key terms argatroban, bivalirudin, hirulog, danaparoid, lepirudin, direct thrombin inhibitor, heparin-induced thrombocytopenia, thrombosis, warfarin, and fondaparinux. Articles were excluded if they were classified as editorials, review articles, or conference abstracts or if they involved patients 18 years of age or older or described disease states not related to thrombosis. Nineteen articles containing 33 case reports were identified and evaluated for this review. Of the 33 cases, 14, 10, 4, and 2 cases described the use of lepirudin, danaparoid, argatroban, and bivalirudin, respectively. Two cases did not report the type of anticoagulant used, and 1 case used aspirin. The most commonly reported complication was bleeding.

Bridge to cardiac transplant in children: Berlin Heart versus extracorporeal membrane oxygenation

BACKGROUND

For small children requiring mechanical circulatory support as a bridge to transplantation (BTT), extracorporeal membrane oxygenation (ECMO) has been the only option until the recent introduction of the Berlin Heart EXCOR ventricular assist device (Berlin Heart AG, Berlin, Germany). We reviewed our recent experience with these two technologies with particular focus on early outcomes.

METHODS

Data for 55 consecutive children undergoing BTT between 2001 and 2008 were abstracted from an institutional database. The analysis excluded 13 patients because EXCOR was not used for acute postcardiotomy BTT. Patients were divided into ECMO (n = 21) and EXCOR groups (n = 21). Specific end points included survival to transplant, overall survival, and bridge to recovery. Incidences of adverse events and the duration of support were determined.

RESULTS

Groups were similar in weight, age, and etiologies of heart failure. Likewise, the incidences of stroke and multisystem organ failure were similar. Survival to transplant, recovery, or continued support was 57% in ECMO and 86% in EXCOR (p = 0.040). EXCOR patients had overall significantly better survival (p = 0.049). Two ECMO patients and 1 EXOR patient were bridged to recovery. The mean duration of support was 15 +/- 12 days in the ECMO group and 42 +/- 43 days in the EXCOR group (p < 0.001).

CONCLUSIONS

In children requiring BTT, EXCOR provided substantially longer support times than ECMO, without significant increase in the rates of stroke or multisystem organ failure. Survival to transplant and long-term survival was higher with EXCOR.