Bradycardia associated with antithymocyte globulin treatment of a pediatric patient with sickle cell disease: a case report and literature review

A case report of fludarabine associated ectopic atrial bradycardia and literature review of fludarabine induced bradycardia

BACKGROUND

Fludarabine is a chemotherapeutic agent with lymphodepleting effects that is increasingly used as part of a conditioning regimen prior to allogeneic stem cell transplantation. Fludarabine is generally considered a relatively safe medication with only rare cases of cardiotoxic side effects.

CASE PRESENTATION

Here, we present a case of a 30-year-old woman who was undergoing conditioning for a haploidentical cell transplantation for treatment of Fanconi anemia with a 5-day course of daily fludarabine infusion. After her second fludarabine infusion, she was noted to have ectopic atrial bradycardia that resolved with supportive therapy and completion of fludarabine infusion.

CONCLUSION

We report the first case of ectopic atrial bradycardia associated with fludarabine. Although rare and transient, clinicians should recognize this rare cardiotoxic side effect of fludarabine.

Safety and efficacy of immunosuppressive therapy for elderly patients with severe aplastic anaemia

Uncertainty remains regarding the safety and tolerability of immunosuppressive therapy (IST) with anti-thymocyte globulin (ATG) and cyclosporine (CSA) in older patients. We retrospectively analysed two prospective clinical trials of IST in treatment-naïve severe aplastic anaemia (SAA) to assess safety in older compared to younger patients. Patients ≥18 years of age who had received IST with ATG and CSA +/- eltrombopag (EPAG) were included. Pre-treatment baseline characteristics and co-morbidities were assessed as predictors of therapy-related complications in younger (<60 years) versus older (≥60 years) patients. Out of 245 eligible patients, 54 were older and 191 were younger. Older patients had a similar frequency of SAEs, ICU admissions and hospital length of stay compared to younger patients. Older patients had a higher frequency of cardiac events related to IST, but none resulted in death. Older patients had worse long-term overall survival, and more relapse and clonal evolution post-IST. However, older patients who responded to IST had a similar survival at a median follow-up to younger patients. Disease-related factors and limited therapeutic options in refractory disease likely contribute to poorer outcomes in older patients, not complications of upfront IST. Therefore, IST should be considered first-line therapy for most older SAA patients.

Bradyarrhythmias in Cardio-Oncology

The relationship between bradyarrhythmias and cancer therapies has not been well described but is increasingly recognized. There have been extensive advances in oncological pharmacotherapy, with several new classes of drugs available including targeted agents, immune checkpoint inhibitors and CAR T cell therapy. This increasing repertoire of available drugs has revolutionized overall prognosis and survival of cancer patients but the true extent of their cardiovascular toxicity is only beginning to be understood. Previous studies and published reviews have traditionally focused on conventional chemotherapies and in arrhythmias in general, particularly tachyarrhythmias. The number of patients with both cancer and cardiovascular problems is increasing globally and oncologists and cardiologists need to be adept at managing arrythmia based scenarios. Greater collaboration between the two specialties including studies with prospective data collection in Cardio-Oncology are much needed to fill in knowledge gaps in this arena. This case-based review summarizes current available evidence of cancer treatment-related bradyarrhythmia incidence (including its different subtypes), possible mechanisms and outcomes. Furthermore, we propose a stepwise surveillance and management protocol for patients with suspected bradyarrhythmia related to cancer treatment.