TB or Non-TB, How to Treat These Infections in a Heart Transplant Patient (That is the Question!)

Abstract

<h3>Introduction</h3> Driveline exit site infections (DLESi) are common complications of left ventricular assist device (LVAD) therapy. Rarely, non-tuberculosis mycobacteria (NTB) cause such infections. We present a case showing successful treatment of a DLESi due to <i>Mycobacterium chelonae</i> which first became clinically apparent after orthotopic heart transplant (OHT). <h3>Case Report</h3> A 61-year-old male with a dilated cardiomyopathy received a Heartmate 3 LVAD followed 4 years later by OHT. Prior to OHT, no infections were reported. Two months after OHT, an abdominal wall abscess at the former driveline exit site was treated with incision and drainage. Abdominal wound drainage continued, with appearance of satellite lesions and chest wall nodules. Although initial cultures were negative, wound cultures collected 3 months later, grew <i>M. chelonae</i>. For rare NTM related DLESi, a standardized regimen is not established. Hence, commonly used macrolide, quinolone, and linezolid were started. Azithromycin was initially chosen over the more frequently studied clarithromycin due to the latter's interaction with tacrolimus. Linezolid was stopped due to pancytopenia and the ensuing susceptibility report showed quinalone resistance. As a result, the patient was functionally on macrolide monotherapy which led to a recurrence of nodules. Thus, multiple antibiotic regimens were started in succession (Figure). The final clofazimine, azithromycin, and tigecycline based regimen was clinically effective, but caused intolerable diarrhea that led to self-discontinuation of treatment after ∼9 months of therapy. He remains asymptomatic 1-year since antibiotic termination. <h3>Summary</h3> Picking an antibiotic regimen for rare, difficult-to-treat NTB related DLESi involves using the sensitivity analysis while accounting for drug-drug interactions with immunosuppressive medications. Our case demonstrates efficacy of a macrolide and clofazimine based regimen for treatment of a LVAD associated NTB infection in an OHT patient.