Rapidly growing mycobacteria in cardiac implantable electronic device infections: a case series and literature review.

PURPOSE: Rapidly growing mycobacteria (RGM) are uncommon causes of cardiac implantable electronic device (CIED) infection and present unique diagnostic and therapeutic challenges. Data describing their clinical characteristics, management, and outcomes remain limited, and comparative information with tuberculous mycobacterial CIED infections is scarce. This study aimed to describe a single-center case series of RGM-associated CIED infections and to synthesize published cases to characterize clinical presentation, management, and outcomes, with exploratory comparison to Mycobacterium tuberculosis CIED infections.

METHODS

We reviewed a prospectively maintained lead extraction registry at a single center (January 2003-August 2024) to identify cases of RGM CIED infection. We also performed a structured literature review of published mycobacterial CIED infections using predefined search terms and eligibility criteria, followed by descriptive analyses and exploratory comparisons between RGM and M. tuberculosis cases.

RESULTS

Among 1120 patients undergoing lead extraction for CIED infection, 3 cases (0.3%) were caused by RGM (Mycobacterium fortuitum, n = 2; Mycobacterium abscessus complex, n = 1). All 3 institutional cases occurred weeks to months after device implantation and presented as pocket or lead-associated infections. Initial blood cultures were negative in 1 case. Complete device removal was achieved in all 3 cases; 2 patients survived following targeted antimicrobial therapy, whereas 1 died from postoperative multiorgan failure. No relapses were observed during available follow-up in the surviving patients (1 and 3 years). The literature review identified 46 additional mycobacterial CIED infections (38 RGM, 8 M. tuberculosis). Patients with RGM infections presented significantly earlier than those with M. tuberculosis infections (median 60 [21-365] vs. 450 [330-1825] days, p = 0.011), and RGM cases were more likely to undergo complete extraction (90% vs. 50%, p = 0.017). Other differences were difficult to interpret because of the small number of cases.

CONCLUSIONS

RGM are rare causes of CIED infection that may present after recent device manipulation or with initially negative cultures. In this exploratory analysis, RGM infections were more often pocket-centered and more frequently managed with complete device extraction than M. tuberculosis infections. Early recognition, microbiologic diagnosis, complete device removal, and targeted multidrug antimicrobial therapy were associated with favorable outcomes in most cases.