Impact of narrowing perioperative antibiotic prophylaxis for left ventricular assist device implantation.

BACKGROUND: Although infections are a significant potential complication among patients undergoing left ventricular assist device (LVAD) implantation, standardized surgical infection prophylaxis (SIP) regimens are not well defined. At Montefiore Medical Center, a 4-drug SIP regimen containing fluconazole, ciprofloxacin, rifampin, and vancomycin was previously utilized. In January 2020, the antimicrobial stewardship program implemented a 2-drug SIP regimen of vancomycin and cefazolin to limit exposure to broad-spectrum antibiotics. This study evaluated LVAD-associated infection rates prior to and following the SIP revision. METHODS: A retrospective review of patients who underwent LVAD implantation from 1/2018 to 4/2021 was performed. Infections were classified using the International Society for Heart and Lung Transplantation definitions. Infection rates at 2 weeks, 30 days, and 90 days post-implantation in the 4-drug SIP regimen (1/2018-12/2019) and the 2-drug SIP regimen (1/2020 to 4/2021) were compared. RESULTS: A total of 71 patients were included. The number of patients with LVAD-associated infections (including surgical site infections) was not significantly different in either SIP group at 2 weeks (9% vs. 4%, p = .64), 30 days (9% vs. 11%, p = .99), or 90 days (19% vs. 14%, p = .75). There was no statistically significant difference in 30 or 90-day mortality. LVAD-associated gram-negative (7% vs. 7%; p > .99) and fungal (5% vs. 0%; p = .51) infections were uncommon. The most common organism isolated was Staphylococcus aureus, and the most common type of infection was pneumonia in both SIP groups. CONCLUSION: No significant difference in LVAD-associated infections or infection-related mortality was observed with de-escalation of perioperative antibiotics. Additional studies with larger sample sizes are needed to endorse the findings of this study.

Effect of glecaprevir/pibrentasvir on weight-adjusted tacrolimus trough/dose ratios in heart and kidney transplant recipients.

OBJECTIVE: The pharmacokinetic implications of direct-acting antiviral (DAA) use on tacrolimus posttransplant are unknown. This study sought to investigate the effects of glecaprevir/pibrentasvir (G/P), a CYP3A4 substrate and inhibitor, on weight-adjusted tacrolimus (FK) trough/dose ratio (T/D) following heart or kidney transplantation. MATERIAL AND METHODS: This was a single-center, retrospective analysis of hepatitis C virus (HCV) viremic donors to HCV negative heart or kidney transplant recipients who received 12 weeks of G/P therapy. Weight-adjusted T/D was assessed while patients were at steady-state before, during, and after G/P treatment. Forty-one HCV negative recipients (three heart, 38 kidney) were evaluated. RESULTS: The weight-adjusted T/D significantly increased during G/P treatment (119.31, IQR 88-173.8) compared to before G/P treatment (67.4, IQR 53.4-115.9) (p < 0.01), but decreased after completion of treatment (90.1, IQR 52.9-122.7) (p < 0.01). There was no difference in weight-adjusted T/D before and after G/P treatment (p = 0.42). Four patients experienced acute rejection. CONCLUSION: Initiation of G/P in heart or kidney transplant recipients induces a reversible change in tacrolimus metabolism. A 33%-50% tacrolimus dose reduction may be considered at the time of G/P initiation. Regardless of tacrolimus dose adjustment, tacrolimus trough levels should be monitored 3 days after initiation of G/P. No clear relationship between HCV viremic organ transplantation and rejection risk was found. Larger studies are warranted to validate these findings.