METHODS: A retrospective audit of heart transplant recipients (n = 87) treated with tacrolimus was performed. Relevant data were collected from the time of transplant to discharge. The concordance of tacrolimus dosing and monitoring according to hospital guidelines was assessed. The observed and software-predicted tacrolimus concentrations (n = 931) were compared for the first 3 weeks of oral immediate-release tacrolimus (Prograf) therapy, and the predictive performance (bias and imprecision) of the software was evaluated.
RESULTS: The majority (96%) of initial oral tacrolimus doses were guideline concordant. Most initial intravenous doses (93%) were lower than the guideline recommendations. Overall, 36% of initial tacrolimus doses were administered to transplant recipients with an estimated glomerular filtration rate of <60 mL/min/1.73 m despite recommendations to delay the commencement of therapy. Of the tacrolimus concentrations collected during oral therapy (n = 1498), 25% were trough concentrations obtained at steady-state. The software displayed acceptable predictions of tacrolimus concentration from day 12 (bias: -6%; 95%confidence interval, -11.8 to 2.5; imprecision: 16%; 95% confidence interval, 8.7-24.3) of therapy.
CONCLUSIONS: Tacrolimus dosing and monitoring were discordant with the guidelines. The Bayesian forecasting software was suitable for guiding tacrolimus dosing after 11 days of therapy in heart transplant recipients. Understanding the factors contributing to the variability in tacrolimus pharmacokinetics immediately after transplant may help improve software predictions.
METHODS: Data from heart transplant recipients (n = 87) administered the oral immediate-release formulation of tacrolimus (Prograf®) were collected. Routine drug monitoring data, principally trough concentrations, were used for model building (n = 1099). A published tacrolimus model was used to inform the estimation of Ka , V2 /F, Q/F and V3 /F. The effect of concomitant azole antifungal use on tacrolimus CL/F was quantified. Fat-free mass was implemented as a covariate on CL/F, V2 /F, V3 /F and Q/F on an allometry scale. Subsequently, stepwise covariate modelling was performed. Significant covariates influencing tacrolimus CL/F were included in the final model. Robustness of the final model was confirmed using prediction-corrected visual predictive check (pcVPC). The final model was externally evaluated for prediction of tacrolimus concentrations of the fourth dosing occasion (n = 87) from one to three prior dosing occasions.
RESULTS: Concomitant azole antifungal therapy reduced tacrolimus CL/F by 80%. Haematocrit (∆OFV = -44, P heart transplant recipients, considering the tacrolimus-azole antifungal interaction was developed. Prospective evaluation is required to assess its clinical utility to improve patient outcomes.
METHODS: All the patients with end-stage heart failure (ESHF) and implanted LVAD who underwent LSG from2013 to January 2017 were studied.
RESULTS: Seven patients with end stage heart failure (ESHF) and implanted LVAD were included. The median age and median preoperative BMI were 39 years (range: 26-62) and 43.6 kg/m2 (range 36.7-56.7), respectively. The median interval between LVAD implantation and LSG was 38 months (range 15-48). The median length of hospital stay was 9 days (rang: 6-23) out of which 4 patients had planned postoperative ICU admission. Thirty-day complications were noted in 5 patients (3 major and 2 minor) without any perioperative mortality. The median duration of follow-up was 24 months (range 2-30). At the last available follow-up, the median BMI, %EWL, and %TWL were 37 kg/m2, 47%, and 16%, respectively. The median LVEF before LSG and at the last follow-up point (before heart transplant) was 19% (range 15-20) and 22% (range, 16-35), respectively. In addition, the median NYHA class improved from 3 to 2 after LSG. Three patients underwent successful heart transplantations.
CONCLUSION: Patients with morbid obesity, ESHF, and implanted LVAD constitute a high-risk cohort. Our results with 7 patients and result from other studies (19 patients) suggested that bariatric surgery may be a reasonable option for LVAD patients with severe obesity. Bariatric surgery appears to provide significant weight loss in these patients and may improve candidacy for heart transplantation.