Development and validation of a nomogram model to predict primary graft dysfunction in patients after lung transplantation based on the clinical factors

BACKGROUND

Primary graft dysfunction (PGD), a significant complication that can affect patients' prognosis and quality of life, develops within 72 h post lung transplantation (LTx). Early detection and prevention of PGD should be given special consideration. The purpose of this study was to create a clinical prediction model to forecast the occurrence of PGD.

METHODS

We collected information on 622 LTx patients from Wuxi People's Hospital from 2016 to 2020 and used the data to construct the prediction model. Information on 224 patients from 2021 to June 2022 was used for external validation. We used LASSO regression for variable screening. A nomogram was developed for model presentation. Distinctness, fit, and calibration were used to evaluate the performance of the model.

RESULTS

Subjects with respiratory failure, who received fresh frozen plasma, donor age, donor gender, donor mechanism of death, donor smoking, donor ventilator use time, and donor PaO 2/FiO 2 ratio were independent predictor variables for the occurrence of PGD. The area under the curve of the nomogram was .779. The Hosmer-Lemeshow test showed a good model fit (P = .158). The calibration curve of the nomogram is fairly close to the ideal diagonal. Moreover, the decision curve analysis revealed a positive net benefit of the model. External validation also confirmed the reliability of the model.

CONCLUSIONS

The nomogram of PGD based on clinical risk factors in postoperative LTx patients was established with high reliability. It provides clinicians and nurses with a new and effective tool for early prediction of PGD and early intervention.

Impact of pre-lung transplant statin use on the development of primary graft dysfunction

BACKGROUND

Primary graft dysfunction (PGD) is a common occurrence following lung transplantation and contributes to short- and long-term morbidity and mortality. Current management strategies are limited, and robust data to support their use is lacking. Preventative strategies attenuating the recipient's inflammatory state suggest statin therapy may decrease the incidence and severity of PGD. This study aims to evaluate the impact of pre-transplant statin use on the incidence and severity of PGD following lung transplantation.

METHODS

A retrospective cohort study was performed evaluating all patients undergoing bilateral lung transplantation from September 2012 to December 2019. The primary outcome was the incidence of PGD by grade, defined as the highest grade of PGD experienced in the first 72 h. Secondary outcomes included length of intensive care unit and hospital stays and mortality.

RESULTS

Of the 357 patients included in the study, 107 received statin therapy prior to transplant (statin group) and 250 did not (no statin group). PGD occurred in 257 (72%) patients; in the entire cohort, 99 (28%) patients experienced PGD grade 1, 59 (17%) grade 2, and 99 (28%) grade 3. A significantly lower incidence of PGD was observed in the statin group (64.5% vs 75.2%, p = 0.039); however, the association did not remain significant on multinominal analysis for an overall incidence of any PGD (p = 0.275) or incidence of severe PGD (p = 0.240). Statin intensity was not associated with the development of PGD.

CONCLUSIONS

Pre-transplant statin therapy did not appear to impact the development of PGD following lung transplantation. Future prospective studies should further evaluate the impact of statin intensity and duration on the incidence and severity of PGD.

Low HDL-Cholesterol Concentrations in Lung Transplant Candidates are Strongly Associated With One-Year Mortality After Lung Transplantation

High-density lipoproteins (HDLs), whose main role is the reverse transport of cholesterol, also have pleiotropic anti-inflammatory, antioxidant, anti-apoptotic and anti-infectious properties. During sepsis, HDL cholesterol (HDL-C) concentration is low, HDL particle functionality is altered, and these modifications are correlated with poor outcomes. Based on the protective effects of HDL, we hypothesized that HDL-C levels could be associated with lung transplantation (LT) outcome. We thus looked for an association between basal HDL-C concentration and one-year mortality after LT. In this single-center prospective study including consecutive LTs from 2015 to 2020, 215 patients were included, essentially pulmonary fibrosis (47%) and chronic obstructive pulmonary disease (COPD) (38%) patients. Mortality rate at one-year was 23%. Basal HDL-C concentration stratified nonsurvivors to survivors at one-year (HDL-C = 1.26 [1.12-1.62] mmol/L vs. HDL-C = 1.55 [1.22-1.97] mmol/L, p = 0.006). Multivariate analysis confirmed that HDL-C concentration during the pretransplant assessment period was the only variable inversely associated with mortality. Moreover, mortality at one-year in patients with HDL-C concentrations ≤1.45 mmol/L was significantly higher (log-rank test, p = 0.00085). In conclusion, low basal HDL-C concentrations in candidates for LT are strongly associated with mortality after LT. To better understand this association, further studies in this field are essential and, in particular, a better characterization of HDL particles seems necessary.